Polymeric metal chelates with piperazine(bis)dithiocarbamate

International Nuclear Information System (INIS)

Larionov, S.V.; Kosareva, L.A.; Ikorskij, V.N.; Uskov, E.M.

1982-01-01

Roentgenoamorphous polymer chelates of Fe 3 , Co 2 , Ni 2 , Cu 2 , Zn 2 , Cd 2 , Pb 2 with tetradentate bridge ligand piperazine-(bis) dithiocarbamate have been synthesized. IR spectra in the region 200-400 cm - 1 point to coordination of sulphur atoms of groups CS 2- with metals. It is found that among the polymers synthesized CuLxH 2 O possesses the lowest electric resistance

Zn(OTf)2 catalyzed indolylation and pyrrolylation of isatins: Efficient ...

Indian Academy of Sciences (India)

praveenithya

Zn(OTf)2 catalyzed indolylation and pyrrolylation of isatins: Efficient synthesis and biochemical assay of 3,3- di(heteroaryl)oxindoles. C PRAVEEN a. , S NARENDIRAN b. , P DHEENKUMAR a,c and P T PERUMAL a,. * a. Organic Chemistry Division, Central Leather Research Institute (CSIR), Adyar, Chennai. 600020 ...

Isatin as an auxin source favoring floral and vegetative shoot regeneration from calli produced by thin layer explants of tomato pedicel

Science.gov (United States)

Applewhite, P. B.; K-Sawhney, R.; Galston, A. W.

1994-01-01

Thin layer explants taken from the pedicels and peduncles of flowering tomato plants yielded calli with great organogenetic potential. Of the 15 cultivars tested, 7 regenerated roots, shoots and eventually entire fruit-bearing plants. Calli grown on modified Murashige-Skoog medium responded to varied auxins and cytokinins with different morphogenetic patterns. Thus, naphthaleneacetic acid yielded root-producing calli, while the auxin precursor isatin (indole 2,3-dione) caused the production of calli with vegetative and floral shoots, rarely yielding roots. This may be related to isatin's slow, steady conversion to an active auxin (Plant Physiol 41:1485-1488, 1966) in contrast with naphthaleneacetic acid's immediate presentation of a high level of active auxin. The highest incidence of vegetative shoot (100%) and flower (50%) formation was obtained with 10 micromoles isatin and 3 micromoles zeatin. A few of the flowers developed into ripe fruits. The high frequency of induction of vegetative shoots and flowers before roots with isatin suggests its utility in micropropagation from plant tissue cultures.

Radical bonding: structure and stability of bis(phenalenyl) complexes of divalent metals from across the periodic table.

Science.gov (United States)

Craciun, Smaranda; Donald, Kelling J

2009-07-06

We examine the bonding possibilities of the bis(phenalenyl) MP(2) sandwich complexes of the divalent metals M = Be, Mg, Ca, Sr, Ba, Zn, Cd, and Hg, at the B3LYP level of theory. The outcome is an extraordinarily diverse class of low symmetry bis(phenalenyl)metal complexes in which bonding preferences and binding enthalpies differ dramatically. The lowest energy group 2 metal MP(2) complexes include an intriguing eta(1),eta(3) BeP(2) structure, and bent eta(6),eta(6) systems for M = Ca, Sr, and Ba. The group 12 bis(phenalenyl) complexes are thermodynamically unstable eta(1),eta(1) slip-sandwich structures. To better understand changes in the structural preferences going from the (eta(6),eta(6)) group 2 to the (eta(1),eta(1)) group 12 complexes, we explored the bonding in the bis(phenalenyl) complexes of transition metals with stable +2 oxidations states between Ca and Zn in period 4. The computed binding enthalpies are large and negative for nearly all of the minimum energy bis(phenalenyl) complexes of the group 2 and the transition metals; they are tiny for MgP(2), and are quite positive for the group 12 systems. The structural preferences and stability of the complexes is a subtle negotiation of several influences: the (un)availability of (n - 1)d and np, orbitals for bonding, the cost of the rehybridization at carbon sites in the phenalenyl rings in preparation for bonding to the metals, and the (P---P) interaction between the phenalenyl radicals.

1,3-Dibromo-5,5-dimethylhydantoin: a versatile catalyst for synthesis of 3,3-bis(indolyloxindoles

Directory of Open Access Journals (Sweden)

Seyyedeh Fatemeh Hojati

2013-10-01

Full Text Available A condensation of various isatins with indole derivatives has been carried out in the presence of 1,3-dibromo-5,5-dimethylhydantoin (DBDMH as catalyst at 50 °C in ethanol in order to form 3,3-bis(indolyl oxindoles. The products were obtained within 20-90 min by 70-96% yields. The efficacy of the procedure has been confirmed by catalyzing the condensation reaction of pyrrole which was used as another sort of heterocycle with indole to obtain its corresponding 3,3-bis(2-pyrrolyloxinole. A plausible mechanism of the condensation based on DBDMH activating role has also been proposed. DBDMH is an effective, commercially available, insensitive to moisture and easily handling catalyst. Simple procedure, easy work-up, mild reaction conditions, high yields and short reaction times are the highlighted points of reported method.

Synthesis and applications of gem-bis-phosphonates, powerful complexing agents of metals

International Nuclear Information System (INIS)

Lecercle, D.

2007-12-01

This thesis was devoted to the development of new ways to prepare gem-bis-phosphonates compounds (BPs), and was carried out under the Program of Nuclear and Environmental Toxicology (ToxNuc-E). Two applications of these compounds have been investigated, the preparation of potent ligands of the uranyl ion for a target of decorporation, and the preparation of new anticancer compounds. The first of these applications was the consequence of work done in the laboratory, that have shown the strong uranium-binding properties of bis-phosphonic ligands. The in vivo tests performed on these compounds have shown the tendency of these ligands to cause liver accumulation of uranium, we wanted to address this problem by modifying the method of anchoring of the bis-phosphonates functions. To this end we have developed a new way to access to these compounds using a metal-carbenoid mediated poly-ols and poly-amines insertion, the metal-carbenoid species bearing the bis-phosphonate function. Regarding the preparation of BPs as anticancer agents, we have developed a new synthetic pathway using a phosphine catalyzed α-P addition of phosphorated pro-nucleophiles to alkynyl-phosphonates as a key step. This enabled us to prepare thirty compound whose activity was evaluated on two cell lines (A431 and HuH7). Five of these compounds possess an activity equivalent to that of the compound described as the most active, the Zoledronate. (author)

Organocatalytic asymmetric allylic amination of Morita–Baylis–Hillman carbonates of isatins

Directory of Open Access Journals (Sweden)

Hang Zhang

2012-08-01

Full Text Available The investigation of a Lewis base catalyzed asymmetric allylic amination of Morita–Baylis–Hillman carbonates derived from isatins afforded an electrophilic pathway to access multifunctional oxindoles bearing a C3-quaternary stereocenter, provided with good to excellent enantioselectivity (up to 94% ee and in high yields (up to 97%.

Novel bis-(−)-nor-meptazinol derivatives act as dual binding site AChE inhibitors with metal-complexing property

Energy Technology Data Exchange (ETDEWEB)

Zheng, Wei [Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 200032 (China); NPFPC Key Laboratory of Contraceptives and Devices, Shanghai Institute of Planned Parenthood Research, 2140 Xietu Road, Shanghai 200032 (China); Li, Juan [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Qiu, Zhuibai [Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 200032 (China); Xia, Zheng [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Li, Wei [Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 200032 (China); Yu, Lining; Chen, Hailin; Chen, Jianxing [NPFPC Key Laboratory of Contraceptives and Devices, Shanghai Institute of Planned Parenthood Research, 2140 Xietu Road, Shanghai 200032 (China); Chen, Yan; Hu, Zhuqin; Zhou, Wei; Shao, Biyun; Cui, Yongyao [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Xie, Qiong, E-mail: xiejoanxq@gmail.com [Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 200032 (China); Chen, Hongzhuan, E-mail: yaoli@shsmu.edu.cn [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China)

2012-10-01

The strategy of dual binding site acetylcholinesterase (AChE) inhibition along with metal chelation may represent a promising direction for multi-targeted interventions in the pathophysiological processes of Alzheimer's disease (AD). In the present study, two derivatives (ZLA and ZLB) of a potent dual binding site AChE inhibitor bis-(−)-nor-meptazinol (bis-MEP) were designed and synthesized by introducing metal chelating pharmacophores into the middle chain of bis-MEP. They could inhibit human AChE activity with IC{sub 50} values of 9.63 μM (for ZLA) and 8.64 μM (for ZLB), and prevent AChE-induced amyloid-β (Aβ) aggregation with IC{sub 50} values of 49.1 μM (for ZLA) and 55.3 μM (for ZLB). In parallel, molecular docking analysis showed that they are capable of interacting with both the catalytic and peripheral anionic sites of AChE. Furthermore, they exhibited abilities to complex metal ions such as Cu(II) and Zn(II), and inhibit Aβ aggregation triggered by these metals. Collectively, these results suggest that ZLA and ZLB may act as dual binding site AChEIs with metal-chelating potency, and may be potential leads of value for further study on disease-modifying treatment of AD. -- Highlights: ► Two novel bis-(−)-nor-meptazinol derivatives are designed and synthesized. ► ZLA and ZLB may act as dual binding site AChEIs with metal-chelating potency. ► They are potential leads for disease-modifying treatment of Alzheimer's disease.

Novel bis-(−)-nor-meptazinol derivatives act as dual binding site AChE inhibitors with metal-complexing property

International Nuclear Information System (INIS)

Zheng, Wei; Li, Juan; Qiu, Zhuibai; Xia, Zheng; Li, Wei; Yu, Lining; Chen, Hailin; Chen, Jianxing; Chen, Yan; Hu, Zhuqin; Zhou, Wei; Shao, Biyun; Cui, Yongyao; Xie, Qiong; Chen, Hongzhuan

2012-01-01

The strategy of dual binding site acetylcholinesterase (AChE) inhibition along with metal chelation may represent a promising direction for multi-targeted interventions in the pathophysiological processes of Alzheimer's disease (AD). In the present study, two derivatives (ZLA and ZLB) of a potent dual binding site AChE inhibitor bis-(−)-nor-meptazinol (bis-MEP) were designed and synthesized by introducing metal chelating pharmacophores into the middle chain of bis-MEP. They could inhibit human AChE activity with IC 50 values of 9.63 μM (for ZLA) and 8.64 μM (for ZLB), and prevent AChE-induced amyloid-β (Aβ) aggregation with IC 50 values of 49.1 μM (for ZLA) and 55.3 μM (for ZLB). In parallel, molecular docking analysis showed that they are capable of interacting with both the catalytic and peripheral anionic sites of AChE. Furthermore, they exhibited abilities to complex metal ions such as Cu(II) and Zn(II), and inhibit Aβ aggregation triggered by these metals. Collectively, these results suggest that ZLA and ZLB may act as dual binding site AChEIs with metal-chelating potency, and may be potential leads of value for further study on disease-modifying treatment of AD. -- Highlights: ► Two novel bis-(−)-nor-meptazinol derivatives are designed and synthesized. ► ZLA and ZLB may act as dual binding site AChEIs with metal-chelating potency. ► They are potential leads for disease-modifying treatment of Alzheimer's disease.

Cross-Aldol Reaction of Isatin with Acetone Catalyzed by Leucinol: A Mechanistic Investigation

Czech Academy of Sciences Publication Activity Database

Kabeshov, M. A.; Kysilka, O.; Rulíšek, Lubomír; Suleimanov, Y. V.; Bella, M.; Malkov, A. V.; Kočovský, Pavel

2015-01-01

Roč. 21, č. 34 (2015), s. 12026-12033 ISSN 0947-6539 R&D Projects: GA ČR(CZ) GA14-31419S Institutional support: RVO:61388963 Keywords : computational studies * enamines * isatins * oxazolidines * self-catalysis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.771, year: 2015

Efficiency of SPIONs functionalized with polyethylene glycol bis(amine) for heavy metal removal

Energy Technology Data Exchange (ETDEWEB)

Wanna, Yongyuth, E-mail: yongyuth.wanna@gmail.com [College of KMITL Nanotechnology, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Rd., Ladkrabang, Bangkok 10520 (Thailand); Nara Machinery Co., Ltd., 2-5-7, Jonan-Jima, Ohta-ku, Tokyo 143-0002 (Japan); Chindaduang, Anon; Tumcharern, Gamolwan [National Nanotechnology Center (NANOTEC), 111 Thailand Science Park, Pahol Yothin Rd, Klong Luang, Pathum Thani 12120 (Thailand); Phromyothin, Darinee [College of KMITL Nanotechnology, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Rd., Ladkrabang, Bangkok 10520 (Thailand); Porntheerapat, Supanit [NECTEC, National Science and Technology Development Agency (NSTDA), 112 Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Khlong Luang, Pathum Thani 12120 (Thailand); Nukeaw, Jiti [College of KMITL Nanotechnology, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Rd., Ladkrabang, Bangkok 10520 (Thailand); Hofmann, Heirich [Laboratory of Powder Technology, Ecole Polytechnique Fédérale de Lausanne (Switzerland); Pratontep, Sirapat [College of KMITL Nanotechnology, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Rd., Ladkrabang, Bangkok 10520 (Thailand)

2016-09-15

Hybrid magnetic nanoparticles based on poly(methylmethacrylate) (PMMA) and super-paramagnetic iron oxide nanopaticles (SPIONs) with selective surface modification has been developed for heavy metal removal by applying external magnetic fields. The nanoparticles were prepared by the emulsion polymerization technique in an aqueous suspension of SPIONs. The hydrolysis of carboxyl functional group was then applied for grafting polyethylene glycol bis(amine)(PEG-bis(amine)) onto the PMMA-coated SPIONs. The morphology, the chemical structure and the magnetic properties of the grafted nanoparticles were investigated. The efficiency of the hybrid nanoparticles for heavy metal removal were conducted on Pb(II), Hg(II), Cu(II) and Co(II) in aqueous solutions.The metal concentration in the solutions after separation by the hybrid nanoparticles was determined by inductively coupled plasma optical emission spectrometer (ICP-OES). The results show the heavy metal uptake ratios of 0.08, 0.04, 0.03, and 0.01 mM per gramme of the grafted SPIONs for Pb(II), Hg(II), Cu(II), and Co(II), respectively. A competitive removal of Cu(II), Pb(II), Co(II) and Hg(II) ions in mixed metal salt solutions has also been studied.The heavy metal removal efficiency of the hybrid nanoparitcles was found to depend on the cation radius, in accordance with capture of metal ions by the amine group. - Highlights: • We synthesis hybrid magnetic nanoparticles for heavy metal removal. • The efficiency of hybrid nanoparticles for heavy metal removal is proposed. • We investigated the characteristic of hybrid nanoparticle. • The heavy metal removal efficiency of the hybrid nanoparticle was founded that depend on the heavy metal cation radius.

Synthesis of novel isatin-type 5'-(4-Alkyl/Aryl-1H-1,2,3-triazoles) via 1,3-dipolar cycloaddition reactions

Energy Technology Data Exchange (ETDEWEB)

Silva, Bianca N. M.; Silva, Barbara V.; Pinto, Angelo C., E-mail: biancanascimento@iq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Quimica; Silva, Fernando C.; Gonzaga, Daniel T. G.; Ferreira, Vitor F. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Quimica

2013-02-15

Isatin and 1H-1,2,3-triazoles are two classes of compounds with great prominence in organic synthesis and medicinal chemistry as they are heterocycle nuclei with a high reactivity allowing to obtain several compounds with important biological properties. Herein, the synthesis of novel 5'-(4-alquil/aril-1H-1,2,3-triazole)-isatin via reaction of 1,3-dipolar cycloaddition catalyzed by acetic acid is reported. (author)

Controlling the oxidation of bis-tridentate cobalt(ii) complexes having bis(2-pyridylalkyl)amines: ligand vs. metal oxidation.

Science.gov (United States)

Anjana, S; Donring, S; Sanjib, P; Varghese, B; Murthy, Narasimha N

2017-08-22

Two bis-tridentate chelated cobalt(ii) complexes, which differ in the ligand structure by a methylene group, activate molecular oxygen (O 2 ), and give different oxidation products. The O 2 reaction of [Co II (pepma) 2 ] 2+ (1) with unsymmetrical 2-(2-pyridyl)-N-(2-pyridylmethyl)ethanamine (pepma) results in ligand oxidation, to the corresponding Co(ii) imine complex [Co II (pepmi) 2 ] 2+ (2). Contrastingly, the Co(ii) complex [Co II (bpma) 2 ] 2+ (3) of similar symmetrical bis(2-pyridylmethyl)amine (bpma), undergoes metal oxidation, yielding a cobalt(iii) complex, [Co III (bpma) 2 ] 2+ (4). The reversibility of the amine to imine conversion and the stability of the Co(ii) imine complex (2) are investigated. Furthermore, the solution dynamics of Co(ii) complexes are highlighted with the help of paramagnetic 1 H-NMR spectroscopy.

A comparative Study of C2-Symmetric Bis(aziridine) Ligands in Some Transition Metal-Mediated Asymmetric Transformations

DEFF Research Database (Denmark)

Tanner, David Ackland; Johansson, Fredrik; Harden, Adrian

1998-01-01

A comparative study has been made of the performance of differently substituted Ca-symmetric bis(aziridine) ligands in a variety of metal-mediated asymmetric reactions. The metals studied were osmium (dihydroxylation), palladium (allylic alkylation) and copper (cyclopropanation and aziridination...

Synthesis and characterization of dioxouranium (VI) complexes of Schiff bases derived from isatin, isovanillin and o-vanillin

International Nuclear Information System (INIS)

Singh, Kavita; Agarwala, B.V.; Naganagowda, G.A.

1996-01-01

Three Schiff bases viz. isatin semicarbazone, isovanillin thiosemicarbazone, o-vanillin para-anisidine and their dioxouranium (VI) complexes have been synthesised and characterized by elemental analysis, IR and NMR spectral studies. (author). 19 refs., 1 tab

Synthesis of novel 1H-1,2,3-triazole tethered C-5 substituted uracil-isatin conjugates and their cytotoxic evaluation

KAUST Repository

Kumar, Kewal; Sagar, Sunil; Esau, Luke; Kaur, Mandeep; Kumar, Vipan

2012-01-01

The present manuscript describes the synthesis of uracil-isatin hybrids via azide-alkyne cycloadditions and their cytotoxic evaluation against three human cancer cell lines viz. HeLa (cervix), MCF-7 (breast) and DU145 (prostate) using MTT assay. The evaluation studies revealed the dependence of cytotoxicity on C-5 substituents of both uracil and isatin as well as the alkyl chain length with compounds 6g and 6k showing IC50 values 18.21 and 13.90 μM respectively against DU145 cell lines. Most of the synthesized conjugates exhibited considerable selectivity against MCF-7 and DU145 cell lines. © 2012 Elsevier Masson SAS. All rights reserved.

Synthesis of novel 1H-1,2,3-triazole tethered C-5 substituted uracil-isatin conjugates and their cytotoxic evaluation

KAUST Repository

Kumar, Kewal

2012-12-01

The present manuscript describes the synthesis of uracil-isatin hybrids via azide-alkyne cycloadditions and their cytotoxic evaluation against three human cancer cell lines viz. HeLa (cervix), MCF-7 (breast) and DU145 (prostate) using MTT assay. The evaluation studies revealed the dependence of cytotoxicity on C-5 substituents of both uracil and isatin as well as the alkyl chain length with compounds 6g and 6k showing IC50 values 18.21 and 13.90 μM respectively against DU145 cell lines. Most of the synthesized conjugates exhibited considerable selectivity against MCF-7 and DU145 cell lines. © 2012 Elsevier Masson SAS. All rights reserved.

Bis(1,3-dithiole) Compounds

DEFF Research Database (Denmark)

Andersen, Jan Rud; Engler, E. M.; Green, D. C.

1977-01-01

There is described the preparation of bis-1,3-dithiole compounds (I) which are key synthetic precursors for the preparation of new polymeric metal bis(dithiolene) (i.e., II) and tetrathiafulvalene compounds (i.e., III): (Image Omitted)...

Pharmacokinetic study of isatin in dog plasma by liquid chromatography tandem mass spectrometry.

Science.gov (United States)

Ren, A; Wang, Q; Fang, Z; Gao, M; Wang, H; Zhang, J; Xu, W; Yue, W; Yin, L; Liu, Z; Li, X; Ding, B

2015-12-01

A sensitive and selective method was developed and validated to study the pharmacokinetics of isatin. The blood samples were pretreated by protein precipitation method using methanol. Quetiapine was used as an internal standard. After pretreatment, the samples were assayed by LC/MS/MS method and the pharmacokinetic parameters were calculated by WinNonlin 5.2 using non-compartment model. The separation was performed on a Venusil XBP PH column (5 µm, 2.0×100 mm) with an isocratic mobile phase consisted of methanol-water (containing 50 mM ammonium formate) (65:35, v/v) at a flow rate of 0.3 mL/min. The Agilent G6410B triple quadrupole LC/MS system was operated under the multiple reactions monitoring mode (MRM) using the electrospray ionization technique in positive mode. The lower limits of quantification (LLOQ) of the analyte of the method was 10 ng/mL. The method was linear with correlation coefficient >0.995. The intraday and interday accuracy and precision of the assay were acceptable. This method has been applied successfully to a pharmacokinetic study involving the oral and intravenous administration of isatin to beagle dogs.

Pd-isatin Schiff base complex immobilized onγ-Fe2O3 as a magnetically recyclable catalyst for the Heck and Suzuki cross-coupling reactions

Institute of Scientific and Technical Information of China (English)

Sara Sobhani; Farzaneh Zarifi

2015-01-01

A Pd‐isatin Schiff base complex immobilized onγ‐Fe2O3 (Pd‐isatin Schiff base‐γ‐Fe2O3) was synthe‐sized and characterized by Fourier transform infrared, scanning electron microscopy, high resolu‐tion transmission electron microscopy, X‐ray diffraction, thermogravimetric gravimetric analysis, inductively‐coupled plasma, X‐ray photoelectron spectroscopy, and elemental analysis. It was used as a magnetically reusable Pd catalyst for the Heck and Suzuki cross‐coupling reactions.

Corrosion Inhibition of Q235A Steel in Acid Medium Using Isatin Derivatives: A Qsar Study

International Nuclear Information System (INIS)

Abdo M Al-Fakih; Madzlan Aziz; Abdo M Al-Fakih; Abdallah, H.H.; Hasmerya Maarof; Rosmahaida Jamaludin; Bishir Usman

2016-01-01

Quantitative Structure-Activity Relationship (QSAR) study was performed on 10 isatin derivatives which were reportedly used as corrosion inhibitors. Dragon software was used to calculate the molecular descriptors. Partial least square (PLS) method was used to run the regression analysis between the descriptors and the corrosion inhibition efficiencies (IE) of the inhibitors. A predictive QSAR model was developed with a correlation coefficient (r 2 cal ) of 0.9676. The model validity was assessed through internal and external validation. The results show that cross-validation regression coefficient (r 2 cv ) and prediction regression coefficient (r 2 pred ) are 0.8163 and 0.9189, respectively. The model was used to predict the IE for ten isatin derivatives. The results confirm a good stability and predictive ability of the model. Dragon-based descriptors provide a very good description of the corrosion inhibition properties of the inhibitors. The results of the QSAR study were found to be consistent with the experimental data. (author)

A novel fluorescent probe (dtpa-bis(cytosine)) for detection of Eu(III) in rare earth metal ions

Science.gov (United States)

Yang, Fan; Ren, Peipei; Liu, Guanhong; Song, Youtao; Bu, Naishun; Wang, Jun

2018-03-01

In this paper, a novel fluorescent probe, dtpa-bis(cytosine), was designed and synthesized for detecting europium (Eu3 +) ion. Upon addition of Eu3 + ions into the dtpa-bis(cytosine) solution, the fluorescence intensity can strongly be enhanced. Conversely, adding other rare earth metal ions, such as Y3 +, Ce3 +, Pr3 +, Nd3 +, Sm3 +, Gd3 +, Tb3 +, Dy3 +, Ho3 +, Er3 +, Yb3 + and Lu3 +, into dtpa-bis(cytosine) solution, the fluorescence intensity is decreased slightly. Some parameters affecting the fluorescence intensity of dtpa-bis(cytosine) solution in the presence of Eu3 + ions were investigated, including solution pH value, Eu3 + ion concentration and interfering substances. The detection mechanism of Eu3 + ion using dtpa-bis(cytosine) as fluorescent probe was proposed. Under optimum conditions, the fluorescence emission intensities of EuIII-dtpa-bis(cytosine) at 375 nm in the concentration range of 0.50 × 10- 5 mol • L- 1-5.00 × 10- 5 mol • L- 1 of Eu3 + ion display a better linear relationship. The limit of detection (LOD) was determined as 8.65 × 10- 7 mol • L- 1 and the corresponding correlation coefficient (R2) of the linear equation is 0.9807. It is wished that the proposed method could be applied for sensitively and selectively detecting Eu3 + ion.

Molecular dynamics-assisted pharmacophore modeling of caspase-3-isatin sulfonamide complex: Recognizing essential intermolecular contacts and features of sulfonamide inhibitor class for caspase-3 binding.

Science.gov (United States)

Kumar, Sivakumar Prasanth; Patel, Chirag N; Jha, Prakash C; Pandya, Himanshu A

2017-12-01

The identification of isatin sulfonamide as a potent small molecule inhibitor of caspase-3 had fuelled the synthesis and characterization of the numerous sulfonamide class of inhibitors to optimize for potency. Recent works that relied on the ligand-based approaches have successfully shown the regions of optimizations for sulfonamide scaffold. We present here molecular dynamics-based pharmacophore modeling of caspase-3-isatin sulfonamide crystal structure, to elucidate the essential non-covalent contacts and its associated pharmacophore features necessary to ensure caspase-3 optimal binding. We performed 20ns long dynamics of this crystal structure to extract global conformation states and converted into structure-based pharmacophore hypotheses which were rigorously validated using an exclusive focussed library of experimental actives and inactives of sulfonamide class by Receiver Operating Characteristic (ROC) statistic. Eighteen structure-based pharmacophore hypotheses with better sensitivity and specificity measures (>0.6) were chosen which collectively showed the role of pocket residues viz. Cys163 (S 1 sub-site; required for covalent and H bonding with Michael acceptor of inhibitors), His121 (S 1 ; π stack with bicyclic isatin moiety), Gly122 (S 1 ; H bond with carbonyl oxygen) and Tyr204 (S 2 ; π stack with phenyl group of the isatin sulfonamide molecule) as stringent binding entities for enabling caspase-3 optimal binding. The introduction of spatial pharmacophore site points obtained from dynamics-based pharmacophore models in a virtual screening strategy will be helpful to screen and optimize molecules belonging to sulfonamide class of caspase-3 inhibitors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Near infrared organic light-emitting diodes based on acceptor-donor-acceptor (ADA) using novel conjugated isatin Schiff bases

International Nuclear Information System (INIS)

Taghi Sharbati, Mohammad; Soltani Rad, Mohammad Navid; Behrouz, Somayeh; Gharavi, Alireza; Emami, Farzin

2011-01-01

Fabrications of a single layer organic light emitting diodes (OLEDs) based on two conjugated acceptor-donor-acceptor (ADA) isatin Schiff bases are described. The electroluminescent spectra of these materials range from 630 to 700 nm and their band gaps were measured between 1.97 and 1.77 eV. The measured maximum external quantum efficiencies (EQE) for fabricated OLEDs are 0.0515% and 0.054% for two acceptor-donor-acceptor chromophores. The Commission International De L'Eclairage (CIE) (1931) coordinates of these two compounds were attained and found to be (0.4077, 0.4128) and (0.4411, 0.4126) for two used acceptor-donor-acceptor chromophores. The measured I-V curves demonstrated the apparent diode behavior of two ADA chromophores. The turn-on voltages in these OLEDs are directly dependent on the thickness. These results have demonstrated that ADA isatin Schiff bases could be considered as promising electroluminescence-emitting materials for fabrication of OLEDs.

Electrochemical Reduction of Isatin-monohydrazone on Mercury Electrode

Directory of Open Access Journals (Sweden)

Ender Biçer

2015-07-01

Full Text Available Electrochemical behaviour of isatin monohydrazone (IM on a hanging mercury drop electrode in the Britton-Robinson (B-R buffer solution of pH = 2.00–9.00 has been investigated using square-wave voltammetry (SWV and cyclic voltammetry (CV techniques. In the pH range of 2.00–5.00, the voltammogram of IM exhibited a single cathodic irreversible peak. When the pH value exceeds 5.00, a new cathodic irreversible peak was also seen. According to the voltammetric data, a plausible electrode reaction mechanism of IM was proposed. The first reduction peak of IM is resulted from the reduction of =N–NH– group with consumption of 2e–/2H+. Also, its second cathodic peak is formed by the participation of 2e–/2H+ for the reduction of –N=N– group on its tautomeric form.

Synthesis, Thermal, Electrical and Catalytic Studies of Some Transition Metal Polychelates of Bis-bidentate Schiff Base

Institute of Scientific and Technical Information of China (English)

BANSOD Ashish; ASWAR Anand

2007-01-01

Polychelates of Mn(Ⅱ),Fe(Ⅱ),Co(Ⅱ), Ni(Ⅱ),Cu(Ⅱ),Zn(Ⅱ) and Cd(Ⅱ) with the bis salen-type ligand derivedfrom 4,4'-bis[(salicylaldehyde-5)azo]biphenyl and 1,4-diaminobutane have been synthesized.All the polychelates have been characterized by elemental analysis,magnetic susceptibility measurements,IR,electronic spectra and thermogravimetric studies.All the complexes isolated in solid state are dark coloured and insoluble in water and common organic solvents.The ligand behaves as a bis-bidentate molecule coordinating through the phenolic oxygen and azomethine nitrogen atoms.The thermal decomposition of these metal complexes was investigated by thermogravimetric analysis and data have been analyzed for kinetic parameters using Broido equation.The solid-state electrical conductivity of the ligand and its polychelates in the form of compressed pellet was studied in the temperature range from 313 to 413 K.All the polychelates were found to show semiconducting nature.The Mn(Ⅱ),Fe(Ⅱ),Co(Ⅱ) and Ni(Ⅱ) polychelates have been assessed for the catalytic epoxidation of styrene.

μ-Carbonato-bis-(bis-{2-[(diethyl-amino)-meth-yl]phen-yl}bis-muth(III)).

Science.gov (United States)

Soran, Albert P; Nema, Mihai G; Breunig, Hans J; Silvestru, Cristian

2011-01-12

The mol-ecular structure of the title compound, [Bi(2)(C(11)H(16)N)(4)(CO(3))], consists of a symmetrically bridging carbonato group which binds two [2-Et(2)NCH(2)C(6)H(4)](2)Bi units that are crystallographically related via a twofold rotation axis bis-ecting the carbonate group. The two Bi atoms and two of the C atoms directly bonded to bis-muth are quasi-planar [deviations of 0.323 (1) and 0.330 (9)Å for the Bi and C atoms, respectively] with the carbonate group. The remaining two ligands are in a trans arrangement relative to the quasi-planar (CBi)(2)CO(3) system. The metal atom is strongly coordinated by the N atom of one pendant arm [Bi-N = 2.739 (6) Å], almost trans to the O atom, while the N atom of the other pendant arm exhibits a weaker intra-molecular inter-action [Bi⋯N = 3.659 (7) Å] almost trans to a C atom. If both these intra-molecular N→Bi inter-actions per metal atom are considered, the overall coordination geometry at bis-muth becomes distorted square-pyramidal [(C,N)(2)BiO cores] and the compound can be described as a hypervalent 12-Bi-5 species. Additional quite short intra-molecular Bi⋯O inter-actions are also present [3.796 (8)-4.020 (9) Å]. Inter-molecular associations through weak η(6)⋯Bi inter-actions [Bi⋯centroid of benzene ring = 3.659 (1) Å] lead to a ribbon-like supra-molecular association.

5-(2-Carboxyethenyl) isatin derivative induces G2/M cell cycle arrest and apoptosis in human leukemia K562 cells

International Nuclear Information System (INIS)

Zhou, Yao; Zhao, Hong-Ye; Han, Kai-Lin; Yang, Yao; Song, Bin-Bin; Guo, Qian-Nan; Fan, Zhen-Chuan; Zhang, Yong-Min; Teng, Yu-Ou; Yu, Peng

2014-01-01

Highlights: • 5-(2-Carboxyethenyl) isatin derivative (HKL 2H) inhibited K562’s proliferation. • HKL 2H caused the morphology change of G 2 /M phase arrest and typical apoptosis. • HKL 2H induced G2/M cell cycle phase arrest in K562 cells. • HKL 2H induced apoptosis in K562 cells through the mitochondrial pathway. - Abstract: Our previous study successfully identified that the novel isatin derivative (E)-methyl 3-(1-(4-methoxybenzyl)-2,3-dioxoindolin-5-yl) acrylate (HKL 2H) acts as an anticancer agent at an inhibitory concentration (IC 50 ) level of 3 nM. In this study, the molecular mechanism how HKL 2H induces cytotoxic activity in the human chronic myelogenous leukemia K562 cells was investigated. Flow cytometric analysis showed that the cells were arrested in the G 2 /M phase and accumulated subsequently in the sub-G 1 phase in the presence of HKL 2H. HKL 2H treatment down-regulated the expressions of CDK1 and cyclin B but up-regulated the level of phosphorylated CDK1. Annexin-V staining and the classic DNA ladder studies showed that HKL 2H induced the apoptosis of K562 cells. Our study further showed that HKL 2H treatment caused the dissipation of mitochondrial membrane potential, activated caspase-3 and lowered the Bcl-2/Bax ratio in K562 cells, suggesting that the HKL 2H-causing programmed cell death of K562 cells was caused via the mitochondrial apoptotic pathway. Taken together, our data demonstrated that HKL 2H, a 5-(2-carboxyethenyl) isatin derivative, notably induces G 2 /M cell cycle arrest and mitochondrial-mediated apoptosis in K562 cells, indicating that this compound could be a promising anticancer candidate for further investigation

Synthesis of rare-earth metal amides bearing an imidazolidine-bridged bis(phenolato) ligand and their application in the polymerization of L-lactide.

Science.gov (United States)

Zhang, Zhongjian; Xu, Xiaoping; Li, Wenyi; Yao, Yingming; Zhang, Yong; Shen, Qi; Luo, Yunjie

2009-07-06

A series of neutral rare-earth metal amides supported by an imidazolidine-bridged bis(phenolato) ligand were synthesized, and their catalytic activity for the polymerization of l-lactide was explored. The amine elimination reactions of Ln[N(TMS)(2)](3)(mu-Cl)Li(THF)(3) with H(2)[ONNO] {H(2)[ONNO] = 1,4-bis(2-hydroxy-3,5-di-tert-butyl-benzyl)-imidazolidine} in a 1:1 molar ratio in tetrahydrofuran (THF) gave the neutral rare-earth metal amides [ONNO]Ln[N(TMS)(2)](THF) [Ln = La (1), Pr (2), Nd (3), Sm (4), Yb (5), and Y (6)] in high isolated yields. All of these complexes are fully characterized. X-ray structural determination revealed that complexes 1-6 are isostructural and have a solvated monomeric structure. The coordination geometry around each of the rare-earth metal atoms can be best described as a distorted trigonal bipyramid. It was found that complexes 1-6 are efficient initiators for the ring-opening polymerization of l-lactide, and the ionic radii of the central metals have a significant effect on the catalytic activity. A further study revealed that these rare-earth metal amides can initiate l-lactide polymerization in a controlled manner in the presence of 1 equiv of isopropyl alcohol.

5-(2-Carboxyethenyl) isatin derivative induces G{sub 2}/M cell cycle arrest and apoptosis in human leukemia K562 cells

Energy Technology Data Exchange (ETDEWEB)

Zhou, Yao; Zhao, Hong-Ye; Han, Kai-Lin; Yang, Yao; Song, Bin-Bin; Guo, Qian-Nan [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Fan, Zhen-Chuan [Key Laboratory of Food Nutrition and Safety (Tianjin University of Science and Technology), Ministry of Education, Tianjin 300457 (China); Obesita and Algaegen LLC, College Station, TX 77845 (United States); Zhang, Yong-Min [Université Pierre et Marie Curie-Paris 6, Institut Parisien de Chimie Moléculaire UMR CNRS 8232, 4 Place Jussieu, 75005 Paris (France); Teng, Yu-Ou, E-mail: tyo201485@tust.edu.cn [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Yu, Peng, E-mail: yupeng@tust.edu.cn [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China)

2014-08-08

Highlights: • 5-(2-Carboxyethenyl) isatin derivative (HKL 2H) inhibited K562’s proliferation. • HKL 2H caused the morphology change of G{sub 2}/M phase arrest and typical apoptosis. • HKL 2H induced G2/M cell cycle phase arrest in K562 cells. • HKL 2H induced apoptosis in K562 cells through the mitochondrial pathway. - Abstract: Our previous study successfully identified that the novel isatin derivative (E)-methyl 3-(1-(4-methoxybenzyl)-2,3-dioxoindolin-5-yl) acrylate (HKL 2H) acts as an anticancer agent at an inhibitory concentration (IC{sub 50}) level of 3 nM. In this study, the molecular mechanism how HKL 2H induces cytotoxic activity in the human chronic myelogenous leukemia K562 cells was investigated. Flow cytometric analysis showed that the cells were arrested in the G{sub 2}/M phase and accumulated subsequently in the sub-G{sub 1} phase in the presence of HKL 2H. HKL 2H treatment down-regulated the expressions of CDK1 and cyclin B but up-regulated the level of phosphorylated CDK1. Annexin-V staining and the classic DNA ladder studies showed that HKL 2H induced the apoptosis of K562 cells. Our study further showed that HKL 2H treatment caused the dissipation of mitochondrial membrane potential, activated caspase-3 and lowered the Bcl-2/Bax ratio in K562 cells, suggesting that the HKL 2H-causing programmed cell death of K562 cells was caused via the mitochondrial apoptotic pathway. Taken together, our data demonstrated that HKL 2H, a 5-(2-carboxyethenyl) isatin derivative, notably induces G{sub 2}/M cell cycle arrest and mitochondrial-mediated apoptosis in K562 cells, indicating that this compound could be a promising anticancer candidate for further investigation.

High pressure synthesis of BiS2

DEFF Research Database (Denmark)

Søndergaard-Pedersen, Simone; Nielsen, Morten Bormann; Bremholm, Martin

crystal structures and electrical properties.1,2 Up until now, the most sulfur rich phase in the Bi-S phase diagram was Bi2S3.3 For BiS2 the Bi atoms have anisotropic charge distribution and more complex structures are expected when comparing the layered structures of transition metal dichalcogenides....... The possibilities of using high pressure synthesis to discover new phases in the Bi-S binary system were investigated as early as the 1960’s.4 The research led to discovery of a compound with BiS2 stoichiometry, but no structure solution of BiS2 was reported. A reason behind making this new phase is to study...... the physical properties since the related compound Bi2S3 is known to be a thermoelectric material.5 In this research the BiS2 compound was synthesized by a high pressure and high temperature method using a multi-anvil large volume press and the structure was solved by single crystal diffraction. The structure...

When Ethyl Isocyanoacetate Meets Isatins: A 1,3-Dipolar/Inverse 1,3-Dipolar/Olefination Reaction for Access to 3-Ylideneoxindoles.

Science.gov (United States)

Yuan, Wen-Kui; Cui, Tao; Liu, Wei; Wen, Li-Rong; Li, Ming

2018-03-16

A new CuI/1,10-phen-catalyzed reaction for the synthesis of 3-ylideneoxindoles from readily available isatins and ethyl isocyanoacetate, in which ethyl isocyanoacetate acts as a latent two-carbon donor like the Wittig reagent, is reported. A tandem procedure including 1,3-dipolar cycloaddition/inverse 1,3-dipolar ring opening/olefination allows the preparation of 3-ylideneoxindoles with broad functional group tolerance.

Fluoroethylene Carbonate-Based Electrolyte with 1 M Sodium Bis(fluorosulfonyl)imide Enables High-Performance Sodium Metal Electrodes.

Science.gov (United States)

Lee, Yongwon; Lee, Jaegi; Lee, Jeongmin; Kim, Koeun; Cha, Aming; Kang, Sujin; Wi, Taeung; Kang, Seok Ju; Lee, Hyun-Wook; Choi, Nam-Soon

2018-05-02

Sodium (Na) metal anodes with stable electrochemical cycling have attracted widespread attention because of their highest specific capacity and lowest potential among anode materials for Na batteries. The main challenges associated with Na metal anodes are dendritic formation and the low density of deposited Na during electrochemical plating. Here, we demonstrate a fluoroethylene carbonate (FEC)-based electrolyte with 1 M sodium bis(fluorosulfonyl)imide (NaFSI) salt for the stable and dense deposition of the Na metal during electrochemical cycling. The novel electrolyte combination developed here circumvents the dendritic Na deposition that is one of the primary concerns for battery safety and constructs the uniform ionic interlayer achieving highly reversible Na plating/stripping reactions. The FEC-NaFSI constructs the mechanically strong and ion-permeable interlayer containing NaF and ionic compounds such as Na 2 CO 3 and sodium alkylcarbonates.

Antiferromagnetic exchange in meta-phenylene bridged bis(tris-o-iminosemiquinonato)metal complexes

International Nuclear Information System (INIS)

Dei, A.; Gatteschi, D.; Sangregorio, C.; Sorace, L.; Vaz, M.G.F.

2004-01-01

By reaction of the ligand N,N' bis(3,5-di-tert-butyl-2-hydroxyphenyl)-1,3-phenylenediamine (1), with Fe, Co or Mn salts, three complexes were synthesized where the bis-bidentate ligand is in the bis-semiquinonato oxidation state. Although the m-phenylene linker is known to afford ferromagnetic coupling in diradicals, the antiferromagnetic interaction of intramolecular origin we observed is not unexpected, given the large torsion angles between the semiquinonato and the m-phenylene planes

Antiferromagnetic exchange in meta-phenylene bridged bis(tris-o-iminosemiquinonato)metal complexes

Energy Technology Data Exchange (ETDEWEB)

Dei, A. E-mail: andrea.dei@unifi.it; Gatteschi, D.; Sangregorio, C.; Sorace, L.; Vaz, M.G.F

2004-05-01

By reaction of the ligand N,N' bis(3,5-di-tert-butyl-2-hydroxyphenyl)-1,3-phenylenediamine (1), with Fe, Co or Mn salts, three complexes were synthesized where the bis-bidentate ligand is in the bis-semiquinonato oxidation state. Although the m-phenylene linker is known to afford ferromagnetic coupling in diradicals, the antiferromagnetic interaction of intramolecular origin we observed is not unexpected, given the large torsion angles between the semiquinonato and the m-phenylene planes.

Asymmetric Ugi 3CR on isatin-derived ketimine: synthesis of chiral 3,3-disubstituted 3-aminooxindole derivatives

Directory of Open Access Journals (Sweden)

Giordano Lesma

2014-06-01

Full Text Available An efficient Ugi three-component reaction of a preformed chiral ketimine derived from isatin with various isonitrile and acid components has been developed. The reactions proceeded smoothly and in a stereocontrolled manner with regard to the new center of the Ugi products due to the stereoinduction of the amine chiral residue. A wide variety of novel chiral 3,3-disubstituted 3-aminooxindoles were obtained, a selection of which were subjected to post-Ugi transformations, paving the way to application as peptidomimetics.

Rare earth metal bis(amide) complexes bearing amidinate ancillary ligands: synthesis, characterization, and performance as catalyst precursors for cis-1,4 selective polymerization of isoprene.

Science.gov (United States)

Luo, Yunjie; Fan, Shimin; Yang, Jianping; Fang, Jianghua; Xu, Ping

2011-03-28

A family of rare earth metal bis(amide) complexes bearing monoanionic amidinate [RC(N-2,6-Me(2)C(6)H(3))(2)](-) (R = cyclohexyl (Cy), phenyl (Ph)) as ancillary ligands were synthesized and characterized. One-pot salt metathesis reaction of anhydrous LnCl(3) with one equivalent of amidinate lithium [RC(N-2,6-Me(2)C(6)H(3))(2)]Li, following the introduction of two equivalents of NaN(SiMe(3))(2) in THF at room temperature afforded the neutral and unsolvated mono(amidinate) rare earth metal bis(amide) complexes [RC(N-2,6-Me(2)C(6)H(3))(2)]Y[N(SiMe(3))(2)](2) (R = Cy (1); R = Ph (2)), and the "ate" mono(amidinate) rare earth metal bis(amide) complex [CyC(N-2,6-Me(2)C(6)H(3))(2)]Lu[N(SiMe(3))(2)](2)(μ-Cl)Li(THF)(3) (3) in 61-72% isolated yields. These complexes were characterized by elemental analysis, NMR spectroscopy, FT-IR spectroscopy, and X-ray single crystal diffraction. Single crystal structural determination revealed that the central metal in complexes 1 and 2 adopts a distorted tetrahedral geometry, and in complex 3 forms a distorted trigonal bipyramidal geometry. In the presence of AlMe(3), and in combination with one equimolar amount of [Ph(3)C][B(C(6)F(5))(4)], complexes 1 and 2 showed high activity towards isoprene polymerization to give high molecular weight polyisoprene (M(n) > 10(4)) with good cis-1,4 selectivity (>90%).

Metal coordination in the high-temperature leaching of roasted NdFeB magnets with the ionic liquid betainium bis(trifluoromethylsulfonyl)imide

OpenAIRE

Orefice, Martina; Binnemans, Koen; Vander Hoogerstraete, Tom

2018-01-01

Ionic liquids are largely used to leach metals from primary (ores) and secondary sources (end-of-life products). However, dry ionic liquids with a carboxylic function on the cation have not yet been used to leach metals at temperature above 100 °C and under atmospheric pressure. The ionic liquid betainium bis(trifluoromethylsulfonyl)imide, [Hbet][Tf2N], was used in the dry state to recover neodymium, dysprosium and cobalt from NdFeB magnets and NdFeB production scrap. The magnets and the scra...

Synthesis of mono- and geminal dimetalated carbanions of bis(phenylsulfonyl)methane using alkali metal bases and structural comparisons with lithiated bis(phenylsulfonyl)imides.

Science.gov (United States)

MacDougall, Dugald J; Kennedy, Alan R; Noll, Bruce C; Henderson, Kenneth W

2005-06-21

The alpha,alpha'-stabilized carbanion complexes [(PhSO2)2CHLi.THF]1, [(PhSO2)2CHNa.THF]2 and [(PhSO2)2CHK]3 were prepared by the direct deprotonation of bis(phenylsulfonyl)methane I in THF with one molar equivalent of MeLi, BuNa and BnK respectively. The geminal dianionic complexes [(PhSO2)2CLi2.THF]4, [(PhSO2)2CNa2.0.55THF]5 and [(PhSO2)2CK2]6 were similarly prepared by the reaction of I with two molar equivalents of MeLi, BuNa and BnK respectively in THF. NMR and MS solution studies of 1-3 are consistent with the formation of charge-separated species in DMSO media. Solutions studies of 4-6, in conjunction with trapping experiments, indicate that the dianions deprotonate DMSO and regenerate the monoanions 1-3. Crystallographic analysis of 1 revealed a 1D chain polymer in which the metal centers are chelated by the bis(sulfonyl) ligands and connect to neighboring units through Li-O(S) interactions. An unexpected feature of 1 is that the polymeric chains are homochiral, since the chelating ligands of the backbone adopt the same relative configuration. Also, the phenyl substituents of each chelate in 1 are oriented in a cisoid manner. The sodium derivative 2 adopts a related solid-state structure, where enantiomeric pairs of chains combine to give a 1D ribbon motif. The lithium bis(phenylsulfonyl)imides [(PhSO2)2NLi.THF]9 and [(PhSO2)2NLi.Pyr2]10 were also prepared and structurally characterized. In the solid state 9 has a similar connectivity to that found for 1 but with heterochiral chains. In comparison, the more highly solvated complex 10 forms a 1D polymeric arrangement without chelation of the ligands and with the phenyl substituents oriented in a transoid fashion.

A Novel Bis(phosphido)pyridine [PNP] 2− Pincer Ligand and Its Potassium and Bis(dimethylamido)zirconium(IV) Complexes

KAUST Repository

Winston, Matthew S.

2010-12-13

A novel PNP bis(secondary phosphine)pyridine pincer ligand, 2,6-bis(2-(phenylphosphino)phenyl)pyridine, has been prepared in high yield, and the properties of the doubly deprotonated form as a ligand in K 4(PNP)2(THF)6 and (PNP)Zr(NMe2) 2 have been investigated. The neutral PNP ligand has been isolated as a mixture of noninterconverting diastereomers, due to the presence of two chirogenic phosphorus atoms of the secondary phopshines, but coordination of the dianionic form to potassium and zirconium allows for isolation of a single diastereomer in near-quantitative yield. The structure of a bis(dimethylamido) zirconium(IV) derivative of the bis(phosphido)pyridine ligand and DFT calculations suggest that the phosphides do not π-bond to early transition metals, likely due to geometric strain and possibly orbital size mismatch between phosphorus and zirconium. As a result, the soft phosphides are prone to formation of insoluble oligomers with substantial bridging of the phosphido lone pairs to other zirconium centers. © 2010 American Chemical Society.

A Novel Bis(phosphido)pyridine [PNP] 2− Pincer Ligand and Its Potassium and Bis(dimethylamido)zirconium(IV) Complexes

KAUST Repository

Winston, Matthew S.; Bercaw, John E.

2010-01-01

A novel PNP bis(secondary phosphine)pyridine pincer ligand, 2,6-bis(2-(phenylphosphino)phenyl)pyridine, has been prepared in high yield, and the properties of the doubly deprotonated form as a ligand in K 4(PNP)2(THF)6 and (PNP)Zr(NMe2) 2 have been investigated. The neutral PNP ligand has been isolated as a mixture of noninterconverting diastereomers, due to the presence of two chirogenic phosphorus atoms of the secondary phopshines, but coordination of the dianionic form to potassium and zirconium allows for isolation of a single diastereomer in near-quantitative yield. The structure of a bis(dimethylamido) zirconium(IV) derivative of the bis(phosphido)pyridine ligand and DFT calculations suggest that the phosphides do not π-bond to early transition metals, likely due to geometric strain and possibly orbital size mismatch between phosphorus and zirconium. As a result, the soft phosphides are prone to formation of insoluble oligomers with substantial bridging of the phosphido lone pairs to other zirconium centers. © 2010 American Chemical Society.

μ-Carbonato-bis­(bis­{2-[(diethyl­amino)­meth­yl]phen­yl}bis­muth(III))

Science.gov (United States)

Soran, Albert P.; Nema, Mihai G.; Breunig, Hans J.; Silvestru, Cristian

2011-01-01

The mol­ecular structure of the title compound, [Bi2(C11H16N)4(CO3)], consists of a symmetrically bridging carbonato group which binds two [2-Et2NCH2C6H4]2Bi units that are crystallographically related via a twofold rotation axis bis­ecting the carbonate group. The two Bi atoms and two of the C atoms directly bonded to bis­muth are quasi-planar [deviations of 0.323 (1) and 0.330 (9)Å for the Bi and C atoms, respectively] with the carbonate group. The remaining two ligands are in a trans arrangement relative to the quasi-planar (CBi)2CO3 system. The metal atom is strongly coordinated by the N atom of one pendant arm [Bi—N = 2.739 (6) Å], almost trans to the O atom, while the N atom of the other pendant arm exhibits a weaker intra­molecular inter­action [Bi⋯N = 3.659 (7) Å] almost trans to a C atom. If both these intra­molecular N→Bi inter­actions per metal atom are considered, the overall coordination geometry at bis­muth becomes distorted square-pyramidal [(C,N)2BiO cores] and the compound can be described as a hypervalent 12-Bi-5 species. Additional quite short intra­molecular Bi⋯O inter­actions are also present [3.796 (8)–4.020 (9) Å]. Inter­molecular associations through weak η6⋯Bi inter­actions [Bi⋯centroid of benzene ring = 3.659 (1) Å] lead to a ribbon-like supra­molecular association. PMID:21522836

Synthesis, characterization, antimicrobial and anthelmentic activities of some metal complexes with a new Schiff base 3-[(Z)-5-amino-1,3,3-trimethyl cyclohexylmethylimino]-1,3-dihydroindol-2-one

International Nuclear Information System (INIS)

Reddy, K. R. K; Mahendra, K.N.

2008-01-01

The complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), dioxouranium(VI), and Th(IV) with a new Schiff base, 3-[(Z)-5-amino-1,3,3-trimethyl cyclohexylmethylimino]-1,3-dihydroindol-2-one formed by the condensation of isatin (Indole-2.3-dione) with isophoronediamine(5-amino-1,3,3-trimethyl-cyclohexane methylamine) were synthesized and characterized by microanalysis, conductivity, UV-visible, FT-IR, 1 H NMR, TGA, and magnetic susceptibility measurements. All the complexes exhibit 1: 1 metal to ligand ratio except for the dioxouranium(VI) and thorium(IV) complexes, where the metal: ligand stoichiometry is 1: 2. The spectral data revealed that the ligand acts as monobasic bidentate, coordinating to the metal ion through the azomethine nitrogen and carbonyl oxygen of the isatin moiety. Tetrahedral geometry for Co(II), Ni(II), Zn(II), Cd(II), and Hg(II) complexes, square planar geometry for Cu(II) complexes, and the coordination numbers 6 and 8 for UO 2 (VI) and Th(IV) complexes, respectively, are proposed. Both the ligand and the metal complexes were screened for their antibacterial activity against Bacillus subtilis, Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas aeruginosa, and the complexes are more potent bactericides than the ligand. The anthelmintic activity of the ligand and its complexes against earthworms was also investigated [ru

KINETICS OF SUBSTITUTION OF CIS-BIS(MALONATO ...

African Journals Online (AJOL)

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In this process, it indicated that the substitution reaction occurs through an Ia mechanism in the ... isotopic water exchange and other anation processes. ... The potassium salt of cis-bis(malonato)diaquochromate(III) was prepared by a reported [26] ... of the synthesized metal complex showed maxima at 415 nm (ε = 41.6 M-1 ...

A bis(3-hydroxy-4-pyridinone)-EDTA derivative as a strong chelator for M3+ hard metal ions: complexation ability and selectivity.

Science.gov (United States)

Gama, Sofia; Dron, Paul; Chaves, Silvia; Farkas, Etelka; Santos, M Amélia

2009-08-21

The study of chelating compounds is very important to solve problems related to human metal overload. 3-Hydroxy-3-pyridinones (HP), namely deferiprone, have been clinically used for chelating therapy of Fe and Al over the last decade. A multi-disciplinary search for alternative molecules led us to develop poly-(3-hydroxy-4-pyridinones) to increase metal chelation efficacy. We present herein a complexation study of a new bis-(3-hydroxy-4-pyridinone)-EDTA derivative with a set of M(3+) hard metal ions (M = Fe, Al, Ga), as well as Zn(2+), a biologically relevant metal ion. Thus a systematic aqueous solution equilibrium study was performed using potentiometric and spectroscopic techniques (UV-Vis, NMR methods). These set of results enables the establishment of specific models as well as the determination of thermodynamic stability constants and coordination modes of the metal complexes. The results indicate that this ligand has a higher affinity for chelating to these hard metal ions than deferiprone, and that the coordination occurs mostly through the HP moieties. Furthermore, it was also found that this ligand has a higher selectivity for chelating to M(3+) hard metal ions (M = Fe, Al, Ga) than Zn(2+).

Synthesis of isatin thiosemicarbazones derivatives: in vitro anti-cancer, DNA binding and cleavage activities.

Science.gov (United States)

Ali, Amna Qasem; Teoh, Siang Guan; Salhin, Abdussalam; Eltayeb, Naser Eltaher; Khadeer Ahamed, Mohamed B; Abdul Majid, A M S

2014-05-05

New derivatives of thiosemicarbazone Schiff base with isatin moiety were synthesized L1-L6. The structures of these compounds were characterized based on the spectroscopic techniques. Compound L6 was further characterized by XRD single crystal. The interaction of these compounds with calf thymus (CT-DNA) exhibited high intrinsic binding constant (k(b)=5.03-33.00×10(5) M(-1)) for L1-L3 and L5 and (6.14-9.47×10(4) M(-1)) for L4 and L6 which reflect intercalative activity of these compounds toward CT-DNA. This result was also confirmed by the viscosity data. The electrophoresis studies reveal the higher cleavage activity of L1-L3 than L4-L6. The in vitro anti-proliferative activity of these compounds against human colon cancer cell line (HCT 116) revealed that the synthesized compounds (L3, L6 and L2) exhibited good anticancer potency. Copyright © 2014 Elsevier B.V. All rights reserved.

Bis-phosphonate sequestering agents. Synthesis and preliminary evaluation for in vitro and in vivo uranium(VI) chelation

Energy Technology Data Exchange (ETDEWEB)

Sawicki, M.; Lecercle, D.; Taran, F. [CEA Saclay, IBiTecS, Serv Chim Bioorgan et Marquage, F-91191 Gif Sur Yvette (France); Grillon, G.; Le Gall, B.; Serandour, A.L.; Poncy, J.L. [CEA, DSV, DRR, Lab Radiotoxicol, F-91680 Bruyeres Le Chatel (France); Bailly, T.; Burgada, R.; Lecouvey, M.; Challeix, V. [CNRS, Lab Chim Struct Biomol, UMR 7033, F-93017 Bobigny (France); Leydier, A.; Pellet-Rostaing, S. [Univ Lyon 1, ICBMS, UMR 5246, Lab Catalyse et Synth Organ, F-69622 Villeurbanne (France); Ansoborlo, E. [CEA, DEN, DRCP, CETAMA, VRH Marcoule, F-30207 Bagnols Sur Ceze (France)

2008-07-01

A library of bis-phosphonate-based ligands was prepared using solution-phase parallel synthesis and tested for its uranium-binding properties. With the help of a screening method, based on a chromo-phoric complex displacement procedure, 23 dipodal and tripodal chelates bearing bis-phosphonate chelating functions were found to display very high affinity for the uranyl ion and were selected for evaluation of their in vivo uranyl-removal efficacy. Among them, 11 ligands induced a huge modification of the uranyl biodistribution by deviating the metal from kidney and bones to liver. Among the other ligands, the most potent was the dipodal bis-phosphonate 3C which reduced the retention of uranyl and increased its excretion by around 10% of the injected metal. (authors)

Crystal structure of bis[2,5-bis(pyridin-2-yl-1,3,4-thiadiazole-κ2N2,N3]bis(thiocyanato-κScopper(II

Directory of Open Access Journals (Sweden)

Abdelhakim Laachir

2016-08-01

Full Text Available The mononuclear title complex, [Cu(SCN2(C12H8N4S2], was obtained by the reaction of 2,5-bis(pyridin-2-yl-1,3,4-thiadiazole and potassium thiocyanate with copper(II chloride dihydrate. The copper cation lies on an inversion centre and displays an elongated octahedral coordination geometry. The equatorial positions are occupied by the N atoms of two 2,5-bis(pyridin-2-yl-1,3,4-thiadiazole ligands, whereas the axial positions are occupied by the S atoms of two thiocyanate anions. The thiadiazole and the pyridyl rings linked to the metal are approximately coplanar, with a maximum deviation from the mean plane of 0.190 (2 Å. The cohesion of the crystal structure is ensured by weak C—H...N hydrogen bonds and π–π interactions between parallel pyridyl rings of neighbouring molecules [centroid-to-centroid distance = 3.663 (2 Å], leading to a three-dimensional network.

Low-temperature CVD of iron, cobalt, and nickel nitride thin films from bis[di(tert-butyl)amido]metal(II) precursors and ammonia

International Nuclear Information System (INIS)

Cloud, Andrew N.; Abelson, John R.; Davis, Luke M.; Girolami, Gregory S.

2014-01-01

Thin films of late transition metal nitrides (where the metal is iron, cobalt, or nickel) are grown by low-pressure metalorganic chemical vapor deposition from bis[di(tert-butyl)amido]metal(II) precursors and ammonia. These metal nitrides are known to have useful mechanical and magnetic properties, but there are few thin film growth techniques to produce them based on a single precursor family. The authors report the deposition of metal nitride thin films below 300 °C from three recently synthesized M[N(t-Bu) 2 ] 2 precursors, where M = Fe, Co, and Ni, with growth onset as low as room temperature. Metal-rich phases are obtained with constant nitrogen content from growth onset to 200 °C over a range of feedstock partial pressures. Carbon contamination in the films is minimal for iron and cobalt nitride, but similar to the nitrogen concentration for nickel nitride. X-ray photoelectron spectroscopy indicates that the incorporated nitrogen is present as metal nitride, even for films grown at the reaction onset temperature. Deposition rates of up to 18 nm/min are observed. The film morphologies, growth rates, and compositions are consistent with a gas-phase transamination reaction that produces precursor species with high sticking coefficients and low surface mobilities

Synthesis, structurale elucidation and antioxidant study of Ortho-substituted N,N’-bis(benzamidothiocarbonyl)hydrazine derivatives

Science.gov (United States)

Firdausiah, Syadza; Hasbullah, S. A.; Yamin, B. M.

2018-03-01

Some bis(thiourea) compounds have been reported to posses excellent performance in pharmaceutical and environmental fields because of their ability to form chelating complexes with various anions and metal ions. Structurally for carbonyl thiourea derivatives, to become a chelating agent, it must adopt cis-configuration. In the present study, four new bis(thiourea) derivatives namely N,N’-bis(o-fluorobenzamidothiocarbonyl)hydrazine (1), N,N’- bis(o-chloro-benzamidothiocarbonyl)hydrazine (2), N,N’-bis(o-nitrobenzamidothiocarbonyl)-hydrazine (3), and N,N’-bis(o-methylbenzamidothiocarbonyl)hydrazine (4) were successfully synthesized and characterized by CHNS microelemental analysis, FTIR, UV-Vis, and 1H and 13C NMR spectroscopy. However chemical crystallography study showed that both thiourea moieties in compound (2) and (3) adopt trans geometry. Therefore they are potential monodentate ligand with two active moieties. DPPH radical scavenging experiment showed that compound (1), (2), and (4) exhibited higher antioxidant activity than ascorbic acid (Vitamin C).

Bis(imidazolin-2-iminato) rare earth metal complexes: synthesis, structural characterization, and catalytic application.

Science.gov (United States)

Trambitas, Alexandra G; Melcher, Daniel; Hartenstein, Larissa; Roesky, Peter W; Daniliuc, Constantin; Jones, Peter G; Tamm, Matthias

2012-06-18

Reaction of anhydrous rare earth metal halides MCl(3) with 2 equiv of 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-imine (Im(Dipp)NH) and 2 equiv of trimethylsilylmethyl lithium (Me(3)SiCH(2)Li) in THF furnished the complexes [(Im(Dipp)N)(2)MCl(THF)(n)] (M = Sc, Y, Lu). The molecular structures of all three compounds were established by single-crystal X-ray diffraction analyses. The coordination spheres around the pentacoordinate metal atoms are best described as trigonal bipyramids. Reaction of YbI(2) with 2 equiv of LiCH(2)SiMe(3) and 2 equiv of the imino ligand Im(Dipp)NH in tetrahydrofuran did not result in a divalent complex, but instead the Yb(III) complex [(Im(Dipp)N)(2)YbI(THF)(2)] was obtained and structurally characterized. Treatment of [(Im(Dipp)N)(2)MCl(THF)(n)] with 1 equiv of LiCH(2)SiMe(3) resulted in the formation of [(Im(Dipp)N)(2)M(CH(2)SiMe(3))(THF)(n)]. The coordination arrangement of these compounds in the solid state at the metal atoms is similar to that found for the starting materials, although the introduction of the neosilyl ligand induces a significantly greater distortion from the ideal trigonal-bipyramidal geometry. [(Im(Dipp)N)(2)Y(CH(2)SiMe(3))(THF)(2)] was used as precatalyst in the intramolecular hydroamination/cyclization reaction of various terminal aminoalkenes and of one aminoalkyne. The complex showed high catalytic activity and selectivity. A comparison with the previously reported dialkyl yttrium complex [(Im(Dipp)N)Y(CH(2)SiMe(3))(2)(THF)(3)] showed no clear tendency in terms of activity.

Photochemical and electrochemical studies on lanthanide complexes of 6-(hydroxymethylpyridine- 2-carboxaldehyde[2- methyl-pyrimidine-4,6-diyl] bis-hydrazone

Directory of Open Access Journals (Sweden)

María Alejandra Fernandez

2014-01-01

Full Text Available Herein we report the synthesis of the 6-(hydroxymethylpyridine-2- carboxaldehyde[2-methyl-pyrimidine- 4,6-diyl]bis-hydrazone by a condensation reaction between 6-(hydroxymethyl picolinaldehyde with 4,6-(bis-hydrazino-2- methylpyrimidine. This bis-hydrazone can be visualized as a two-arm system which exhibits photochemical induced [E,E]/[E,Z]/[Z,Z’] isomerizations and double coordination to metal centers. Configurational changes, upon UV light irradiation, were followed over time by 1 H NMR, establishing that isomerization, in both arms, is a consecutive reaction that follows first-order kinetics (k1 = 4.06 x 10-4 s-1 and k2 = 2.80 x 10-4 s-1. Furthermore, the synthesis of bis-hydrazone metal complexes with La (III and Sm (III ions was achieved; subsequently, the absorption and emission properties of these complexes were studied, determining the fluorescence quantum yields, La= 0.2024 and Sm= 0.1413. Electrochemical studies of the complexes were conducted by square wave voltammetry, demonstrating that the bis-hydrazone and its complexes are electroactive species between +1.5 and -2.5 V.

Synthesis of bis(oxamato) transition metal complexes and Ni nanoparticles and their structural, magnetic, optical, and magneto-optical characterization

Energy Technology Data Exchange (ETDEWEB)

Braeuer, Bjoern

2008-07-02

In the framework of this thesis mono- and oligonuclear Cu(II)- anf Ni(II)-bis(oxamato) complexes are synthesized in view on their magneto-optical properties and structurally characterized. About transition-charge and transition-metal induced deviations from the general reaction behaviour described in literature is reported. From electron-spin-resonance studies the spin-density distribution in the mononuclear Cu(II) complexes is derived. The influence on this by coordination geometry as well as the effects of the superexchange interaction are discussed and compared with results from the density functional theory (DFT). Trinuclear bis(oxamato) complexes are for the first time deposited on Si(111) substrates by spin coating and studied by means of the spectroscopic ellipsometry as well as the Raman spectroscopy and evaluated by means of DFT calculations. Magneto-optical Kerr-effect studies were performed on thin layers of these complexes as well as phthalocyanines. For the comparison the magnetic and magneto-optical properties of Ni nanoparticles in different organic matrices were studied. By means of the photoelectron spectroscopy the oxidation behaviour of these is studied and conclusions on charge-transfer processes between the matrices and the nanoparticles are drawn. [German] Im Rahmen dieser Arbeit werden ein- und mehrkernige Cu(II)- und Ni(II)-bis-(oxamato)-Komplexe im Hinblick auf ihre magneto-optischen Eigenschaften gezielt hergestellt und strukturell charakterisiert. Ueber ladungs- und uebergangsmetallinduzierte Abweichungen vom allgemeinen in der Literatur beschriebenen Reaktionsverhalten wird berichtet. Aus Elektronenspinresonanz-Untersuchungen wird die Spindichteverteilung in den einkernigen Cu(II)-Komplexen abgeleitet. Die Beeinflussung dieser durch die Koordinationsgeometrie sowie die Auswirkungen auf die Superaustausch- Wechselwirkung werden diskutiert und mit Ergebnissen der Dichtefunktionaltheorie (DFT) verglichen. Dreikernige bis

Nootropic effects of bis(citratogermanates (stannates with different metals (Mg, Co in their structure

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V. V. Godovan

2014-10-01

Full Text Available Aim. Nootropic effects of bis(citratogermanates (stannates with different metals (Mg, Co have been investigated in this article. With this aim the peculiarities of conditioned reflex formation as well as short- and long-term memory manifestations under the influence of the investigated coordinative compounds have been studied for 256 rats with the help of pathophysiological and pharmacological methods. Methods and results. It has been shown that stannates influence on the development of active avoidance conditioned reflex as well as on the manifestations of mnestic functions. It has been found that germacit and gercocit induce positive nootropic effects that occur in case of low dose drugs administration and are characterized by relief of conditioned reflex formation and by short- and long-term memory improvement at the same time. Conclusion. Stanmacit and stancocit also have nootropic effects that dependent on dose and are characterized by nootropic effect during administration in low doses and by amnestic effect at doses starting from 1/40 LD50. This indicates that stannates show nootropic activity

New isatin derivative inhibits neurodegeneration by restoring insulin signaling in brain.

Science.gov (United States)

Aftab, Meha Fatima; Afridi, Shabbir Khan; Mughal, Uzma Rasool; Karim, Aneela; Haleem, Darakhshan Jabeen; Kabir, Nurul; Khan, Khalid M; Hafizur, Rahman M; Waraich, Rizwana S

2017-04-01

Diabetes is associated with neurodegeneration. Glycation ensues in diabetes and glycated proteins cause insulin resistance in brain resulting in amyloid plaques and NFTs. Also glycation enhances gliosis by promoting neuroinflammation. Currently there is no therapy available to target neurodegenration in brain therefore, development of new therapy that offers neuroprotection is critical. The objective of this study was to evaluate mechanistic effect of isatin derivative URM-II-81, an anti-glycation agent for improvement of insulin action in brain and inhibition of neurodegenration. Methylglyoxal induced stress was inhibited by treatment with URM-II-81. Also, Ser473 and Ser9 phosphorylation of Akt and GSK-3β respectively were restored by URM-II-81. Effect of URM-II-81 on axonal integrity was studied by differentiating Neuro2A using retinoic acid. URM-II-81 restored axonal length in MGO treated cells. Its effects were also studied in high fat and low dose streptozotocin induced diabetic mice where it reduced RBG levels and inhibited glycative stress by reducing HbA1c. URM-II-81 treatment also showed inhibition of gliosis in hippocampus. Histological analysis showed reduced NFTs in CA3 hippocampal region and restoration of insulin signaling in hippocampii of diabetic mice. Our findings suggest that URM-II-81 can be developed as a new therapeutic agent for treatment of neurodegenration. Copyright © 2017 Elsevier B.V. All rights reserved.

40 CFR 721.1630 - 1,2-Ethanediol bis(4-methylbenzenesulfonate); 2,2-oxybis-ethane bis(4-methylbenzenesulfonate...

Science.gov (United States)

2010-07-01

...-methylbenzenesulfonate); 2,2-oxybis-ethane bis(4-methylbenzenesulfonate); ethanol, 2,2â²-[oxybis(2,1-ethanediyl oxy)]bis-, bis(4-methylbenzenesulfonate); ethanol, 2,2â²-[oxybis (2,1-ethane diyloxy)] bis-, bis(4...); 2,2-oxybis-ethane bis(4-methylbenzenesulfonate); ethanol, 2,2′-[oxybis(2,1-ethanediyl oxy)]bis-, bis...

N-doping of organic semiconductors by bis-metallosandwich compounds

Science.gov (United States)

Barlow, Stephen; Qi, Yabing; Kahn, Antoine; Marder, Seth; Kim, Sang Bok; Mohapatra, Swagat K.; Guo, Song

2016-01-05

The various inventions disclosed, described, and/or claimed herein relate to the field of methods for n-doping organic semiconductors with certain bis-metallosandwich compounds, the doped compositions produced, and the uses of the doped compositions in organic electronic devices. Metals can be manganese, rhenium, iron, ruthenium, osmium, rhodium, or iridium. Stable and efficient doping can be achieved.

Twisting and Tilting 1,1 '-Bis(dialkylphosphino)ferrocene Bound to Low Valent Tricarbonylmaganese(I to -I)

Czech Academy of Sciences Publication Activity Database

Schäfer, K. M.; Reinders, L.; Fiedler, Jan; Ringenberg, M. R.

2017-01-01

Roč. 56, č. 23 (2017), s. 14688-14696 ISSN 0020-1669 Institutional support: RVO:61388955 Keywords : 1,1´-Bis(dialkylphosphino)ferrocene DPPF * metal-metal bonds * Fe interactions Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 4.857, year: 2016

Biochemical characterization of propylglyoxal bis(guanylhydrazone). Facile synthesis of monoalkylglyoxal bis(guanylhydrazones).

Science.gov (United States)

Elo, H; Laine, R; Alhonen-Hongisto, L; Jänne, J; Mutikainen, I; Lumme, P

1985-01-01

Propylglyoxal bis(guanylhydrazone) sulfate, a novel analog of the well-known antileukemic drug methylglyoxal bis(guanylhydrazone), has been prepared from 2,2-dibromopentanal, and the compound has been characterized biochemically. Although it is a powerful inhibitor of S-adenosylmethionine decarboxylase, its Ki value (0.2 microM) is considerably higher than that of ethylglyoxal bis(guanylhydrazone) (0.06 microM). The compound is only poorly taken up by tumor cells, and its accumulation is not stimulated by a prior exposure of the tumor cells to difluoromethylornithine, a compound that causes polyamine depletion. Thus, the uptake characteristics of the compound are similar to those of ethylglyoxal bis(guanylhydrazone), but in striking contrast to those of methylglyoxal and glyoxal bis(guanylhydrazones). Since the configuration of the double bonds in glyoxal, methylglyoxal and propylglyoxal bis(guanylhydrazones) has been shown to be identical, the different uptake characteristics are probably only due to differences in side chain size and/or hydrophobicity.

Rare earth metal bis(silylamide) complexes bearing pyridyl-functionalized indenyl ligand: synthesis, structure and performance in the living polymerization of L-lactide and rac-lactide.

Science.gov (United States)

Wang, Yibin; Lei, Yinlin; Chi, Shuhui; Luo, Yunjie

2013-02-07

Amine elimination of rare earth tris(silylamide) complexes Ln[N(SiHMe(2))(2)](3)(THF)(2) (Ln = La, Sm, Er, Lu) with 1 equiv. of the pyridyl-functionalized indenyl ligand C(9)H(7)CMe(2)CH(2)C(5)H(4)N-α afforded a series of neutral mono-indenyl-ligated rare earth metal bis(silylamide) complexes (C(9)H(6)CMe(2)CH(2)C(5)H(4)N-α)Ln[N(SiHMe(2))(2)](2) (Ln = La (1), Sm (2), Er (3), Lu (4)) in 83-87% isolated yields. Reaction of La[N(SiHMe(2))(2)](3)(THF)(2) with 2 equivalents of C(9)H(7)CMe(2)CH(2)C(5)H(4)N-α provided the neutral bis(indenyl) lanthanum mono(silylamide) complex (C(9)H(6)CMe(2)CH(2)C(5)H(4)N-α)(2)LaN(SiHMe(2))(2) (5). These complexes were characterized by elemental analysis, FT-IR and NMR (except for 3 for the strong paramagnetic property of the central metal). X-ray single crystal structural diffraction showed that 1-4 are isostructural and the central metals are four-coordinated by one indenyl ring, one nitrogen atom from the pendant pyridyl group, and two amide groups to form a distorted tetrahedral geometry; while the central metal in 5 is five-coordinated by two indenyl rings, two nitrogen atoms from the pendant pyridyl groups, and one amide group to adopt a distorted pyramidal geometry, if the indenyl ring is regarded as occupying an independent vertex. The monoanionic pyridyl-functionalized indenyl ligand is bonded to the central metal in η(5)/κ(1) constrained geometry configuration (CGC) mode. 1-4 are highly active for the ring-opening polymerization of L-lactide and rac-lactide. In the presence of 2 equivalents of benzyl alcohol, 1 shows high activity toward L-lactide and rac-lactide in a living fashion.

Synthesis and Photophysical and Electrochemical Properties of Functionalized Mono-, Bis-, and Trisanthracenyl Bridged Ru(II Bis(2,2′:6′,2″-terpyridine Charge Transfer Complexes

Directory of Open Access Journals (Sweden)

Adewale O. Adeloye

2014-01-01

Full Text Available With the aim of developing new molecular devices having long-range electron transfer in artificial systems and as photosensitizers, a series of homoleptic ruthenium(II bisterpyridine complexes bearing one to three anthracenyl units sandwiched between terpyridine and 2-methyl-2-butenoic acid group are synthesized and characterized. The complexes formulated as bis-4′-(9-monoanthracenyl-10-(2-methyl-2-butenoic acid terpyridyl ruthenium(II bis(hexafluorophosphate (RBT1, bis-4′-(9-dianthracenyl-10-(2-methyl-2-butenoic acid terpyridyl ruthenium(II bis(hexafluorophosphate (RBT2, and bis-4′-(9-trianthracenyl-10-(2-methyl-2-butenoic acid terpyridyl ruthenium(II bis(hexafluorophosphate (RBT3 were characterized by elemental analysis, FT-IR, UV-Vis, photoluminescence, 1H and 13C NMR spectroscopy, and electrochemical techniques by elemental analysis, FT-IR, UV-Vis, photoluminescence, 1H and 13C NMR spectroscopy, and electrochemical techniques. The cyclic voltammograms (CVs of (RBT1, (RBT2, and (RBT3 display reversible one-electron oxidation processes at E1/2 = 1.13 V, 0.71 V, and 0.99 V, respectively (versus Ag/AgCl. Based on a general linear correlation between increase in the length of π-conjugation bond and the molar extinction coefficients, the Ru(II bisterpyridyl complexes show characteristic broad and intense metal-to-ligand charge transfer (MLCT band absorption transitions between 480–600 nm, ε=9.45×103 M−1 cm−1, and appreciable photoluminescence spanning the visible region.

μ-1,2-Bis(diphenylphosphinoethane-κ2P:P′-bis{[1,2-bis(diphenylphosphinoethane-κ2P,P′]bromidocopper(I} acetone disolvate

Directory of Open Access Journals (Sweden)

Wen-Juan Shi

2008-10-01

Full Text Available In the crystal structure of the title compound, [Cu2Br2(dppe3]·2CH3COCH3 [dppe is 1,2-bis(diphenylphosphinoethane, C26H24P2], the two Cu centers are bridged by a dppe ligand and each metal center carries one chelating dppe unit, with the fourth coordination site available for the Br− anion. The molecule is centrosymmetric, with the center of symmetry located between the methylene C atoms of the bridging dppe ligand. The crystal structure is stabilized by intramolecular C—H...Br hydrogen bonds and intermolecular π–π interactions, with a centroid-to-centroid distance of 3.2055 (1 Å.

New metal-organic complexes based on bis(tetrazole) ligands: Synthesis, structures and properties

Science.gov (United States)

Du, Ceng-Ceng; Fan, Jian-Zhong; Wang, Xin-Fang; Zhou, Sheng-Bin; Wang, Duo-Zhi

2017-04-01

In this paper, a series of new complexes, [Zn2(HL1)2(H2O)4]·H2O (1), [Co2(HL1)2]·TEA (2), [Co3(HL1)2(H2L1)2(H2O)4]n (3), [Cu(HL1)(H2O)2]n (4), {[Cu5(HL2)2(OH)4(ClO4)2]·4H2O}n (5) and [Cu2(L3)]n (6) were successfully prepared by utilizing three bis(tetrazole) ligands [bis-(1H-tetrazol-5-ylmethyl)-amine (H3L1), bis-(1H-tetrazol-5-ylethyl)-amine (H3L2) and 1,5-bis(5-tetrazolo)-3-thiapentane (H2L3)], all of which have been characterized by elemental analyses, FT-IR spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analyses as well as single-crystal X-ray diffraction analyses showing different dimensionalities (0D, 1D and 3D). Complexes 1 and 2 are 0D structures, 1 shows a dinuclear structure, 2 displays two crystallographically different mononuclear structures, 1 and 2 are further assembled to form 3D supramolecular framework and 2D supramolecular network by hydrogen-bonding interactions, respectively. Complexes 3, 4 and 5 are 1D structures, 3 features a mononuclear unit and a 1D chain, which are arranged into 3D supramolecular architecture by hydrogen-bonding interactions, 4 presents a zigzag chain, 5 shows an infinite chain structure constructed from pentanuclear Cu(II) subunits and ClO4- anions. Complex 6 exhibits a 3D coordination framework based on cyclic [Cu4(L3)2] dimmer subunits as nodes possessing an 8-connected network topology with the point symbol {424·64}. Further, semiconductor behaviors, the solid-state luminescent properties of the complexes 1-3 and 6 were measured and studied seriously at room temperature.

Synthesis of Schiff and Mannich Bases of Isatin Derivatives with 4-Amino-4,5-Dihydro-1H-1,2,4-Triazole-5-Ones

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Hakan Bektas

2008-09-01

Full Text Available Ethyl imidate hydrochlorides 1 were prepared by passing HCl gas through solutions of substituted benzyl cyanides and absolute ethanol. Ethoxycarbonylhydrazones 2 were synthesized from the reaction of compounds 1 with ethyl carbazate. Treatment of 2 with hydrazine hydrate leads to the formation of substituted 4-amino-4,5-dihydro-1H-1,2,4-triazole-5-ones 3. Isatin and 5-chloroisatin were added to 3 to form Schiff bases 4 and N-Mannich bases 5 of these compounds were synthesized by reacting with formaldehyde and piperidine. Their chemical structures were confirmed by means of IR, 1H- and 13C-NMR data and by elemental analysis.

Optical and magneto-optical properties of spin coated films of novel trinuclear bis(oxamato) and bis(oxamidato) type complexes

Energy Technology Data Exchange (ETDEWEB)

Abdulmalic, Mohammad A. [Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Institut für Chemie, Straße der Nationen 62, D-09111 Chemnitz (Germany); Fronk, Michael [Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Institut für Physik, Reichenhainer Straße 70, D-09107 Chemnitz (Germany); Bräuer, Björn [Stanford Institute of Materials and Energy Science, Stanford University, Stanford, CA 94025 (United States); Zahn, Dietrich R.T. [Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Institut für Physik, Reichenhainer Straße 70, D-09107 Chemnitz (Germany); Salvan, Georgeta, E-mail: salvan@physik.tu-chemnitz.de [Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Institut für Physik, Reichenhainer Straße 70, D-09107 Chemnitz (Germany); Eya' ane Meva, Francois [Department of Pharmaceutical Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, BP 2701 (Cameroon); and others

2016-12-01

This work reports the first example of the spectroscopic measurements of the Magneto-Optical Kerr Effect (MOKE) of films being composed of trinuclear transition metal complexes on a non-transparent substrate at room temperature. The thin films of the tailor-made trinuclear bis(oxamidato) type complex 5 ([Cu{sub 3}(opbo{sup n}Pr{sub 2})(tmcd){sub 2}(NO{sub 3}){sub 2}], opbo{sup n}Pr{sub 2} = o-phenylenebis(N’-{sup n}propyloxamido, tmcd=trans-(1 R,2 R)-N,N,N′,N′-tetramethyl-cyclohexanediamine) and of the bis(oxamato) type complexes 11 ([Cu{sub 2}Ni(opbaCF{sub 3})(pmdta){sub 2}(NO{sub 3}){sub 2}], opbaCF{sub 3} = 4-trifluoromethyl-o-phenylenebis(oxamato), pmdta = N,N,N,′N″,N″-pentamethyldiethylenetriamine) and 12 ([Cu{sub 3}(opba)(bppe){sub 2}(NO{sub 3}){sub 2}] (opba = o-phenylenebis(oxamato), bppe = S-N,N-bis(2-picolyl)−1-phenylethylamine) were fabricated by spin-coating and their thicknesses in the range between 0.5 µm and 2 µm was determined by spectroscopic ellipsometry. Based on the spectroscopic ellipsometry results it was also possible to determine the optical constants of the film and compare them with the absorption of the complexes in solution in order to confirm the complex integrity after the film deposition. The fabrication of high-quality films which exhibit Kerr rotation up to 0.2 mrad (11.5 mdeg) was only possible due to tailor-made synthesis, which allows circumventing intermolecular interactions of the trinuclear complexes during the film formation. - Highlights: • Tailor-made trinuclear bis(oxamidato) and bis(oxamato) type complexes were synthesized. • Thin films (between 0.5 µm and 2 µm) were fabricated by spin-coating. • The film optical constants indicate the complex integrity after the deposition. • Film quality enabled first spectroscopic MOKE measurements of multi-nuclear complexes. • Magneto-optical Kerr rotation up to 11.5 mdeg was observed at RT (in 1.7 T).

Extraction of niobium and tantalum with bis-2-ethylhexyl acetamide

International Nuclear Information System (INIS)

Ohmori, Hiroshi; Shibata, Junji; Sano, Makoto; Nishimura, Sanji

1986-01-01

Extraction of Nb and Ta from acid solutions with bis-2-ethylhexyl acetamide and stripping of these metals with sulphuric acid solutions were investigated. The organic phase was a binary solution of bis-2-ethylhexyl acetamide and xylene, while the aqueous phase was composed of hydrofluoric acid solution or hydrofluoric-sulphuric acid solution containing 3.5 - 13 kg/m 3 Nb and 5 - 10 kg/m 3 Ta. Sulphuric acid, hydrochloric acid and nitric acid were used as salting out agents to understand the effect on the extraction. Both metals were not sufficiently extracted from hydrofluoric acid solutions, whereas the extraction of both metals remarkably increased with an addition of sulphuric acid to the aqueous phase. The separation factor decreased with an increase in the concentration of hydrofluoric acid at the constant sulphuric acid concentration of 5.8N, and both metals were completely coextracted in the aqueous condition of 6N hydrofluoric acid and 8N sulphuric acid. The stripping occurred for both metals with a high efficiency, when water or dilute sulphuric acid solution was used as a stripping agent. The increase in sulphuric acid concentration caused less stripping of Ta, while the stripping of Nb was maintained at 80 % up to 7N sulphuric acid. The separation factor reached the maximum with the value of 116 in the use of 6.5N sulphuric acid. The extraction behavior of Fe(II), Fe(III), Sn(IV) and Mn(II) was also examined with the results that these metals were not extracted even to the extent of the lowest limit of atomic absorption spectrophotometer. Moreover, the comparison of this extractant with MIBK and TBP, which were in common use, was carried out. (author)

Synthesis, spectroscopic investigations, DFT studies, molecular docking and antimicrobial potential of certain new indole-isatin molecular hybrids: Experimental and theoretical approaches

Science.gov (United States)

Almutairi, Maha S.; Zakaria, Azza S.; Ignasius, P. Primsa; Al-Wabli, Reem I.; Joe, Isaac Hubert; Attia, Mohamed I.

2018-02-01

Indole-isatin molecular hybrids 5a-i have been synthesized and characterized by different spectroscopic methods to be evaluated as new antimicrobial agents against a panel of Gram positive bacteria, Gram negative bacteria, and moulds. Compound 5h was selected as a representative example of the prepared compounds 5a-i to perform computational investigations. Its vibrational properties have been studied using FT-IR and FT-Raman with the aid of density functional theory approach. The natural bond orbital analysis as well as HOMO and LUMO molecular orbitals investigations of compound 5h were carried out to explore its possible intermolecular delocalization or hyperconjugation and its possible interactions with the target protein. Molecular docking of compound 5h predicted its binding mode with the fungal target protein.

Metal and base free synthesis of primary amines via ipso amination of organoboronic acids mediated by [bis(trifluoroacetoxy)iodo]benzene (PIFA).

Science.gov (United States)

Chatterjee, Nachiketa; Goswami, Avijit

2015-08-07

A metal and base free synthesis of primary amines has been developed at ambient temperature through ipso amination of diversely functionalized organoboronic acids, employing a combination of [bis(trifluoroacetoxy)iodo]benzene (PIFA)-N-bromosuccinimide (NBS) and methoxyamine hydrochloride as the aminating reagent. The amines were primarily obtained as their trifluoroacetate salts which on subsequent aqueous alkaline work up provided the corresponding free amines. The combination of PIFA-NBS is found to be the mildest choice compared to the commonly used strong bases (e.g. n-BuLi, Cs2CO3) for activating the aminating agent. The reaction is expected to proceed via activation of the aminating reagent followed by B-N 1,2-aryl migration.

Potential of ethylenediaminedi(o-hydroxyphenylacetic acid) and N,N'-bis(hydroxybenzyl)ethylenediamine-N,N'-diacetic acid for the determination of metal ions by capillary electrophoresis.

Science.gov (United States)

Krokhin, O V; Kuzina, O V; Hoshino, H; Shpigun, O A; Yotsuyanagi, T

2000-08-25

Two aromatic polyaminocarboxylate ligands, ethylenediaminedi(o-hydroxyphenylacetic acid) (EDDHA) and N,N'-bis(hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED), were applied for the separation of transition and heavy metal ions by the ion-exchange variant of electrokinetic chromatography. EDDHA structure contains two chiral carbon centers. It makes it impossible to use the commercially available ligand. All the studied metal ions showed two peaks, which correspond to meso and rac forms of the ligand. The separation of metal-HBED chelates was performed using poly(diallyldimethylammonium) polycations in mixed acetate-hydroxide form. Simultaneous separation of nine single- and nine double-charged HBED chelates, including In(III), Ga(III), Co(II)-(III) and Mn(II)-(III) pairs demonstrated the efficiency of 40,000-400,000 theoretical plates. The separation of Co(III), Fe(III) complexes with different arrangements of donor groups and oxidation of Co(II), Mn(H), Fe(II) ions in reaction with HBED have been discussed.

Self-assembly of metal-organic supramolecules: from a metallamacrocycle and a metal-organic coordination cage to 1D or 2D coordination polymers based on flexible dicarboxylate ligands.

Science.gov (United States)

Dai, Fangna; Dou, Jianmin; He, Haiyan; Zhao, Xiaoliang; Sun, Daofeng

2010-05-03

To assemble metal-organic supramolecules such as a metallamacrocycle and metal-organic coordination cage (MOCC), a series of flexible dicarboxylate ligands with the appropriate angle, 2,2'-(2,3,5,6-tetramethyl-1,4-phenylene)bis(methylene)bis(sulfanediyl)dibenzoic acid (H(2)L(1)), 2,2'-(2,5-dimethyl-1,4-phenylene)bis(methylene)bis(sulfanediyl)dibenzoic acid (H(2)L(2)), 2,2'-(2,4,6-trimethyl-1,3-phenylene)bis(methylene)bis(sulfanediyl)dinicotinic acid (H(2)L(3)), and 2,2'-(2,4,6-trimethyl-1,3-phenylene)bis(methylene)bis(sulfanediyl)dibenzoic acid (H(2)L(4)), have been designed and synthesized. Using these flexible ligands to assemble with metal ions, six metal-organic supramolecules, Cd(2)(L(1))(2)(dmf)(4)(H(2)O)(2).H(2)O (1), Mn(3)((1)L(2))(2)((2)L(2))(dmf)(2)(H(2)O)(2).5dmf (2), Cu(4)(L(3))(4)(H(2)O)(4).3dmf (3), Cu(4)(L(4))(4)(dmf)(2)(EtOH)(2).8dmf.6H(2)O (4), Mn(4)(L(4))(4)(dmf)(4)(H(2)O)(4).6dmf.H(2)O (5), and Mn(3)(L(4))(3)(dmf)(4).2dmf.3H(2)O (6), possessing a rectangular macrocycle, MOCCs or their extensions, and 1D or 2D coordination polymers, have been isolated. All complexes have been characterized by single-crystal X-ray diffraction, elemental analysis, and thermogravimetric analysis. Complex 1 is a discrete rectangular macrocycle, while complex 2 is a 2D macrocycle-based coordination polymer in which the L(2) ligand adopts both syn and anti conformations. Complexes 3-5 are discrete MOCCs in which two binuclear metal clusters are engaged by four organic ligands. The different geometries of the secondary building units (SBUs) and the axial coordinated solvates on the SBUs result in their different symmetries. Complex 6 is a 1D coordination polymer, extended from a MOCC made up of two metal ions and three L(4) ligands. All of the flexible dicarboxylate ligands adopt a syn conformation except that in complex 2, indicating that the syn conformational ligand is helpful for the formation of a metallamacrocycle and a MOCC. The magnetic properties of complexes 5

Zirconium and Titanium Propylene Polymerization Precatalysts Supported by a Fluxional C 2 -Symmetric Bis(anilide)pyridine Ligand

KAUST Repository

Tonks, Ian A.

2012-03-12

Titanium and zirconium complexes supported by a bis(anilide)pyridine ligand (NNN = pyridine-2,6-bis(N-mesitylanilide)) have been synthesized and crystallographically characterized. C 2-symmetric bis(dimethylamide) complexes were generated from aminolysis of M(NMe 2) 4 with the neutral, diprotonated NNN ligand or by salt metathesis of the dipotassium salt of NNN with M(NMe 2) 2Cl 2. In contrast to the case for previously reported pyridine bis(phenoxide) complexes, the ligand geometry of these complexes appears to be dictated by chelate ring strain rather than metal-ligand π bonding. The crystal structures of the five-coordinate dihalide complexes (NNN)MCl 2 (M = Ti, Zr) display a C 1-symmetric geometry with a stabilizing ipso interaction between the metal and the anilido ligand. Coordination of THF to (NNN)ZrCl 2 generates a six-coordinate C 2-symmetric complex. Facile antipode interconversion of the C 2 complexes, possibly via flat C 2v intermediates, has been investigated by variable-temperature 1H NMR spectroscopy for (NNN)MX 2(THF) n (M = Ti, Zr; X = NMe 2, Cl) and (NNN)Zr(CH 2Ph) 2. These complexes were tested as propylene polymerization precatalysts, with most complexes giving low to moderate activities (10 2-10 4 g/(mol h)) for the formation of stereoirregular polypropylene. © 2012 American Chemical Society.

Interaction and Binding Modes of bis-Ruthenium(II Complex to Synthetic DNAs

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Hasi Rani Barai

2016-06-01

Full Text Available [μ-(linkerL2(dipyrido[3,2-a:2′,3′-c]phenazine2(phenanthroline2Ru(II2]2+ with linker: 1,3-bis-(4-pyridyl-propane, L: PF6 (bis-Ru-bpp was synthesized and their binding properties to a various polynucleotides were investigated by spectroscopy, including normal absorption, circular dichroism(CD, linear dichroism(LD, and luminescence techniques in this study. On binding to polynucleotides, the bis-Ru-bpp complex with poly[d(A-T2], and poly[d(I-C2] exhibited a negative LDr signal whose intensity was as large as that in the DNA absorption region, followed by a complicated LDr signal in the metal-to-ligand charge transfer region. Also, the emission intensity and equilibrium constant of the bis-Ru-bpp complex with poly[d(A-T2], and poly[d(I-C2] were enhanced. It was reported that both of dppz ligand of the bis-Ru-bpp complex intercalated between DNA base-pairs when bound to native, mixed sequence DNA. Observed spectral properties resemble to those observed for poly[d(A-T2] and poly[d(I-C2], led us to be concluded that both dppz ligands intercalate between alternated AT and IC bases-pairs In contrast when bis-Ru-bpp complex was bound to poly[d(G-C2], the magnitude of the LDr in the dppz absorption region, as well as the emission intensity, was half in comparison to that of bound to poly[d(A-T2], and poly[d(I-C2]. Therefore the spectral properties of the bis-Ru-bpp-poly[d(G-C2] complex suggested deviation from bis-intercalation model in the poly[d(G-C2] case. These results can be explained by a model whereby one of the dppz ligands is intercalated while the other is exposed to solvent or may exist near to phosphate. Also it is indicative that the amine group of guanine in the minor groove provides the steric hindrance for incoming intercalation binder and it also takes an important role in a difference in binding of bis-Ru-bpp bound to poly[d(A-T2] and poly[d(I-C2].

[μ-1,2-Bis(diphenylphosphinoethane-κ2P:P′]bis{[1,2-bis(diphenylphosphinoethane-κ2P,P′]cyanidocopper(I} methanol disolvate

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Rong Wang

2010-08-01

Full Text Available The title centrosymmetric complex, [Cu2(CN2(C26H24P23]·2CH3OH, consists of two five-membered [Cu(dppeCN] rings [dppe is 1,2-bis(diphenylphosphinoethane] bridged by one μ2-dppe ligand, and two methanol solvent molecules. The angles around the central metal atom indicate that each CuI atom is located in the center of a distorted tetrahedron. The coordination sphere of each CuI atom is formed by three P atoms from two dppe ligands, and one C atom from the cyanide ligand. The crystal structure is stabilized by O—H...N hydrogen bonds, which are formed by the O—H donor group from methanol and the N-atom acceptor from a cyanide ligand.

Microwave assisted synthesis of bis and tris(ω-bromoacetophenones): versatile precursors for novel bis(imidazo[1,2-a]pyridines), bis(imidazo[1,2-a]pyrimidines) and their tris-analogs

Science.gov (United States)

2013-01-01

Background α-Bromination of the side chain of aromatic ketones using NBS in the presence of p-toluenesulfonic acid (p-TsOH) in acetonitrile is very common. However, regioselective bromination of bis and tris(ω-bromoacetophenones) with NBS in the presence of p-TsOH in acetonitrile under microwave irradiation is quite novel. The bis- and tris(ω-bromoacetophenones) are used in synthesis of bis and tris(heterocycles). bis(heterocycles) have received a great deal of attention, because many biologically active natural and synthetic products have molecular symmetry. The use of the pressurized microwave irradiation is very advantageous to many syntheses and provide a large rate enhancement. Results Bis and tris(ω-bromoacetophenones) were obtained as single monobrominated derivatives in a shorter time than the conventional conditions. The results clearly demonstrate the better reactivity and selectivity of NBS/p-TsOH/CH3CN as a brominating mixture under microwave conditions. The reaction of bis and tris(ω-bromoacetophenone) with 2-aminopyridine and 2-aminopyrimidine proceeded smoothly in a mixture of anhydrous ethanol and DMF under reflux or using 300 W/105°C/ 20 min microwave irradiation conditions to afford the corresponding bis(imidazo[1,2-a]pyridine), bis(imidazo[1,2-a]pyrimidine) and tris(imidazo[1,2-a]pyridine) derivatives in moderate to excellent yields. The carbonyl analogue of the targeted bis(imidazopyridines) could be synthesized by the reaction of N,N-dimethyl-N'-(pyridin-2-yl)formimidamide with bis(ω-bromoacetophenone) in refluxing ethanol. The structures of the newly synthesized compounds were confirmed by their spectral data as well as their elemental analyses. Conclusion In conclusion, selective α-bromination of bis- and tris(acetophenones) has been accomplished efficiently utilizing NBS/p-TsOH/CH3CN under microwave irradiation. In addition, a facile synthesis of novel series of bis- and tris(imidazopyridine) and bis(imidazopyrimidine) derivatives

Energetic co-ordination compounds: synthesis, characterization and thermolysis studies on bis-(5-nitro-2H-tetrazolato-N2)tetraammine cobalt(III) perchlorate (BNCP) and its new transition metal (Ni/Cu/Zn) perchlorate analogues

International Nuclear Information System (INIS)

Talawar, M.B.; Agrawal, A.P.; Asthana, S.N.

2005-01-01

Bis-(5-nitro-2H-tetrazolato-N 2 )tetraammine[cobalt(III)/nickel(III)] perchlorates (BNCP/BNNP) and mono-(5-nitro-H-tetrazolato-N)triammine [copper(II)/zinc(II)] perchlorates (MNCuP/MNZnP) have been synthesized during this work. The synthesis was carried out by addition of carbonato tetraammine metal [Co/Ni/Cu/Zn] nitrate [CTCN/CTNN/CTCuN/CTZnN] to the aqueous solution of sodium salt of 5-nitrotetrazole followed by reaction with perchloric acid. The precursors were synthesized by the reaction of aqueous solution of their respective nitrates with ammonium carbonate at 70 deg. C. The complexes and their precursors were characterized by determining metal and perchlorate content as well as infrared (IR), electron spectra for chemical analysis (ESCA) and X-ray diffraction (XRD) techniques. The TG profiles indicated that BNCP, BNNP and MNCuP are thermally stable up to the temperature of 260-278 deg. C unlike MNZnP (150 deg. C). Sudden exothermic decomposition was observed in case of bis-(5-nitro-2H-tetrazolato-N 2 )tetraammine cobalt(III) perchlorate, bis-(5-nitro-2H-tetrazolato-N 2 )tetraammine nickel(III) perchlorate and mono-(5-nitro-H-tetrazolato-N)triammine zinc(II) perchlorate resulting in the severe damage of the sample cup. Sensitivity data indicated that the Co/Ni/Cu complexes are more friction sensitive (3-4.8 kg) than mono-(5-nitro-H-tetrazolato-N)triammine zinc(II) perchlorate (14 kg). The impact sensitivity results of the complexes corresponded to h 50% of 30-36 cm

Porphyrin amino acids-amide coupling, redox and photophysical properties of bis(porphyrin) amides.

Science.gov (United States)

Melomedov, Jascha; Wünsche von Leupoldt, Anica; Meister, Michael; Laquai, Frédéric; Heinze, Katja

2013-07-14

New trans-AB2C meso-substituted porphyrin amino acid esters with meso-substituents of tunable electron withdrawing power (B = mesityl, 4-C6H4F, 4-C6H4CF3, C6F5) were prepared as free amines 3a-3d, as N-acetylated derivatives Ac-3a-Ac-3d and corresponding zinc(II) complexes Zn-Ac-3a-Zn-Ac-3d. Several amide-linked bis(porphyrins) with a tunable electron density at each porphyrin site were obtained from the amino porphyrin precursors by condensation reactions (4a-4d) and mono- and bis(zinc(II)) complexes Zn(2)-4d and Zn(1)Zn(2)-4d were prepared. The electronic interaction between individual porphyrin units in bis(porphyrins) 4 is probed by electrochemical experiments (CV, EPR), electronic absorption spectroscopy, steady-state and time-resolved fluorescence spectroscopy in combination with DFT/PCM calculations on diamagnetic neutral bis(porphyrins) 4 and on respective charged mixed-valent radicals 4(+/-). The interaction via the -C6H4-NHCO-C6H4- bridge, the site of oxidation and reduction and the lowest excited singlet state S1, is tuned by the substituents on the individual porphyrins and the metalation state.

Synthesis, characterization and antibacterial activity of some novel symmetrical n/sup 3/, n/sup 3/-bis(disubstituted)isophthalyl-bis(thioureas) and their Cu(II) and Ni(II) complexes

International Nuclear Information System (INIS)

Jamil, M.; Zubair, M.; Rasool, N.; Bukhari, I.H.; Farid, M.A.; Altaf, A.A.

2013-01-01

A series of some novel N/sup 3/,N/sup 3/-bis(disubstituted) isophthalyl-bis(thioureas) compounds with general formula (C/sub 6/H/sub 4/(CONHCSNHR)/sub 2/), where R = 4-C/sub 6/H/sub 4/COOH(L/sub 1/), 3-NO/sub 2/C/sub 6/H/sub 4/(L/sub 2/), 2-NO/sub 2/C/sub 6/H/sub 4/(L/sub 3/), 4-CH/sub 3/C/sub 6/H/sub 4/(L/sub 4/), 2-CH/sub 3/C/sub 6/H/sub 4/(L/sub 5/), 3-CH/sub 3/C/sub 6/H/sub 4/(L/sub 6/) and their Cu(II) and Ni(II) complexes have been synthesized. (L/sub 1/-L/sub 6/) have been prepared in good to excellent yields by reaction of isophthaloyl isothiocyanate with primary amines using dry acetone as solvent. The stoichiometric reaction between the metal (II) ion and synthesized ligands in molar ratio of M : L (1 : 1) resulted in the formation of the metal complexes of type (ML)2 (where M = Cu(II) and Ni(II). These compounds (L/sub 1/-L/sub 6/) and their metal (II) complexes have been characterized by elemental analyses, Infrared spectroscopy, /sup 1/H-NMR spectroscopy, magnetic moments, and electronic spectral measurements. These compounds (L/sub 1/-L/sub 6/) and their metal (II) complexes were also screened for their antibacterial activity against bacterial species, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Shigella sonnei, Salmonella typhi and Pseudomonas aeroginosa. Some compounds showed potential activity against a number of bacterial strains. The results of these studies also show the metal (II) complexes to be having stronger antibacterial activityl against one or more species as compared to the uncomplexed ligands. It was concluded that these compounds may be the potential source of active antibacterial agents. (author)

Metal complex derivatives of hydrogen uranyl phosphate

International Nuclear Information System (INIS)

Grohol, D.; Blinn, E.L.

1994-01-01

Derivatives of hydrogen uranyl phosphate were prepared by incorporating transition metal complexes into the uranyl phosphate matrix. The transition metal complexes employed include bis(ethylenediamine)copper(II), bis(1,3-propanediamine)copper(II) chloride, (triethylenetetramine)copper(II), (1,4,8,11-tetraazacyclotetradecane)copper(II), (1,4,8,12-tetraazacyclopentadecane)copper(II), (1,4,8,11-tetraazacyclotetradecane)nickel(II) chloride, (triethylenetetramine)nickel(II) and others. The chemical analyses of these derivatives indicated that the incorporation of the transition metal complexes into the uranyl phosphate matrix via ion exchange was not stoichiometric. The extent of ion exchange is dependent on the size and structure of the transition metal complex. All complexes were characterized by X-ray powder diffractometry, electronic and infrared spectra, thermal analyses and chemical analysis. An attempt was made to correlate the degree of quenching of the luminescence of the uranyl ion to the spacing between the uranyl phosphate layers in the derivatives

Transition metal complexes of oxazolinylboranes and cyclopentadienyl-bis(oxazolinyl)borates: Catalysts for asymmetric olefin hydroamination and acceptorless alcohol decarbonylation

Energy Technology Data Exchange (ETDEWEB)

Manna, Kuntal [Ames Lab., Ames, IA (United States)

2012-12-17

The research presented and discussed in this dissertation involves the synthesis of transition metal complexes of oxazolinylboranes and cyclopentadienyl-bis(oxazolinyl)borates, and their application in catalytic enantioselective olefin hydroamination and acceptorless alcohol decarbonylation. Neutral oxazolinylboranes are excellent synthetic intermediates for preparing new borate ligands and also developing organometallic complexes. Achiral and optically active bis(oxazolinyl)phenylboranes are synthesized by reaction of 2-lithio-2-oxazolide and 0.50 equiv of dichlorophenylborane. These bis(oxazolinyl)phenylboranes are oligomeric species in solid state resulting from the coordination of an oxazoline to the boron center of another borane monomer. The treatment of chiral bis(oxazolinyl)phenylboranes with sodium cyclopentadienide provide optically active cyclopentadienyl-bis(oxazolinyl)borates H[PhB(C₅H₅)(Ox^R)₂] [Ox^R = Ox^4S-iPr,Me2, Ox^4R-iPr,Me2, Ox^4S-tBu]. These optically active proligands react with an equivalent of M(NMe₂)₄ (M = Ti, Zr, Hf) to afford corresponding cyclopentadienyl-bis(oxazolinyl)borato group 4 complexes {PhB(C₅H₄)(Ox^R)₂}M(NMe₂)₂ in high yields. These group 4 compounds catalyze cyclization of aminoalkenes at room temperature or below, providing pyrrolidine, piperidine, and azepane with enantiomeric excesses up to 99%. Our mechanistic investigations suggest a non-insertive mechanism involving concerted C-N/C-H bond formation in the turnover limiting step of the catalytic cycle. Among cyclopentadienyl-bis(oxazolinyl)borato group 4 catalysts, the zirconium complex {PhB(C₅H₄)(Ox4^S-iPr,Me2)₂}Zr(NMe₂)₂ ({S-2}Zr(NMe₂)₂) displays highest activity and enantioselectivity. Interestingly, _S-2

Novel Rearrangements in the Reactions Directed Toward Preparation of Spiro-N,N-ketals: Reactions of Naphthalene-1,8-diamine with Ninhydrin and Isatin

Directory of Open Access Journals (Sweden)

Keiji Kobayashi

2012-11-01

Full Text Available Spiro-N,N-ketal 5, consisting of a phthaloperine heterocyclic ring and a naphtha[1,8-ef][1,4]diazepine ring, was obtained along with spiro-N,N-ketal 2 via 2,2-condensation in the reaction of ninhydrin with naphthalene-1,8-diamine. Their molecular structures were elucidated by X-ray crystal structural analysis. Aside from these spiro compounds, the diazapleiadiene compound 3 formed by 1,2-condensation and the 1,4-isoquinolinedione compound 4 arising from ring expansion were isolated. When isatin was reacted with naphthalene-1,8-diamine, spiro-N,N-ketal 6 and the two 1H-perimidine-based compounds 7 and 8 were isolated. Compound 8 was revealed to undergo a fast dynamic prototropic tautomerization in solution. Plausible mechanisms of the formation of the products are proposed.

Electronic structure of surface-supported bis(phthalocyaninato) terbium(III) single molecular magnets.

Science.gov (United States)

Vitali, Lucia; Fabris, Stefano; Conte, Adriano Mosca; Brink, Susan; Ruben, Mario; Baroni, Stefano; Kern, Klaus

2008-10-01

The electronic structure of isolated bis(phthalocyaninato) terbium(III) molecules, a novel single-molecular-magnet (SMM), supported on the Cu(111) surface has been characterized by density functional theory and scanning tunneling spectroscopy. These studies reveal that the interaction with the metal surface preserves both the molecular structure and the large spin magnetic moment of the metal center. The 4f electron states are not perturbed by the adsorption while a strong molecular/metal interaction can induce the suppression of the minor spin contribution delocalized over the molecular ligands. The calculations show that the inherent spin magnetic moment of the molecule is only weakly affected by the interaction with the surface and suggest that the SMM character might be preserved.

Briefwechsel uber die Partikel "bis" (An Exchange of Letters about the Particle "bis").

Science.gov (United States)

Ludwig, Horst; Holschuh, Albrecht

1990-01-01

A discussion, in the form of an animated letter exchange, argues that, contrary to most current grammatical descriptions, the German particle "bis" should not be viewed as a preposition governing the accusative case. Rather, it is demonstrated that "bis" most often occurs as a proclitic adverb. (16 references) (JTC)

Facile, novel two-step syntheses of benzimidazoles, bis-benzimidazoles, and bis-benzimidazole-dihydroquinoxalines.

Science.gov (United States)

Xu, Zhigang; Shaw, Arthur Y; Dietrich, Justin; Cappelli, Alexandra P; Nichol, Gary; Hulme, Christopher

2012-02-01

Three scaffolds of benzimidazoles, bis-benzimidazoles, and bis-benzimidazole-dihydroquinoxalines were synthesized via Ugi/de-protection/cyclization methodology. Benzimidazole forming ring closure was enabled under microwave irradiation in the presence of 10% TFA/DCE. The methodology demonstrates the utility of 2-(N-Boc-amino)-phenyl-isocyanide for the generation of new molecular diversity.

Facile, novel two-step syntheses of benzimidazoles, bis-benzimidazoles, and bis-benzimidazole-dihydroquinoxalines

OpenAIRE

Xu, Zhigang; Shaw, Arthur Y.; Dietrich, Justin; Cappelli, Alexandra P.; Nichol, Gary; Hulme, Christopher

2012-01-01

Three scaffolds of benzimidazoles, bis-benzimidazoles, and bis-benzimidazole-dihydroquinoxalines were synthesized via Ugi/de-protection/cyclization methodology. Benzimidazole forming ring closure was enabled under microwave irradiation in the presence of 10% TFA/DCE. The methodology demonstrates the utility of 2-(N-Boc-amino)-phenyl-isocyanide for the generation of new molecular diversity.

The Synthesis of Dicationic Extended Bis-Benzimidazoles

OpenAIRE

Kang, Zhijan; Dykstra, Christine C.; Boykin, David W.

2004-01-01

The synthesis of extended dicationic bis-benzimidazoles starting from trans-1,2-bis(4-cyanophenyl)ethene and trans-1,2-bis(4-cyanophenyl)cyclopropane is reported. The target diamidines show significant in vitro activity against B. subtilis.

Tunable regioselectivity in 1,3-butadiene polymerization by using 2,6-bis(dimethyl-2-oxazolin-2-yl)pyridine incorporated transition metal (Cr, Fe and Co) catalysts

KAUST Repository

Gong, Dirong; Liu, Wen; Pan, Weijing; Chen, Tao; Jia, Xiaoyu; Huang, Kuo-Wei; Zhang, Xuequan

2015-01-01

Tridentate complexes Cr(III)Cl3L, [L = 2,6-bis(dimethyl-2-oxazolin-2-yl) pyridine], Fe(III)Cl3L, Fe(II)Cl2L and Co(II)Cl2L have been prepared and fully characterized. The solid structures of Cr(III)Cl3L, Fe(III)Cl3L and Co(II)Cl2L have been revealed by single crystal X-ray diffraction, and the Cr(III)Cl3L and Fe(III)Cl3L complexes both exhibit a distorted octahedral geometry, while the Co(II)Cl2L complex has a trigonal bipyramidal conformation. Four complexes have been examined in regioselective polymerization of butadiene in combination with MAO in toluene at room temperature. The trans-1,4, cis-1,4 enchainment of resultant polybutadiene are controlled by the metal center. Activated by MAO, complex Cr(III)Cl3L produces high level of trans-1,4 selectivity (trans-1,4 up to 93.3%) with moderate polymer yield, complexes Fe(III)Cl3L and Fe(II)Cl2L both show equal cis-1,4 and trans-1,4 with minor 1,2 selectivity (<10%), and Co(II)Cl2L catalyst displays predominated cis-1,4 selectivity, which can be shifted to 1,2 selectivity by adding PPh3 as an additive. Thus, tuning of the cis-1,4, trans-1,4 and 1,2 selectivity in full range via central metal and additive chosen by these 2,6-bis(dimethyl-2-oxazolin-2-yl) pyridine supported catalysts has been achieved. © 2015 Elsevier B.V. All rights reserved.

Tunable regioselectivity in 1,3-butadiene polymerization by using 2,6-bis(dimethyl-2-oxazolin-2-yl)pyridine incorporated transition metal (Cr, Fe and Co) catalysts

KAUST Repository

Gong, Dirong

2015-05-21

Tridentate complexes Cr(III)Cl3L, [L = 2,6-bis(dimethyl-2-oxazolin-2-yl) pyridine], Fe(III)Cl3L, Fe(II)Cl2L and Co(II)Cl2L have been prepared and fully characterized. The solid structures of Cr(III)Cl3L, Fe(III)Cl3L and Co(II)Cl2L have been revealed by single crystal X-ray diffraction, and the Cr(III)Cl3L and Fe(III)Cl3L complexes both exhibit a distorted octahedral geometry, while the Co(II)Cl2L complex has a trigonal bipyramidal conformation. Four complexes have been examined in regioselective polymerization of butadiene in combination with MAO in toluene at room temperature. The trans-1,4, cis-1,4 enchainment of resultant polybutadiene are controlled by the metal center. Activated by MAO, complex Cr(III)Cl3L produces high level of trans-1,4 selectivity (trans-1,4 up to 93.3%) with moderate polymer yield, complexes Fe(III)Cl3L and Fe(II)Cl2L both show equal cis-1,4 and trans-1,4 with minor 1,2 selectivity (<10%), and Co(II)Cl2L catalyst displays predominated cis-1,4 selectivity, which can be shifted to 1,2 selectivity by adding PPh3 as an additive. Thus, tuning of the cis-1,4, trans-1,4 and 1,2 selectivity in full range via central metal and additive chosen by these 2,6-bis(dimethyl-2-oxazolin-2-yl) pyridine supported catalysts has been achieved. © 2015 Elsevier B.V. All rights reserved.

Antiferromagnetism in the organic conductor bis-tetramethyltetraselenafulvalene hexafluoroarsenate [(TMTSF)2AsF6]: Static magnetic susceptibility

DEFF Research Database (Denmark)

Mortensen, Kell; Tomkiewicz, Yaffa; Bechgaard, Klaus

1982-01-01

The anisotropy in the static magnetic susceptibility of bis-tetramethyltetraselenafulvalene hexafluoroarsenate [(TMTSF)2AsF6] has been investigated above and below the metal-to-insulator transition for a range of fields between 0.5 and 30 kG. The results are consistent with the expectations of a ...

Synthesis, characterization, DNA interaction and antimicrobial screening of isatin-based polypyridyl mixed-ligand Cu(II and Zn(II complexes

Directory of Open Access Journals (Sweden)

NATARAJAN RAMAN

2010-06-01

Full Text Available Several mixed ligand Cu(II/Zn(II complexes using 3-(phenyl-imino-1,3-dihydro-2H-indol-2-one (obtained by the condensation of isatin and aniline as the primary ligand and 1,10-phenanthroline (phen/2,2’-bipyridine (bpy as an additional ligand were synthesized and characterized analytically and spectroscopically by elemental analyses, magnetic susceptibility and molar conductance measurements, as well as by UV–Vis, IR, NMR and FAB mass spectroscopy. The interaction of the complexes with calf thymus (CT DNA was studied using absorption spectra, cyclic voltammetric and viscosity measurements. They exhibit absorption hypochromicity, and the specific viscosity increased during the binding of the complexes to calf thymus DNA. The shifts in the oxidation–reduction potential and changes in peak current on addition of DNA were shown by CV measurements. The Cu(II/Zn(II complexes were found to promote cleavage of pUC19 DNA from the supercoiled form I to the open circular form II and linear form III. The complexes show enhanced antifungal and antibacterial activities compared with the free ligand.

Synthesis, Spectral, Thermogravimetric, XRD, Molecular Modelling and Potential Antibacterial Studies of Dimeric Complexes with Bis Bidentate ON–NO Donor Azo Dye Ligands

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Bipin Bihari Mahapatra

2013-01-01

Full Text Available The dimeric complexes of Co(II, Ni(II, Cu(II, Zn(II, Cd(II, and Hg(II with two new symmetrical ON–NO donor bis bidentate (tetradentate azo dye ligands, LH2 = 4,4′-bis(4′-hydroxyquinolinolinylazodiphenylsulphone, and L′H2 = 4,4′-bis(acetoacetanilideazodiphenylsulphone have been synthesized. The metal complexes have been characterised by elemental analytical, conductance, magnetic susceptibility, IR, electronic spectra, ESR, NMR, thermogravimetry, X-ray diffraction (powder pattern spectra, and molecular modelling studies. The Co(II and Ni(II complexes are found to be octahedral, Cu(II complexes are distorted octahedral, and a tetrahedral stereochemistry has been assigned to Zn(II, Cd(II, and Hg(II complexes. The thermogravimetric study indicates that compounds are quite stable. The energy optimized structures are proposed using the semiempirical ZINDO/1 quantum mechanical calculations. The potential antibacterial study of the ligands and some metal complexes has been made with one gram positive bacteria Staphylococcus aureus and one gram negative bacteria E. coli which gives encouraging results. Both the Co(II complexes are found to possess monoclinic crystal system.

Syntheses and crystal structures of a series of new divalent metal phosphonates with imino-bis(methylphosphonic acid)

International Nuclear Information System (INIS)

Yang Bingping; Prosvirin, Andrey V.; Zhao, Han-Hua; Mao, Jiang-Gao

2006-01-01

Hydrothermal reactions of divalent transition metal salts with imino-bis(methylphosphonic acid), NH(CH 2 PO 3 H 2 ) 2 (H 4 L) afforded three new metal phosphonates, namely, Cu[NH(CH 2 PO 3 H) 2 ] 1, {Co[NH 2 (CH 2 PO 3 H)(CH 2 PO 3 )](H 2 O) 2 }.H 2 O 2 and Mn[NH 2 (CH 2 PO 3 H)(CH 2 PO 3 )](H 2 O) 3. When HO 2 C(CH 2 ) 3 N(CH 2 PO 3 H 2 ) 2 was used as the phosphonate ligand and 4,4'-bipy as the second metal linker, {Cu 4 [NH(CH 2 PO 3 ) 2 ] 2 (4,4'-bipy)(H 2 O) 4 }.9H 2 O 4 with a pillared layered architecture was obtained. The NH(CH 2 PO 3 ) 2 anion resulted from the cleavage of the HO 2 C(CH 2 ) 3 -group during the reaction. Although compounds 1-3 have a same M/L ratio (1:1), they exhibit totally different structures.Compound 1 has a linear chain structure, in which each pair of square-pyramidal coordinated copper(II) ions are bridged by two phosphonate oxygen atoms to form a Cu 2 O 2 dimeric unit, and such dimeric units are further interconnected via phosphonate groups to form a [010] chain. Compound 2 has a layered architecture built from CoO 6 octahedra bridged by phosphonate ligands. In compound 3, the interconnection of the manganese(II) ions by bridging imino-diphosphonate ligands leads to a 3D network. Compound 4 has a pillar-layered structure, the layers composed of Cu(II) ions bridged by aminodiphosphonate ligands are interconnected by 4,4'-bipy ligands to form channels along c-axis. Several factors that affect the structures of the metal phosphonates formed have also been discussed. Compounds 2 and 3 show predominant antiferromagnetic interactions between magnetic centers. -- Graphical abstract: Four new metal phosphonates, namely, Cu[NH(CH 2 PO 3 H) 2 ] 1, {Co[NH 2 (CH 2 PO 3 H)(CH 2 PO 3 )](H 2 O) 2 }.H 2 O 2, Mn[NH 2 (CH 2 PO 3 H)(CH 2 PO 3 )](H 2 O) 3 and {Cu 4 [NH(CH 2 PO 3 ) 2 ] 2 (4,4'-bipy)(H 2 O) 4 }.9H 2 O 4 have been synthesized and structurally characterized. Compound 1 has a linear chain structure, and compound 2 is layered. Compound 3 is

[Bis(TrimethylsilylMethyl]Lithium and -Sodium: Solubility in Alkanes and Complexes with O- and N- Donor Ligands

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Markus von Pilgrim

2017-06-01

Full Text Available In contrast to alkyl compounds of lithium, which play an important role in organometallic chemistry, the corresponding heavier alkali metal compounds are less investigated. These compounds are mostly insoluble in inert solvents or undergo solvolysis in coordinating solvents due to their high reactivity. An exception from this typical behavior is demonstrated by bis(trimethylsilylmethylsodium. This study examines alkane solutions of bis(trimethylsilylmethyllithium and -sodium by NMR spectroscopic and cryoscopic methods. In addition, structural studies by X-ray crystallography of the corresponding compounds coordinated by O- and N- ligands (tetrahydrofuran and tetramethylethylenediamine present possible structural motifs of the uncoordinated compounds in solution.

New dual emission fluorescent sensor for pH and Pb(II) based on bis(napfthalimide) derivative

International Nuclear Information System (INIS)

Pina-Luis, Georgina; Martínez-Quiroz, Marisela; Ochoa-Terán, Adrián; Santacruz-Ortega, Hisila; Mendez-Valenzuela, Eduardo

2013-01-01

This paper describes a novel dual emission bis-1,8-naphthalimide sensor for selective determination of pH and Pb 2+ ions. The influence of the variability in the backbone that links the two fluorophores (naphthalimides) as a function of pH and metal ions was studied by UV–visible and fluorescence spectroscopy. Compounds 1(a–d) with different length alkyl linkers (CH 2 ) n (n=1, 2, 4 and 6) showed no excimer formation in aqueous solution. Fluorescence emission of these derivatives varied in a narrow range of pH (5–8) and was only slightly influenced by the addition of metal ions in CH 3 CN solutions. However, derivative 1e with amino-containing spacer (CH 2 –NH–CH 2 ) showed excimer emission in aqueous solution, a wide response to pH (2.5–9.5) and fluorescence enhancement with selective behavior towards metal ions. The pH sensor based in derivative 1e has a sufficient selectivity for practical pH monitoring in the presence of Li + , Na + , K + , Cs + , Ca 2+ , Mg 2+ , Ba 2+ , Cu 2+ , Pb 2+ , Ni 2+ , Zn 2+ and Cd 2+ . The coordination chemistry of these complexes was studied by UV–Vis, fluorescence and 1 H NMR. This chemosensor displayed high selectivity fluorescence enhancement toward Pb 2+ ions in the presence of the metals ions mentioned in CH 3 CN solutions. Competitive assays show that a 1-fold of metal cations in each case, compared with Pb 2+ ions, results in less than ±5% fluorescence intensity changes. Linear calibration up to 1×10 −5 M for Pb(II) ions (R=0.9968) was obtained and detection limit resulted of 5.0×10 −8 M. - Highlights: ► A novel dual emission bis-1,8-naphthalimide sensor for pH and Pb 2+ ions is synthetized. ► The excimer formation depends on the spacer that links the two naphthalimide groups. ► Bis(naphthalimide) with amino-containing spacer showed a wide selective response to pH. ► This chemosensor displayed a selective fluorescence enhancement effect towards Pb 2+ ions. ► Mechanism for the fluorescence OFF�

Reacciones de adición a 1,1-BIS (Difenilfosfino) eteno activada por coordinación en compuestos ciclometalados de Pd(II) : complejos de metales de transición con disfosfinas funcionalizadas

OpenAIRE

Mosteiro Taboada, Roberto

2016-01-01

[Resumen] El trabajo consta de dos partes. La primera estudia la reactividad del doble enlace vinílico de la difosfina 1,1 bis (difenilfosfino)eteno (vdpp) frente a diferentes nucleófilos cuando ésta se encuentra coordinada actuando como ligando bidentado quelato en compuestos ciclometalados. Si bien el doble enlace del grupo vinílico de las fosfina libre presenta una reactividad muy limitada, la coordinación al metal produce su activación permitiendo llevar a cabo reaccion...

Poly[[[diisothiocyanatocobalt(II]-bis[μ-4-tert-butyl-2,6-bis(1,2,4-triazol-1-ylmethylphenol

Directory of Open Access Journals (Sweden)

2009-03-01

Full Text Available In the title compound, {[Co(NCS2(C16H20N6O2]·2C3H7NO·2H2O}n, each CoII ion located on an inversion center is six-coordinated by four equatorial N atoms from four different 4-tert-butyl-2,6-bis(1,2,4-triazol-1-ylmethylphenol (L ligands, and by two N atoms from two axial thiocyanate anions [Co—N = 2.104 (3–2.144 (3 Å]. The metal centres are connected via the bidentate L ligands into two-dimensional polymeric layers parallel to bc plane. The dimethylformamide and solvent water molecules participate in intermolecular O—H...O and O—H...S hydrogen bonds, which consolidate the crystal packing.

From bis(imidazole-2-thion-4-yl)phosphane to a flexible P-bridged bis(NHC) ligand and its silver complex.

Science.gov (United States)

Majhi, Paresh Kumar; Schnakenburg, Gregor; Streubel, Rainer

2014-11-28

Synthesis of the first P(V)-bridged bis(NHC) ligand 7 was achieved via deprotonation of P(V)-functionalized bis(imidazolium) salt 6, which was obtained via oxidative desulfurization of bis(imidazole-2-thion-4-yl)phosphane 2. Bis(imidazolium) salt 6 was also employed to synthesize the corresponding silver complex 8. All new products were firmly established by spectroscopic and spectrometric methods as well as elemental analysis and, in addition, X-ray crystal structure analysis in the case of 3.

Thermal, spectral, magnetic and biological studies of thiosemicarbazones complexes with metal ions: Cu(II), Co(II), Ni(II), Fe(III), Zn(II), Mn(II) and UO2(VI)

International Nuclear Information System (INIS)

Mashaly, M.M.; Seleem, H.S.; El-Behairy, M.A.; Habib, H.A.

2004-01-01

Thiosemicarbazones ligands, isatin-3-thiosemicarbazone(HIT) and N-acetylisatin-3-thiosemicarbazone (HAIT), which have tridentate ONN coordinating sites were prepared. The complexes of both ligands with Cu(II), Co(II), Ni(II), Fe(III), Zn(II), Mn(II) and UO 2 (VI) ions were isolated. The ligands and their metal complexes were characterized by elemental analysis, IR, UV-Vis and mass spectra, also by conductance, magnetic moment and TG-DSC measurements. All the transition metal complexes have octahedral configurations, except Cu-complexes which have planar geometry and the UO 2 (VI) complexes which have coordination number 8 and may acquire the distorted dodecahedral geometry. Thermal studies explored the possibility of obtaining new complexes. Inversion from octahedral to square-planar configuration occurred upon heating the parent Ni-HIAT complex to form the corresponding pyrolytic product. The antifungal activity against the tested organisms showed that some metal complexes enhanced the activity with respect to the parent ligands. (author)

The determination of some heavy metals in food samples by flame atomic absorption spectrometry after their separation-preconcentration on bis salicyl aldehyde, 1,3 propan diimine (BSPDI) loaded on activated carbon

International Nuclear Information System (INIS)

Ghaedi, M.; Shokrollahi, A.; Kianfar, A.H.; Mirsadeghi, A.S.; Pourfarokhi, A.; Soylak, M.

2008-01-01

A sensitive and simple method for the simultaneous preconcentration of Cr 3+ , Fe 3+ , Cu 2+ , Ni 2+ , Co 2+ and Zn 2+ in real samples has been reported. The method is based on the adsorption of analytes on bis salicyl aldehyde, 1,3 propan diimine (BSPDI) loaded on activated carbon. The adsorbed metals on modified activated carbon were eluted using 8 mL of 2 mol L -1 nitric acid in acetone or 10 mL of 4 mol L -1 HNO 3 . The influences of the analytical parameters including pH and sample volume were investigated. The effects of matrix ions on the retentions of the analytes were also examined. The recoveries of analytes were generally quantitative. The method has been successfully applied for these metals content evaluation in some food samples

Crystal structures of eight 3D molecular adducts derived from bis-imidazole, bis(benzimidazole), and organic acids

Science.gov (United States)

Ding, Aihua; Jin, Shouwen; Jin, Shide; Hu, KaiKai; Lin, Zhihao; Liu, Hui; Wang, Daqi

2018-01-01

Cocrystallization of the bis(imidazole)/bis(benzimidazole) with a series of organic acids gave a total of eight molecular adducts with the compositions: (3,6-bis(imidazole-1-yl)pyridazine): (trichloroacetic acid)2(1) [(H2L1)2+ · (tca-)2, L1 = 3,6-bis(imidazole-1-yl)pyridazine, tca- = trichloroacetate], (bis(N-imidazolyl)methane): (suberic acid) (2) [(L2) · (H2suba), L2 = bis(N-imidazolyl)methane, H2suba = suberic acid], bis(N-imidazolyl)methane: (3-nitrophthalic acid): 3H2O (3) [(H2L2)2+ · (3-Hnpa-)2 · 3H2O, 3-Hnpa- = 3-nitro hydrogenphthalate], (bis(N-imidazolyl)butane)0.5: (4-nitrophthalic acid): H2O (4) [(H2L3)0.5+ · (4-Hnpa-)- · H2O, L3 = bis(N-imidazolyl)butane, 4-Hnpa- = 4-nitro hydrogenphthalate], (1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole): (3,5-dinitrosalicylic acid) (5) [(HL4) · (3,5-dns-), L4 = 1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole, 3,5-dns- = 3,5-dinitrosalicylate], (1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole): (3-nitrophthalic acid) (6) [(H2L4) · (3-npa2-), L4 = 1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole, 3-npa2-=3-nitrogenphthalate], (bis(N-imidazolyl)butane): (pamoic acid) (7) [(H2L3) · (pam), pam = pamoate], and (3,6-bis(imidazole-1-yl)pyridazine): (1,5-naphthalenedisulfonic acid) [(H2L1)2+ · (npda)2- = 1,5-naphthalenedisulfonate] (8). The eight adducts have been characterized by X-ray diffraction technique, infrared spectrum, and elemental analysis, and the melting points of all adducts were also reported. And their structural and supramolecular aspects are fully analyzed. The result reveals that among the eight investigated crystals both the end ring N in the bis(imidazole) moieties are protonated when the organic acids are deprotonated except 2, and 5, and the crystal packing is interpreted in terms of the strong ionic Nsbnd H⋯O H-bond between the imidazolium and the deprotonated acidic groups. Except the Nsbnd H⋯O H-bond, the Osbnd H⋯O H-bonds were also found at the salts 3, 4

Coordination compounds of titanium, zirconium, tin, thorium and uranium

International Nuclear Information System (INIS)

Deshpande, S.G.; Jain, S.C.

1990-01-01

Reactions of isatin, furoic acid and picolinic acid have been carried out with titanium tetrachloride, tin tetrachloride, thorium tetrachloride, zirconyl chloride and uranyl nitrate. While 2:3(metal:ligand) type compounds of isatin have been obtained with Ti(IV) and Sn(IV), zirconium(IV), thorium(IV), and uranium(VI) do not react with the ligand under similar experimental conditions. Furoic acid (FAH) and picolinic acid(PicH) form various chloro furoates and picolinates when reacted with TiCl 4 , ZrOCl 2 and ThCl 4 , but do not react with SnCl 4 . The various compounds synthesised have been characterised on the basis of elemental analysis, infrared studies, conductivity and thermogravimetric measurements. (author). 1 tab., 10 refs

Crystal Structure of N,N-bis-(3-Carbomethoxy-5-methyl-pyrazol-1-ylmethylaniline

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Taibi Ben-Hadda

2002-09-01

Full Text Available The tripodal ligand N,N-bis-(3-carbomethoxy-5-methylpyrazol-1-ylmethyl aniline (2 has been prepared by the condensation of aniline with two equivalents of N-hydroxymethyl[3-carbomethoxy-5-methyl]pyrazole. The molecule consists of two structurally analogous 3-carbomethoxy-5-methylpyrazol-1-ylmethyl moieties, which adopt a transoidal conformation via a central aniline ring, suggesting that this tripodal ligand is highly flexible and could accommodate many metals by coordination.

New 14-membered octaazamacrocyclic complexes of divalent transition metal ions with their antimicrobial and spectral studies

Science.gov (United States)

Singh, D. P.; Kumar, Krishan; Sharma, Chetan

2010-01-01

A novel series of macrocyclic complexes of the type [M(C 18H 14N 10S 2)X 2]; where M = Co(II), Ni(II), Cu(II), Zn(II) and Cd(II); X = Cl -, NO 3-, CH 3COO - has been synthesized by [2+2] condensation of thiocarbohydrazide and isatin in the presence of divalent metal salts in methanolic medium. The complexes have been characterized with the help of elemental analyses, conductance measurements, magnetic measurements, electronic, NMR and infrared spectral studies. The low value of molar conductance indicates them to be non-electrolytes. On the basis of various studies a distorted octahedral geometry may be proposed for all of these complexes. These metal complexes were also tested for their in vitro antimicrobial activities against some Gram-positive bacteria viz. Staphylococcus aureus, Bacillus subtilis, and some Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa and some fungal strains Aspergillus niger, Aspergillus flavus (molds), Candida albicans, Saccharomyces cerevisiae (yeasts). The results obtained were compared with standard antibiotic: Ciprofloxacin and the standard antifungal drug: Amphotericin-B.

Positional isomerism-driven two 3D pillar-layered metal-organic frameworks: Syntheses, topological structures and photoluminescence properties

Energy Technology Data Exchange (ETDEWEB)

Sun, Yayong; Zhao, Siwei; Ma, Haoran; Han, Yi; Liu, Kang; Wang, Lei, E-mail: inorchemwl@126.com

2016-06-15

Two novel three-dimensional (3D) pillar-layered metal-organic frameworks (MOFs), namely [Zn{sub 2}(μ{sub 2}-OH)(boaba)(1,4-bmimb)]{sub n} (1) and {[Zn_5K_2(μ_2-H_2O)_2(boaba)_4(1,2-bmimb)_2(H_2O)_2]·H_2O}{sub n} (2), were prepared by hydrothermal reactions (H{sub 3}boaba=3,5-bis-oxyacetate-benzoic acid; 1,4-bmimb=1,4-bis((2-methyl-1H-imidazol-1-yl)methyl)benzene; 1,2-bmimb =1,2-bis((2-methyl-1H-imidazol-1-yl)methyl)benzene). Notably, 1 exhibits a (3,5)-connected binodal (6{sup 3})(6{sup 9}·8)-gra net with binuclear [Zn{sub 2}(μ{sub 2}-OH)(COO)]{sup 2+} clusters, while 2 shows a novel (4,4,5,9)-connected 4-nodal net constructed from the unique Zn(II)-K(I) heterometal rod-like substructures. The results indicate that the disposition of the 2-methylimidazolyl groups of bis(imidazole) ligands have a significant effect on structural diversity. Moreover, the photoluminescence properties of 1 and 2 have been investigated. - Graphical abstract: Two novel 3D pillar-layered metal-organic coordination networks with aromatic multicarboxylate anion and bis(imidazole) ligands have been synthesized and structurally characterized. Display Omitted - Highlights: • It is rarely reported that metal-organic frameworks prepared with 3,5-bis-oxyacetate-benzoic acid. • Two metal-organic frameworks based on positional isomeric ligands were synthesized and structurally characterized. • Compond 1 displays unique (3,5)-connected binodal gra topology. • Compound 2 exhibits (4,4,5,9)-connected 4-nodal topology based on the Zn(II)-K(I) heterometal rod-like substructures. • The photoluminescence properties of compound 1 and 2 have been investigated.

Bis(tetramethylcyclopentadienyl)titanium chemistry. Molecular structures of [(C(5)HMe(4))(mu-eta(1) : eta(5)-C(5)Me(4))Ti](2) and [(C(5)HMe(4))(2)Ti]N-2(2)

NARCIS (Netherlands)

deWolf, JM; Blaauw, R; Meetsma, A; Teuben, JH; Gyepes, R; Varga, [No Value; Mach, K; Veldman, N; Spek, AL

1996-01-01

Thermolysis of bis(tetramethylcyclopentadienyl)-stabilized titanium(III) compounds (C(5)HMe(4))(2)TiR (R = Me (2), Ph (3)) yields, in marked contrast with the bis(pentamethylcyclopentadienyl) analog, the dimeric product [(C(5)HMe(4))(mu-eta(1):eta(5)-C(5)Me(4))Ti](2) (4), With a bridging metalated

Synthesis of Acridine-based DNA Bis-intercalating Agents

Directory of Open Access Journals (Sweden)

P. Mack

2001-02-01

Full Text Available Methods for the synthesis of N1, N8-bis(9-acridinyl-N4-(4-hydroxybenzyl-spermidine and N1, N7-(hydroxybenzyl-bis-(3-aminopropylamine were investigated. Thus monocyanoethylation of 4-methoxybenzylamine followed by treatment with 4-chlorobutyronitrile gave the dinitrile N-(2-cyanoethyl-N-(3-cyanopropyl-4-methoxybenzylamine. Subsequent in situ reduction with lithium aluminium hydride gave the corresponding diamine. Biscyanoethylation of 4-methoxybenzylamine with 2 mole of acrylonitrile followed by reduction yielded the diamine N, N-bis-(3-aminopropyl-4-methoxybenzylamine. Both diamines reacted smoothly with 9-methoxyacridine to give the bis-(9-acridinyl compounds 11 and 15 but with 4,5-dimethyl-9-methoxyacridine, the bis compound 16 was produced in only low yields. Demethylation of the dinitriles by a variety of approaches all failed to give the corresponding hydroxybenzyl derivatives. These studies yielded useful methylated tyrosine derivatives which could also be iodinated. This study has been useful for elucidating chemical methods needed for the synthesis of the desired tyrosine-based bis acridine compound and for alerting us to the need to synthesise a more labile protected tyrosine intermediate which will be easily deprotected to afford the desired tyrosine-based bis acridine compound.

Enhanced explosive sensing based on bis(methyltetraphenyl)silole nanoaggregate

Science.gov (United States)

Shin, Bomina; Sohn, Honglae

2018-01-01

New photoluminescent bis(methyltetraphenyl)silole nanoaggregates for the detection of trinitrotoluene (TNT) were developed by using aggregation-induced emission property. Bis(methyltetraphenyl)silole nanoaggregates exhibited that photoluminescence (PL) intensity was increased when the water fraction was increased to 90% by volume. Relative PL efficiency of bis(methyltetraphenyl)silole nanoaggregates was exponentially increased to the percent of water fraction and particle diameter was dependent on solvent composition. Particle size of bis(methyltetraphenyl)silole nanoaggregates was tuned by controlling the water fraction by volume. Absolute quantum yield of bis(methyltetraphenyl)silole nanoaggregates in 90% water volume fraction were 32.4%, which increases by about 40 times. Detection of TNT was achieved from the quenching PL measurement of bis(methyltetraphenyl)silole nanoaggregates by adding the TNT. A linear Stern-Volmer relationship was observed for the detection of TNT.

Uptake of 153Sm-DTPA-bis-biotin and 99mTc-DTPA-bis-biotin in rat as-30D-hepatoma cells

International Nuclear Information System (INIS)

Correa-Gonzalez, Luis; Arteaga de Murphy, Consuelo; Ferro-Flores, Guillermina; Pedraza-Lopez, Martha; Murphy-Stack, Eduardo; Mino-Leon, Dolores; Perez-Villasenor, Graciela; Diaz-Torres, Yaneth; Munoz-Olvera, Rodrigo

2003-01-01

Labeled biotin has been used mainly for pretargeted therapy, an approach for increasing the amount of radioactivity delivered to a cancer cell. The aim of this investigation was to prepare 153 Sm-DTPA-bis-biotin and 99m Tc-DTPA-bis-biotin in order to study their in vitro and in vivo uptake in rat AS-30D hepatoma cells found in ascites and in implanted tumor. DTPA-bis-biotin (pH 8) was 153 Sm labeled with 153 SmCl 3 and 99m Tc-DTPA-bis-biotin was prepared via SnCl 2 reduction. Radiochemical purity was >98% in both cases. AS-30D hepatoma cells were obtained from ascites of a rat with hepatoma and were propagated in the peritoneum cavity of normal rats. In vitro ascites cell 153 Sm-DTPA-bis-biotin uptake was compared with 153 SmCl 3 cell uptake. The ratio cell 153 Sm-DTPA-bis-biotin/ 153 SmCl 3 was 39.6 and when avidin was added it increased to 50. The ratio 99m Tc-DTPA-bis-biotin/TcO 4 Na was 8.7. Concentration of 153 Sm-DTPA-bis-biotin in tumor 2, 3 and 24 h after administration, was 5, 15 and 3 times higher than in normal muscle (T/nT). Biodistribution in a 0.083-24 h time period showed that 153 Sm-DTPA-bis-biotin was taken up only by ascites tumor cells and hepatoma cells. Two and 3 h ratio ascites/liver (As/Lv) was 6.4 and 6.0. For 99m Tc-DTPA-bis-biotin 2 and 3 h T/nT was 15.7 and 4.7 and 2 h As/Lv was 1.4. In conclusion, both radiopharmaceuticals show high uptake in rat AS-30D hepatoma cells in ascites and in implanted tumor. Since lung, thyroid, kidney, liver or pancreas carcinomas are ascites producing cancers 153 Sm-DTPA-bis-biotin would be an adequate therapeutic radiopharmaceutical for these patients whose life quality would be enhanced with control of ascites, and a reduction of the primary tumor and its metastases

Accelerated optical holographic recording using bis-DNO

DEFF Research Database (Denmark)

Rasmussen, Palle H.; Ramanujam, P.S.; Hvilsted, Søren

1999-01-01

The design, synthesis and optical holographic recording properties of bis-DNO are reported. Bis-DNO is composed of two identical azobenzene oligoornithine segments (DNO) connected via a dipeptide linker. The two segments were assembled in a parallel fashion at the two amino groups of the dipeptid...... linker by Merrifield synthesis. Surprisingly, the response time of films of bis-DNOs was found to be much faster than that of their linear counterparts. (C) 1999 Elsevier Science Ltd. All rights reserved....

Quando o índice bispectral (BIS pode fornecer valores espúrios Cuando el índice bispectral (BIS puede suministrar valores falsos When the bispectral index (Bis can give false results

Directory of Open Access Journals (Sweden)

Leonardo Teixeira Domingues Duarte

2009-02-01

Full Text Available JUSTIFICATIVA E OBJETIVOS: O índice bispectral (BIS é um parâmetro multifatorial derivado do eletroencefalograma (EEG que permite a monitorização do componente hipnótico da anestesia. Foi obtido a partir de algoritmo derivado da análise de grande número de EEGs de voluntários e pacientes submetidos a sedações e anestesia geral com diferentes agentes anestésicos. Além de outros benefícios, o uso do BIS para monitorização da profundidade da anestesia reduz a ocorrência de despertar e memória intra-operatória. Esta revisão teve o objetivo de apresentar situações clínicas em que o BIS aponta valores espúrios, falsamente elevados ou reduzidos, em decorrência de condições do paciente ou ações de anestésicos não-previstos quando da elaboração do seu algoritmo. CONTEÚDO: Os valores do BIS podem sofrer alteração e influência em variadas situações clínicas em que há padrões anormais do EEG; efeito de diferentes anestésicos e outros fármacos não-incluídos na elaboração de seu algoritmo; interferência de equipamentos elétricos; bem como decorrentes de peculiaridades do monitor. CONCLUSÃO: Apesar de o algoritmo do BIS ter sofrido diversas alterações desde a sua primeira versão, essas situações que determinam variações espúrias dos valores do BIS devem ser reconhecidas pelo anestesiologista a fim de evitar complicações, sejam conseqüentes à sobredose anestésica, sejam por subdoses que poderão causar despertar e memória intra-operatória.JUSTIFICATIVA Y OBJETIVOS: El índice bispectral (BIS es un parámetro multifactorial derivado del electroencefalograma (EEG, que permite la monitorización del componente hipnótico de la anestesia. Fue obtenido a partir de algoritmo derivado del análisis de un gran número de EEG de voluntarios y pacientes sometidos a sedaciones y anestesia general con diferentes agentes anestésicos. Además de otros beneficios, el uso del BIS para la monitorización de la

New dual emission fluorescent sensor for pH and Pb(II) based on bis(napfthalimide) derivative

Energy Technology Data Exchange (ETDEWEB)

Pina-Luis, Georgina, E-mail: gpinaluis@yahoo.com [Centro de Graduados e Investigacion en Quimica, Instituto Tecnologico de Tijuana, AP 1166, Tijuana 22500, BC (Mexico); Martinez-Quiroz, Marisela; Ochoa-Teran, Adrian [Centro de Graduados e Investigacion en Quimica, Instituto Tecnologico de Tijuana, AP 1166, Tijuana 22500, BC (Mexico); Santacruz-Ortega, Hisila [Departamento de investigacion en Polimeros y Materiales, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico); Mendez-Valenzuela, Eduardo [Centro de Graduados e Investigacion en Quimica, Instituto Tecnologico de Tijuana, AP 1166, Tijuana 22500, BC (Mexico)

2013-02-15

This paper describes a novel dual emission bis-1,8-naphthalimide sensor for selective determination of pH and Pb{sup 2+} ions. The influence of the variability in the backbone that links the two fluorophores (naphthalimides) as a function of pH and metal ions was studied by UV-visible and fluorescence spectroscopy. Compounds 1(a-d) with different length alkyl linkers (CH{sub 2}){sub n} (n=1, 2, 4 and 6) showed no excimer formation in aqueous solution. Fluorescence emission of these derivatives varied in a narrow range of pH (5-8) and was only slightly influenced by the addition of metal ions in CH{sub 3}CN solutions. However, derivative 1e with amino-containing spacer (CH{sub 2}-NH-CH{sub 2}) showed excimer emission in aqueous solution, a wide response to pH (2.5-9.5) and fluorescence enhancement with selective behavior towards metal ions. The pH sensor based in derivative 1e has a sufficient selectivity for practical pH monitoring in the presence of Li{sup +}, Na{sup +}, K{sup +}, Cs{sup +}, Ca{sup 2+}, Mg{sup 2+}, Ba{sup 2+}, Cu{sup 2+}, Pb{sup 2+}, Ni{sup 2+}, Zn{sup 2+} and Cd{sup 2+}. The coordination chemistry of these complexes was studied by UV-Vis, fluorescence and {sup 1}H NMR. This chemosensor displayed high selectivity fluorescence enhancement toward Pb{sup 2+} ions in the presence of the metals ions mentioned in CH{sub 3}CN solutions. Competitive assays show that a 1-fold of metal cations in each case, compared with Pb{sup 2+} ions, results in less than {+-}5% fluorescence intensity changes. Linear calibration up to 1 Multiplication-Sign 10{sup -5} M for Pb(II) ions (R=0.9968) was obtained and detection limit resulted of 5.0 Multiplication-Sign 10{sup -8} M. - Highlights: Black-Right-Pointing-Pointer A novel dual emission bis-1,8-naphthalimide sensor for pH and Pb{sup 2+} ions is synthetized. Black-Right-Pointing-Pointer The excimer formation depends on the spacer that links the two naphthalimide groups. Black-Right-Pointing-Pointer Bis

Synthesis, spectral characterization and in vitro antifungal activity of Lanthanum(III) and Praseodymium(III) complexes with Schiff bases derived from 5-substituted-4-amino-5-hydrazino-1,2,4-triazoles and isatin

International Nuclear Information System (INIS)

Singh, Shweta; Tripathi, Priti; Pandey, Om P.; Sengupta, Soumitra K.

2013-01-01

The new lanthanum(III) and praseodymium(III) complexes of the general formula (LnCl(L)(H 2 O) 2 ) (Ln = La III or Pr III ; H 2 L = Schiff bases derived from 3-substituted-4-amino-5-hydrazino-1,2,4-triazoles and isatin) have been prepared. The complexes have been characterized by elemental analyses, molecular weight by FAB-mass, thermogravimetry, electrical conductance, magnetic moment and spectral (electronic, infrared, far-infrared, 1 H NMR and 13 C NMR) data. The ligands and all prepared complexes were assayed for antifungal (Aspergillus niger and Helminthosporium oryzae) activities. The activities have been correlated with the structures of the complexes. (author)

Construction, Structural Diversity and Properties of Five Coordination Polymers Based on 5-Nitroisophthalate and Bis(imidazole) Linkers

Science.gov (United States)

Arıcı, Mürsel

2018-06-01

Five coordination polymers, namely, [Cd(μ3-5-nip)(μ-obix)]n (1), [Co(μ3-5-nip)(μ-obix)]n (2), [Zn(μ-5-nip)(μ-obix)]n (3 and 4) and [Cd(μ-5-nip)(μ-bisobix)]n (5) (5-nip: 5-nitroisophthalate, obix: 1,2-bis(imidazol-1ylmethyl)benzene, bisobix: 1,2-bis(2-isopropylimidazol-1ylmethyl)benzene) were hydrothermally synthesized and characterized by IR spectroscopy, elemental analysis, single crystal and powder X-ray diffraction and thermal analysis (TG/DTA). X-ray results showed that the complexes displayed structural diversity depending on metal ions and conformations of bis(imidazole) linkers. Complexes 1 and 2 were 1D structures and obix ligand displayed cis-conformation. Complexes 3 and 4 exhibited 2D and 3D structures with same components depending on obix conformation. In complex 5, 3D+3D→3D interpenetrated structure was obtained with dia topology when bisobix having sterically hindered groups on imidazole rings was used. Moreover, thermal, photoluminescence and optical properties of the complexes were also investigated.

Synergistic extraction of Eu(III) with N-phosphorylated bis-ureas and chlorinated cobalt bis(dicarbollide) ion

Czech Academy of Sciences Publication Activity Database

Selucký, P.; Bubeníková, M.; Rais, J.; Grüner, Bohumír; Brusko, V.V.

2013-01-01

Roč. 101, č. 1 (2013), s. 27-31 ISSN 0033-8230 R&D Projects: GA ČR GA104/09/0668 Institutional support: RVO:61388980 Keywords : liquid-liquid extraction * lanthanides * actinides * N-phosphorylated bis-ureas * chlorinated cobalt bis(dicarbollide) ion * high level liquid waste Subject RIV: CA - Inorganic Chemistry Impact factor: 1.411, year: 2013

‘Transnationalising’ Ne Bis In Idem: How the Rule of Ne Bis In Idem Reveals the Principle of Personal Legal Certainty

Directory of Open Access Journals (Sweden)

Juliette Lelieur

2013-09-01

Full Text Available Since Article 54 of the Convention implementing the Schengen Agreement gave the rule of ne bis in idem a transnational dimension, talk of the ‘transnational ne bis in idem principle’ has been commonplace. Thus, when looking for general principles of transnational criminal law, scholars refer to the principle of ‘transnational ne bis in idem’. It is doubtful, however, that ne bis in idem qualifies as a principle of law. It should be regarded, rather, as a rule of criminal procedure, traditionally based on the principle of res judicata. Giving the rule of ne bis in idem a transnational dimension therefore requires either transnationalising the principle of res judicata, or giving the rule of ne bis in idem a new foundation.The principle of res judicata principally serves the credibility of the justice system in a given jurisdiction by prohibiting several tribunals, all acting within the parameters of their jurisdiction, from contradicting each other’s interpretation of the same facts. For this reason, the principle of res judicata does not provide an adequate basis for a transnationalised rule of ne bis in idem.From a human rights perspective, multiple prosecutions against the same person for the same facts collides with protecting individuals against arbitrary judicial treatment. This is true whether the multiple prosecutions all take place in one country or in several different countries. The rule of ne bis in idem could therefore be regarded as a manifestation of the (new ‘principle of personal legal certainty’.

Comparisons Between Tridentate Bis(benzazoles-pyridine and Bis(benzazolestriazine Ligands: a Theoretical Study

Directory of Open Access Journals (Sweden)

Mihaiela Andoni

2015-12-01

Full Text Available Twelve bis(benzazole structures with potential ligand character were investigated by means of computational chemistry. Global and local reactivity descriptors within DFT (Density Functional Theory theory (Fukui functions, chemical potential, hardness, electrophilicity index have been computed at B3LYP/6-31G(d,p level of theory. NICS(0 (Nucleus Independent Chemical Shift index computations were employed for the evaluation of the local aromatic character of each heterocyclic moiety. Best results have been reported for the bis(benzimidazole derivatives. Copper and zinc complexes of the investigated tridentate ligands have been proposed.

Isolation of a Bis-Iodurated Tetra-THF as a Trace Product from the Oxidation of Squalene with RuO4 and Its Double Ring Expansion to a Novel bis-THF-bis-THP Compound

Directory of Open Access Journals (Sweden)

Nicola Borbone

2011-06-01

Full Text Available A novel bis-iodurated polyether compound, based on an unprecedented tetra-THF backbone, has been isolated as a trace by-product of the oxidation of squalene with the catalytic system RuO2(cat./NaIO4. The double erythro configuration of the central portion of the molecule furnishes the first indirect support of the previously postulated pathway operating in the oxidative pentacyclization of the isoprenoid substrate. A bidirectional double oxidative bis-cyclization is invoked to explain the formation of this compound. The isolated substance was successfully subjected to a double rearrangement-ring expansion to give a novel bis-THF-bis-THP compound.

Synthesis and X-Ray Crystal Structures of Mononuclear Complexes of 1,3-Bis(8-quinolyloxy)propane

International Nuclear Information System (INIS)

Al-Mandhary, M.R.; Steel, P.

2002-01-01

The preparations and X-ray crystal structures of the first transition metal complexes of 1,3-bis(8-quinolyloxy)propane are described. The ligand acts as a trans-chelating N,N'-bidentate ligand in the three-coordinate silver nitrate complex and four-coordinate copper chloride complex, but as an N,O,O',N'-tetradentate ligand in the octahedral nickel chloride complex. Copyright (2002) CSIRO Australia

A Bis-Triazacyclononane Tris-Pyridyl N9 -Azacryptand "Beer Can" Receptor for Complexation of Alkali Metal and Lead(II) Cations.

Science.gov (United States)

Brown, Asha; Bunchuay, Thanthapatra; Crane, Christopher G; White, Nicholas G; Thompson, Amber L; Beer, Paul D

2018-04-18

A new bis-triazacyclononane tris-pyridyl N 9 -azacryptand ligand is prepared via a convenient one-pot [2+3] condensation reaction between triazacyclononane and 2,6-bis(bromomethyl) pyridine in the presence of M 2 CO 3 (M=Li, Na, K). The proton, lithium, sodium, potassium and lead(II) complexes of the ligand are characterised in the solid state. Preliminary solution-phase competition experiments indicate that the cryptand ligand preferentially binds lead(II) in the presence of sodium, calcium, potassium and zinc cations in methanol solution. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Practical synthesis, anticonvulsant, and antimicrobial activity of N-allyl and N-propargyl di(indolyl)indolin-2-ones.

Science.gov (United States)

Praveen, Chandrasekaran; Ayyanar, Asairajan; Perumal, Paramasivan Thirumalai

2011-07-01

An operation friendly protocol for the synthesis of novel di(indolyl)indolin-2-ones via Cu(OTf)(2) catalyzed bis-addition of N-allyl and N-propargyl indole with isatin was developed. This methodology allowed us to achieve the products in excellent yields without requiring purification technique like column chromatography. All the synthesized compounds were evaluated for their in vivo anticonvulsant activity against maximal electroshock test. Six compounds showed maximum activity compared to the standard drug phenytoin. The scope of the new molecules as antimicrobial agents were tested against two bacterial strains (Staphylococcus aureus and Escherichia coli) and one fungal strain (Candida albicans). Copyright © 2011 Elsevier Ltd. All rights reserved.

Bis-ligated Ti and Zr complexes of chelating N-heterocyclic carbenes

KAUST Repository

El-Batta, Amer

2011-07-01

In this communication we report the synthesis of novel titanium and zirconium complexes ligated by bidentate "salicylaldimine-like" N-heterocyclic carbenes (NHC). Double addition of the NHC chelate to either TiCl4(thf)2 or ZrCl4 forms bis-ligated organometallic fragments with a distorted octahedral geometry. These complexes are rare examples of group IV transition-metal NHC adducts. Preliminary catalytic tests demonstrate that in the presence of methylaluminoxane (MAO) these complexes are useful initiators for the polymerization of ethylene and the copolymerization of ethylene with norbornene and 1-octene. © 2011 Elsevier B.V. All rights reserved.

DNA-Directed alkylating agents. 7. Synthesis, DNA interaction, and antitumor activity of bis(hydroxymethyl)- and bis(carbamate)-substituted pyrrolizines and imidazoles.

Science.gov (United States)

Atwell, G J; Fan, J Y; Tan, K; Denny, W A

1998-11-19

A series of bis(hydroxymethyl)-substituted imidazoles, thioimidazoles, and pyrrolizines and related bis(carbamates), linked to either 9-anilinoacridine (intercalating) or 4-(4-quinolinylamino)benzamide (minor groove binding) carriers, were synthesized and evaluated for sequence-specific DNA alkylation and cytotoxicity. The imidazole and thioimidazole analogues were prepared by initial synthesis of [(4-aminophenyl)alkyl]imidazole-, thioimidazole-, or pyrrolizine dicarboxylates, coupling of these with the desired carrier, and reduction to give the required bis(hydroxymethyl) alkylating moiety. The pyrrolizines were the most reactive alkylators, followed by the thioimidazoles, while the imidazoles were unreactive. The pyrrolizines and some of the thioimidazoles cross-linked DNA, as measured by agarose gel electrophoresis. Strand cleavage assays showed that none of the compounds reacted at purine N7 or N3 sites in the gpt region of the plasmid gpt2Eco, but the polymerase stop assay showed patterns of G-alkylation in C-rich regions. The corresponding thioimidazole bis(carbamates) were more selective than the bis(hydroxymethyl) pyrrolizines, with high-intensity bands at 5'-NCCN, 5'-NGCN and 5'-NCGN sequences in the PCR stopping assay ( indicates block sites). The data suggest that these targeted compounds, like the known thioimidazole bis(carbamate) carmethizole, alkylate exclusively at guanine residues via the 2-amino group, with little or no alkylation at N3 and N7 guanine or adenine sites. The cytotoxicities of the compounds correlated broadly with their reactivities, with the bis(hydroxymethyl)imidazoles being the least cytotoxic (IC50s >1 microM; P388 leukemia) and with the intercalator-linked analogues being more cytotoxic than the corresponding minor-groove-targeted ones. This was true also for the more reactive thioimidazole bis(carbamates) (IC50s 0.8 and 11 microM, respectively), but both were more active than the analogous "untargeted" carmethizole (IC50 20

A review on bis-hydrazonoyl halides: Recent advances in their synthesis and their diverse synthetic applications leading to bis-heterocycles of biological interest

Directory of Open Access Journals (Sweden)

Ahmad Sami Shawali

2016-11-01

Full Text Available This review covers a summary of the literature data published on the chemistry of bis-hydrazonoyl halides over the last four decades. The biological activities of some of the bis-heterocyclic compounds obtained from these bis-hydrazonoyl halides are also reviewed and discussed.

Evaluation of functionalized silica's for the adsorptive recovery of homogeneous catalysts through interaction with the metal centre

NARCIS (Netherlands)

Djekic, T.; Ham, van der A.G.J.; Haan, de A.B.

2007-01-01

The goal of this paper is the evaluation of functionalized silica's for the recovery of homogeneous catalysts by adsorption via its metal centre. As model catalysts, we selected bis(triphenylphosphine)cobalt(II)dichloride (CoCl2(PPh3)2), bis(triphenylphosphine)palladium(II)dichloride (PdCl2(PPh3)2)

Homogeneous Liquid–Liquid Extraction of Rare Earths with the Betaine—Betainium Bis(trifluoromethylsulfonyl)imide Ionic Liquid System

Science.gov (United States)

Hoogerstraete, Tom Vander; Onghena, Bieke; Binnemans, Koen

2013-01-01

Several fundamental extraction parameters such as the kinetics and loading were studied for a new type of metal solvent extraction system with ionic liquids. The binary mixture of the ionic liquid betainium bis(trifluoromethylsulfonyl)imide and water shows thermomorphic behavior with an upper critical solution temperature (UCST), which can be used to avoid the slower mass transfer due to the generally higher viscosity of ionic liquids. A less viscous homogeneous phase and mixing on a molecular scale are obtained when the mixture is heated up above 55 °C. The influence of the temperature, the heating and cooling times, were studied for the extraction of neodymium(III) with betaine. A plausible and equal extraction mechanism is proposed in bis(trifluoromethylsulfonyl)imide, nitrate, and chloride media. After stripping of the metals from the ionic liquid phase, a higher recovery of the ionic liquid was obtained by salting-out of the ionic liquid fraction lost by dissolution in the aqueous phase. The change of the upper critical solution temperature by the addition of HCl or betaine was investigated. In addition, the viscosity was measured below and above the UCST as a function of the temperature. PMID:24169434

Different efflux rates may determine the cellular accumulation of various bis(guanylhydrazones).

Science.gov (United States)

Alhonen-Hongisto, L; Fagerström, R; Laine, R; Elo, H; Jänne, J

1984-01-01

Three bis(guanylhydrazones) (those of methylglyoxal, glyoxal and ethylglyoxal) were compared for their affinity for the putative polyamine carrier and for their cellular retention in L1210 mouse leukaemia cells. All the bis(guanylhydrazones) inhibited equally effectively the uptake of spermidine by the tumour cells, indicating that the compounds had roughly equal affinity for the polyamine carrier. The fact that methylglyoxal bis(guanylhydrazone) and glyoxal bis(guanylhydrazone) were much more effectively concentrated in the animal cells than was ethylglyoxal bis(guanylhydrazone) was obviously attributable to the finding that the efflux rate of ethylglyoxal bis(guanylhydrazone) greatly exceeded that of the other bis(guanylhydrazones). The rate of efflux of the drugs was slowed down if the tumour cells were treated with 2-difluoromethylornithine before exposure to the bis(guanylhydrazones). These results suggest that intracellular binding of the bis(guanylhydrazones) determines their cellular accumulation. PMID:6431972

Homo- and heterodinuclear coordination polymers based on a tritopic cyclam bis-terpyridine unit: Structure and rheological properties

Energy Technology Data Exchange (ETDEWEB)

Qu, Li; Fan, Jiangxia; Ren, Yong; Xiong, Kun [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Yan, Minhao, E-mail: yanminhao@swust.edu.cn [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Tuo, Xianguo, E-mail: tuoxg@swust.edu.cn [Laboratory of National Defense for Radioactive Waste and Environmental Security, Southwest University of Science and Technology, Mianyang 621010 (China); Terech, Pierre [SPrAM, UMR CEA/CNRS/UJF-Grenoble 1, INAC, Grenoble F-38054 (France); Royal, Guy [Université Joseph Fourier Grenoble I, Département de Chimie Moléculaire, UMR CNRS-5250, Institut de Chimie Moléculaire de Grenoble, FR CNRS-2607, BP 53, 38041 Grenoble Cedex 9 (France)

2015-03-01

An innovative coordination polymer based on a tritopic ligand having the bis-terpyridine cyclam (CHTT) unit is explored. Homo- or heteronuclear 1D coordination polymers can be formed with bivalent metal ions such as Co(II) and Ni(II) in solvent DMF. Creep-recovery curves of the (Co{sup II}){sub 2}CHTT gels formed from 1D coordination polymers were analyzed with the Burgers model and demonstrated an original self-healing property, unusual in the class of molecular gels. The influence of the metal type was studied through the structural features using small-angle neutron scattering (SANS) experiments. In gels, the corresponding network involves genuine fibers (R ≈ 35 Å), bundles of these fibers and also a fraction of finite size aggregates (rods with aspect ratio f ≈ 3–5). We found that the distribution of these latter structural components is sensitive to the metal ions type. Such tritopic 1D coordination polymers exhibit a range of original structural features and a facile control of the developed structures in solutions and gels by tuning their thermodynamic parameters. The versatility associated to the intrinsic dynamic ability of the systems should pave the way to original properties for molecular devices. - Graphical abstract: A tritopic ligand with a bis-terpyridine cyclam (CHTT) unit can form homo- and heterobinuclear coordination polymers with bivalent metal ions in DMF. Gels exhibit a remarkable self-healing property while structures of solutions and gels are studied by small-angle neutron scattering. - Highlights: • Homo- and heteronuclear coordination polymers based on innovative tritopic ligand. • The gels formed from the coordination polymers demonstrated self-healing property. • Influence of the metal type was studied through the structural properties by SANS. • Versatility of the singular system present original properties for molecular device.

Methylene-bis[(aminomethyl)phosphinic acids]: synthesis, acid-base and coordination properties.

Science.gov (United States)

David, Tomáš; Procházková, Soňa; Havlíčková, Jana; Kotek, Jan; Kubíček, Vojtěch; Hermann, Petr; Lukeš, Ivan

2013-02-21

Three symmetrical methylene-bis[(aminomethyl)phosphinic acids] bearing different substituents on the central carbon atom, (NH(2)CH(2))PO(2)H-C(R(1))(R(2))-PO(2)H(CH(2)NH(2)) where R(1) = OH, R(2) = Me (H(2)L(1)), R(1) = OH, R(2) = Ph (H(2)L(2)) and R(1),R(2) = H (H(2)L(3)), were synthesized. Acid-base and complexing properties of the ligands were studied in solution as well as in the solid state. The ligands show unusually high basicity of the nitrogen atoms (log K(1) = 9.5-10, log K(2) = 8.5-9) if compared with simple (aminomethyl)phosphinic acids and, consequently, high stability constants of the complexes with studied divalent metal ions. The study showed the important role of the hydroxo group attached to the central carbon atom of the geminal bis(phosphinate) moiety. Deprotonation of the hydroxo group yields the alcoholate anion which tends to play the role of a bridging ligand and induces formation of polynuclear complexes. Solid-state structures of complexes [H(2)N=C(NH(2))(2)][Cu(2)(H(-1)L(2))(2)]CO(3)·10H(2)O and Li(2)[Co(4)(H(-1)L(1))(3)(OH)]·17.5H(2)O were determined by X-ray diffraction. The complexes show unexpected geometries forming dinuclear and cubane-like structures, respectively. The dinuclear copper(II) complex contains a bridging μ(2)-alcoholate group with the (-)O-P(=O)-CH(2)-NH(2) fragments of each ligand molecule chelated to the different central ion. In the cubane cobalt(II) complex, one μ(3)-hydroxide and three μ(3)-alcoholate anions are located in the cube vertices and both phosphinate groups of one ligand molecule are chelating the same cobalt(II) ion while each of its amino groups are bound to different neighbouring metal ions. All such three metal ions are bridged by the alcoholate group of a given ligand.

Thermal behavior of poly(2-hydroxyethyl methacrylate-bis-[trimethoxysilylpropyl]amine) networks

International Nuclear Information System (INIS)

Bustos Figueroa, L A; Salgado Delgado, R; García Hernandez, E; Vargas Galarza, Z; Rubio Rosas, E; Salgado Rodriguez, R

2013-01-01

Poly(HEMA-BisSi) networks were prepared by using acid-catalyzed sol-gel of bis-[trimethoxysilylpropyl]amine (BisSi) and free radical polymerization of 2-hydroxyethyl methacrylate (HEMA). The thermal properties of the poly(HEMA-BisSi) networks were investigated with differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The thermal behavior of these networks was also compared with homopolymers (The networks formed in both PHEMA and PBisSi gels were identified). The glass transition temperature (T g ) of PHEMA homopolymer was found as 103.74 °C. The thermal degradation of the poly(HEMA-BisSi) networks with different silica contents (e.g. 10, 15 and 25 wt%) were evaluated with use of DTG. It was observed that the thermal degradation temperature of poly(HEMA-BisSi) networks changed much with the BisSi content.

Yttrium and lanthanide nitrate complexes of N,N1-bis(4-antipyryl methylidene) ethylenediamine

International Nuclear Information System (INIS)

Joseph, Siby; Radhakrishnan, P.K.

1998-01-01

Complexes of yttrium and lanthanide nitrates with a Schiff base, N, N 1 -bis(4-antipyrylmethylidene)ethylenediamine (BAME) having the general formula [Ln(BAME) 2 (NO 3 )](NO 3 ) 2 , where Ln = Y, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho and Er have been synthesised and characterised by elemental analyses, molar conductance in non-aqueous solvents, electronic, infrared and proton NMR spectra. BAME acts as a neutral bidentate ligand coordinating through both azomethine nitrogen atoms. One of the nitrate groups is coordinated in a bidentate manner. A coordination number of six may be assigned to the metal ion in these complexes. The covalency parameters evaluated from the solid state electronic spectra suggest weak covalent character of the metal-ligand bond. (author)

Effect of preparation conditions on the properties of Cu3BiS3 thin films grown by a two - step process

Science.gov (United States)

Mesa, F.; Gordillo, G.

2009-05-01

Cu3BiS3 thin films were prepared on soda-lime glass substrates by co-evaporation of the precursors in a two-step process; for that, the metallic precursors were evaporated from a tungsten boat in presence of elemental sulfur evaporated from a tantalum effusion cell. The films were characterized by spectral transmittance, atomic force microscopy AFM and x-ray diffraction (XRD) measurements to investigate the effect of the growth conditions on the optical, morphological and structural properties. The results revealed that, independently of the deposition conditions, the films grow only in the orthorhombic Cu3BiS3 phase. It was also found that the Cu3BiS3 films present p-type conductivity, a high absorption coefficient (greater than 104 cm-1) and an energy band gap Eg of about 1.41 eV, indicating that this compound has good properties to perform as absorbent layer in thin film solar cells.

Maternal BIS Sensitivity, Overprotective Parenting, and Children’s Internalizing Behaviors

Science.gov (United States)

Kiel, Elizabeth J.; Maack, Danielle J.

2012-01-01

Although sensitivity to the Behavioral Inhibition System within Gray’s (1970) reinforcement sensitivity theory relates to individuals’ own depressive and anxious symptomatology, less is known about how parental BIS sensitivity relates to early indicators of internalizing problems in young children. Moreover, the extent to which this parental characteristic relates to parenting behavior, and children’s internalizing problems above and beyond parenting, remains unknown. The current study assessed maternal BIS sensitivity, overprotective parenting, and toddlers’ internalizing behaviors in a sample of 91 mothers while controlling for mothers’ own internalizing symptomatology. Heightened BIS sensitivity related to both overprotective parenting and internalizing behaviors. Overprotective parenting partially mediated the relation between BIS sensitivity and children’s internalizing behaviors, although BIS sensitivity maintained a marginal relation to internalizing behaviors. Maternal BIS sensitivity and toddler internalizing behaviors may represent a shared disposition towards inhibition that is somewhat accounted for by overprotective parenting. PMID:22904590

Isoelectric focusing of small non-covalent metal species from plants.

Science.gov (United States)

Köster, Jessica; Hayen, Heiko; von Wirén, Nicolaus; Weber, Günther

2011-03-01

IEF is known as a powerful electrophoretic separation technique for amphoteric molecules, in particular for proteins. The objective of the present work is to prove the suitability of IEF also for the separation of small, non-covalent metal species. Investigations are performed with copper-glutathione complexes, with the synthetic ligand ethylenediamine-N,N'-bis(o-hydroxyphenyl)acetic acid (EDDHA) and respective metal complexes (Fe, Ga, Al, Ni, Zn), and with the phytosiderophore 2'-deoxymugineic acid (DMA) and its ferric complex. It is shown that ethylenediamine-N,N'-bis(o-hydroxyphenyl)acetic acid and DMA species are stable during preparative scale IEF, whereas copper-glutathione dissociates considerably. It is also shown that preparative scale IEF can be applied successfully to isolate ferric DMA from real plant samples, and that multidimensional separations are possible by combining preparative scale IEF with subsequent HPLC-MS analysis. Focusing of free ligands and respective metal complexes with di- and trivalent metals results in different pIs, but CIEF is usually needed for a reliable estimation of pI values. Limitations of the proposed methods (preparative IEF and CIEF) and consequences of the results with respect to metal speciation in plants are discussed. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metal-containing radiation-sensitive polymers

International Nuclear Information System (INIS)

Lee, A.Y.

1986-01-01

The copolymers of methyl methacrylate with alkali metal salts (Na, K, and Cs) of methacrylic acid have been prepared by saponification K, and Cs) of methylacrylic acid have been prepared by saponification of the homopolymer poly(methyl methacrylate), PMMA. Low degrees of hydrolysis have been achieved by a heterogeneous system, and from the infrared spectra it has been confirmed that the ester groups of the methyl methacrylates are directly converted to the metal salts of methacrylic acid. These ionomers exhibit pseudo high molecular weights in gel permeation chromatogram, but no appreciable increase in intrinsic viscosities is observed in comparison to PMMA. The coordinated inorganic polymers poly[(dithio-2,2'-diacetato)bis(dimethylsulfoxide)dioxouranium(VI)] and poly[{methylenebis(thio)-2,2'-bis(acetato)}bis(dimethylsulfoxide)dioxouranium(VI)]have been synthesized in dimethyl sulfoxide solution with about 90% yield. The degree of polymerization and the number of average molecular weights of these polymers have been assessed by high resolution nuclear magnetic resonance, with which the acetato end group to the bridging ligand group ratios have been determined. The polymers bridging ligand group ratios have been determined. The polymers have been characterized by employing various techniques: infrared spectra, thermal gravimetric analysis, 13 C solid state nuclear magnetic resonance, and gel permeation chromatography. The prepared polymer samples have been subjected to various doses of 137 Cs gamma radiation under which the polymers predominantly undergo chain scission. The radiation sensitivities of the polymers are assessed by G values which are obtained from gel permeation chromatograms. These uranyl polymers exhibit unusually high G values

Evaluation of functionalized silica¿s for the adsorptive recovery of homogenous catalysts through interaction with the metal centre

NARCIS (Netherlands)

Djekic, T.; van der Ham, Aloysius G.J.; de Haan, A.B.

2007-01-01

The goal of this paper is the evaluation of functionalized silica's for the recovery of homogeneous catalysts by adsorption via its metal centre. As model catalysts, we selected bis(triphenylphosphine)cobalt(II)dichloride (CoCl2(PPh3)2), bis(triphenylphosphine)palladium(II)dichloride (PdCl2(PPh3)2)

Synthesis & Characterization of New bis-Symmetrical Adipoyl ...

African Journals Online (AJOL)

Full Title: Synthesis and Characterization of New bis-Symmetrical Adipoyl, Terepthaloyl, Chiral Diimido-di-L-alanine Diesters and Chiral Phthaloyl-L-alanine Ester of Tripropoxy p-tert-Butyl Calix[4]arene and Study of Their Hosting Ability for Alanine and Na+. Bis-symmetrical tripropoxy p-tert-butyl calix[4]arene esters were ...

F-element metalated dipyrrins: synthesis and characterization of a family of uranyl bis(dipyrrinate) complexes.

Science.gov (United States)

Bolotaulo, Duer; Metta-Magaña, Alejandro; Fortier, Skye

2017-03-07

Using an improved, chromatography-free dipyrrin synthesis, the α,β-unsubstituted dipyrrins [RC(C 4 H 2 N) 2 H] (2) (R = tolyl (2toly l ), p-OMe-C 6 H 4 (2anis), mesityl (2mes), ferrocenyl (2Fc)) were isolated in good to excellent yields. Deprotonation of 2 with Na[N(SiMe 3 ) 2 ] gives the alkali metal salts [Na(DME) n ][RC(C 4 H 2 N) 2 ] (3) which reacts with UO 2 Cl 2 (THF) 3 to give the uranyl bis(dipyrrinates) UO 2 [RC(C 4 H 2 N) 2 ] 2 (L) (L = THF (4R-THF); DMAP (4R-DMAP)) (R = tolyl, p-OMe-C 6 H 4 , mesityl, ferrocenyl). The THF adducts, 4R-THF, are unstable in aromatic and nonpolar solvents and rapidly decompose to 2 and an intractable uranium-containing solid. On the other hand, the DMAP adducts, 4R-DMAP, are indefinitely stable in solution. The solid-state structures of 4R-THF and 4R-DMAP reveal distorted trigonal bipyramidal geometries. In the solid-state, the dipyrrinate ligands exhibit significant distortions including bowing and, in some instances, out-of-plane equatorial N-atom coordination, likely as a consequence of steric crowding and interligand repulsion. The complexes, 4R-DMAP, have been fully characterized by NMR, UV/Vis, and fluorescence spectroscopies, and their electrochemical properties have been investigated through cyclic voltammetry. The cyclic voltammograms of 4R-DMAP display several redox features but present a reversible wave at ca. -1.9 V (vs. Fc 0/+ ) attributable to a ligand centred reduction. Fluorescence measurements of all compounds reveal that only the mesityl derivatives 2mes, 3mes, and 4mes fluoresce with modest Stokes shift that ranges from ca. 30-70 nm, with 4mes displaying the greatest relative emission intensity.

Surprisingly Different Reaction Behavior of Alkali and Alkaline Earth Metal Bis(trimethylsilyl)amides toward Bulky N-(2-Pyridylethyl)-N'-(2,6-diisopropylphenyl)pivalamidine.

Science.gov (United States)

Kalden, Diana; Oberheide, Ansgar; Loh, Claas; Görls, Helmar; Krieck, Sven; Westerhausen, Matthias

2016-07-25

N-(2,6-Diisopropylphenyl)-N'-(2-pyridylethyl)pivalamidine (Dipp-N=C(tBu)-N(H)-C2 H4 -Py) (1), reacts with metalation reagents of lithium, magnesium, calcium, and strontium to give the corresponding pivalamidinates [(tmeda)Li{Dipp-N=C(tBu)-N-C2 H4 -Py}] (6), [Mg{Dipp-N=C(tBu)-N-C2 H4 -Py}2 ] (3), and heteroleptic [{(Me3 Si)2 N}Ae{Dipp-N=C(tBu)-N-C2 H4 -Py}], with Ae being Ca (2 a) and Sr (2 b). In contrast to this straightforward deprotonation of the amidine units, the reaction of 1 with the bis(trimethylsilyl)amides of sodium or potassium unexpectedly leads to a β-metalation and an immediate deamidation reaction yielding [(thf)2 Na{Dipp-N=C(tBu)-N(H)}] (4 a) or [(thf)2 K{Dipp-N=C(tBu)-N(H)}] (4 b), respectively, as well as 2-vinylpyridine in both cases. The lithium derivative shows a similar reaction behavior to the alkaline earth metal congeners, underlining the diagonal relationship in the periodic table. Protonation of 4 a or the metathesis reaction of 4 b with CaI2 in tetrahydrofuran yields N-(2,6-diisopropylphenyl)pivalamidine (Dipp-N=C(tBu)-NH2 ) (5), or [(thf)4 Ca{Dipp-N=C(tBu)-N(H)}2 ] (7), respectively. The reaction of AN(SiMe3 )2 (A=Na, K) with less bulky formamidine Dipp-N=C(H)-N(H)-C2 H4 -Py (8) leads to deprotonation of the amidine functionality, and [(thf)Na{Dipp-N=C(H)-N-C2 H4 -Py}]2 (9 a) or [(thf)K{Dipp-N=C(H)-N-C2 H4 -Py}]2 (9 b), respectively, are isolated as dinuclear complexes. From these experiments it is obvious, that β-metalation/deamidation of N-(2-pyridylethyl)amidines requires bases with soft metal ions and also steric pressure. The isomeric forms of all compounds are verified by single-crystal X-ray structure analysis and are maintained in solution. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation of 177Lu-DTPA-BIS-BIOTIN and biodistribution evaluation in normal mice

International Nuclear Information System (INIS)

Deng Xinrong; Luo Zhifu; Du Jin

2010-01-01

The labeling method for 177 Lu-DTPA-BIS-BIOTIN was established, and the biodistribution of 177 Lu-DTPA-BIS-BIOTIN in normal mice was carried out as well. Under the optimal experimental condition (DTPA-BIS-BIOTIN 25 μg, pH=4.5 reacting at 80 degree C for 20 min), the labeling yield of 177 Lu-DTPA-BIS-BIOTIN is more than 99.0%. 177 Lu-DTPA-BIS-BIOTIN shows pretty good in vitro stability. The biodistribution of 177 Lu-DTPA-BIS-BIOTIN in normal mice shows a rapid blood clearance. The uptake of 177 Lu-DTPA-BIS-BIOTIN is mainly accumulated in liver, spleen and kidney. 177 Lu-DTPA-BIS-BIOTIN is excreted by kidney. The results provide the basis for further study on 177 Lu-DTPA-BIS-BIOTIN used in pretargeted radioimage and radiotherapy of cancer. (authors)

Impregnation of chelating agent 3,3-bis-N,N bis-(carboxymethylaminomethyl-o-cresolsulfonephthalein in biopolymer chitosan: adsorption equilibrium of Cu(II in aqueous medium

Directory of Open Access Journals (Sweden)

Luciano Vitali

2006-06-01

Full Text Available The aim of this study was to impregnate the chelating agent 3,3-bis-N,N,bis-(carboxymethylaminomethyl-o-cresolsulfonephthalein in chitosan and to investigate the adsorption of Cu(II ions. The chemical modification was confirmed by FTIR spectrometry, thermogravimetric analysis (TGA and energy dispersive x-ray spectroscopy (EDX. The adsorption studies were carried out with Cu(II ions in a batch process and were shown to be dependent on pH. The adsorption kinetics was tested using three models: pseudo first-order, pseudo second order and intraparticle diffusion. The experimental kinetics data were best fitted with the pseudo second-order model (R² = 0.999, which provided a rate constant, k2, of 1.21 x 10-3 g mg-1 min-1. The adsorption rate depended on the concentration of Cu(II ions on the adsorbent surface and on the quantity of Cu(II ions adsorbed at equilibrium. The Langmuir isotherm model provided the best fit for the equilibrium data in the concentration range investigated, with the maximum adsorption capacity being 81.0 mg of Cu(II per gram of adsorbent, as obtained from the linear equation of the isotherm. Desorption tests revealed that around 90% of the adsorbed metal was removed, using EDTA solution as the eluent. This result suggests that the polymeric matrix can be reused.

Off-on fluorescent sensor based on the bis(2,4,7,8,9-pentamethyldipyrrolylmethene-3-yl)methane for detection of Cd{sup 2+} and Hg{sup 2+} cations

Energy Technology Data Exchange (ETDEWEB)

Bumagina, Natalia A., E-mail: nad@isc-ras.ru [G.A. Krestov Institute of Solution Chemistry of Russian Academy of Sciences (ISC RAS), 1 Akademicheskaya St., 153045 Ivanovo (Russian Federation); Antina, Elena V., E-mail: eva@isc-ras.ru [G.A. Krestov Institute of Solution Chemistry of Russian Academy of Sciences (ISC RAS), 1 Akademicheskaya St., 153045 Ivanovo (Russian Federation); Sozonov, Dmitry I., E-mail: super_dk@mail.ru [Ivanovo State University of Chemistry and Technology (ISUCT), 7 Sheremetevskij Prosp., 153000 Ivanovo (Russian Federation)

2017-03-15

The off-on fluorescent chemosensor based on the bis(2,4,7,8,9-pentamethyldipyrrolylmethene-3-yl)methane for detection of Cd{sup 2+} and Hg{sup 2+} ions was obtained and its metal ion sensing properties were investigated. The bis(dipyrrin) exhibited remarkably fluorescence enhancement (150- and 40-fold) to Cd{sup 2+} and Hg{sup 2+} ions, respectively, with significant color change on the background of other metal ions in propanol-1/cyclohexane (1:30) binary mixture. Consequently, it can be used as a “naked eye” indicator with an obvious color change from yellow-orange to orange-green color upon the addition of Cd{sup 2+} and Hg{sup 2+}. The fluorescent response mechanism of bis(dipyrrin) to Cd{sup 2+} and Hg{sup 2+} was based on the fluorescence enhancement effect upon complexation (CHEF) due to formation of a metal–ligand (2:2) complex [M{sub 2}L{sub 2}]. The detection limit of Cd{sup 2+} and Hg{sup 2+} ions was 2 × 10{sup –9} and 1.7 × 10{sup –8} M ions, respectively.

Chiral bis(amino acid)- and bis(amino alcohol)-oxalamide gelators. Gelation properties, self-assembly motifs and chirality effects.

Science.gov (United States)

Frkanec, Leo; Zinić, Mladen

2010-01-28

Bis(amino acid)- and bis(amino alcohol)oxalamide gelators represent the class of versatile gelators whose gelation ability is a consequence of strong and directional intermolecular hydrogen bonding provided by oxalamide units and lack of molecular symmetry due to the presence of two chiral centres. Bis(amino acid)oxalamides exhibit ambidextrous gelation properties, being capable to form gels with apolar and also highly polar solvent systems and tend to organise into bilayers or inverse bilayers in hydrogel or organic solvent gel assemblies, respectively. (1)H NMR and FTIR studies of gels revealed the importance of the equilibrium between the assembled network and smaller dissolved gelator assemblies. The organisation in gel assemblies deduced from spectroscopic structural studies are in certain cases closely related to organisations found in the crystal structures of selected gelators, confirming similar organisations in gel assemblies and in the solid state. The pure enantiomer/racemate gelation controversy is addressed and the evidence provided that rac-16 forms a stable toluene gel due to resolution into enantiomeric bilayers, which then interact giving gel fibres and a network of different morphology compared to its (S,S)-enantiomer gel. The TEM investigation of both gels confirmed distinctly different gel morphologies, which allowed the relationship between the stereochemical form of the gelator, the fibre and the network morphology and the network solvent immobilisation capacity to be proposed. Mixing of the constitutionally different bis(amino acid) and bis(amino alcohol)oxalamide gelators resulted in some cases in highly improved gelation efficiency denoted as synergic gelation effect (SGE), being highly dependent also on the stereochemistry of the component gelators. Examples of photo-induced gelation based on closely related bis(amino acid)-maleic acid amide and -fumaramide and stilbene derived oxalamides where gels form by irradiation of the solution of

Reaction of CO2 with propylene oxide and styrene oxide catalyzed by a chromium(III) amine-bis(phenolate) complex.

Science.gov (United States)

Dean, Rebecca K; Devaine-Pressing, Katalin; Dawe, Louise N; Kozak, Christopher M

2013-07-07

A diamine-bis(phenolate) chromium(III) complex, {CrCl[O2NN'](BuBu)}2 catalyzes the copolymerization of propylene oxide with carbon dioxide. The synthesis of this metal complex is straightforward and it can be obtained in high yields. This catalyst incorporates a tripodal amine-bis(phenolate) ligand, which differs from the salen or salan ligands typically used with Cr and Co complexes that have been employed as catalysts for the synthesis of such polycarbonates. The catalyst reported herein yields low molecular weight polymers with narrow polydispersities when the reaction is performed at room temperature. Performing the reaction at elevated temperatures causes the selective synthesis of propylene carbonate. The copolymerization activity for propylene oxide and carbon dioxide, as well as the coupling of carbon dioxide and styrene oxide to give styrene carbonate are presented.

Glyoxal bis(guanylhydrazone) as an inhibitor of polyamine biosynthesis in tumour cells.

Science.gov (United States)

Seppänen, P; Fagerström, R; Alhonen-Hongisto, L; Elo, H; Lumme, P; Jänne, J

1984-07-15

Glyoxal bis(guanylhydrazone), the parent compound of methylglyoxal bis(guanylhydrazone), was synthesized and tested for its ability to inhibit the biosynthesis of polyamines. It was found to be a powerful competitive inhibitor of adenosylmethionine decarboxylase (EC 4.1.1.50), yet the lack of the methyl group at the glyoxal portion increased the apparent Ki value for the enzyme by about 30-fold in comparison with methylglyoxal bis(guanylhydrazone). Glyoxal bis(guanylhydrazone) inhibited diamine oxidase (EC 1.4.3.6) activity as effectively as did methylglyoxal bis(guanylhydrazone). The cellular accumulation curves of glyoxal bis(guanylhydrazone) in L1210 cells were practically superimposable with those of methylglyoxal bis(guanylhydrazone), and the uptake of both compounds was distinctly stimulated by a prior treatment with 2-difluoromethylornithine. The drug decreased the concentration of spermidine in a dose-dependent manner and, in contrast with methylglyoxal bis(guanylhydrazone), without a concomitant accumulation of putrescine. The fact that putrescine concentrations were decreased in cells exposed to glyoxal bis(guanylhydrazone) was, at least in part, attributable to an inhibition of ornithine decarboxylase (EC 4.1.1.17) activity in cells treated with the compound. Under these experimental conditions equivalent concentrations of methylglyoxal bis(guanylhydrazone) [1,1'-[(methylethanediylidine)dinitrilo]diguanidine] elicited large increases in the enzyme activity. When combined with difluoromethylornithine, glyoxal bis(guanylhydrazone) potentiated the growth-inhibitory effect of that drug. Taking into consideration the proven anti-leukaemic activity of glyoxal bis(guanylhydrazone), its effectiveness to inhibit spermidine biosynthesis (without raising the concentration of putrescine) as well as its suitability for combined use with inhibitors of ornithine decarboxylase, this drug is apparently worthy of further testing in tumour-bearing animals, especially in

Ethylglyoxal bis(guanylhydrazone) as an inhibitor of polyamine biosynthesis in L1210 leukemia cells.

Science.gov (United States)

Seppänen, P; Ruohola, H; Jänne, J

1984-04-16

Ethylglyoxal bis(guanylhydrazone), a close derivative of the known anti-cancer drug methylglyoxal bis(guanylhydrazone), is also a powerful inhibitor of S-adenosylmethionine decarboxylase (EC 4.1.1.50), the enzyme needed for the synthesis of spermidine and spermine. There were, however, marked differences between the ethyl and methyl derivatives of glyoxal bis(guanylhydrazone) when tested in cultured L1210 cells. The cellular accumulation of ethylglyoxal bis(guanylhydrazone) represented only a fraction (20-25%) of that of the methyl derivative. Moreover, polyamine depletion, which is known to strikingly stimulate the uptake of methylglyoxal bis(guanylhydrazone), decreased, if anything, the uptake of ethylglyoxal bis(guanylhydrazone) by L1210 cells. The compound produced spermidine and spermine depletion fully comparable to that achieved with methylglyoxal bis(guanylhydrazone) at micromolar concentrations. Ethylglyoxal bis(guanylhydrazone) was growth-inhibitory to L1210 cells and produced an additive antiproliferative action when used together with 2-difluoromethylornithine. Ethylglyoxal bis(guanylhydrazone) was distinctly less effective than methylglyoxal bis(guanylhydrazone) in releasing bound polyamines from isolated cell organelles in vitro. Ethylglyoxal bis(guanylhydrazone) was also devoid of the early and profound mitochondrial toxicity typical to methylglyoxal bis(guanylhydrazone). These findings may indicate that this compound is a more specific inhibitor of polyamine biosynthesis with less intracellular polyamine 'receptor-site' activity than methylglyoxal bis(guanylhydrazone).

Dinuclear Cu(II) complexes of isomeric bis-(3-acetylacetonate)benzene ligands: synthesis, structure, and magnetic properties.

Science.gov (United States)

Rancan, Marzio; Dolmella, Alessandro; Seraglia, Roberta; Orlandi, Simonetta; Quici, Silvio; Sorace, Lorenzo; Gatteschi, Dante; Armelao, Lidia

2012-05-07

Highly versatile coordinating ligands are designed and synthesized with two β-diketonate groups linked at the carbon 3 through a phenyl ring. The rigid aromatic spacer is introduced in the molecules to orient the two acetylacetone units along different angles and coordination vectors. The resulting para, meta, and ortho bis-(3-acetylacetonate)benzene ligands show efficient chelating properties toward Cu(II) ions. In the presence of 2,2'-bipyridine, they promptly react and yield three dimers, 1, 2, and 3, with the bis-acetylacetonate unit in bridging position between two metal centers. X-ray single crystal diffraction shows that the compounds form supramolecular chains in the solid state because of intermolecular interactions. Each of the dinuclear complexes shows a magnetic behavior which is determined by the combination of structural parameters and spin polarization effects. Notably, the para derivative (1) displays a moderate antiferromagnetic coupling (J = -3.3 cm(-1)) along a remarkably long Cu···Cu distance (12.30 Å).

Gas-phase fragmentation of coordination compounds: loss of CO(2) from inorganic carbonato complexes to give metal oxide ions

Science.gov (United States)

Dalgaard; McKenzie

1999-10-01

Using electrospray ionization mass spectrometry, novel transition metal oxide coordination complex ions are proposed as the products of the collision-induced dissociation (CID) of some carbonato complex ions through the loss of a mass equivalent to CO(2). CID spectra of [(tpa)CoCO(3)](+) (tpa = tris(2-pyridylmethyl)methylamine), [(bispicMe(2)en)Fe(&mgr;-O)(&mgr;-CO(3))Fe(bispicMe(2)en)]2+ (bispicMe(2)en = N,N'-dimethyl-N,N'-bis(2-pyridylmethy)eth- ane-1, 2-diamine) and [(bpbp)Cu(2)CO(3)](+) (bpbp(-) = bis[(bis-(2-pyridylmethyl)amino)methyl]-4-tertbutylpheno-lato(1-)), show peaks assigned to the mono- and dinuclear oxide cations, [(tpa)CoO](+), [(bispicMe(2)en)(2)Fe(2)(O)(2)]2+ and [(bpbp)Cu(2)O](+), as the dominant species. These results can be likened to the reverse of typical synthetic reactions in which metal hydroxide compounds react with CO(2) to give metal carbonato compounds. Because of the lack of available protons in the gas phase, novel oxide species rather than the more common hydroxide ions are generated. These oxide ions are relevant to the highly oxidizing species proposed in oxygenation reactions catalysed by metal oxides and metalloenzymes. Copyright 1999 John Wiley & Sons, Ltd.

The general properties of water - nitrobenzene - crown - bis-1,2-dicarbollylcobaltate extraction systems

International Nuclear Information System (INIS)

Vanura, P.

2003-01-01

The extraction and stability constants in the system water - nitrobenzene have been collected and general rules valid for water - nitrobenzene - crown - bis-1,2-dicarbollylcobaltate extraction system have been found. The main principles are size compatibility of ion diameter and crown cavity diameters, the flexibility of crown, the basicity of crown and the steric factor of both the ligand and the extracted ion. The extraction in the system water - mineral acid or salt polyoxyethylene compound - bis-1,2-dicarbollylcobaltate - nitrobenzene is more complicated than can be expected from usually used ion diameter - crown cavity diameter compatibility principle. The other important factors are the basicity and the deformability of crown, steric aspect and the angles of bonds of extracted ion. The binuclear 'sandwich' complexes with H + ion and Sr 2+ or Ba 2+ ions have been proved for dibenzo-18-crown-6 (DB18C6). On the other hand, only SrL 2 and BaL 2 (L = 15C5) complexes are formed in nitrobenzene saturated with water. The addition of polyoxyethylene compound usually increases the distribution ratio of alkali earth metal ions and the selectivity of its mutual separation. (authors)

新型靛红衍生化β-环糊精键合SBA-15液相色谱固定相的制备与表征%Preparation and Characterization of a Novel Isatin Derivative of β-Cyclodextrin-bonded SBA-15 Stationary Phase for HPLC

Institute of Scientific and Technical Information of China (English)

张杨; 李来生; 程彪平; 周仁丹; 聂桂珍

2014-01-01

利用靛红的羰基与β-环糊精单取代乙二胺的缩合反应，合成得到一种靛红衍生化β-环糊精Schiff碱类化合物。以3-异氰酸丙基三乙氧基硅烷为偶联剂，将其键合到自制的有序介孔二氧化硅材料SBA-15表面，制得一种新型的靛红衍生化β-环糊精键合SBA-15液相色谱固定相( ISCDP)。分别对β-环糊精衍生物、SBA-15及固定相进行必要的结构表征。在反相色谱条件下，以卤代尿嘧啶类极性化合物和二取代苯位置异构体为探针，评价新固定相的基本色谱性能。在极性有机溶剂和反相模式下，将新固定相分别用于β-受体阻滞剂药物和丹磺酰化氨基酸对映体的拆分，探讨了相关色谱分离机理。实验表明，靛红吲哚环的引入，增强了环糊精类固定相对卤代尿嘧啶的反相色谱分离能力，分析时间小于7 min。固定相分离硝基苯胺、氨基苯酚和苯二酚的位置异构体时也表现出较高的立体选择性，其中对位异构体均最后被洗脱，这与包结作用相关；靛红衍生化β-环糊精配体也提高了固定相的手性分离能力，除疏水作用外，靛红衍生化β-环糊精配体还能提供偶极、氢键、π-π和包结等作用，多种协同作用力有利于提高新固定相的手性和非手性分离的选择性。 SBA-15作为键合基质，其有序的孔结构有利于保持色谱柱的良好渗透性和小的传质阻力，在快速高效分离分析中具有应用潜能。%An isatin derivative ofβ-cyclodextrin Schiff base was first synthesized by the condensation reaction between the carbonyl group of isatin and ethylenediamino group of the mono-substituted β-cyclodextrin. The Schiff base ligand was chemically linked to homemade ordered mesoporous SBA-15 silica gel via 3-( triethoxysilyl) propyl isocyanate coupling agent. In this way, a novel isatin derivative of β-cyclodextrin-bonded SBA-15 stationary phase ( ISCDP) was prepared

Studies on heavy metal contamination in Godavari river basin

Science.gov (United States)

Hussain, Jakir; Husain, Ikbal; Arif, Mohammed; Gupta, Nidhi

2017-12-01

Surface water samples from Godavari river basin was analyzed quantitatively for the concentration of eight heavy metals such as arsenic, cadmium, chromium, copper, iron, lead, nickel and zinc using atomic absorption spectrophotometer. The analyzed data revealed that iron and zinc metals were found to be the most abundant metals in the river Godavari and its tributaries. Iron (Fe) recorded the highest, while cadmium (Cd) had the least concentration. Arsenic, cadmium, chromium, iron and zinc metals are within the acceptable limit of BIS (Bureau of Indian Standards (BIS) 1050 (2012) Specification for drinking water, pp 1-5). The analysis of Godavari river and its tributary's water samples reveals that the water is contaminated at selected points which are not suitable for drinking. Nickel and Copper concentration is above acceptable limit and other metal concentration is within the acceptable limit. Comprehensive study of the results reveals that out of 18 water quality stations monitored, water samples collected at 7 water quality stations are found to be within the permissible limit for all purposes. While Rajegaon, Tekra, Nandgaon, P. G. Bridge, Bhatpalli, Kumhari, Pauni, Hivra, Ashti, Bamini, and Jagda stations were beyond the desirable limit due to presence of copper and nickel metals. The contents of copper metal ions were higher at some water quality stations on Wunna river (Nandgaon); Wardha river (Hivra) and Wainganga river (Kumhari, Pauni, Ashti) during Feb. 2012, while nickel concentration during Feb. 2012, June 2012, March 2013 and Aug. 2013 at some water quality stations on rivers Bagh, Indravati, Pranhita, Wunna, Penganga, Peddavagu, Wainganga and Wardha. It can be concluded that rapid population growth and industrialization have brought about resource degradation and a decline in environmental quality.

2,6-Bis(oxazolinyl)phenylnickel(II) Bromide and 2,6-Bis(ketimine)phenylnickel(II) Bromide: Synthesis, Structural Features, and Redox Properties

NARCIS (Netherlands)

Stol, M.; Snelders, D.J.M.|info:eu-repo/dai/nl/304836257; Godbole, M.D.; Havenith, R.W.A.|info:eu-repo/dai/nl/205279546; Haddleton, D.M.; Clarkson, G.; Lutz, M.|info:eu-repo/dai/nl/304828971; Spek, A.L.|info:eu-repo/dai/nl/156517566; van Klink, G.P.M.|info:eu-repo/dai/nl/170637964; van Koten, G.|info:eu-repo/dai/nl/073839191

2007-01-01

2,6-Bis(oxazolinyl)phenylnickel bromide complexes [NiBr(R,R'-Phebox)] (2) were synthesized via two synthetic routes (A and B). In route A, selective bis-ortho lithiation of [R,R'-PheboxBr], followed by a transmetalation reaction with [NiBr2(PEt3)2], yielded not only complexes 2 with an

Toward engineering intra-receptor interactions into bis(crown ethers).

Science.gov (United States)

Krause, Martin R; Kubik, Stefan

2012-03-01

A synthetic receptor was designed in which cooperative binding of two crown ether moieties to an alkali metal ion simultaneously causes two hydrophobic substituents not involved in direct host-guest interactions to converge. Hydrophobic interactions between these substituents can be expected to contribute to the overall complex stability. Independent binding studies involving two diastereoisomers of this bis(crown ether), one in which intra-receptor interactions between the substituents are potentially possible and one in which they are not, using isothermal titration calorimetry showed that both isomers bind potassium ions in different solvent mixtures with the same overall affinity. Profound differences were observed for each isomer, however, in the enthalpies and entropies of binding, which are consistent with intra-receptor interactions in one compound. These interactions are counteracted by enthalpy-entropy compensation so that no overall improvement in cation affinity could be observed.

Novel dimeric bis(7)-tacrine proton-dependently inhibits NMDA-activated currents

International Nuclear Information System (INIS)

Luo, Jialie; Li, Wenming; Liu, Yuwei; Zhang, Wei; Fu, Hongjun; Lee, Nelson T.K.; Yu, Hua; Pang, Yuanping; Huang, Pingbo; Xia, Jun; Li, Zhi-Wang; Li, Chaoying; Han, Yifan

2007-01-01

Bis(7)-tacrine has been shown to prevent glutamate-induced neuronal apoptosis by blocking NMDA receptors. However, the characteristics of the inhibition have not been fully elucidated. In this study, we further characterize the features of bis(7)-tacrine inhibition of NMDA-activated current in cultured rat hippocampal neurons. The results show that with the increase of extracellular pH, the inhibitory effect decreases dramatically. At pH 8.0, the concentration-response curve of bis(7)-tacrine is shifted rightwards with the IC 50 value increased from 0.19 ± 0.03 μM to 0.41 ± 0.04 μM. In addition, bis(7)-tacrine shifts the proton inhibition curve rightwards. Furthermore, the inhibitory effect of bis(7)-tacrine is not altered by the presence of the NMDA receptor proton sensor shield spermidine. These results indicate that bis(7)-tacrine inhibits NMDA-activated current in a pH-dependent manner by sensitizing NMDA receptors to proton inhibition, rendering it potentially beneficial therapeutic effects under acidic conditions associated with stroke and ischemia

Vapor deposition of molybdenum oxide using bis(ethylbenzene) molybdenum and water

International Nuclear Information System (INIS)

Drake, Tasha L.; Stair, Peter C.

2016-01-01

Three molybdenum precursors—bis(acetylacetonate) dioxomolybdenum, molybdenum isopropoxide, and bis(ethylbenzene) molybdenum—were tested for molybdenum oxide vapor deposition. Quartz crystal microbalance studies were performed to monitor growth. Molybdenum isopropoxide and bis(ethylbenzene) molybdenum achieved linear growth rates 0.01 and 0.08 Å/cycle, respectively, using atomic layer deposition techniques. Negligible MoO_x growth was observed on alumina powder using molybdenum isopropoxide, as determined by inductively coupled plasma optical emission spectroscopy. Bis(ethylbenzene) molybdenum achieved loadings of 0.5, 1.1, and 1.9 Mo/nm"2 on alumina powder after one, two, and five cycles, respectively, using atomic layer deposition techniques. The growth window for bis(ethylbenzene) molybdenum is 135–150 °C. An alternative pulsing strategy was also developed for bis(ethylbenzene) molybdenum that results in higher growth rates in less time compared to atomic layer deposition techniques. The outlined process serves as a methodology for depositing molybdenum oxide for catalytic applications. All as-deposited materials undergo further calcination prior to characterization and testing.

Glyoxal bis(guanylhydrazone) as an inhibitor of polyamine biosynthesis in tumour cells.

OpenAIRE

Seppänen, P; Fagerström, R; Alhonen-Hongisto, L; Elo, H; Lumme, P; Jänne, J

1984-01-01

Glyoxal bis(guanylhydrazone), the parent compound of methylglyoxal bis(guanylhydrazone), was synthesized and tested for its ability to inhibit the biosynthesis of polyamines. It was found to be a powerful competitive inhibitor of adenosylmethionine decarboxylase (EC 4.1.1.50), yet the lack of the methyl group at the glyoxal portion increased the apparent Ki value for the enzyme by about 30-fold in comparison with methylglyoxal bis(guanylhydrazone). Glyoxal bis(guanylhydrazone) inhibited diami...

Spectrophotometric study of some metal ions using some Schiff's bases

International Nuclear Information System (INIS)

Elnager, Nawal Mohomed Ibrahim

2000-05-01

In this work two schiff bases namely N,N Bis(benzoyl acetone)-o-phenylene diamine (NNBBPD) and N,N Bis(benzoyl acetone)-isopropylene diamine (NNBBAID) were prepared by direct coupling of benzoyl acetone with o-phenylene and isopropylene diamine respectively. The two reagents were identified by IR spectra, thin layer chromatography (TLC) and determination of the percentage of nitrogen contents (N%). It is found that the two reagents form coloured chelates with Fe (II), Fe (III), Cu (II), U (VI), Ni (II) and Co (II). The two reagents were used for the determination of Fe (II), Fe (III) and U (VI). The formulate of these metal ion complexes were obtained using continuous variations, mole ratio and slope ratio methods. Effect of two micelles, namely sodium n-dodecyl sulphate (SDS) and hexadecyl pyridinum broinide monohydrate (HPB) on metal ion complexes were studied. It is found that both of them increase the solubility and the absorbances of the metal ion complexes with variable effects of the absorption maxima. Calibration curves for Fe (II), Fe (II) and U (VI) were obtained in optimum conditions of pH and micelles solutions. (Author)

In Vitro Antioxidant Evaluation of Some Mannich Bases which Contain Bis-1,2,4 -Triazole Derivative

International Nuclear Information System (INIS)

Parlak, A. E.; Karatepe, M.; Koparir, M.; Alayunt, N. O.; Keser, S.; Dastan, S. D.; Ulas, M.; Celik, S.

2015-01-01

This study aims to examine the antioxidant effects of some Mannich bases containing bis-1, 2, 4 triazole, which are synthesized afresh. The antioxidant activities of the derivatives were measured using different methods in this study, including reducing power capacity, metal chelating activity, superoxide anion radicals scavenging activity, H/sub 2/ O/sub 2/ scavenging activity and hydroxyl radical scavenging. As a result, derivatives had efficient antioxidant and free radical scavenging activity when compared to ascorbic acid, BHT and alpha-tocopherol as associated antioxidants. (author)

40 CFR 721.982 - Calcium, bis(2,4-pentanedionato-O,O′).

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Calcium, bis(2,4-pentanedionato-O,Oâ²... Substances § 721.982 Calcium, bis(2,4-pentanedionato-O,O′). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance calcium, bis(2,4-pentanedionato-O,O′) (PMN P-93-214, CAS...

Studies on Oligomer Metal Complexes Derived from Bisamic Acid of Pyromellitic Dianhydride and 4-Bromoaniline

OpenAIRE

Patel, Yogesh S.

2014-01-01

Novel oligomer metal complexes (2a–f) of the ligand 2,5-bis((4-bromophenyl)carbamoyl) terephthalic acid (1) were prepared using transition metal salts and characterized by various spectroscopic techniques. The geometry of oligomer metal complexes was carried out by electronic spectral analysis and magnetic measurement studies. Polymeric properties have also been carried out. Ligand was synthesized using pyromellitic dianhydride and 4-bromoaniline. It was duly characterized. All novel synthesi...

Thermodynamics of complexation of lanthanides with 2,6-bis(5,6-diethyl-1,2,4-triazin-3-yl) pyridine

Energy Technology Data Exchange (ETDEWEB)

Rawat, N.; Bhattacharyya, A.; Tomar, B.S. [Bhabha Atomic Research Centre, Trombay, Mumbai (India). Radiochemistry Div.; Ghosh, S.K.; Gadly, T. [Bhabha Atomic Research Centre, Trombay, Mumbai (India). Bioorganic Div.

2011-07-01

Solvent extraction studies on separation of trivalent actinides from lanthanides using 2,6-bis(5,6-dialkyl-1,2,4-triazin-3-yl) pyridines have shown promising results with respect to separation factor and efficiency in acidic medium. In order to understand their complexation behavior, the stability constant (log {beta}) of trivalent lanthanides (La, Nd, Eu, Tb, Ho, Tm, Lu) with 2,6-bis(5,6-diethyl-1,2,4-triazin-3-yl)pyridine (ethyl-BTP) have been determined in methanol medium (ionic strength 0.01 M) using spectrophotometric titrations. The stoichiometry of the complexes is found to vary with the ionic size of lanthanide ion. The variation in log {beta} across the lanthanide series is attributed to variation in solvation characteristics of the metal ion. Comparison of log {beta} for Ln(III)-ethyl-BTP complexes with other alkyl derivatives showed increase in the stability with increasing length of the alkyl group due to hydrophobic interaction. In the case of Eu(III), the speciation was also corroborated by time resolved fluorescence spectroscopy. The thermodynamic parameters ({delta} G, {delta} H, {delta} S) for complexation of Eu(III) with ethyl-BTP, were determined by microcalorimetry, which revealed strong metal ion-ligand interaction with the reactions driven mainly by enthalpy. (orig.)

Activity-guided isolation of cytotoxic bis-bibenzyl constituents from Dumortiera hirsuta.

Science.gov (United States)

Toyota, Masao; Ikeda, Risa; Kenmoku, Hiromichi; Asakawa, Yoshinori

2013-01-01

Activity-guided fractionation of the ether extract of Dumortiera hirsute (Japanese liverwort), using cytotoxicity testing with cultured HL 60 and KB cells, resulted in the isolation of a new cytotoxic bis-bibenzyl compound, along with the two known bis-bibenzyls: isomarchantin C and isoriccardin C. The structural determination of the new bis-bibenzyl through extensive NMR spectral data indicated a derivative of marchantin A, which has been isolated from the liverwort Marchantia polymorpha. The cytotoxicity of the bis-bibenzyls was evaluated by the MTT (3-(4,5-di-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay using cultured HL 60 and KB cells.

[(Nitrato-κO,O')(nitrito-κO,O')(0.25/1.75)]bis-(1,10-phenanthroline-κN,N')cadmium(II).

Science.gov (United States)

Najafi, Ezzatollah; Amini, Mostafa M; Ng, Seik Weng

2011-01-22

The reaction of cadmium nitrate and sodium nitrite in the presence of 1,10-phenanthroline yields the mixed nitrate-nitrite title complex, [Cd(NO(2))(1.75)(NO(3))(0.25)(C(12)H(8)N(2))(2)]. The metal ion is bis-chelated by two N-heterocycles as well as by the nitrate/nitrite ions in a distorted dodeca-hedral CdN(4)O(4) coordination environment. One nitrite group is ordered; the other is disordered with respect to a nitrate group (ratio 0.75:0.25) concerning the O atom that is not involved in bonding to the metal ion.

Synthesis, Characterization, and Photoelectrochemical Catalytic Studies of a Water-Stable Zinc-Based Metal-Organic Framework.

Science.gov (United States)

Altaf, Muhammad; Sohail, Manzar; Mansha, Muhammad; Iqbal, Naseer; Sher, Muhammad; Fazal, Atif; Ullah, Nisar; Isab, Anvarhusein A

2018-02-09

Metal-organic frameworks (MOFs) are class of porous materials that can be assembled in a modular manner by using different metal ions and organic linkers. Owing to their tunable structural properties, these materials are found to be useful for gas storage and separation technologies, as well as for catalytic applications. A cost-effective zinc-based MOF ([Zn(bpcda)(bdc)] n ) is prepared by using N,N'-bis(pyridin-4-ylmethylene)cyclohexane-1,4-diamine [N,N'-bis(pyridin-4-ylmethylene)cyclohexane-1,4-diamine] and benzenedicarboxylic acid (bdc) linkers. This new material exhibits remarkable photoelectrochemical (PEC) catalytic activity in water splitting for the evolution of oxygen. Notably, this non-noble metal-based MOF, without requiring immobilization on other supports or containing metal particles, produced a highest photocurrent density of 31 μA cm -2 at 0.9 V, with appreciable stability and negligible photocorrosion. Advantageously for the oxygen evolution process, no external reagents or sacrificial agents are required in the aqueous electrolyte solution. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Relation between constructs of BisBas questionnaire and some personality constructs

Directory of Open Access Journals (Sweden)

Nataša Sedlar

2008-04-01

Full Text Available The goal of this study was to examine relation between constructs relevant for Gray's neuropsychological model of motivation. According to Gray's theory, two general motivational systems underlie behavior and affect: a behavioral inhibition system (BIS and a behavioral activation system (BAS. BIS is sensitive to aversive stimuli, causes avoidance behaviors and is responsible for individual differences in anxiety. BAS is responsive to appetitive stimuli, triggers approach behavior and has been associated with individual differences in impulsivness. BIS activity has been related to the experience of negative emotions, whereas BAS activity has been associated with the experience of positive emotions. A total of 122 Slovenian students, aged 17–19 years, completed the BIS/BAS scale, the Impulsiveness-Venturesome-Empathy Scale IVE, State Trait Anxiety Inventory STAI-X2, The Positive and Negative Affect Schedule PANAS, and The Big Five Questionairre BFQ. Our results are consistent with those from recent empirical studies and provide support for Gray's theory. Measures of BIS were found to be positively related to trait anxiety and neuroticism, whereas measures of BAS were found to be positively related to impulsiveness and extraversion. Emotional component measured with PANAS did not distinguish BIS from BAS constructs. Both were found to be related to negative affect. With respect to construct validity these findings suggest that BIS/BAS scale is reasonably effective.

Group 11 Metal Compounds with Tripodal Bis(imidazole Thioether Ligands. Applications as Catalysts in the Oxidation of Alkenes and as Antimicrobial Agents

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Armando Varela-Ramírez

2011-08-01

Full Text Available New group 11 metal complexes have been prepared using the previously described tripodal bis(imidazole thioether ligand (N-methyl-4,5-diphenyl-2-imidazolyl2C(OMeC(CH32S(tert-Bu ({BITOMe,StBu}, 2. The pincer ligand offers a N2S donor atom set that can be used to coordinate the group 11 metals in different oxidation states [AuI, AuIII, AgI, CuI and CuII]. Thus the new compounds [Au{BITOMe,StBu}Cl][AuCl4]2 (3, [Au{BITOMe,StBu}Cl] (4, [Ag{BITOMe,StBu}X] (X = OSO2CF3- 5, PF6- 6 and [Cu{BITOMe,StBu}Cl2] (7 have been synthesized from reaction of 2 with the appropriate metal precursors, and characterized in solution. While attempting characterization in the solid state of 3, single crystals of the neutral dinuclear mixed AuIII-AuI species [Au2{BITOMe,S}Cl3] (8 were obtained and its crystal structure was determined by X-ray diffraction studies. The structure shows a AuIII center coordinated to the pincer ligand through one N and the S atom. The soft AuI center coordinates to the ligand through the same S atom that has lost the tert-butyl group, thus becoming a thiolate ligand. The short distance between the AuI-AuIII atoms (3.383 Å may indicate a weak metal-metal interaction. Complexes 2-7 and the previously described CuI compound [Cu{BITOMe,StBu}]PF6 (9 have been evaluated in the oxidation of biphenyl ethylene with tert-butyl hydrogen peroxide (TBHP as the oxidant. Results have shown that the AuI and AgI complexes 4 and 6 (at 10 mol % loading are the more active catalysts in this oxidative cleavage. The antimicrobial activity of compounds 2-5, 7 and 9 against Gram-positive and Gram-negative bacteria and yeast has also been evaluated. The new gold and silver compounds display moderate to high antibacterial activity, while the copper derivatives are mostly inactive. The gold and silver complexes were also potent against fungi. Their cytotoxic properties have been analyzed in vitro utilizing HeLa human cervical carcinoma cells. The compounds displayed a

Dust Measurement of Two Organophosphorus Flame Retardants, Resorcinol Bis(diphenylphosphate) (RBDPP) and Bisphenol A Bis(diphenylphosphate) (BPA-BDPP), Used as Alternatives for BDE-209

NARCIS (Netherlands)

Brandsma, S.H.; Sellström, U.; de Wit, C.A.; de Boer, J.; Leonards, P.E.G.

2013-01-01

Resorcinol bis(diphenylphosphate) (RBDPP) and bisphenol A bis(diphenylphosphate) (BPA-BDPP) are two halogen-free organophosphorus flame retardant (PFRs) that are used as an alternative for the decabromodiphenyl ether (Deca-BDE) technical mixture in TV/flatscreen housing and other electronic consumer

LA REINCIDENCIA VULNERA EL “NON BIS IN IDEM”

OpenAIRE

Roger Cabrera Paredes

2011-01-01

El presente artículo explica como la “Reincidencia vulnera el  Non bis in ídem”; empezamos con la “Introducción” que comprende los antecedentes, la formulación del problema y la justificación de esta investigación. Continuamos con las “Bases Teóricas”, la misma que comprende el sentido de los principios penales, el principio “Non bis in Idem”, la Reincidencia y la Problemática de la Reincidencia como vulneración del Principio Non bis in ídem. En la “Metodología”, encontramos la tipología y me...

Bis(phenylethylamide) derivatives of Gd-DTPA as potential receptor-specific MRI contrast agents

OpenAIRE

Laurent, Sophie; Parac-Vogt, Tatjana; Kimpe, Kristof; Thirifays, Coralie; Binnemans, Koen; Muller, Robert N.; Vander Elst, Luce

2007-01-01

DTPA-bis(amide) derivatives bearing phenyl, phenol or catechol groups that mimic side chains of naturally occurring amino acids, such as phenylatanine, tyrosine or dopamine, were synthesized and characterized by elemental analysis, electrospray mass spectrometry, NMR spectroscopy and IR spectroscopy. The gadolinium(III) complexes of the ligands DTPA-bis(tyramide) [DTPA-(TA)(2)], DTPA-bis(3-hydroxytyramide) [DTPA-(HTA)(2)] and DTPA-bis(phenylalanine ethyl ester) [DTPA-(PAE)(2)], were prepared ...

Electrolyte Chemistry for Simultaneous Stabilization of Potassium Metal and Superoxide in K-O₂ Batteries.

Science.gov (United States)

Xiao, Neng; Gourdin, Gerald; Wu, Yiying

2018-05-22

In the superoxide batteries based on O2/O2- redox chemistry, identifying an electrolyte to stabilize both alkali metal and superoxide remains challenging due to their reactivity towards electrolyte components. Bis(fluorosulfonyl)imide (FSI-) has been recognized as a "magical anion" for passivating alkali metals. Herein, we illustrate the chemical reactions between FSI- and superoxide, and the resultant dilemma when considering an anode-compatible electrolyte vs. a cathode-compatible one in K-O2 batteries. On one side, the KFSI-dimethoxyethane (DME) electrolyte passivates the potassium metal anode via the cleavage of S-F bond and formation of a KF-rich solid electrolyte interface (SEI). Nevertheless, the KFSI salt is chemically unstable due to the nucleophilic attack by superoxide and/or hydroxide species. On the other hand, potassium bis(trifluorosulfonyl)imide (KTFSI) is stable for KO2, but results in mossy deposition and irreversible plating and stripping. In order to circumvent this dilemma, we develop an artificial SEI for K metal anode to achieve long cycle-life K-O2 batteries. This work contributes to the understanding of electrolyte chemistry and guides the development of stable electrolytes and artificial SEI in metal-O2 batteries. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Neutral bidentate N-heterocyclic ligands - phase transfer reagents improving the kinetics of solvent extraction of Am(III) and Eu(III) ions with tetradentate 6,6'-bis-(diethyl-1,2,4-triazin-3-yl)-2,2'-bipyridine

International Nuclear Information System (INIS)

Narbutt, J.; Krejzler, J.

2008-01-01

Poor kinetics of solvent extraction of Am(III) and Eu(III) ions from 1 M HNO 3 with 6,6'-bis-(diethyl-1,2,4-triazin-3-yl)-2,2'-bipyridine (etBTBP) has been improved by adding an auxiliary bidentate N-heterocyclic ligand to the extraction system. Two such ligands were studied, derivatives of bis-triazine and pyridine-triazine, which alone poorly extract the metal ions, but together with etBTBP they act as phase transfer reagents, improving the extraction kinetics to a different degree. The ability to transfer the metal ions from aqueous to organic phase depends on lipophilicity and acid/base properties of these auxiliary ligands, as well as on the mode of shaking the two liquid phases - gentle or vigorous. (orig.)

Bis(μ-bis{[4-(2-pyridylpyrimidin-2-yl]sulfanyl}methanedisilver(I bis(perchlorate

Directory of Open Access Journals (Sweden)

Hai-Bin Zhu

2010-12-01

Full Text Available In the macrocyclic centrosymmetric dinuclear complex, [Ag2(C19H14N6S22](ClO42, the AgI atom, bis{[4-(2-pyridylpyrimidin-2-yl]sulfanyl}methane (2-bppt ligand and perchlorate anion each lie on a twofold rotation axis. The 2-bppt ligand chelates two four-coordinated AgI atoms through its two bipyridine-like arms. The O atoms of the perchlorate anion are disordered each over two positions of equal occupancy. Adjacent complex molecules are linked by π–π interactions between the pyridine and pyrimidine rings [centroid–centroid distance = 3.663 (8 Å].

Comparison of non-electrophoresis grade with electrophoresis grade BIS in NIPAM polymer gel preparation

Science.gov (United States)

Khodadadi, Roghayeh; Khajeali, Azim; Farajollahi, Ali Reza; Hajalioghli, Parisa; Raeisi, Noorallah

2015-01-01

Introduction:The main objective of this study was to investigate the possibility of replacing electrophoresis cross-linker with non-electrophoresis N, N′-methylenebisacrylamide (BIS) in N-isopropyl acrylamide (NIPAM) polymer gel and its possible effect on dose response. Methods: NIPAM polymer gel was prepared from non-electrophoresis grade BIS and the relaxation rate (R2) was measured by MR imaging after exposing the gel to gamma radiation from Co-60 source. To compare the response of this gel with the one that contains electrophoresis grade BIS, two sets of NIPAM gel were prepared using electrophoresis and non-electrophoresis BIS and irradiated to different gamma doses. Results: It was found that the dose–response of NIPAM gel made from the non-electrophoresis grade BIS is coincident with that of electrophoresis grade BIS. Conclusion:Taken all, it can be concluded that the non-electrophoresis grade BIS not only is a suitable alternative for the electrophoresis grade BIS but also reduces the cost of gel due to its lower price. PMID:26457250

The inverse-trans-influence in tetravalent lanthanide and actinide bis(carbene) complexes

Science.gov (United States)

Gregson, Matthew; Lu, Erli; Mills, David P.; Tuna, Floriana; McInnes, Eric J. L.; Hennig, Christoph; Scheinost, Andreas C.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Kerridge, Andrew; Liddle, Stephen T.

2017-02-01

Across the periodic table the trans-influence operates, whereby tightly bonded ligands selectively lengthen mutually trans metal-ligand bonds. Conversely, in high oxidation state actinide complexes the inverse-trans-influence operates, where normally cis strongly donating ligands instead reside trans and actually reinforce each other. However, because the inverse-trans-influence is restricted to high-valent actinyls and a few uranium(V/VI) complexes, it has had limited scope in an area with few unifying rules. Here we report tetravalent cerium, uranium and thorium bis(carbene) complexes with trans C=M=C cores where experimental and theoretical data suggest the presence of an inverse-trans-influence. Studies of hypothetical praseodymium(IV) and terbium(IV) analogues suggest the inverse-trans-influence may extend to these ions but it also diminishes significantly as the 4f orbitals are populated. This work suggests that the inverse-trans-influence may occur beyond high oxidation state 5f metals and hence could encompass mid-range oxidation state actinides and lanthanides. Thus, the inverse-trans-influence might be a more general f-block principle.

Peripherally Metalated Porphyrins with Applications in Catalysis, Molecular Electronics and Biomedicine.

Science.gov (United States)

Longevial, Jean-François; Clément, Sébastien; Wytko, Jennifer A; Ruppert, Romain; Weiss, Jean; Richeter, Sébastien

2018-04-24

Porphyrins are conjugated, stable chromophores with a central core that binds a variety of metal ions and an easily functionalized peripheral framework. By combining the catalytic, electronic or cytotoxic properties of selected transition metal complexes with the binding and electronic properties of porphyrins, enhanced characteristics of the ensemble are generated. This review article focuses on porphyrins bearing one or more peripheral transition metal complexes and discusses their potential applications in catalysis or biomedicine. Modulation of the electronic properties and intramolecular communication through coordination bond linkages in bis-porphyrin scaffolds is also presented. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

(Acetonitrile[bis(2-pyridylmethylamine]bis(perchloratocopper(II

Directory of Open Access Journals (Sweden)

Ray J. Butcher

2008-01-01

Full Text Available In the title compound, [Cu(ClO42(C12H13N3(C2H3N], the CuII atom is six-coordinate in a Jahn–Teller distorted octahedral geometry, with coordination by the tridentate chelating ligand, an acetonitrile molecule, and two axial perchlorate anions. The tridentate ligand bis(2-pyridylmethylamine chelates meridionally and equatorially while an acetonitrile molecule is coordinated at the fourth equatorial site. The two perchlorate anions are disordered with site occupancy factors of 0.72/0.28. The amine H is involved in intramolecular hydrogen bonding to the perchlorate O atoms and there are extensive but weak intermolecular C—H...O interactions.

Derivatized Pentadentate Macrocyclic Ligands and Their Transition Metal Complexes

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Muhammad S. Khan

2002-06-01

Full Text Available The reaction of the pendant hydroxyethyl group in the planar pentadentate macrocyclic ligand,1,11-bis(2’-hydroxyethyl-4,8;12,16;17,21-trinitrilo-1,2,10,11-tetraazacyclohenicosa- 2,4,6,9,12,14,18,20-octaene (L2, derived from the condensation of 2,6-pyridinedialdehyde with 6,6’-bis(2’ hydroxyethylhydrazino -2,2’-bipyridine (L1, has been investigated. Esterification reactions are facile, and the reaction of the hydroxyethyl-substituted macrocycle with thionyl chloride yields a chloroethyl derivative. Metal complexes of the new derivatized macrocyclic ligands L3-6having general formula ML3-6X2.nH2O (M = Mn, Fe, Co, Ni, Cu, Zn are readily prepared.

Near-infrared dichroism of a mesogenic transition metal complex and its solubility in nematic hosts

International Nuclear Information System (INIS)

Marshall, K.L.; Jacobs, S.D.

1987-01-01

A transition metal complex possessing the nematic phase, bis (p-n-butylstyryl-1, 2-dithiolato) nickel, was synthesized and its optical properties and solubility in the nematic hosts K15 and MBBA were investigated. The metal complex displayed a high solubility in both host materials (up to 10% wt/wt) and a strong near-infrared absorption band centered at 860 nm. A blocking extinction of greater than OD = 3 was obtained with a 100 micron pathlength of a 0.5% wt/wt mixture of the nematic metal complex in K15, suggesting its usefulness for passive blocking of near infrared radiation. A 24 micron thick, homogeneously aligned guest-host cell containing a 1% wt/wt mixture of the metal complex in K15 possessed a contrast ratio of nearly 5:1 and a blocking extinction of OD = 3.5 at 860 nm, demonstrating for the first time the existence of near-infrared dichroism in this class of materials. The solubility and blocking extinction of the mesogenic metal complex in K15 was considerably superior to the non-mesogenic near ir laser dye bis(dimethylaminodithiobenzil) nickel in the same host. An interaction of the nematic metal complex in mixtures with MBBA which resulted in the creation of a new absorption band at 1050 nm was also observed. 21 refs., 9 figs

A cytotoxic study of eugenol and its ortho dimer (bis-eugenol)

Energy Technology Data Exchange (ETDEWEB)

Kashiwagi, Yasushi [Meikai Univ., Sakado, Saitama (Japan). School of Dentistry

2000-07-01

Eugenol is widely used not only as a dental material such as pulp capping material, provisional cement, root canal sealer, and impression paste, but also as a perfume ingredients. Eugenol has antioxidant, bactericidal, and sedative activities, inhibits and non-enzymatic peroxidation. It was previously reported that eugenol exhibited the cytotoxic activity toward pulp cells and gingial fibroblasts and also that the cytotoxic activity was predominantly performed by radicals derived from the oxidation of eugenol. This study was based on the hypothesis that the toxicity of eugenol may be greately reduced if the radicalization of eugenol was diminished by the dimerization of eugenol. Thus, bis-eugenol, the dimer of eugenol, was synthesized to characterize the effect of this eugenol-related compound. The cytotoxic activity of bis-eugenol against human gingival fibroblasts (HGF cell) or human submandibular gland cancer cells (HSG cell) was studied in the presence or absence of light irradiation (visible or ultraviolet light), and compared with that of eugenol. The cytotoxic activity of eugenol was significantly greater than that of bis-eugenol. The cytotoxic activity of irradiated eugenol, but not that of irradiated bis-eugenol, was significantly higher than that of the non-irradiated counterpart. Bis-eugenol at a relatively low concentration declined the phototoxic activity of irradiation on living cells. Also, the generation of reactive oxygen in HSG cells in the ab-sence or the presence of irradiated bis-eugenol or eugenol was evaluated by an ACAS laser cytometry, and the results indicated that eugenol, but not bis-eugenol, generated reactive oxygen in the cells. The DPPH-radical scavenging activity of bis-eugenol was larger than that of eugenol. Furthermore, eugenol had a positive apoptosis-inducing effect on HSG cells. The structure-activity relationships of eugenol-related compounds showed that the nature of the substituent at the ortho or para-position of eugenol

A cytotoxic study of eugenol and its ortho dimer (bis-eugenol)

International Nuclear Information System (INIS)

Kashiwagi, Yasushi

2000-01-01

Eugenol is widely used not only as a dental material such as pulp capping material, provisional cement, root canal sealer, and impression paste, but also as a perfume ingredients. Eugenol has antioxidant, bactericidal, and sedative activities, inhibits and non-enzymatic peroxidation. It was previously reported that eugenol exhibited the cytotoxic activity toward pulp cells and gingial fibroblasts and also that the cytotoxic activity was predominantly performed by radicals derived from the oxidation of eugenol. This study was based on the hypothesis that the toxicity of eugenol may be greately reduced if the radicalization of eugenol was diminished by the dimerization of eugenol. Thus, bis-eugenol, the dimer of eugenol, was synthesized to characterize the effect of this eugenol-related compound. The cytotoxic activity of bis-eugenol against human gingival fibroblasts (HGF cell) or human submandibular gland cancer cells (HSG cell) was studied in the presence or absence of light irradiation (visible or ultraviolet light), and compared with that of eugenol. The cytotoxic activity of eugenol was significantly greater than that of bis-eugenol. The cytotoxic activity of irradiated eugenol, but not that of irradiated bis-eugenol, was significantly higher than that of the non-irradiated counterpart. Bis-eugenol at a relatively low concentration declined the phototoxic activity of irradiation on living cells. Also, the generation of reactive oxygen in HSG cells in the ab-sence or the presence of irradiated bis-eugenol or eugenol was evaluated by an ACAS laser cytometry, and the results indicated that eugenol, but not bis-eugenol, generated reactive oxygen in the cells. The DPPH-radical scavenging activity of bis-eugenol was larger than that of eugenol. Furthermore, eugenol had a positive apoptosis-inducing effect on HSG cells. The structure-activity relationships of eugenol-related compounds showed that the nature of the substituent at the ortho or para-position of eugenol

Highly sensitive colour change system within slight differences in metal ion concentrations based on homo-binuclear complex formation equilibrium for visual threshold detection of trace metal ions

International Nuclear Information System (INIS)

Mizuguchi, Hitoshi; Atsumi, Hiroshi; Hashimoto, Keigo; Shimada, Yasuhiro; Kudo, Yuki; Endo, Masatoshi; Yokota, Fumihiko; Shida, Junichi; Yotsuyanagi, Takao

2004-01-01

A new technique of expressing slight differences in metal ion concentrations by clear difference in colour was established for visual threshold detection of trace metal ions. The proposed method is based on rapid change of the mole fraction of the homo-binuclear complex (M 2 L) about a ligand in a narrow range of the total metal ion concentration (M T ) in a small excess, in case the second metal ion is bound to the reagent molecule which can bind two metal ions. Theoretical simulations showed that the highly sensitive colour change within slight differences in metal ion concentrations would be realized under the following conditions: (i) both of the stepwise formation constants of complex species are sufficiently large; (ii) the stepwise formation constant of the 1:1 complex (ML) is larger than that of M 2 L; and (iii) the absorption spectrum of M 2 L is far apart from the other species in the visible region. Furthermore, the boundary of the colour region in M T would be readily controlled by the total ligand concentration (L T ). Based on this theory, the proposed model was verified with the 3,3'-bis[bis(carboxymethyl)amino]methyl derivatives of sulphonephthalein dyes such as xylenol orange (XO), methylthymol blue (MTB), and methylxylenol blue (MXB), which can bind two metal ions at both ends of a π-electron conjugated system. The above-mentioned model was proved with the iron(III)-XO system at pH 2. In addition, MTB and MXB were suitable reagents for the visual threshold detection of trivalent metal ions such as iron(III), aluminium(III), gallium(III) and indium(III) ion in slightly acidic media. The proposed method has been applied successfully as a screening test for aluminium(III) ion in river water sampled at the downstream area of an old mine

Characterization and Antimicrobial Studies of Five Substituted Bis-Thioureas

International Nuclear Information System (INIS)

Nurulain Kamalulazmy; Sahilah Abd Mutalib; Fatin Ilyani Nasir; Nurul Izzaty Hassan

2016-01-01

Thioureas play an important role in medicinal chemistry and agricultures due to their biological activity such as antibacterial, antifungal, antiviral, herbicides, rodenticides, phenoloxidase enzymatic inhibitors, anti-HIV and anti-tumor agents. In this study, five substituted bis-thioureas have been synthesized. The isophthaloyl chloride and 2,6- pyridine dicarbonyl dichloride were easily converted to bis-isothiocyanate compound via the reaction with ammonium thiocyanate by solid-liquid phase transfer catalysis of polyethylene glycol-400 (PEG-400). Bis-isothiocyanate compound was reacted with aniline derivatives to produce substituted bis-thioureas in good yield at room temperature. All the novel compounds were obtained as yellow solid after recrystallization using DMF/EtOH/H_2O. Their chemical structures were confirmed by Infrared spectroscopy (IR), Nuclear Magnetic Resonance (NMR) "1H and "1"3C and mass spectrometry. The five synthesized compounds were screened for antimicrobial activities using disc diffusion method for antimicrobial activity against Gram-positive bacteria (Bacillus Subtilis and Staphylococcus Aureus), Gram-negative bacteria (Escherichia Coli and Salmonella Typhi) and a mold (Aspergillus Niger). All tested compounds showed low antimicrobial activity since the diameter of inhibition zone (IZ) measure was less than positive control inhibition zone. (author)

Bis(5,7-dimethyl-8-hydroxyquinolinato)beryllium(II) complex as optoelectronic material

Energy Technology Data Exchange (ETDEWEB)

Singh, Devender, E-mail: devjakhar@gmail.com; Singh, Kapoor; Bhagwan, Shri; Saini, Raman Kumar; Kadyan, Pratap Singh; Singh, Ishwar

2016-01-15

Metal complex bis(5,7-dimethyl-8-hydroxyquinolinato)beryllium(II) as a light emissive material had been synthesized and characterized by various spectral techniques. The beryllium complex had high thermal stability (>250 °C) as well as high glass transition temperature (>115 °C). The prepared metal chelate had a strong photoluminescence (PL) emission at 558 nm (FWHM=72 nm) and electroluminescence (EL) at 561 nm (FWHM=55 nm) with good efficiency. Density functional theoretical calculations have been performed to demonstrate the three-dimensional geometries and the frontier molecular orbital energy levels of this metal complex. Sublimed metal chelate formed thin transparent film and found appropriate material for exploring their opto-electronic applications. OLED device was fabricated using this metal complex by vacuum deposition technique with the device configuration of ITO/TPD(30 nm)/Be-complex(30 nm)/BCP(6 nm)/Alq{sub 3}(28 nm)/LiF(1 nm)/Al(100 nm). The emitted color of the EL device showed Commission Internationale d'Eclairage (CIE) color coordinates as x=0.625, y=0.366 corresponding to greenish yellow color. The maximum luminescence of the fabricated device was reported 1364 Cd/m{sup 2} at 22 V. The maximum current efficiency and power efficiency were 1.75 Cd/A and 0.51 lm/W at 10 V respectively for the fabricated OLED device. - Highlights: • Novel greenish yellow light emitting beryllium complex with 5,7-dimethyl-8-hydroxyquinoline was prepared. • The prepared metal complex were characterized by elemental analysis, infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy ({sup 1}H NMR), thermogravimetric analysis (TGA) as well as differential scanning calorimetry (DSC) techniques. • Electron density distribution and the frontier molecular orbital energy levels of resulting metal complex were computed by density functional theory in the course of DFT/B3LYP/6-31G(d,p) studies. • Sublimed synthesized metal complex of beryllium

Bis(5,7-dimethyl-8-hydroxyquinolinato)beryllium(II) complex as optoelectronic material

International Nuclear Information System (INIS)

Singh, Devender; Singh, Kapoor; Bhagwan, Shri; Saini, Raman Kumar; Kadyan, Pratap Singh; Singh, Ishwar

2016-01-01

Metal complex bis(5,7-dimethyl-8-hydroxyquinolinato)beryllium(II) as a light emissive material had been synthesized and characterized by various spectral techniques. The beryllium complex had high thermal stability (>250 °C) as well as high glass transition temperature (>115 °C). The prepared metal chelate had a strong photoluminescence (PL) emission at 558 nm (FWHM=72 nm) and electroluminescence (EL) at 561 nm (FWHM=55 nm) with good efficiency. Density functional theoretical calculations have been performed to demonstrate the three-dimensional geometries and the frontier molecular orbital energy levels of this metal complex. Sublimed metal chelate formed thin transparent film and found appropriate material for exploring their opto-electronic applications. OLED device was fabricated using this metal complex by vacuum deposition technique with the device configuration of ITO/TPD(30 nm)/Be-complex(30 nm)/BCP(6 nm)/Alq 3 (28 nm)/LiF(1 nm)/Al(100 nm). The emitted color of the EL device showed Commission Internationale d'Eclairage (CIE) color coordinates as x=0.625, y=0.366 corresponding to greenish yellow color. The maximum luminescence of the fabricated device was reported 1364 Cd/m 2 at 22 V. The maximum current efficiency and power efficiency were 1.75 Cd/A and 0.51 lm/W at 10 V respectively for the fabricated OLED device. - Highlights: • Novel greenish yellow light emitting beryllium complex with 5,7-dimethyl-8-hydroxyquinoline was prepared. • The prepared metal complex were characterized by elemental analysis, infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy ( 1 H NMR), thermogravimetric analysis (TGA) as well as differential scanning calorimetry (DSC) techniques. • Electron density distribution and the frontier molecular orbital energy levels of resulting metal complex were computed by density functional theory in the course of DFT/B3LYP/6-31G(d,p) studies. • Sublimed synthesized metal complex of beryllium gave greenish

[(Nitrato-κ2O,O′(nitrito-κ2O,O′(0.25/1.75]bis(1,10-phenanthroline-κ2N,N′cadmium(II

Directory of Open Access Journals (Sweden)

Ezzatollah Najafi

2011-02-01

Full Text Available The reaction of cadmium nitrate and sodium nitrite in the presence of 1,10-phenanthroline yields the mixed nitrate–nitrite title complex, [Cd(NO21.75(NO30.25(C12H8N22]. The metal ion is bis-chelated by two N-heterocycles as well as by the nitrate/nitrite ions in a distorted dodecahedral CdN4O4 coordination environment. One nitrite group is ordered; the other is disordered with respect to a nitrate group (ratio 0.75:0.25 concerning the O atom that is not involved in bonding to the metal ion.

Disorder-derived, strong tunneling attenuation in bis-phosphonate monolayers

International Nuclear Information System (INIS)

Pathak, Anshuma; Bora, Achyut; Tornow, Marc; Liao, Kung-Ching; Schwartz, Jeffrey; Schmolke, Hannah; Jung, Antje; Klages, Claus-Peter

2016-01-01

Monolayers of alkyl bisphosphonic acids (bisPAs) of various carbon chain lengths (C4, C8, C10, C12) were grown on aluminum oxide (AlO x ) surfaces from solution. The structural and electrical properties of these self-assembled monolayers (SAMs) were compared with those of alkyl monophosphonic acids (monoPAs). Through contact angle (CA) and Kelvin-probe (KP) measurements, ellipsometry, and infrared (IR) and x-ray photoelectron (XPS) spectroscopies, it was found that bisPAs form monolayers that are relatively disordered compared to their monoPA analogs. Current–voltage (J–V) measurements made with a hanging Hg drop top contact show tunneling to be the prevailing transport mechanism. However, while the monoPAs have an observed decay constant within the typical range for dense monolayers, β mono   =  0.85  ±  0.03 per carbon atom, a surprisingly high value, β bis   =  1.40  ±  0.05 per carbon atom, was measured for the bisPAs. We attribute this to a strong contribution of ‘through-space’ tunneling, which derives from conformational disorder in the monolayer due to strong interactions of the distal phosphonic acid groups; they likely form a hydrogen-bonding network that largely determines the molecular layer structure. Since bisPA SAMs attenuate tunnel currents more effectively than do the corresponding monoPA SAMs, they may find future application as gate dielectric modification in organic thin film devices. (paper)

Chiral Diamine Bis(phenolate) Ti-IV and Zr-IV Complexes - Synthesis, Structures and Reactivity

NARCIS (Netherlands)

Barroso, Sonia; Adao, Pedro; Duarte, M. Teresa; Meetsma, Auke; Pessoa, Joao Costa; Bouwkamp, Marco W.; Martins, Ana M.

Neutral and cationic titanium and zirconium diamine bis(phenolate) complexes supported by chiral ligands L-1 and L-2 are described [L-1 = (R)-6,6'-{1-(dimethylamino)propan-2-ylazanediyl}bis(methylene)-bis(2,4-di-tert-butylphenolate); L-2 =

Electrical transport through a metal-molecule-metal junction; Transport electrique a travers une jonction metal-molecule-metal

Energy Technology Data Exchange (ETDEWEB)

Kergueris, Ch

1998-12-17

We investigate the electrical transport through a very few molecules connected to metallic electrodes at room temperature. First, the state of the art in molecular electronics is outlined. We present the most convincing molecular devices reported so far in the literature and the theoretical tools available to analyze the electron transport mechanism through a molecular junction. Second, we describe the use of mechanically controllable break junctions to investigate the electron transport properties through a metal-molecule-metal junction. Two kindsof molecules were adsorbed on the two facing gold electrodes, dodecane-thiol (DT) and bis-thiol-ter-thiophene ({alpha},{omega} T3), that are basically expected to behave as an insulator and as a molecular wire, respectively. In the latter case, we study the chemical reactivity of the molecule and show that {alpha},{omega} T3 is chemically adsorbed on gold electrodes. Current-voltage characteristics of the junction were observed at room temperature. The Gold-DT-Gold junction behaves as a simple metal-insulator-metal junction. On the other hand, the electron transport through a Gold-{alpha},{omega} T3-Gold junction explicitly involves the electronic structure of the molecule which gives rise to step-like features in the current-voltage characteristics. The measured zero bias conductance is interpreted using the scattering theory. At high bias, we discuss two different models: a coherent model where the electron has no time to be completely re-localized in the molecule and a sequential model where the electron is localized in the molecule during the transfer. Finally, we show that the mechanical action of decreasing the inter-electrodes spacing can be used to induce a strong modification of the current-voltage characteristics. (author)

STRUCTURAL STUDY OF BIS(2,6-BIS(PYRAZOL-3-YLPYRIDINENICKEL(II BY CALORIMETRY AND EXAFS SPECTROMETRY

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Kristian H Sugiyarto

2010-06-01

Full Text Available The main aim of this work is to reveal the complex formation of 2,6-bis(pyrazol-3-ylpyridine, bpp, with nickel(II perchlorate in DMF by calorimetric stepwise complex formation and then followed by EXAFS spectrometry. It was found that the complex formation follows two stepwise pathways namely the formation of mono pyrazolyl-pyridine, [Ni(DMF3 bpp]2+, and bis pyrazolyl-pyridine, [Ni(bpp2]2+;  the formation constants being  log β1 = 6.57, and log β2 = 5.02, and the total value of log β  = 11.58. The final formation of six-coordinated compound was confirmed by EXAFS analysis with the mean Ni-Nbpp bond length of 2.0646(0.0014 Å.   Keywords: nickel(II, bpp, EXAFS

Separation of alkali and alkaline earth metals by polyethers using extraction chromatography

International Nuclear Information System (INIS)

Smulek, W.; Lada, W.A.

1979-01-01

The separation of alkali and alkaline earth metals by means of an acyclic polyether, 1,13-bis(8-chinolinyl)-1, 4, 7, 10, 13-pentaoxatridecane (CPOD), and cyclic polyethers, benzo-15-crown-5 (BC), dibenzo-18-crown-6 (DBC) and dicyclohexyl-18-crown-6 (DCHC), using extraction chromatography has been studied. The alkali metals can be effectively separated using SCN - as the accompanying ion. For alkaline earth metals, the best results were obtained with ClO 4 - ions. Different elution sequences for these groups were observed using chloroform and/meen=/ sitylene as diluents for the polyethers. (author)

Polyamine deprivation-induced enhanced uptake of methylglyoxal bis(guanylhydrazone) by tumor cells.

Science.gov (United States)

Seppänen, P; Alhonen-Hongisto, L; Jänne, J

1981-05-05

1. Putrescine and spermidine depletion produced by alpha-difluoromethylornithine, an irreversible inhibitor or ornithine decarboxylase (EC 4.1.1.17), resulted in a strikingly enhanced cellular uptake of methylglyoxal bis(guanylhydrazone) in cultured Ehrlich ascites carcinoma cells and human lymphocytic leukemia cells. 2. A prior priming of the cells with difluoromethylornithine followed by a short exposure of the cells to methylglyoxal bis(guanylhydrazone) rapidly established intracellular concentrations of the latter drug approaching 10 mM. 3. The enhanced transport of methylglyoxal bis(guanylhydrazone) into the tumor cells apparently required metabolic energy as the uptake of extracellular drug rapidly ceased and intracellular methylglyoxal bis(guanylhydrazone) was excreted into the medium when the glycolysis of the tumor cells was inhibited by iodoacetate. 4. A sequential treatment of cultured tumor cells with difluoromethylornithine until established polyamine depletion followed by an addition of low concentrations of methylglyoxal bis(guanylhydrazone) produced an antiproliferative action not achieved with either of the drugs alone. 5. A similar treatment schedule, i.e a priming of mice inoculated with Ehrlich ascites cells with difluoromethylornithine for a few days, likewise enhanced the uptake of methylglyoxal bis(guanylhydrazone) by the carcinoma cells, but only marginally increased the drug concentration in the liver and small intestine of the animals.

Poly[4,4'-(propane-1,3-diyl)dipyridinium bis{tetraaquabis(μ2-5-carboxybenzene-1,2,4-tricarboxylato)bis[μ2-1,3-bis(4-pyridyl)propane]dicobalt(II)} pentahydrate].

Science.gov (United States)

Atria, Ana María; Corsini, Gino; Garland, Maria Teresa; Baggio, Ricardo

2011-11-01

The title polymeric compound, {(C(13)H(16)N(2))[Co(C(10)H(3)O(8))(C(13)H(14)N(2))(H(2)O)(2)](2)·5H(2)O}(n), is an ionic structure comprising an anionic two-dimensional mesh characterized by a {[Co(Hbtc)(bpp)(H(2)O)(2)](-)}(2) motif [Hbtc is 5-carboxybenzene-1,2,4-tricarboxylate and bpp is 1,3-bis(4-pyridyl)propane], with interspersed 4,4'-(propane-1,3-diyl)dipyridinium cations, denoted (H(2)bpp)(2+), and water molecules providing the charge balance and structure stabilization. The reticular mesh consists of two independent types of [Co(H(2)O)(2)](2+) cationic nodes (lying on inversion centres), interconnected in the [101] direction by two independent sets of neutral bridging bpp ligands, both types of ligands being split by non-equivalent twofold axes. One set is formed by genuinely symmetric moieties, while those in the second set are only symmetric by disorder in the central propane bridge. These chains contain only one type of Co(II) centre and one type of bpp ligand; the metal cations therein are laterally bridged by Hbtc anions, thus forming transverse chains of alternating types of Co(II) cations. The elemental motif of the resulting grid is a highly distorted parallelogram, with metal-metal distances of 13.5242 (14) Å in the bpp direction and 9.105 (2) Å in the Hbtc direction, and a large internal angle of 138.42 (18)°. These two-dimensional structures have a profusion of hydrogen-bonding interactions with each other, either directly (with the aqua molecules as donors and the Hbtc anions as acceptors) or mediated by the unbound (H(2)bpp)(2+) cations and water molecules of hydration. These interactions generate a very complex hydrogen-bonding scheme involving all of the available N-H and O-H groups and which links these two-dimensional grids into a three-dimensional network.

Synthesis of a Bis(thiophenolate)pyridine Ligand and Its Titanium, Zirconium, and Tantalum Complexes

KAUST Repository

Lenton, Taylor N.

2012-11-12

A precursor to a new tridentate LX 2 type ligand, bis(thiophenol)pyridine ((SNS)H 2 = (2-C 6H 4SH) 2-2,6-C 5H 3N), was prepared. Bis(thiophenolate)pyridine complexes of Ti, Zr, and Ta having dialkylamido coligands were synthesized and structurally characterized. The zirconium complex (SNS)Zr(NMe 2) 2 (4) displays C 2 symmetry in the solid state, unlike a related bis(phenolate)pyridine compound, C s-symmetric (ONO)Ti(NMe 2) 2. This change is likely the result of strain about the sulfur atom in the six-membered chelate with longer metal-sulfur and carbon-sulfur bonds. Solid-state structures of tantalum complexes (SNS)Ta(NMe 2) 3 (5) and (SNS)TaCl(NEt 2) 2 (6) also display pronounced C 2 twisting of the SNS ligand. 1D and 2D NMR experiments show that 5 is fluxional, with rotation about the Ta-N(amide) bonds occurring on the NMR time scale that interchange the equatorial amide methyl groups (ΔG ‡ 393 = 25.0(3) kcal/mol). The fluxional behavior of 6 in solution was also studied by variable-temperature 1H NMR. Observation of separate signals for the diastereotopic protons of the methylene unit of the diethylamide indicates that the complex remains locked on the NMR time scale in one diastereomeric conformation at temperatures below -50 °C, fast rotation about the equatorial amide Ta-N bonds occurs at higher temperature (ΔG ‡ 393 = 13.4(3) kcal/mol), and exchange of diastereomeric methylene protons occurs via inversion at Ta that interconverts antipodes (ΔG ‡ 393 ≈ 14(1) kcal/mol). © 2012 American Chemical Society.

Synthesis, Crystal Structure and Luminescent Property of A Novel Cd(II) Coordination Polymer with Bis-imidazole Ligand

International Nuclear Information System (INIS)

Zhou, Yong Hong

2013-01-01

The key to the successful design of metal-organic coordination polymers is the judicious selection of organic ligand. Recently, polydentate aromatic nitrogen heterocyclic ligands with five-membered rings have been well-studied in the construction of supramolecular structure for their N-coordinated sites apt to coordinating to transition metals. Similar to six-membered N-heterocyclic ligands, the azole-based five-membered N-heterocyclic ligands, such as imidazoles, triazoles and tetrazoles have been extensively employed in the construction of various coordination polymers with diverse topologies and interesting properties. The bis(azole) ligands in which N-donor azole rings (imidazole, triazole, or tetrazole) are separated by alkyl, (CH 2 ) n , spacers are good choices for flexible bridging ligands. The conformational flexibility of the spacers makes the ligands adaptable to various coordination networks with one-, two-, and three dimensional structures

Discovery of novel alkylated (bis)urea and (bis)thiourea polyamine analogues with potent antimalarial activities.

Science.gov (United States)

Verlinden, Bianca K; Niemand, Jandeli; Snyman, Janette; Sharma, Shiv K; Beattie, Ross J; Woster, Patrick M; Birkholtz, Lyn-Marie

2011-10-13

A series of alkylated (bis)urea and (bis)thiourea polyamine analogues were synthesized and screened for antimalarial activity against chloroquine-sensitive and -resistant strains of Plasmodium falciparum in vitro. All analogues showed growth inhibitory activity against P. falciparum at less than 3 μM, with the majority having effective IC(50) values in the 100-650 nM range. Analogues arrested parasitic growth within 24 h of exposure due to a block in nuclear division and therefore asexual development. Moreover, this effect appears to be cytotoxic and highly selective to malaria parasites (>7000-fold lower IC(50) against P. falciparum) and is not reversible by the exogenous addition of polyamines. With this first report of potent antimalarial activity of polyamine analogues containing 3-7-3 or 3-6-3 carbon backbones and substituted terminal urea- or thiourea moieties, we propose that these compounds represent a structurally novel class of antimalarial agents.

Combined chelation based on glycosyl-mono- and bis-hydroxypyridinones for aluminium mobilization: solution and biodistribution studies.

Science.gov (United States)

Chaves, Sílvia; Dron, Paul I; Danalache, Florina A; Sacoto, Diana; Gano, Lurdes; Santos, M Amélia

2009-11-01

Taking into account the recognized interest of a poly-pharmacological strategy in chelation therapy, a study of aluminium combined chelation based on 3-hydroxy-4-pyridinone (3,4-HP) compounds with complementary properties, associated to different denticity, size and extrafunctionality, is presented herein. In particular, Al-chelation has been explored, using a tetradentate IDA bis-(3,4-HP) ligand, L, and two N-glycosyl mono-(3,4-HP) derivatives (A or B). Combined complexation studies with the tetradentate and the most promising bidentate ligand (A) evidenced the formation of ternary complexes with high thermodynamic stability (Al-L-A) being the predominant species at physiological pH. In vivo studies on the ability for radiotracer ((67)Ga) removal from loaded mice, as a model of aluminium accumulation in body, have shown that the simultaneous administration to (67)Ga-loaded mice of a mono- and a bis-(3,4-HP) chelator (e.g. A and L) leads to a rapid metal elimination from main organs and whole animal model. This may be rationalized by coadjuvation and eventual synergistic effects, due to complementary accessibility of the chelators to different cellular compartments.

Aromatic carboxylate effect on dimensionality of three bis(benzimidazole)-based cobalt(II) coordination polymers: Syntheses, structures and properties

International Nuclear Information System (INIS)

Zhang, Ju-Wen; Gong, Chun-Hua; Hou, Li-Li; Tian, Ai-Xiang; Wang, Xiu-Li

2013-01-01

Three new metal-organic coordination polymers [Co(4-bbc) 2 (bbbm)] (1), [Co(3,5-pdc)(bbbm)]·2H 2 O (2) and [Co(1,4-ndc)(bbbm)] (3) (4-Hbbc=4-bromobenzoic acid, 3,5-H 2 pdc=3,5-pyridinedicarboxylic acid, 1,4-H 2 ndc=1,4-naphthalenedicarboxylic acid and bbbm=1,1-(1,4-butanediyl)bis-1H-benzimidazole) were hydrothermally synthesized and structurally characterized. Polymer 1 is a 1D chain formed by the bbbm ligands and Co II ions. Polymer 2 exhibits a 2D network with a (3·4·5)(3 2 ·4·5·6 2 ·7 4 ) topology. Polymer 3 possesses a 3D three-fold interpenetrating framework. The versatile structures of title polymers indicate that the aromatic carboxylates have an important influence on the dimensionality of 1–3. Moreover, the thermal stability, electrochemical and luminescent properties of 1–3 were investigated. - graphical abstract: Three bis(benzimidazole)-based cobalt(II) coordination polymers tuned by aromatic carboxylates were hydrothermally synthesized and structurally characterized. The aromatic carboxylates play a key role in the dimensionality of three polymers. The electrochemical and luminescent properties of three polymers were investigated. Display Omitted - Highlights: • Three bis(benzimidazole)-based cobalt(II) coordination polymers tuned by aromatic carboxylates were obtained. • The aromatic carboxylates have an important influence on the dimensionality of three polymers. • The electrochemical and luminescent properties of three polymers were investigated

What a difference a 5f element makes: trivalent and tetravalent uranium halide complexes supported by one and two bis[2-(diisopropylphosphino)-4-methylphenyl]amido (PNP) ligands.

Science.gov (United States)

Cantat, Thibault; Scott, Brian L; Morris, David E; Kiplinger, Jaqueline L

2009-03-02

The coordination behavior of the bis[2-(diisopropylphosphino)-4-methylphenyl]amido ligand (PNP) toward UI3(THF)4 and UCl4 has been investigated to access new uranium(III) and uranium(IV) halide complexes supported by one and two PNP ligands. The reaction between (PNP)K (6) and 1 equiv of UI3(THF)4 afforded the trivalent halide complex (PNP)UI2(4-tBu-pyridine)2 (7) in the presence of 4-tert-butylpyridine. The same reaction carried out with UCl4 and no donor ligand gave [(PNP)UCl3]2 (8), in which the uranium coordination sphere in the (PNP)UCl3 unit is completed by a bridging chloride ligand. When UCl4 is reacted with 1 equiv (PNP)K (6) in the presence of THF, trimethylphosphine oxide (TMPO), or triphenylphosphineoxide (TPPO), the tetravalent halide complexes (PNP)UCl3(THF) (9), (PNP)UCl3(TMPO)2 (10), and (PNP)UCl3(TPPO) (11), respectively, are formed in excellent yields. The bis(PNP) complexes of uranium(III), (PNP)2UI (12), and uranium(IV), (PNP)2UCl2 (13), were easily isolated from the analogous reactions between 2 equiv of 6 and UI3(THF)4 or UCl4, respectively. Complexes 12 and 13 represent the first examples of complexes featuring two PNP ligands coordinated to a single metal center. Complexes 7-13 have been characterized by single-crystal X-ray diffraction and 1H and 31P NMR spectroscopy. The X-ray structures demonstrate the ability of the PNP ligand to adopt new coordination modes upon coordination to uranium. The PNP ligand can adopt both pseudo-meridional and pseudo-facial geometries when it is kappa3-(P,N,P) coordinated, depending on the steric demand at the uranium metal center. Additionally, its hemilabile character was demonstrated with an unusual kappa2-(P,N) coordination mode that is maintained in both the solid-state and in solution. Comparison of the structures of the mono(PNP) and bis(PNP) complexes 7, 9, 11-13 with their respective C5Me5 analogues 1-4 undoubtedly show that a more sterically congested environment is provided by the PNP ligand. The

Preparation, characterization, magnetic and thermal studies of some chelate polymers of first series transition metal ions

International Nuclear Information System (INIS)

Ukey, Vaishali V.; Juneja, H.D.; Borkar, S.D.; Ghubde, R.S.; Naz, S.

2006-01-01

Azelaoyl-bis-hydroxamic acid used as bis ligand for the preparation of chelate polymers of Mn(II), Co(II), Ni(II) and Zn(II). These chelate polymers have been synthesized by refluxing the metal acetate and bis ligand as 1:1 stoichiometry. In the present work, structural determination of these newly synthesized chelate polymers has been studied on the basis of elemental analyses, infrared and reflectance spectral, magnetic and thermal studies. The decomposition temperature and the order of reaction have been determined by TGA analysis. On the basis of these studies, the Zn(II) chelate polymer has tetrahedral geometry, whereas Mn(II), Co(II) and Ni(II) chelate polymers have octahedral geometry and have the thermal stability in the order Ni(II) > Mn(II) > Zn(II) > Co(II)

Studies on Oligomer Metal Complexes Derived from Bisamic Acid of Pyromellitic Dianhydride and 4-Bromoaniline.

Science.gov (United States)

Patel, Yogesh S

2014-01-01

Novel oligomer metal complexes (2a-f) of the ligand 2,5-bis((4-bromophenyl)carbamoyl) terephthalic acid (1) were prepared using transition metal salts and characterized by various spectroscopic techniques. The geometry of oligomer metal complexes was carried out by electronic spectral analysis and magnetic measurement studies. Polymeric properties have also been carried out. Ligand was synthesized using pyromellitic dianhydride and 4-bromoaniline. It was duly characterized. All novel synthesized compounds 1 and 2a-f were evaluated for their antibacterial and antifungal activity. The results showed significantly higher antibacterial and antifungal activity of oligomer metal complexes compared to the ligand.

Blessures Skaten (BIS): Blessurevrij skaten?

NARCIS (Netherlands)

Hespen, A. van; Stubbe, J.; Stege, J.

2009-01-01

Sportblessures: niemand zit erop te wachten, maar jaarlijks krijgen ongeveer 1,5 miljoen mensen in Nederland ermee te maken. Om effectief aan preventie te doen, is inzicht in het aantal en soort sportblessures onmisbaar. Dit kan met het web-based Blessure Informatie Systeem (BIS) van TNO Kwaliteit

Blessures badmington (BIS): blessurevrij badmintonnen?

NARCIS (Netherlands)

Hespen, A. van; Stubbe, J.; Stege, J.; Ooijendijk, W.

2008-01-01

Sportblessures: niemand zit erop te wachten, maar jaarlijks krijgen ongeveer 1,5 miljoen mensen in Nederland ermee te maken. Om effectief aan preventie te doen, is inzicht in het aantal en soort sportblessures onmisbaar. Dit kan met het web-based Blessure Informatie Systeem (BIS) van TNO Kwaliteit

LA REINCIDENCIA VULNERA EL “NON BIS IN IDEM”

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Roger Cabrera Paredes

2011-06-01

Full Text Available El presente artículo explica como la “Reincidencia vulnera el  Non bis in ídem”; empezamos con la “Introducción” que comprende los antecedentes, la formulación del problema y la justificación de esta investigación. Continuamos con las “Bases Teóricas”, la misma que comprende el sentido de los principios penales, el principio “Non bis in Idem”, la Reincidencia y la Problemática de la Reincidencia como vulneración del Principio Non bis in ídem. En la “Metodología”, encontramos la tipología y metodología de la investigación. En los “Resultados”,  están los análisis y la decisión final de las entrevistas y encuestas a Docentes y abogados especializados en el tema y al personal de Juzgados, Fiscalías y abogados, respectivamente, del Distrito Judicial de Iquitos de la Provincia de Maynas, región Loreto. En la “Discusión”, explicamos que la Reincidencia debe desaparecer porque va en contra del principio Non bis in ídem, colocando en las “Conclusiones” nuestra posición.

LA REINCIDENCIA VULNERA EL “NON BIS IN IDEM”

Directory of Open Access Journals (Sweden)

Roger Cabrera-Paredes

2011-07-01

Full Text Available El presente artículo explica como la “Reincidencia vulnera el  Non bis in ídem”; empezamos con la “Introducción” que comprende los antecedentes, la formulación del problema y la justificación de esta investigación. Continuamos con las “Bases Teóricas”, la misma que comprende el sentido de los principios penales, el principio “Non bis in Idem”, la Reincidencia y la Problemática de la Reincidencia como vulneración del Principio Non bis in ídem. En la “Metodología”, encontramos la tipología y metodología de la investigación. En los “Resultados”,  están los análisis y la decisión final de las entrevistas y encuestas a Docentes y abogados especializados en el tema y al personal de Juzgados, Fiscalías y abogados, respectivamente, del Distrito Judicial de Iquitos de la Provincia de Maynas, región Loreto. En la “Discusión”, explicamos que la Reincidencia debe desaparecer porque va en contra del principio Non bis in ídem, colocando en las “Conclusiones” nuestra posición.

Combinatorial synthesis of oxazol-thiazole bis-heterocyclic compounds.

Science.gov (United States)

Murru, Siva; Nefzi, Adel

2014-01-13

A combinatorial library of novel oxazol-thiazole bis-heterocycles was synthesized in good to excellent overall yields with high purity using a solution and solid-phase parallel synthesis approach. Oxazole amino acids, prepared from serine methyl ester and amino acids via coupling and cyclodehydration, were treated with Fmoc-NCS and α-haloketones for the parallel synthesis of diverse bis-heterocycles. Fmoc-isothiocyanate is used as a traceless reagent for thiazole formation. Oxazole diversity can be achieved by using variety of amino acids, whereas thiazole diversity is produced with various haloketones.

Synthesis and characterization of poly(phenylacetylene)s with Ru(II) bis-terpyridine complexes in the side-chain.

Science.gov (United States)

Breul, Alexander M; Kübel, Joachim; Häupler, Bernhard; Friebe, Christian; Hager, Martin D; Winter, Andreas; Dietzek, Benjamin; Schubert, Ulrich S

2014-04-01

An alkyne-functionalized ruthenium(II) bis-terpyridine complex is directly copolymerized with phenylacetylene by alkyne polymerization. The polymer is characterized by size-exclusion chromatography (SEC), (1) H NMR spectroscopy, cyclic voltammetry (CV) measurements, and thermal analysis. The photophysical properties of the polymer are studied by UV-vis absorption spectroscopy. In addition, spectro-electrochemical measurements are carried out. Time-resolved luminescence lifetime decay curves show an enhanced lifetime of the metal complex attached to the conjugated polymer backbone compared with the Ru(tpy)2 (2+) model complex. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Di-tert-butyl N-[2,6-bis(methoxymethoxyphenyl]iminodiacetate

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Ben Capuano

2009-04-01

Full Text Available The title molecule, C20H31NO8, has pseudo-C2 symmetry about the C—N bond, with the bis(tert-butoxycarbonylamino group twisted from the benzene ring plane by ca 60° and the bulky tert-butoxycarbonyl (Boc groups are orientated away from the substituted aniline group. As part of an antibacterial drug discovery programme furnishing analogues of platensimycin, we unexpectedly synthesized the bis-Boc-protected aniline.

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

′)-diones has been expediently accomplished by a reaction of isatin(s) / cyclic ketone and anthranilamide in ethanol at ambient temprature. Excellent yields of the products in short time duration, operational simplicity, and simple work-up ...

Bis-pyrene-modified unlocked nucleic acids: synthesis, hybridization studies, and fluorescent properties

DEFF Research Database (Denmark)

Perlíková, Pavla; Ejlersen, Maria; Langkjaer, Niels

2014-01-01

Efficient synthesis of a building block for the incorporation of a bis-pyrene-modified unlocked nucleic acid (UNA) into oligonucleotides (DNA*) was developed. The presence of bis-pyrene-modified UNA within a duplex leads to duplex destabilization that is more profound in DNA*/RNA and less distinc......)uracil:pyrene exciplex emission in the single-stranded form. Such fluorescent properties enable the application of bis-pyrene-modified UNA in the development of fluorescence probes for DNA/RNA detection and for detection of deletions at specific positions....

COLORING PROPERTIES OF WOOL FABRIC COLORED BY NEW DYESTUFFS - AZOMETHINES

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DJORDJEVIC Dragan

2016-05-01

Full Text Available The azomethines have broad applications in food and dyestuff industries, and in analytical chemistry, catalysis and also in the field of agrochemical. These have played an influential part in the improvement of modern coordination chemistry, but also they can also be found at key points in the development of inorganic biochemistry, catalysis and also in optical materials. The present paper describes coloring properties of wool fabric colored by new dyestuffs - azomethines, derivate of isatin. Synthesizing of dyestuffs can often have one to six chromogen, which can be defined as the photoactive components that contain colored or uncolored absorbent components. In addition of monoazo, diazo, poly-azo, anthraquinone, xanthan and similar systems, the azomethines or imines, also includes to the chromogen groups. Azomethines, such as, isatin-3-hydrazone, isatin-3-thiosemicarbazone and isatin-3-phenylhydrazone, were synthesized and their coloring performance on wool fabric assessed. The synthesized azomethines showed very good substantively for wool fibers with good coloring performance according to CIEL*a*b* system which characterized quantitative and qualitative coloring property. Dyestuff 3 or isatin-3-phenylhydrazone bound to woolen textiles to a greater extent and greater intensity (minimum value of L. Dyestuff 2 or isatin-3-thiosemicarbazone linked to the minimum amount for textiles (the largest value of L. Although it must be noted that it is a lighter shade (yellow color as opposed to the dyestuff 3 (red color.

Preparation and use of crystalline bis-monoorganic phosphonate and phosphate salts of tetravalent metals

Science.gov (United States)

Maya, L.

1980-06-26

A method of preparing and using the crystalline organic derivatives of the tetravalent metal phosphates and phosphonates provides for the contacting of an aqueous solution of a metal nitrate, with a solution of an organophosphorus acid for a period of time at room temperature that is sufficient for the formation of a metal phosphate product, and thereafter recovering said product. According to the invention, the product of the disclosed process is used in effecting analytical separations, such as ion exchange and chromatography.

Synthesis, characterization and biological behavior of some Schiff's and Mannich base derivatives of Lamotrigine

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A.A. Kulkarni

2017-02-01

Full Text Available A series of various Schiff's and Mannich base derivatives (N1–2 & ND1–6 of Lamotrigine with isatin and substituted isatin were synthesized to get more potent anticonvulsant agents. The starting material for the synthesis of various new Schiff's and Mannich base derivatives was isatin (1H-indole- 2, 3-dione which in turn was prepared from substituted isonitrosoacetanilide using aniline. Lamotrigine reacts with isatin & substituted isatin gave Schiff's bases (N1–2 which on reaction with various secondary amines (dimethylamine, diethylamine, morpholine produced Mannich bases (ND1–6. The structures of newly synthesized compounds were characterized by using TLC, UV, FT-IR, 1HNMR and studied for their anticonvulsant activity. Anticonvulsant activity of all the derivatives was evaluated by MES method using phenobarbitone sodium & Lamotrigine as standard drugs and % reduction of time spent by animals in extension, flexion, clonus, and stupor phase were noted. Compounds ND-4 and ND-6 showed significant anticonvulsant activity when compared with that of standard drugs. The remaining all compounds show moderate activity. Biological activity data of the synthesized derivatives revealed that, the synthesized derivatives are good anticonvulsant agents as compared to Lamotrigine.

Ne bis in idem põhimõte Euroopa Liidu õiguses / Uno Lõhmus

Index Scriptorium Estoniae

Lõhmus, Uno, 1952-

2009-01-01

Ne bis in idem põhimõtte ehk teistkordse kohtumõistmise ja karistamise keelu territoriaalsest kohaldamisest. Schengeni rakenduskonventsiooni artiklis 54 sisalduva ne bis in idem põhimõtte tõlgendustest. Mõistetest "sama tegu" ja "lõplik kohtuotsus"

Crystal structure of bis(azido-κNbis[2,5-bis(pyridin-2-yl-1,3,4-thiadiazole-κ2N2,N3]cobalt(II

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Abdelhakim Laachir

2015-05-01

Full Text Available In the mononuclear title complex, [Co(N32(C12H8N4S2], the cobalt(II atom is located on an inversion centre and displays an axially weakly compressed octahedral coordination geometry. The equatorial positions are occupied by the N atoms of two 2,5-bis(pyridin-2-yl-1,3,4-thiadiazole ligands, whereas the axial positions are occupied by N atoms of the azide anions. The thiadiazole and pyridine rings linked to the metal are almost coplanar, with a maximum deviation from the mean plane of 0.0273 (16 Å. The cohesion of the crystal is ensured by weak C—H...N hydrogen bonds and by π–π interactions between pyridine rings [intercentroid distance = 3.6356 (11 Å], forming a layered arrangement parallel to (001. The structure of the title compound is isotypic with that of the analogous nickel(II complex [Laachir et al. (2013. Acta Cryst. E69, m351–m352].

Normative data of the Barratt Impulsiveness Scale 11 (BIS-11 for Brazilian adults

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Leandro F. Malloy-Diniz

2015-09-01

Full Text Available Objective:The Barratt Impulsiveness Scale (BIS-11 is a valid and reliable instrument, and one of the most often used tools to assess impulsivity. This study assesses the performance of a large sample of adults by using a version of BIS-11 adapted to Brazilian Portuguese.Methods:We assessed 3,053 adults from eight Brazilian states. Internal consistencies and performance data were presented for two correction criteria of BIS-11: original and the two-factor score.Results:The associations between age, sex, region, and education and the BIS-11 scores present very small effect sizes. Therefore, we provided a percentile rank parameter for the different BIS-11 subscores considering the whole sample. Given the internal consistency of the two correction systems, we found that only the two-factor system fulfills the psychometric criteria of Cronbach’s alpha (cutoff value of at least 0.6.Conclusion:Our results support the use of the Brazilian adaptation of BIS-11 in different regions of the country as a measure of impulsivity. Since high impulsiveness is a characteristic of several dysfunctional behaviors, the establishment of normative parameters is of utmost relevance and should be extended to other age ranges and populations in future studies.

Neutral coordination polymers based on a metal-mono(dithiolene) complex: synthesis, crystal structure and supramolecular chemistry of [Zn(dmit)(4,4'-bpy)]n, [Zn(dmit)(4,4'-bpe)]n and [Zn(dmit)(bix)]n (4,4'-bpy = 4,4'-bipyridine, 4,4'-bpe = trans-1,2-bis(4-pyridyl)ethene, bix = 1,4-bis(imidazole-1-ylmethyl)-benzene.

Science.gov (United States)

Madhu, Vedichi; Das, Samar K

2011-12-28

This article describes a unique synthetic route that enables a neutral mono(dithiolene)metal unit, {Zn(dmit)}, to link with three different organic molecules, resulting in the isolation of a new class of neutral coordination polymers. The species {Zn(dmit)} coordinates with 4,4'-bipyridine (4,4'-bpy), trans-1,2-bis(4-pyridyl)ethene (4,4'-bpe) and 1,4-bis(imidazole-1-ylmethyl)-benzene (bix) as linkers giving rise to the formation of coordination polymers [Zn(dmit)(4,4'-bpy)](n) (1), [Zn(dmit)(4,4'-bpe)](n) (2) and [Zn(dmit)(bix)](n) (3) respectively. Compounds 1-3 were characterized by elemental analyses, IR, diffuse reflectance and single crystal X-ray diffraction studies. Compounds 1 and 3 crystallize in the monoclinic space group P2(1)/n, whereby compound 2 crystallizes in triclinic space group P1[combining macron]. In the present study, we chose three linkers 4,4'-bpy, 4,4'-bpe and bix (see , respectively, for their structural drawings), that differ in terms of their molecular dimensions. The crystal structures of compounds 1-3 are described here in terms of their supramolecular diversities that include π-π interactions, not only among aromatic stacking (compounds 1 and 3), but also between an aromatic ring and an ethylenic double bond (compound 2). The electronic absorption spectroscopy of compounds 1-3 support these intermolecular π-π interactions. This journal is © The Royal Society of Chemistry 2011

Thermodynamic Investigation and Mixed Ligand Complex Formation of 1,4-Bis-(3-aminopropyl)-piperazine and Biorelevant Ligands.

Science.gov (United States)

El-Sherif, Ahmed A; Shehata, Mohamed R; Shoukry, Mohamed M; Barakat, Mohammad H

2012-01-01

Thermodynamic parameters for protonation of 1,4-bis(3-aminopropyl)-piperazine (BAPP) and its metal complexation with some divalent metal ions were determined in aqueous solution at constant ionic strength (0.1 M NaNO(3)) using a potentiometric technique. The order of -ΔG(0) and -ΔH(0) was found to obey Co(2+) Zn(2+), in accordance with the Irving-Williams order. The formation equilibria of zinc (II) complexes and the ternary complexes Zn(BAPP)L, where L = amino acid, amides, or DNA constituents), have been investigated. Ternary complexes are formed by a simultaneous mechanism. The concentration distribution of the complexes in solution was evaluated as a function of pH. Stoichiometry and stability constants for the complexes formed are reported and discussed. The stability of ternary complexes was quantitatively compared with their corresponding binary complexes in terms of the parameter Δlog K.

Suppression of phytohemagglutinin-induction of thymidine uptake in guinea pig lymphocytes by methylglyoxal bis(guanylhydrazone) treatment.

Science.gov (United States)

Otani, S; Matsui, I; Morisawa, S

1977-10-18

Treatment with methylglyoxal bis(guanylhydrazone), a specific inhibitor of S-adenosylmethionine decarboxylase (EC 4.1.1.50), suppressed the phytohemagglutinin-induction of [3H]thymidine uptake by guinea pig lymphocytes. The kinetics of [3H]thymidine uptake revealed that the Km value for thymidine was not changed, but the V value was markedly lowered by the methylglyoxal bis(guanylhydrazone) treatment. The induction of ATP: thymidine 5'-phosphotransferase (EC 2.7.1.75) (thymidine kinase) activity by phytohemagglutinin was suppressed to about the same extent as the induction of thymidine uptake. These suppressions were dependent on the methylglyoxal bis(guanylhydrazone) doses and on duration of the methylglyoxal bis(guanylhydrazone) treatment. Analysis of [3H]thymidine labelled compounds of the acid-soluble fraction showed that conversion of thymidine to thymidine 5'-triphosphate was inhibited by the methylglyoxal bis(guanylhydrazone) treatment. DNA polymerase activity was less inhibited by the methylglyoxal bis(guanylhydrazone) treatment in comparison with the methylglyoxal bis(guanylhydrazone) inhibition of thymidine uptake by whole cells. These results strongly suggested that blocking of polyamine accumulation by the methylglyoxal bis(guanylhydrazone) treatment influenced phytohemagglutinin induction of thymidine phosphorylation, resulting in a decrease of thymidine incorporation into DNA.

Behavioral inhibition system (BIS), Behavioral activation system (BAS) and schizophrenia : Relationship with psychopathology and physiology

NARCIS (Netherlands)

Scholten, Marion R. M.; van Honk, Jack; Aleman, Andre; Kahn, Rene S.

2006-01-01

Objective: The Behavioral Inhibition System (BIS) and the Behavioral Activation System (BAS) have been conceptualized as two neural motivational systems that regulate sensitivity to punishment (BIS) and reward (BAS). Imbalance in BIS and BAS levels has been reported to be related to various forms of

Studies on trivalent lanthanide complexes of bis-vanillin p-phenylenediamine

International Nuclear Information System (INIS)

Shahma, Abu; Ahmad, Naseer

1983-01-01

The coordination interaction of lanthanide(III) chlorides with bis-vanillin o-phenylenediamine was studied by Ansari and Ahmad (1977). It was thought fruitful to compare these with the complexes of trivalent lanthanide ions with bis-vanillin p-phenylenediamine. The newly synthesized complexes were subjected to elemental, thermogravimetric and differential thermal analyses and their melting points, magnetic susceptibilities, molar conductances determined and infrared and electronic spectra taken. (author)

SYNTHESIS AND STRUCTURE OF BIS(PHENYLTETRAMETHYLCYCLOPENTADIENYL)TITANIUM(III) HYDRIDE - THE FIRST MONOMERIC BIS(CYCLOPENTADIENYL)TITANIUM(III) HYDRIDE : The First Monomeric Bis(cyclopentadienyl)titanium(III) Hydride

NARCIS (Netherlands)

de Wolf, J.M.; Meetsma, A.; Teuben, J.H

1995-01-01

The first structurally characterized monomeric bis(cyclopentadienyl)titanium(III) hydride, (C(5)PhMe(4))(2)TiH (4), was synthesized by hydrogenolysis of (C(5)PhMe(4))(2)TiMe (5). Hydride 4 was found to be a monomeric bent sandwich by X-ray diffraction methods, and the pentamethylcyclopentadienyl

Validity and Reliability of the Abbreviated Barratt Impulsiveness Scale in Spanish (BIS-15S)*

Science.gov (United States)

Orozco-Cabal, Luis; Rodríguez, Maritza; Herin, David V.; Gempeler, Juanita; Uribe, Miguel

2010-01-01

Objective This study determined the validity and reliability of a new, abbreviated version of the Spanish Barratt Impulsiveness Scale (BIS-15S) in Colombian subjects. Method The BIS-15S was tested in non-clinical (n=283) and clinical (n=164) native Spanish-speakers. Intra-scale reliability was calculated using Cronbach’s α, and test-retest reliability was measured with Pearson correlations. Psychometric properties were determined using standard statistics. A factor analysis was performed to determine BIS-15S factor structure. Results 447 subjects participated in the study. Clinical subjects were older and more educated compared to non-clinical subjects. Impulsivity scores were normally distributed in each group. BIS-15S total, motor, non-planning and attention scores were significantly lower in non-clinical vs. clinical subjects. Subjects with substance-related disorders had the highest BIS-15S total scores, followed by subjects with bipolar disorders and bulimia nervosa/binge eating. Internal consistency was 0.793 and test-retest reliability was 0.80. Factor analysis confirmed a three-factor structure (attention, motor, non-planning) accounting for 47.87% of the total variance in BIS-15S total scores. Conclusions The BIS-15S is a valid and reliable self-report measure of impulsivity in this population. Further research is needed to determine additional components of impulsivity not investigated by this measure. PMID:21152412

Extraordinary photoluminescence behavior of an efficient electrochemiluminophore: Tb(III) chelated by 2,6-bis[N,N-bis(carboxymethyl)aminomethyl]-4-benzoylphenol

International Nuclear Information System (INIS)

Kuosmanen, Päivi; Pusa, Matti; Salminen, Kalle; Kulmala, Sakari

2016-01-01

The reactivities of lanthanide ions in their excited states are first considered in water and the energy diagrams of most important of them are sketched to illustrate the highly oxidizing and reducing species involved reacting with one-electron steps. Anomalous photoluminescence behavior of Tb(III) chelated by 2,6-bis[N,N-bis(carboxymethyl)aminomethyl]-4-benzoylphenol is studied. The present chelate is known to show relative strong chemiluminescence in the presence of hydrated electron and oxidizing radicals but it shows an extraordinarily short luminescence lifetime of radiative relaxation of its 5 D 4 state under photoexcitation.

Extraordinary photoluminescence behavior of an efficient electrochemiluminophore: Tb(III) chelated by 2,6-bis[N,N-bis(carboxymethyl)aminomethyl]-4-benzoylphenol

Energy Technology Data Exchange (ETDEWEB)

Kuosmanen, Päivi, E-mail: paivi.kuosmanen@aalto.fi; Pusa, Matti; Salminen, Kalle; Kulmala, Sakari

2016-05-15

The reactivities of lanthanide ions in their excited states are first considered in water and the energy diagrams of most important of them are sketched to illustrate the highly oxidizing and reducing species involved reacting with one-electron steps. Anomalous photoluminescence behavior of Tb(III) chelated by 2,6-bis[N,N-bis(carboxymethyl)aminomethyl]-4-benzoylphenol is studied. The present chelate is known to show relative strong chemiluminescence in the presence of hydrated electron and oxidizing radicals but it shows an extraordinarily short luminescence lifetime of radiative relaxation of its {sup 5}D{sub 4} state under photoexcitation.

Transition metal redox switches for reversible "on/off" and "slow/fast" single-molecule magnet behaviour in dysprosium and erbium bis-diamidoferrocene complexes.

Science.gov (United States)

Dickie, Courtney M; Laughlin, Alexander L; Wofford, Joshua D; Bhuvanesh, Nattamai S; Nippe, Michael

2017-12-01

Single-molecule magnets (SMMs) are considered viable candidates for next-generation data storage and quantum computing. Systems featuring switchability of their magnetization dynamics are particularly interesting with respect to accessing more complex logic gates and device architectures. Here we show that transition metal based redox events can be exploited to enable reversible switchability of slow magnetic relaxation of magnetically anisotropic lanthanide ions. Specifically, we report anionic homoleptic bis-diamidoferrocene complexes of Dy 3+ (oblate) and Er 3+ (prolate) which can be reversibly oxidized by one electron to yield their respective charge neutral redox partners (Dy: [1] - , 1 ; Er: [2] - , 2 ). Importantly, compounds 1 and 2 are thermally stable which allowed for detailed studies of their magnetization dynamics. We show that the Dy 3+ [1] - / 1 system can function as an "on"/"off" or a "slow"/"fast" redox switchable SMM system in the absence or presence of applied dc fields, respectively. The Er 3+ based [2] - / 2 system features "on"/"off" switchability of SMM properties in the presence of applied fields. Results from electrochemical investigations, UV-vis-NIR spectroscopy, and 57 Fe Mössbauer spectroscopy indicate the presence of significant electronic communication between the mixed-valent Fe ions in 1 and 2 in both solution and solid state. This comparative evaluation of redox-switchable magnetization dynamics in low coordinate lanthanide complexes may be used as a potential blueprint toward the development of future switchable magnetic materials.

"Rocking-Chair"-Type Metal Hybrid Supercapacitors.

Science.gov (United States)

Yoo, Hyun Deog; Han, Sang-Don; Bayliss, Ryan D; Gewirth, Andrew A; Genorio, Bostjan; Rajput, Nav Nidhi; Persson, Kristin A; Burrell, Anthony K; Cabana, Jordi

2016-11-16

Hybrid supercapacitors that follow a "rocking-chair"-type mechanism were developed by coupling divalent metal and activated carbon electrodes in nonaqueous electrolytes. Conventional supercapacitors require a large amount of electrolyte to provide a sufficient quantity of ions to the electrodes, due to their Daniell-type mechanism that depletes the ions from the electrolyte while charging. The alternative "rocking-chair"-type mechanism effectively enhances the energy density of supercapacitors by minimizing the necessary amount of electrolyte, because the ion is replenished from the metal anode while it is adsorbed to the cathode. Newly developed nonaqueous electrolytes for Mg and Zn electrochemistry, based on bis(trifluoromethylsulfonyl)imide (TFSI) salts, made the metal hybrid supercapacitors possible by enabling reversible deposition on the metal anodes and reversible adsorption on an activated carbon cathode. Factoring in gains through the cell design, the energy density of the metal hybrid supercapacitors is projected to be a factor of 7 higher than conventional devices thanks to both the "rocking-chair"-type mechanism that minimizes total electrolyte volume and the use of metal anodes, which have substantial merits in capacity and voltage. Self-discharge was also substantially alleviated compared to conventional supercapacitors. This concept offers a route to build supercapacitors that meet dual criteria of power and energy densities with a simple cell design.

Synthesis and structure of unprecedented samarium complex with bulky bis-iminopyrrolyl ligand via intramolecular C=N bond activation

Energy Technology Data Exchange (ETDEWEB)

Das, Suman; Anga, Srinivas; Harinath, Adimulam; Panda, Tarun K. [Department of Chemistry, Indian Institute of Technology, Hyderabad (India); Pada Nayek, Hari [Department of Applied Chemistry, Indian Institute of Technology, (ISM) Dhanbad, Jharkhand (India)

2017-12-29

An unprecedentate samarium complex of the molecular composition [{κ"3-{(Ph_2CH)N=CH}{sub 2}C{sub 4}H{sub 2}N}{κ"3-{(Ph_2CHN=CH)(Ph_2CHNCH)C_4H_2N}Sm}{sub 2}] (2), which was isolated by the reaction of a potassium salt of 2,5-bis{N-(diphenylmethyl)-iminomethyl}pyrrolyl ligand [K(THF){sub 2}{(Ph_2CH)N=CH}{sub 2}C{sub 4}H{sub 2}N] (1) with anhydrous samarium diiodide in THF at 60 C through the in situ reduction of imine bond is presented. The homoleptic samarium complex [[κ{sup 3}-{(Ph_2CH)-N=CH}{sub 2}C{sub 4}H{sub 2}N]{sub 3}Sm] (3) can also be obtained from the reaction of compound 1 with anhydrous samarium triiodide (SmI{sub 3}) in THF at 60 C. The molecular structures of complexes 2 and 3 were established by single-crystal X-ray diffraction analysis. The molecular structure of complex 2 reveals the formation of a C-C bond in the 2,5-bis{N-(diphenylmethyl)iminomethyl}pyrrole ligand moiety (Ph{sub 2}Py{sup -}). However, complex 3 is a homoleptic samarium complex of three bis-iminopyrrolyl ligands. In complex 2, the samarium ion adopts an octahedral arrangement, whereas in complex 3, a distorted three face-centered trigonal prismatic mode of nine coordination is observed around the metal ion. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Conductivity and thermopower studies of bis-tetramethyltetraselenafulvalenium hexafluorophosphide, bis-tetramethyltetrathiafulvalenium hexafluorophosphide, and their solid solutions, (TMTSF1-xTMTTFx)2PF6

DEFF Research Database (Denmark)

Mortensen, Kell; Engler, E. M.

1984-01-01

The conductivity σ and the thermoelectric power S have been studied experimentally on the organic conductors bis-tetramethyltetraselenafulvalenium hexafluorophosphide [(TMTSF)2PF6] and bis-tetramethyltetrathiafulvalenium hexafluorophosphide [(TMTTF)2PF6] and their solid solutions: (TMTSF1-xTMTTFx)2......PF6. Dramatic effects are seen in σ already when dilute concentrations of TMTTF molecules are introduced in the TMTSF chains, and for x=0.1, σ shows generally activated behavior. The thermopower, on the contrary, remains basically unaffected for x at least as large as 0.25. These unusual findings...

Gray's BIS/BAS dimensions in non-comorbid, non-medicated social anxiety disorder.

NARCIS (Netherlands)

Morgan, B.E.; Honk, J. van; Hermans, E.J.; Scholten, M.R.; Stein, D.J.; Kahn, R.S.

2009-01-01

Gray's behavioural inhibition and behavioural activation (BIS/BAS) neural systems model has led to research on approach and withdrawal as the two most fundamental dimensions of affective behaviour, and their role in psychopathology. Although Gray proposed the BIS as the neurological basis of

[(Nitrato-κ2 O,O′)(nitrito-κ2 O,O′)(0.25/1.75)]bis­(1,10-phenanthroline-κ2 N,N′)cadmium(II)

Science.gov (United States)

Najafi, Ezzatollah; Amini, Mostafa M.; Ng, Seik Weng

2011-01-01

The reaction of cadmium nitrate and sodium nitrite in the presence of 1,10-phenanthroline yields the mixed nitrate–nitrite title complex, [Cd(NO2)1.75(NO3)0.25(C12H8N2)2]. The metal ion is bis-chelated by two N-heterocycles as well as by the nitrate/nitrite ions in a distorted dodeca­hedral CdN4O4 coordination environment. One nitrite group is ordered; the other is disordered with respect to a nitrate group (ratio 0.75:0.25) concerning the O atom that is not involved in bonding to the metal ion. PMID:21522904

Coordination of bis(pyrazol-1-ylamine to palladium(II: influence of the co-ligands and counter-ions on the molecular and crystal structures

Directory of Open Access Journals (Sweden)

María de los Angeles Mendoza

2015-01-01

Full Text Available The structures of a series of complexes with general formula n[Pd(pzaX]Y·mH2O (n = 1, 2; X = Cl, Br, I, N3, NCS; Y = NO3, I, N3, [Pd(SCN4]; m = 0, 0.5, 1 have been determined, where pza is the tridentate ligand bis[2-(3,5-dimethylpyrazol-1-ylethyl]amine, C14H23N5. In all complexes, {bis[2-(3,5-dimethylpyrazol-1-yl-κN2ethyl]amine-κN}chloridopalladium nitrate, [Pd(pzaCl]NO3, (1, {bis[2-(3,5-dimethylpyrazol-1-yl-κN2ethyl]amine-κN}bromidopalladium nitrate, [Pd(pzaBr]NO3, (2, {bis[2-(3,5-dimethylpyrazol-1-yl-κN2ethyl]amine-κN}iodidopalladium iodide hemihydrate, [Pd(pzaI]I·0.5H2O, (3, azido{bis[2-(3,5-dimethylpyrazol-1-yl-κN2ethyl]amine-κN}palladium azide monohydrate, [Pd(pzaN3]N3·H2O, (4, and bis[{bis[2-(3,5-dimethylpyrazol-1-yl-κN2ethyl]amine-κN}(thiocyanato-κNpalladium] tetrakis(thiocyanato-κSpalladate, [Pd(pzaNCS]2[Pd(SCN4], (5, the [Pd(pzaX]+ complex cation displays a square-planar coordination geometry, and the pza ligand is twisted, approximating twofold rotation symmetry. Although the pza ligand is found with the same conformation along the series, the dihedral angle between pyrazole rings depends on the co-ligand X. This angle span the range 79.0 (3–88.6 (1° for the studied complexes. In (3, two complex cations, two I− anions and one water molecule of crystallization are present in the asymmetric unit. In (5, the central amine group of pza is disordered over two positions [occupancy ratio 0.770 (18:0.230 (18]. The complex [Pd(SCN4]2− anion of this compound exhibits inversion symmetry and shows the Pd2+ transition metal cation likewise in a square-planar coordination environment. Compound (5 is also a rare occurrence of a non-polymeric compound in which the pseudohalide ligand NCS− behaves both as thiocyanate and isothiocyanate, i.e. is coordinating either through the N atom (in the cation or the S atom (in the anion.

Synergistic extraction of Eu(III) with N-phosphorylated bis-ureas and chlorinated cobalt bis(dicarbollide) ion

Energy Technology Data Exchange (ETDEWEB)

Selucky, P.; Bubenikova, M.; Rais, J. [UJV Rez, a.s., Rez near Prague (Czech Republic); Gruener, B. [Academy of Sciences of the Czech Republic, Rez near Prague (Czech Republic). Inst. of Inorganic Chemistry; Brusko, V.V. [JSC NIIneftepromchim, Kazan (Russian Federation)

2013-03-01

Extraction of Eu(III) with a synergistic mixture of polydentate N-phosphorylated bis-ureas with the general formula (i-PrO){sub 2}P(O)NHC(O)NHXNHC(O)NHP(O)(Oi-Pr){sub 2} (X = (CH{sub 2}){sub 7}, (CH{sub 2}){sub 2}O(CH{sub 2}){sub 2} and (CH{sub 2}){sub 2}O(CH{sub 2}){sub 2}O(CH{sub 2}){sub 2}) and chlorinated cobalt bis(dicarbollide) ion (CCD-) with formula closo-[(1,2-C{sub 2}B{sub 9}H{sub 8}Cl{sub 3}){sub 2}-3-Co]{sup -} was studied using nitrobenzene as the solvent. Extraction of Eu(III) was very effective up to high concentrations of nitric acid. Eu(III) is most likely extracted into the organic phase as the [EuL{sub 2}]{sup 3+} species whereas the positive charge of extracted complex is compensated by CCD and/or nitrate anions. (orig.)

DTPA: Bis benzimidazole as multi model imaging agent

International Nuclear Information System (INIS)

Srivastava, Vikas; Tiwari, A.K.; Sharma, H.; Sharma, R.; Mishra, A.K.

2010-01-01

Full text: The DTPA bis benzimidazole analogue has been tested for radiopharmaceutical efficacy. The radiolabelling was found more then 98% after 8 hrs and blood kinetics was fast. The compound was also tested for optical imaging agent. The Eu 3+ ion has an absorption band in the visible spectrum (578-582 nm) whose wavelength is very sensitive to even small changes in the coordination environment. Although the intensity of this 7F0 → 5D0 transition is low, the bands are relatively narrow, which allows distinguishing different coordination states of the metal. For Eu 3+ complexes which have two differently hydrated forms in aqueous solution, one observes two absorption bands belonging to the two species. High-resolution UV-visible spectra were recorded in aqueous solutions which show a temperature invariant absorption with two distinct, temperature-dependent absorption bands. The intensity ratio of these two bands changes with temperature: the band at shorter wavelengths is decreasing very slightly, while that at longer wavelengths is increasing with the temperature. The ratio of the integrals of the two bands is related to the equilibrium constant, and its temperature dependence yields the reaction enthalpy and entropy

Cytotoxicity Evaluation of Two Bis-Acryl Composite Resins Using Human Gingival Fibroblasts.

Science.gov (United States)

Gonçalves, Fabiano Palmeira; Alves, Gutemberg; Guimarães, Vladi Oliveira; Gallito, Marco Antônio; Oliveira, Felipe; Scelza, Míriam Zaccaro

2016-01-01

Bis-acryl resins are used for temporary dental restorations and have shown advantages over other materials. The aim of this work was to evaluate the in vitro cytotoxicity of two bis-acryl composite resins (Protemp 4 and Luxatemp Star), obtained at 1, 7 and 40 days after mixing the resin components, using a standardized assay employing human primary cells closely related to oral tissues. Human gingival fibroblast cell cultures were exposed for 24 h to either bis-acryl composite resins, polystyrene beads (negative control) and latex (positive control) extracts obtained after incubation by the different periods, at 37 °C under 5% CO2. Cell viability was evaluated using a multiparametric procedure involving sequential assessment (using the same cells) of mitochondrial activity (XTT assay), membrane integrity (neutral red test) and total cell density (crystal violet dye exclusion test). The cells exposed to the resin extracts showed cell viability indexes exceeding 75% after 24 h. Even when cells were exposed to extracts prepared with longer conditioning times, the bis-acryl composite resins showed no significant cytotoxic effects (p>0.05), compared to the control group or in relation to the first 24 h of contact with the products. There were no differences among the results obtained for the bis-acryl composite resins evaluated 24 h, 7 days and 40 days after mixing. It may be concluded that the bis-acryl resins Protemp 4 and Luxatemp Star were cytocompatible with human gingival fibroblasts, suggesting that both materials are suitable for use in contact with human tissues.

Electron paramagnetic resonance and density-functional theory studies of Cu(II)-bis(oxamato) complexes.

Science.gov (United States)

Bräuer, Björn; Weigend, Florian; Fittipaldi, Maria; Gatteschi, Dante; Reijerse, Edward J; Guerri, Annalisa; Ciattini, Samuele; Salvan, Georgeta; Rüffer, Tobias

2008-08-04

In this work we present the investigation of the influence of electronic and structural variations induced by varying the N,N'-bridge on the magnetic properties of Cu(II)- bis(oxamato) complexes. For this study the complexes [Cu(opba)] (2-) ( 1, opba = o-phenylene- bis(oxamato)), [Cu(nabo)] (2-) ( 2, nabo = 2,3-naphthalene- bis(oxamato)), [Cu(acbo)] (2-) ( 3, acbo = 2,3-anthrachinone- bis(oxamato)), [Cu(pba)] (2-) ( 4, pba = propylene- bis(oxamato)), [Cu(obbo)] (2-) ( 5, obbo = o-benzyl- bis(oxamato)), and [Cu(npbo)] (2-) ( 6, npbo = 1,8-naphthalene- bis(oxamato)), and the respective structurally isomorphic Ni(II) complexes ( 8- 13) have been prepared as ( (n)Bu 4N) (+) salts. The new complex ( (n)Bu 4N) 2[Cu(R-bnbo)].2H 2O ( 7, R-bnbo = (R)-1,1'-binaphthalene-2,2'- bis(oxamato)) was synthesized and is the first chiral complex in the series of Cu(II)-bis(oxamato) complexes. The molecular structure of 7 has been determined by single crystal X-ray analysis. The Cu(II) ions of the complexes 1- 7 are eta (4)(kappa (2) N, kappa (2) O) coordinated with a more or less distorted square planar geometry for 1- 6 and a distorted tetrahedral geometry for 7. Using pulsed Electron Nuclear Double Resonance on complex 6, detailed information about the relative orientation of the hyperfine ( A) and nuclear quadrupole tensors ( Q) of the coordinating nitrogens with respect to the g tensor were obtained. Electron Paramagnetic Resonance studies in the X, Q, and W-band at variable temperatures were carried out to extract g and A values of N ligands and Cu ion for 1- 7. The hyperfine values were interpreted in terms of spin population on the corresponding atoms. The obtained trends of the spin population for the monomeric building blocks were shown to correlate to the trends obtained in the dependence of the exchange interaction of the corresponding trinuclear complexes on their geometry.

3,5-bis(acylamino) benzamides

International Nuclear Information System (INIS)

1976-01-01

Certain 3,5-disubstituted, 2,4,6-triiodoanilides of polyhydroxymonobasic acids have recently been found useful as non-ionic x-ray contrast agents. The 3-(lower acylamino)-5-amino-2,4,6-triiodobenzamides are prepared by hydrogenation of a 3,5-dinitrobenzamide, acylation of the resulting diamino compound to the bis-(acylamino) level and iodination of the acylamino compound

Synthesis and Molecular Structures of Two [1,4-bis(3-pyridyl)-2,3-diazo-1,3-butadiene]-dichloro-Zn(II) Coordination Polymers

OpenAIRE

Lee, Gene-Hsiang; Wang, Hsin-Ta

2006-01-01

Two novel coordination polymers with 3D metal-organic frameworks (MOFs) have been synthesized by reacting 1,4-bis(3-pyridyl)-2,3-diazo-1,3-butadiene (L) with zinc dichloride. Both compounds have the same repeating unit consisting of a distorted tetrahedral Zn(II) center coordinated by two chlorides and two pyridyl nitrogen atoms of two bridging bismonodentate L ligands, however, different structural conformations have been found, one forming a helical chain and the other producing a square-wa...

Normative data of the Barratt Impulsiveness Scale 11 (BIS-11) for Brazilian adults

OpenAIRE

Malloy-Diniz,Leandro F.; Paula,Jonas J. de; Vasconcelos,Alina G.; Almondes,Katie M. de; Pessoa,Rockson; Faria,Leonardo; Coutinho,Gabriel; Costa,Danielle S.; Duran,Victor; Coutinho,Thales V.; Corrêa,Humberto; Fuentes,Daniel; Abreu,Neander; Mattos,Paulo

2015-01-01

Objective:The Barratt Impulsiveness Scale (BIS-11) is a valid and reliable instrument, and one of the most often used tools to assess impulsivity. This study assesses the performance of a large sample of adults by using a version of BIS-11 adapted to Brazilian Portuguese.Methods:We assessed 3,053 adults from eight Brazilian states. Internal consistencies and performance data were presented for two correction criteria of BIS-11: original and the two-factor score.Results:The associations betwee...

Design, synthesis and photoelectrochemical properties of hexagonal metallomacrocycles based on triphenylamine: [M6(4,4'-bis(2,2':6',2''-terpyridinyl)triphenylamine)6(X)12]; [M = Fe(II), PF6- and Zn(II), BF4-].

Science.gov (United States)

Hwang, Seok-Ho; Moorefield, Charles N; Wang, Pingshan; Fronczek, Frank R; Courtney, Brandy H; Newkome, George R

2006-08-07

Synthesis of a novel bis(terpyridine) ligand, 4,4'-bis(2,2':6',2''-terpyridinyl)triphenylamine, utilizing triphenylamine, as a specific angle controller, has led to the self-assembly of a unique hexagonal metallomacrocycle family, [Fe6(2)6(PF6)12] and [Zn6(2)6(BF4)12], utilizing terpyridine-metal(II)-terpyridine connectivity. The crystal structure of the novel ligand shows that the angle between the two terpyridinyl moieties is 119.69 degrees , which enabled the formation of the hexagonal-shaped macrocycles. The crystal packing architectures of this starting ligand revealed channels induced by solvent encapsulation. Following complexation of this ligand with transition metals [Fe(II) or Zn(II)] in a one-pot reaction, the resultant structures were characterized by (1)H and (13)C NMR, UV/Vis and mass spectroscopies. The expected metal-to-ligand charge transfer (MLCT; lambda(max) = 582 nm) and emission (lambda(em) = 575 nm) characteristics were exhibited by both [Fe6(2)6(PF6)12] and[Zn6(2)6(BF4)12]. The photoelectrochemical characteristics of these hexagonal metallomacrocycles demonstrate that they can be used as sensitizers in dye-sensitized solar cells.

Theory and experiment studies of the 1,4-bis(4-methoxylstyryl)benzene as a wavelength shifter of liquid scintillator

Energy Technology Data Exchange (ETDEWEB)

Zheng, Zhanlong [School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, Mianyang 621010 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Zhu, Jiayi [Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, Mianyang 621010 (China); Bi, Yutie, E-mail: biyutie@sina.com [Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, Mianyang 621010 (China); Xu, Yewei [School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Zhang, Qianfeng [Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, Mianyang 621010 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Zhang, Xing [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Li, Junjiang [Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026 (China); Zhang, Lin, E-mail: zhlmy@sina.com [School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, Mianyang 621010 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China)

2017-03-15

A novel wavelength shifter of the 1,4-bis(4-methoxylstyryl)benzene (bis-4-MOSB) was synthesized by employing the classical Horner-Wadsworth-Emmons reaction. Feasible analysis of the bis-4-MOSB as the wavelength shifter in a ternary liquid scintillator, in which p-xylene (PX) was as the solvent and 2,5-diphenyloxazole (PPO) was as the primary fluor, was carried out. The optimum prescription with 3.5 g/L PPO and 25 mg/L bis-4-MOSB was obtained with regard to the light yield. A series of characterization tests based on the optimal formulation were performed. Compared with the 1,4-bis(2-methylstyryl)benzene (bis-MSB), the maximum absorption peak at 356 nm and maximum emission peak at 421 nm in n-hexane with the red shift of 10 nm and 3 nm, respectively, were measured accordingly. The light yield characterized by using a relative measurement method achieved as high as 75.85% of the anthracene crystal. A brief density functional calculation was conducted to have an insight into the electronic structure characteristic of the bis-4-MOSB in the scintillation process. - Graphic abstract: In our work, 1,4-bis(4-methoxylstyryl)benzene (bis-4-MOSB), as a novel wavelength shifter of liquid scintillator, was designed and synthesized. A comparison including absorption spectra and electronic structure characteristic between bis-4-MOSB and bis-MSB were conducted. Its maximum emission peak lied at 421 nm in n-hexane was corresponded to the maximum response range wavelength of PMT for the bis-4-MOSB. Furthermore, compared with the bis-MSB, the wavelength shifter of bis-4-MOSB showed a better luminescence performance.

Theory and experiment studies of the 1,4-bis(4-methoxylstyryl)benzene as a wavelength shifter of liquid scintillator

International Nuclear Information System (INIS)

Zheng, Zhanlong; Zhu, Jiayi; Bi, Yutie; Xu, Yewei; Zhang, Qianfeng; Zhang, Xing; Li, Junjiang; Zhang, Lin

2017-01-01

A novel wavelength shifter of the 1,4-bis(4-methoxylstyryl)benzene (bis-4-MOSB) was synthesized by employing the classical Horner-Wadsworth-Emmons reaction. Feasible analysis of the bis-4-MOSB as the wavelength shifter in a ternary liquid scintillator, in which p-xylene (PX) was as the solvent and 2,5-diphenyloxazole (PPO) was as the primary fluor, was carried out. The optimum prescription with 3.5 g/L PPO and 25 mg/L bis-4-MOSB was obtained with regard to the light yield. A series of characterization tests based on the optimal formulation were performed. Compared with the 1,4-bis(2-methylstyryl)benzene (bis-MSB), the maximum absorption peak at 356 nm and maximum emission peak at 421 nm in n-hexane with the red shift of 10 nm and 3 nm, respectively, were measured accordingly. The light yield characterized by using a relative measurement method achieved as high as 75.85% of the anthracene crystal. A brief density functional calculation was conducted to have an insight into the electronic structure characteristic of the bis-4-MOSB in the scintillation process. - Graphic abstract: In our work, 1,4-bis(4-methoxylstyryl)benzene (bis-4-MOSB), as a novel wavelength shifter of liquid scintillator, was designed and synthesized. A comparison including absorption spectra and electronic structure characteristic between bis-4-MOSB and bis-MSB were conducted. Its maximum emission peak lied at 421 nm in n-hexane was corresponded to the maximum response range wavelength of PMT for the bis-4-MOSB. Furthermore, compared with the bis-MSB, the wavelength shifter of bis-4-MOSB showed a better luminescence performance.

Separation of Am(III) from Eu(III) by mixtures of triazynylbipyridine and bis(dicarbollide) extractants. The composition of the metal complexes extracted

International Nuclear Information System (INIS)

Narbutt, J.; Krejzler, J.

2006-01-01

Separation of trivalent actinides, in particular americium and curium, from lanthanides is an important step in an advanced partitioning process for future reprocessing of spent nuclear fuels. The use of soft donor (N and S) ligands makes it possible to separate the two groups of elements, probably because of the more covalent character in the complexes with actinides compared to the lanthanides. The aim of present work was to study solvent extraction of Am(III) and Eu(III) in a similar system with diethylhemi-BTP and COSAN: protonated bis(chlorodicarbollido)cobalt(III) or commo-3,3-cobalta-bis(8,9,12-trichlora-1,2-dicarbaclosododecaborane)ic acid. The present research was focused on both the determination of conditions for the separation of 241 Am(III) from 152 Eu in aqueous nitrate solution by using a synergistic extraction system and on the modelling of the process by slope analysis. Obtained values of the separation factors supported by the computer modelling permitted drawing the conclusions on the mechanism of the process and on the structure of extracted species

The preparation and use of metal salen complexes derived from cyclobutane diamine

Science.gov (United States)

Patil, Smita

The helix is an important chiral motif in nature, there is increasing development in field of helical transition metal complexes and related supramolecular structures. Hence, the goals of this work are to apply the principles of helicity in order to produce metal complexes with predictable molecular shapes and to study their properties as asymmetric catalysts. Computational studies suggest that the (1R,2 R)-cyclobutyldiamine unit can produce highly twisted salen complexes with a large energy barrier between the M and P helical forms. To test this prediction, the tartrate salt of (1R,2R)-cyclobutyldiamine was synthesized and condensed with a series of saliclaldehydes to produce novel salen ligands. The salicylaldehydes chosen have extended phenanthryl or benz[a]anthryl sidearms to encourage formation of helical coordination complexes. These ligands were metallated with zinc, iron and manganese salts to produce salen metal complexes which were characterized by NMR analysis, high-resolution mass spectrometry, and IR spectroscopy. A second ligand type, neutral bis(pyridine-imine) has also been synthesized from (1R,2R)-cyclobutyldiamine and quinolylaldehydes. The synthesis of bis(pyridine-imine) ligands was conducted using greener method, solvent assisted grinding. These ligands, in-situ with nickel metal salts, showed good catalytic activity for asymmetric Diels-Alder reactions. The third ligand type studied was chiral acid-functionalized Schiff-base ligands. These were synthesized by the condensation of 3-formyl-5-methyl salicylic acid and (1R,2R)-cyclobutyldiamine. With this type of ligand, there is possibility of producing both mono and dinuclear metal complexes. In our studies, we were only able to synthesize mononuclear complexs. These were tested as catalysts for asymmetric direct Mannich-type reaction, but were found to be ineffective.

Disorder-derived, strong tunneling attenuation in bis-phosphonate monolayers

Science.gov (United States)

Pathak, Anshuma; Bora, Achyut; Liao, Kung-Ching; Schmolke, Hannah; Jung, Antje; Klages, Claus-Peter; Schwartz, Jeffrey; Tornow, Marc

2016-03-01

Monolayers of alkyl bisphosphonic acids (bisPAs) of various carbon chain lengths (C4, C8, C10, C12) were grown on aluminum oxide (AlO x ) surfaces from solution. The structural and electrical properties of these self-assembled monolayers (SAMs) were compared with those of alkyl monophosphonic acids (monoPAs). Through contact angle (CA) and Kelvin-probe (KP) measurements, ellipsometry, and infrared (IR) and x-ray photoelectron (XPS) spectroscopies, it was found that bisPAs form monolayers that are relatively disordered compared to their monoPA analogs. Current-voltage (J-V) measurements made with a hanging Hg drop top contact show tunneling to be the prevailing transport mechanism. However, while the monoPAs have an observed decay constant within the typical range for dense monolayers, β mono  =  0.85  ±  0.03 per carbon atom, a surprisingly high value, β bis  =  1.40  ±  0.05 per carbon atom, was measured for the bisPAs. We attribute this to a strong contribution of ‘through-space’ tunneling, which derives from conformational disorder in the monolayer due to strong interactions of the distal phosphonic acid groups; they likely form a hydrogen-bonding network that largely determines the molecular layer structure. Since bisPA SAMs attenuate tunnel currents more effectively than do the corresponding monoPA SAMs, they may find future application as gate dielectric modification in organic thin film devices.

2-(1,3-Dithiolan-2-ylidene)-5-(1,3-dithian-2-ylidene)-1,3,4,6- tetrathiapentalene(DHDA-TTP), a hybrid of BDH-TTP and BDA-TTP, and its metallic cation-radical salts.

Science.gov (United States)

Yamada, Jun-ichi; Watanabe, Maki; Toita, Takashi; Akutsu, Hiroki; Nakatsuji, Shin'ichi; Nishikawa, Hiroyuki; Ikemoto, Isao; Kikuchi, Koichi

2002-05-21

The synthesis and electrochemical properties of the DHDA-TTP donor, a hybrid of 2,5-bis(1,3-dithiolan-2-ylidene)-1,3,4,6-tetrathiapentalene (BDH-TTP) and 2,5-bis(1,3-dithian-2-ylidene)-1,3,4,6-tetrathiapentalene (BDA-TTP), has been investigated, and its ability to form metallic cation-radical salts is elucidated.

Preparation of a Bis-GMA-Free Dental Resin System with Synthesized Fluorinated Dimethacrylate Monomers

Directory of Open Access Journals (Sweden)

Shuzhen Luo

2016-12-01

Full Text Available With the aim of reducing human exposure to Bisphenol A (BPA derivatives in dentistry, a fluorinated dimethacrylate monomer was synthesized to replace 2,2-bis[4-(2-hydroxy-3-methacryloy-loxypropyl-phenyl]propane (Bis-GMA as the base monomer of dental resin. After mixing with reactive diluent triethyleneglycol dimethacrylate (TEGDMA, fluorinated dimethacrylate (FDMA/TEGDMA was prepared and compared with Bis-GMA/TEGDMA in physicochemical properties, such as double bond conversion (DC, volumetric shrinkage (VS, water sorption (WS and solubility (WSL, flexural strength (FS and modulus (FM. The results showed that, when compared with Bis-GMA based resin, FDMA-based resin had several advantages, such as higher DC, lower VS, lower WS, and higher FS after water immersion. All of these revealed that FDMA had potential to be used as a substitute for Bis-GMA. Of course, many more studies, such as biocompatibility testing, should be undertaken to prove whether FDMA could be applied in clinic.

Synthesis and Anti-Proliferative Effects of Mono- and Bis-Purinomimetics Targeting Kinases

Directory of Open Access Journals (Sweden)

Andrea Bistrović

2017-11-01

Full Text Available A series of mono-pyrrolo[2,3-d]pyrimidines 4a–4k, unsymmetrical bis-purine isosteres 5a–5e and symmetrical bis-pyrrolo[2,3-d]pyrimidines 6a and 6b connected via di(1,2,3-triazolylphenyl linker were synthesized by click chemistry. Whereas mono- 4g and bis-pseudopurine 5e showed selective inhibitory activities on cervical carcinoma (HeLa cells, bis-pyrrolo[2,3-d]pyrimidine 6b exhibited potent and selective anti-proliferative effect in the nanomolar range on pancreatic carcinoma (CFPAC-1 cells. Among these, compound 6b induced a significant reduction in the expression level of CDK9 (cyclin-dependent kinase 9/cyclin T1 in CFPAC-1 cells concomitant with attenuation of proliferative signaling mediated by c-Raf (rapidly accelerated fibrosarcoma and p38 MAP (mitogen-activated protein kinases. Our findings encourage further development of novel structurally related analog of 6b to obtain more selective anticancer agent for treating pancreatic cancer.

Impact of age on both BIS values and EEG bispectrum during anaesthesia with sevoflurane in children.

Science.gov (United States)

Wodey, E; Tirel, O; Bansard, J Y; Terrier, A; Chanavaz, C; Harris, R; Ecoffey, C; Senhadji, L

2005-06-01

The aim of this study was to evaluate the potential relationship between age, BIS (Aspect), and the EEG bispectrum during anaesthesia with sevoflurane. BIS and raw EEG were recorded at a steady state of 1 MAC in 100 children, and during a decrease from 2 to 0.5 MAC in a sub-group of 29 children. The bispectrum of the EEG was estimated using MATLAB software. For analysis, the bispectrum was divided into 36 frequencies of coupling (P(i))--the MatBis. A multiple correspondence analysis (MCA) was used to establish an underlying structure of the pattern of each individual's MatBis at 1 MAC. Clustering of children into homogeneous groups was conducted by a hierarchical ascending classification (HAC). The level of statistical significance was set at 0.05. At 1 MAC, the BIS values for all children ranged from 20 to 74 (median 40). Projection of both age and BIS value recorded at 1 MAC onto the structured model of the MCA showed them to be distributed along the same axis, demonstrating that the different values of BIS obtained in younger or older children are mainly dependent on their MatBis. At 1 MAC, six homogeneous groups of children were obtained through the HAC. Groups 5 (30 months; range 23-49) and 6 (18 months; range 6-180) were the younger children and Group 1 (97 months; range 46-162) the older. Groups 5 and 6 had the highest median values of BIS (54; range 50-59) (55; range 26-74) and Group 1 the lowest values (29; range 22-37). The EEG bispectrum, as well as the BIS appeared to be strongly related to the age of children at 1 MAC sevoflurane.

Structural and electrochemical studies of TiO2 complexes with (4,4'-((1E,1'E)-(2,5-bis(octyloxy)-1,4-phenylene)bis(ethene-2,1-diyl))bis-(E)-N-(2,5-bis(octyloxy)benzylidene)) imine derivative bases towards organic devices.

Science.gov (United States)

Rozycka, Anna; Iwan, Agnieszka; Bogdanowicz, Krzysztof Artur; Filapek, Michal; Górska, Natalia; Hreniak, Agnieszka; Marzec, Monika

2018-06-12

Three (4,4'-((1E,1'E)-(2,5-bis(octyloxy)-1,4-phenylene)bis(ethene-2,1-diyl))bis-(E)-N-(2,5-bis(octyloxy)benzylidene)) imine derivatives were synthesized via a condensation reaction with p-toluenesulfonic acid as a catalyst. The effects of the end groups and vinylene (-HC[double bond, length as m-dash]CH-) moieties on the structural, thermal, optical, electrochemical and photovoltaic properties of imines were investigated to check the influence of TiO2 on the imine properties. The thermal behavior of imines and their complexes with TiO2 was widely investigated using FT-IR, XRD, DSC and POM methods in order to determine the order type in the imine structure. All imines present the highest occupied molecular orbital (HOMO) levels of about -5.39 eV (SAI1 and SAI2) and -5.27 eV (SAI3) and the lowest unoccupied molecular orbital (LUMO) levels at about -3.17 eV. The difference of the end groups in the imines in each case did not affect redox properties. Generally, both oxidation and reduction are easier after TiO2 addition and it also changes the HOMO-LUMO levels of imines. Moreover, changes in the characteristic bands for imines in the region 1500-1700 cm-1 observed as a drastic decrease of intensity or even disappearance of bands in the imine : TiO2 mixture suggest the formation of a complex (C[double bond, length as m-dash]N)-TiO2. Organic devices with the configuration of ITO/TiO2/SAIx (or SAIx : TiO2)/Au were fabricated and investigated in the presence and absence of visible light irradiation with an intensity of 93 mW cm-2. In all imines and complexes with TiO2, the generation of the photocurrent indicates their use as photodiodes and the best result was observed for SAI3 : TiO2 complexes.

Acoplamiento molecular y actividad antibacteriana de las tioureas (R,R-N,N´-bis(1-ciclohexiletiltiourea y (R,R-N,N´-bis(1-feniletiltiourea

Directory of Open Access Journals (Sweden)

Fabían Martínez Flores

2013-05-01

Full Text Available Las tioureas, son compuestos resultantes de sustituir el átomo de oxígeno de la urea (NH2CONH2 por un átomo de azufre (NH2CSNH2. Actualmente se ha visto que las tioureas presentan diversas actividades biológicas, dentro de las que se encuentra la antimicrobiana. En el presente estudio se evaluó la actividad antibacteriana mediante acoplamiento molecular entre la enzima DNA girasa (receptor y las tioureas (R, R-N,N´-bis(1 ciclohexiletiltiourea (CYTU1 y (R,R-N,N´-bis(1-feniletiltiourea (CYTU2 como ligando en busca del posible mecanismo de acción de estos compuestos, los resultados muestran que existe interacción entre la enzima y ambas tioureas en el sitio activo. Por otro lado, también se evaluó la actividad antibacteriana frente a cepas de Sthapylococcus aureus, Escherichia coli y Pseudomonas fluorescens, mediante el método de microdilución en caldo con la adición de bromuro de 3-(4,5-dimetil-2-tiazolil-2,5-difeniltetrazolium (MTT, como parte del ensayo de viabilidad, mostrando una disminución de la misma sólo contra las bacterias gram negativas, siendo la tiourea CYTU2 la que mostró mejor actividad antibacteriana. Molecular docking and antibacterial activity thioureas (R,R-N,N´-bis(1-cyclohexyethylthiourea and (R,R-N,N´-bis(1-phenylethylthiourea Abstract Thioureas are resultant compounds of substitute the oxygen atom from urea (NH2CONH2 for a sulfur atom (NH2CSNH2. There are evidential that show the biological activity of thioureas, within which are antibacterial activity. We studied the antibacterial activity of two thioureas (R,R-N,N´-bis(1 cyclohexylethylthiourea (CYTU1 y (R,R-N,N´-bis(1 phenylethylthiourea (CYTU2 in silico using Molecular Docking between the DNA gyrase enzyme (receptor and the two thioureas (ligand. The results showed interaction between DNA girase and both thioureas on the pocket of the enzyme. By other hand, the biological activity was evaluated against the following bacterial strains: Sthapylococcus

Temperature induced reversible polymorphic phase transformations in a bis-hydrazone compound

Science.gov (United States)

Jayant, Vikrant; Das, Dinabandhu

2018-03-01

Two reversible polymorphic phase transformation of 2,3-butanedione, 2,3- bis[4,4‧-bis(diethylamino)benzophenone hydrazone] (DEBH) have been identified in DSC experiment. Topotactic phase transformation of three polymorphs has been observed in variable temperature Single Crystal X-ray Diffraction experiment. The reversible phase transformation of bulk material has been confirmed by Powder X-ray diffraction study.

Correlating electronic structure with corrosion inhibition potentiality of some bis-benzimidazole derivatives for mild steel in hydrochloric acid: Combined experimental and theoretical studies

International Nuclear Information System (INIS)

Dutta, Alokdut; Saha, Sourav Kr.; Banerjee, Priyabrata; Sukul, Dipankar

2015-01-01

Highlights: • Bis-benzimidazole derivatives as good corrosion inhibitors for mild steel in acid. • Simultaneous both way electron-transfer is expected to occur during adsorption. • Role of molecular conformation on inhibition efficiency is demonstrated. • Good correlation between inhibition efficiency and molecular parameters established. • MD simulation results support experimental observations. - Abstract: Four different bis-benzimidazole (BBI) derivatives, tested as potential corrosion inhibitors for mild steel in 1 M HCl, have revealed good inhibition efficiency for long period of exposure. Inhibitors impart high resistance towards charge transfer across metal–electrolyte interface and behave broadly as mixed type. DFT calculations are used to correlate inhibition potentiality with intrinsic molecular parameters. From the optimized geometry of BBI derivatives, electron distribution in HOMO and LUMO and Fukui indices of each atom, possible modes of interaction of BBI derivatives with mild steel surface have been predicted. Energy corresponding to inhibitor-metal surface interaction is evaluated following molecular dynamics simulation

Metallic conductivity in a disordered charge-transfer salt derived from cis-BET-TTF

Energy Technology Data Exchange (ETDEWEB)

Rovira, C. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Tarres, J. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Ribera, E. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Veciana, J. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Canadell, E. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Molins, E. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Mas, M. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Laukhin, V. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain)]|[Rossijskaya Akademiya Nauk, Chernogolovka (Russian Federation). Inst. Khimicheskoj Fiziki; Doublet, M.L. [Lab. de Structure et Dynamique (CNRS), Univ. de Montpellier 2 (France); Cowan, D.O. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Chemistry; Yang, S. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Chemistry

1997-02-28

The first example of a metallic charge-transfer salt derived from cis-bis(ethylenethio)-tetrathiafulvalene (BET-TTF) is reported. (BET-TTF){sub 2}SCN and (BET-TTF)SCN salts were obtained by electrocrystallization starting from trans-BET-TTF. X-ray crystal structure of the mixed-valence salt revealed that trans-cis isomerization occurs upon one electron oxidation. In spite of the structural disorder in both BET-TTF and the counterion, 2:1 salt is metallic down to 60 K and then resistance increases slowly down to 4 K. (orig.)

Comprehensive and Facile Synthesis of Some Functionalized Bis-Heterocyclic Compounds Containing a Thieno[2,3-b]thiophene Motif

Science.gov (United States)

Mabkhot, Yahia N.; Barakat, Assem; Al-Majid, Abdullah M.; Alshahrani, Saeed A.

2012-01-01

A comprehensive and facile method for the synthesis of new functionalized bis-heterocyclic compounds containing a thieno[2,3-b]thiophene motif is described. The hitherto unknown bis-pyrazolothieno[2,3-b]thiophene derivatives 2a–c, bis-pyridazin othieno[2,3-b]thiophene derivatives 4, bis-pyridinothieno[2,3-b]thiophene derivatives 6a,b, and to an analogous bis-pyridinothieno[2,3-b]thiophene nitrile derivatives 7 are obtained. Additionally, the novel bis-pyradazinonothieno[2,3-b]thiophene derivatives 9, and nicotinic acid derivatives 10, 11 are obtained via bis-dienamide 8. The structures of all newly synthesized compounds have been elucidated by 1H, 13C NMR, GCMS, and IR spectrometry. These compounds represent a new class of sulfur and Nitrogen containing heterocycles that should also be of interest as new materials. PMID:22408452

A novel one-pot synthesis of spirooxindole derivatives catalyzed by ...

African Journals Online (AJOL)

Nano zinc oxide was explored as a heterogeneous and reusable catalyst for the one-pot synthesis of spirooxindoles via three-component reaction between urea, isatin, and 1,3-dicarbonyl compounds. KEY WORDS: Nano-ZnO, Spirooxindoles, Isatin. Bull. Chem. Soc. Ethiop. 2013, 27(2), 309-314.

Activity of cationically substituted bis-benzimidazoles against experimental Pneumocystis carinii pneumonia.

Science.gov (United States)

Tidwell, R R; Jones, S K; Naiman, N A; Berger, L C; Brake, W B; Dykstra, C C; Hall, J E

1993-01-01

On the basis of a previously observed correlation between the antimicrobial activity and DNA binding strength of dicationic molecules, a series of 10 dicationically substituted bis-benzimidazoles were tested for activity in the rat model of Pneumocystis carinii pneumonia. One of the compounds, 1,4-bis[5-(2-imidazolinyl)-2-benzimidazolyl]butane, was found to be more potent and less toxic than pentamidine. PMID:8215291

Correlation of bispectral index (BIS monitoring and end-tidal sevoflurane concentration in a patient with lobar holoprosencephaly

Directory of Open Access Journals (Sweden)

Dario Galante

2015-10-01

Full Text Available ABSTRACTOBJECTIVE: The bispectral index (BIS is a parameter derived by electroencephalography (EEG which provides a direct measurement of the effects of sedatives and anesthetics on the brain and offers guidance on the adequacy of anesthesia. The literature lacks studies on BIS monitoring in pediatric patients with congenital brain disease undergoing general anesthesia.CLINICAL FEATURES: A 13-year-old child weighing 32 kg, suffering from lobar holoprosencephaly, underwent surgery in which the bispectral index (BIS monitoring the depth of anesthesia showed an abnormal response. Detailed analysis of the trends of BIS values in the different observation times demonstrated sudden falls and repetitive values of BIS likely related to repetitive epileptiform electrical activity caused by sevoflurane.CONCLUSION: The BIS is a very useful monitoring tool for assessing the degree of depth of anesthesia and to analyze the electroencephalographic variations of anesthetics. Particular attention should be given to patients with congenital disorders of the central nervous system in which the BIS may give abnormal responses that do not reflect an accurate assessment of the depth of anesthesia.

Synthesis, chemical and biological properties of the new mono- and bis-derivatives of imidazoles

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E. V. Welchinska

2014-12-01

Full Text Available The aim of research. The problem of finding effective antitumour medical preparation with low toxicity is an important issue of medical and pharmaceutical chemistry. Knowledge of cancer cell features and its metabolism enables to predict the direction of chemical and biological research, to conduct a targeted synthesis of potential drugs, and to assess their applicability in oncological practice as antitumor agents. The purpose of work is to explain preformed heterocycles as purines, its synthesis and investigation of chemical and biological properties. After construction of the potential active structures we proposed the new method of original derivatives synthesis which are received on the base of imidazole, from one side, and fluorocontaining common anesthetic halothane (2-bromo-1,1,1-trifluoro-2-chloroethane from other side. Molecular complex of more perspective biologically active bis-imidazole with antitumour bacterial lectine has been received. With the purpose to synthesize potential antitumour compounds on the base of halothane and imidazole, new convenient methods for the preparation of original heterocyclic derivatives of imidazole have been described. The structure and composition of synthesized compound has been confirmed by the methods of elemental analysis, IR- and NMRІН-spectra. Materials and methods. The majority of the absolute organic solvents (benzene, dimethylformamide, ethyl ester employed in the present studies were distilled before their use. Organic solvents were dried over anhydrous magnesium sulfate or metallic sodium. Gas-liquid chromatography was carried out by Perkin Elmer chromatograph with UV-detector ("Perkin", Germany. IR spectra were recorded in a UR-20 spectrometer ("Charles Ceise Hena", Germany. The 1HNMR spectra were recorded in DMSO-d6 on a 200 MHz BrakerWP-200 ("Braker", Switzerland or Varian T-60 spectrometer ("Varian", USA. Investigation of critical toxicity of new compounds was carried out at

Monitoring sleep depth: analysis of bispectral index (BIS) based on polysomnographic recordings and sleep deprivation.

Science.gov (United States)

Giménez, Sandra; Romero, Sergio; Alonso, Joan Francesc; Mañanas, Miguel Ángel; Pujol, Anna; Baxarias, Pilar; Antonijoan, Rosa Maria

2017-02-01

The assessment and management of sleep are increasingly recommended in the clinical practice. Polysomnography (PSG) is considered the gold standard test to monitor sleep objectively, but some practical and technical constraints exist due to environmental and patient considerations. Bispectral index (BIS) monitoring is commonly used in clinical practice for guiding anesthetic administration and provides an index based on relationships between EEG components. Due to similarities in EEG synchronization between anesthesia and sleep, several studies have assessed BIS as a sleep monitor with contradictory results. The aim of this study was to evaluate objectively both the feasibility and reliability of BIS for sleep monitoring through a robust methodology, which included full PSG recordings at a baseline situation and after 40 h of sleep deprivation. Results confirmed that the BIS index was highly correlated with the hypnogram (0.89 ± 0.02), showing a progressive decrease as sleep deepened, and an increase during REM sleep (awake: 91.77 ± 8.42; stage N1: 83.95 ± 11.05; stage N2: 71.71 ± 11.99; stage N3: 42.41 ± 9.14; REM: 80.11 ± 8.73). Mean and median BIS values were lower in the post-deprivation night than in the baseline night, showing statistical differences for the slow wave sleep (baseline: 42.41 ± 9.14 vs. post-deprivation: 39.49 ± 10.27; p = 0.02). BIS scores were able to discriminate properly between deep (N3) and light (N1, N2) sleep. BIS values during REM overlapped those of other sleep stages, although EMG activity provided by the BIS monitor could help to identify REM sleep if needed. In conclusion, BIS monitors could provide a useful measure of sleep depth in especially particular situations such as intensive care units, and they could be used as an alternative for sleep monitoring in order to reduce PSG-derived costs and to increase capacity in ambulatory care.

Formation of Mixed-Ligand Complexes of Pd2+ with Nucleoside 5'-Monophosphates and Some Metal-Ion-Binding Nucleoside Surrogates

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Oleg Golubev

2014-10-01

Full Text Available Formation of mixed-ligand Pd2+ complexes between canonical nucleoside 5'-monophosphates and five metal-ion-binding nucleoside analogs has been studied by 1H-NMR spectroscopy to test the ability of these nucleoside surrogates to discriminate between unmodified nucleobases by Pd2+-mediated base pairing. The nucleoside analogs studied included 2,6-bis(3,5-dimethylpyrazol-1-yl-, 2,6-bis(1-methylhydrazinyl- and 6-(3,5-dimethylpyrazol-1-yl-substituted 9-(β-d-ribofuranosylpurines 1–3, and 2,4-bis(3,5-dimethylpyrazol-1-yl- and 2,4-bis(1-methylhydrazinyl-substituted 5-(β-d-ribofuranosyl-pyrimidines 4–5. Among these, the purine derivatives 1-3 bound Pd2+ much more tightly than the pyrimidine derivatives 4, 5 despite apparently similar structures of the potential coordination sites. Compounds 1 and 2 formed markedly stable mixed-ligand Pd2+ complexes with UMP and GMP, UMP binding favored by 1 and GMP by 2. With 3, formation of mixed-ligand complexes was retarded by binding of two molecules of 3 to Pd2+.

Correlation of bispectral index (BIS monitoring and end-tidal sevoflurane concentration in a patient with lobar holoprosencephaly

Directory of Open Access Journals (Sweden)

Dario Galante

2015-09-01

Full Text Available Objective: The bispectral index (BIS is a parameter derived by electroencephalography (EEG which provides a direct measurement of the effects of sedatives and anesthetics on the brain and offers guidance on the adequacy of anesthesia. The literature lacks studies on BIS monitoring in pediatric patients with congenital brain disease undergoing general anesthesia. Clinical features: A 13-year-old child weighing 32 kg, suffering from lobar holoprosencephaly, underwent surgery in which the bispectral index (BIS monitoring the depth of anesthesia showed an abnormal response. Detailed analysis of the trends of BIS values in the different observation times demonstrated sudden falls and repetitive values of BIS likely related to repetitive epileptiform electrical activity caused by sevoflurane. Conclusion: The BIS is a very useful monitoring tool for assessing the degree of depth of anesthesia and to analyze the electroencephalographic variations of anesthetics. Particular attention should be given to patients with congenital disorders of the central nervous system in which the BIS may give abnormal responses that do not reflect an accurate assessment of the depth of anesthesia. Resumo: Objetivo: O índice bispectral (BIS é um parâmetro derivado por eletroencefalografia (EEG que fornece uma medida direta dos efeitos de sedativos e anestésicos no cérebro e orientação sobre a adequação da anestesia. A literatura carece de estudos sobre a monitoração do BIS em pacientes pediátricos com doença cerebral congênita submetidos à anestesia geral. Características clínicas: Criança de 13 anos de idade, pesando 32 kg, com holoprosencefalia lobar, foi submetida à cirurgia em que a monitoração da profundidade da anestesia com o uso do BIS mostrou uma resposta anormal. A análise detalhada das tendências dos valores do BIS nos diferentes tempos de observação mostrou quedas súbitas e valores repetitivos do BIS, provavelmente relacionados �

Non-Heme Iron Catalysts with a Rigid Bis-Isoindoline Backbone and Their Use in Selective Aliphatic C−H Oxidation

NARCIS (Netherlands)

Chen, Jianming; Lutz, Martin; Milan, Michela; Costas, Miquel; Otte, Matthias; Klein Gebbink, Bert

2017-01-01

Iron complexes derived from a bis-isoindoline-bis-pyridine ligand platform based on the BPBP ligand (BPBP=N,N′-bis(2-picolyl)-2,2′-bis-pyrrolidine) have been synthesized and applied in selective aliphatic C−H oxidation with hydrogen peroxide under mild conditions. The introduction of benzene

Bis(heterocumulenes) derived from the 1,4-diphenyl-1,3-butadiyne framework. Synthesis of three new classes of axially chiral biheteroaryls.

Science.gov (United States)

Alajarín, Mateo; Bonillo, Baltasar; Vidal, Angel; Bautista, Delia

2008-01-04

Bis(ketenimines) and bis(carbodiimides) derived from 1,4-bis(2-aminophenyl)-1,3-butadiynes via two independent biradical cyclizations provided, respectively, axially chiral bis(benzocarbazoles) and bis(quinindolines). Mixed biheteroaryls, consisting of benzocarbazole and quinindoline units, have been also prepared by a slightly modified strategy.

Evaluation of extractant-coated magnetic microparticles for the recovery of hazardous metals from waste solution

International Nuclear Information System (INIS)

Kaminski, M. D.

1998-01-01

A magnetically assisted chemical separation (MACS) process was developed earlier at Argonne National Laboratory (ANL). This compact process was designed for the separation of transuranics (TRU) and radionuclides from the liquid waste streams that exist at many DOE sites, with an overall reduction in waste volume requiring disposal. The MACS process combines the selectivity afforded by solvent extractant/ion exchange materials with magnetic separation to provide an efficient chemical separation. Recently, the MACS process has been evaluated with acidic organophosphorus extractants for hazardous metal recovery from waste solutions. Moreover, process scale-up design issues have been addressed with respect to particle filtration and recovery. Two acidic organophosphorus compounds have been investigated for hazardous metal recovery, bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanexreg-sign 272) and bis(2,4,4-trimethylpentyl) dithiophosphinic acid (Cyanexreg-sign 301). Coated onto magnetic microparticles, these extractants demonstrated superior recovery of hazardous metals from solution, relative to what was expected on the basis of results from solvent extraction experiments. The results illustrate the diverse applications of MACS technology for dilute waste streams. Preliminary process scale-up experiments with a high-gradient magnetic separator at Oak Ridge National Laboratory have revealed that very low microparticle loss rates are possible

Polyaza macroligands as potential agents for heavy metal removal from wastewater

Directory of Open Access Journals (Sweden)

Elizondo Martínez Perla

2013-01-01

Full Text Available Two polyaza macroligands N,N´-bis(2-aminobenzyl-1,2- ethanediamine (L1 and 3,6,9,12-tetraaza-4(1,2,11(1,2-dibenzo-1(1,3- piridinaciclotridecafano (L2 were characterized and investigated for their metal ion extraction capabilities. The nature of all complexes was established by spectroscopic techniques. The equilibrium constants were determined by spectrophotometric and potentiometric techniques and the residual concentration of metals in the solutions by Atomic Absorption Spectrometry (AAS. The capacity of the ligands to remove heavy metals such as Cu(II, Ni(II, Cd(II, Zn(II and Pb(II as insoluble complexes was evaluated in wastewater from industrial effluents. These agents showed high affinity for the studied metals. The values of equilibrium constants of the isolated complexes (between 1 x 104 and 2 x 107 demonstrated the feasibility of applying these chelating agents as an alternative to remove heavy metals from industrial effluents.

[Preparation of clear thermosetting resin for veneered crown from several bisMEPP monomers (author's transl)].

Science.gov (United States)

Tanaka, T; Nakabayashi, N; Masuhara, E

1978-07-01

The whitish translucent shade of a thermosetting resin cured from a mixture of a 2,2-Bis (p-methacryloxy (ethoxy)1-2 phenyl)-propane monomer and PMMA pearls makes it difficult to reconstruct a shade of the natural tooth. The attempt to improve the transparency of the mixed polymer was made in this study. Varying the molecular weight of BisMEPP monomer, PMMA polymer and curing temperature, cured specimens were prepared and their transparency was measured with a spectrophotometer. The results obtained are as follows. 1) In any molecular weight of PMMA, BisMEPP with 2.3 to 3.3 average number of ethylene oxide linkage showed the highest transpalency on the specimen. 2) With increasing the curing temperature, transpalency of the specimens made from BisME4.0 PP increased. With another molecular of BisMEPP, transpalency of the cured specimens showed the highest transpalency at the curing temperature of 120 degrees C. 3) With increasing the molecular weight of PMMA, the transpalency increased.

Rahumeelse läbisõidu õigus Venemaa Föderatsiooni Soome lahe vetest / Alexander Lott

Index Scriptorium Estoniae

Lott, Alexander, 1987-

2017-01-01

Venemaa Föderatsiooni õigusraamistikust ja praktikast välisriikide laevade rahumeelse läbisõidu õiguse kohta oma Soome lahe territoriaalmeres ja olukorrast, et Venemaa ei tunnusta rahumeelse läbisõidu õigust selles merealas

Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver carboxylate precursors

Energy Technology Data Exchange (ETDEWEB)

Uznanski, Pawel, E-mail: puznansk@cbmm.lodz.pl; Zakrzewska, Joanna [Centre of Molecular and Macromolecular Studies, PAS (Poland); Favier, Frederic, E-mail: fredf@univ-montp2.fr [Université Montpellier II, ICGM - UMR5253- Equipe AIME (France); Kazmierski, Slawomir; Bryszewska, Ewa [Centre of Molecular and Macromolecular Studies, PAS (Poland)

2017-03-15

A comparative study of amine and silver carboxylate adducts [R{sub 1}COOAg-2(R{sub 2}NH{sub 2})] (R{sub 1} = 1, 7, 11; R{sub 2} = 8, 12) as a key intermediate in NPs synthesis is carried out via differential scanning calorimetry, solid-state FT-infrared spectroscopy, {sup 13}C CP MAS NMR, powder X-ray diffraction and X-ray photoelectron spectroscopy, and various solution NMR spectroscopies ({sup 1}H and {sup 13}C NMR, pulsed field gradient spin-echo NMR, and ROESY). It is proposed that carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination as opposed to bridging bidentate coordination of pure silver carboxylates resulting from the formation of dimeric units. All complexes are packed as lamellar bilayer structures. Silver carboxylate/amine complexes show one first-order melting transition. The evidence presented in this study shows that phase behavior of monovalent metal carboxylates are controlled, mainly, by head group bonding. In solution, insoluble silver salt is stabilized by amine molecules which exist in dynamic equilibrium. Using (bis)amine-silver carboxylate complex as precursor, silver nanoparticles were fabricated. During high-temperature thermolysis, the (bis)amine-carboxylate adduct decomposes to produce silver nanoparticles of small size. NPs are stabilized by strongly interacting carboxylate and trace amounts of amine derived from the silver precursor interacting with carboxylic acid. A corresponding aliphatic amide obtained from silver precursor at high-temperature reaction conditions is not taking part in the stabilization. Combining NMR techniques with FTIR, it was possible to follow an original stabilization mechanism.

Induction of spermidine/spermine N1-acetyltransferase by methylglyoxal bis(guanylhydrazone).

Science.gov (United States)

Pegg, A E; Erwin, B G; Persson, L

1985-10-17

The anti-tumor agent methylglyoxal bis(guanylhydrazone) was found to be a competitive inhibitor of spermidine/spermine N1-acetyltransferase with a Ki of about 8 microM. Treatment of rats with this drug lead to a very large increase in the total amount of spermidine/spermine N1-acetyltransferase in liver, kidney and spleen. The total increase as measured using a specific antiserum amounted to 700-fold in liver and 100-fold in kidney within 18 h of treatment with 80 mg/kg doses. At least part of this induction was due to a pronounced increase in the half-life of the acetyltransferase which increased from 15 min to more than 12 h. The very large increase in the amount of the enzyme is likely to overwhelm the direct inhibition, and a net increase in the acetylation of polyamines by this enzyme would be expected to occur after treatment with methylglyoxal bis(guanylhydrazone). The acetylated polyamines are known to be rapidly degraded by polyamine oxidase producing putrescine. Direct evidence that a substantial part of the increase in the content of putrescine in the liver of rats treated with methylglyoxal bis(guanylhydrazone) occurs via the induction of this acetylase/oxidase pathway was obtained. These results indicate that methylglyoxal bis(guanylhydrazone) affects cellular polyamine levels not only by means of its inhibitory effect on S-adenosylmethionine decarboxylase and diamine oxidase but also by the induction of spermidine/spermine N1-acetyltransferase. They also raise the possibility that the enormous increase in this enzyme which occurs with higher doses may contribute to the very severe toxicity of methylglyoxal bis(guanylhydrazone).

openBIS ELN-LIMS: an open-source database for academic laboratories.

Science.gov (United States)

Barillari, Caterina; Ottoz, Diana S M; Fuentes-Serna, Juan Mariano; Ramakrishnan, Chandrasekhar; Rinn, Bernd; Rudolf, Fabian

2016-02-15

The open-source platform openBIS (open Biology Information System) offers an Electronic Laboratory Notebook and a Laboratory Information Management System (ELN-LIMS) solution suitable for the academic life science laboratories. openBIS ELN-LIMS allows researchers to efficiently document their work, to describe materials and methods and to collect raw and analyzed data. The system comes with a user-friendly web interface where data can be added, edited, browsed and searched. The openBIS software, a user guide and a demo instance are available at https://openbis-eln-lims.ethz.ch. The demo instance contains some data from our laboratory as an example to demonstrate the possibilities of the ELN-LIMS (Ottoz et al., 2014). For rapid local testing, a VirtualBox image of the ELN-LIMS is also available. © The Author 2015. Published by Oxford University Press.

Synthesis, Characterization and Antimicrobial Activities of Transition Metal Complexes of methyl 2-(((E)-(2-hydroxyphenyl)methylidene)amino)benzoate

International Nuclear Information System (INIS)

Ikram, M.; Rehman, S.

2016-01-01

New metal complexes with Schiff base ligand methyl 2-(((E)-(2-hydroxyphenyl)methylidene)amino)benzoate, were synthesized and characterized. Elemental analyses, EI-MS, 1H and 13C(1H)-NMR were used for ligand characterization whereas elemental analyses, EI-MS, IR and UV-Visible spectroscopic techniques were used for the transition metal compounds. All these analyses reveal the bis arrangement of the ligand around the metal centres. The compounds were studied for their antimicrobial activities against different pathogenic microbial species. It was found that the Schiff base ligand was completely inactive in comparison to the transition metal compounds. It was also observed that nickel based metal complex shown good results against Candida albican (25 mm) and zinc based metal complex against Agrobacterium tumefaciens (16 mm). (author)

Steric and electronic parameters of a bulky yet flexible N-heterocyclic carbene: 1,3-bis(2,6-bis(1-ethylpropyl)phenyl)imidazol-2-ylidene (IPent)

KAUST Repository

Collado, Alba; Balogh, Já nos; Meiries, Sé bastien; Slawin, Alexandra M. Z.; Falivene, Laura; Cavallo, Luigi; Nolan, Steven P.

2013-01-01

The free N-heterocyclic carbene IPent (1; IPent = 1,3-bis(2,6-bis(1- ethylpropyl)phenyl)imidazol-2-ylidene) was prepared from the corresponding imidazolium chloride salt (2). The steric and electronic parameters of 1 were determined by synthesis of the gold(I) chloride complex [Au(IPent)Cl] (3) and the nickel-carbonyl complex [Ni(IPent)(CO)3] (4), respectively. 3 and 4 were fully characterized by NMR spectroscopy, elemental analysis, and X-ray diffraction studies on single crystals. © 2013 American Chemical Society.

Steric and electronic parameters of a bulky yet flexible N-heterocyclic carbene: 1,3-bis(2,6-bis(1-ethylpropyl)phenyl)imidazol-2-ylidene (IPent)

KAUST Repository

Collado, Alba

2013-06-10

The free N-heterocyclic carbene IPent (1; IPent = 1,3-bis(2,6-bis(1- ethylpropyl)phenyl)imidazol-2-ylidene) was prepared from the corresponding imidazolium chloride salt (2). The steric and electronic parameters of 1 were determined by synthesis of the gold(I) chloride complex [Au(IPent)Cl] (3) and the nickel-carbonyl complex [Ni(IPent)(CO)3] (4), respectively. 3 and 4 were fully characterized by NMR spectroscopy, elemental analysis, and X-ray diffraction studies on single crystals. © 2013 American Chemical Society.

Synthesis of Ethylene Bis-stearamide for Acrylonitrile-Butadiene-Styrene Polymer

Directory of Open Access Journals (Sweden)

M.A. Sayyadnejad

2009-12-01

Full Text Available Ethylene bis-stearamide is one of the important acrylonitrile-butadiene-styrene (ABS( polymer additives, which is used as lubricant, slip agent and mold release agent. In this research, ethylene bis-stearamide for ABS application was synthesized using stearic acid and ethylene diamine under reflux condition. Refluxing prevented ethylenediamine from evaporation and thus the initial molar ratio was maintained unchanged. The other role of refluxing was to prevent the oxidation of ethylene diamine by removal of oxygen which might have been present inside the reactor. The synthesized samples were characterized by Fourier transform infrared spectroscopy (FTIR(, total acid number and melting point. The total acid number of the synthesized samples in the lab, bench scale 1 kg( and pilot scale 30 kg( were 6.5, 8.7 and 8.6 mgKOH/g, respectively, and their melting points were in 141-144 °C range. It was found that total acid number values of samples are inversely proportional with reaction time. The longer the reaction time, the higher was the total acid number and sample purity. Compounding was carried out using ABS containing synthesized and reference ethylene bis-stearamide and the physical-mechanical properties of the samples were measured. The obtained results showed that, the measured properties such as melt flow index, impact resistance, softening temperature, heat deflection temperature, tensile strength and hardness for the compound prepared using synthesized ethylene bis-stearamide match very well with those of reference compound.

21 CFR 73.3106 - 1,4-Bis[4-(2-methacryloxyethyl) phenylamino]anthraquinone copolymers.

Science.gov (United States)

2010-04-01

...]anthraquinone copolymers. 73.3106 Section 73.3106 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... § 73.3106 1,4-Bis[4-(2-methacryloxyethyl) phenylamino]anthraquinone copolymers. (a) Identity. The color additive is 1,4-bis[4-(2-methacryloxyethyl) phenylamino]anthraquinone (CAS Reg. No. 121888-69-5...

Development of [103Pd]-labeled-bis(N4-methylthiosemicarbazone) complexes as possible therapeutic agents

International Nuclear Information System (INIS)

Jalilian, A.R.; Sadeghi, M.; Kamrani, Y.Y.

2006-01-01

Due to interesting tumor seeking properties of bis-thiosemicarbazones, two radio palladium-bis-thiosemicarbazone complexes, i.e., [ 103 Pd]-pyruvaldehyde-bis(N 4 -methylthiosemicarbazone) ([ 103 Pd] PTSM) and [ 103 Pd]-diacetyl-bis(N 4 -methylthiosemicarbazone) ([ 103 Pd]ATSM) were prepared according to the analogy of radio copper homologs. Palladium-103 (t 1/2 = 16.96 d) was produced via the 103 Rh(p, n) 103 Pd nuclear reaction with proton energy 18 MeV. The final activity was eluted in form of Pd(NH 3 ) 2 Cl 2 in order to react with bis-thiosemicarbazones to yield [ 103 Pd]-labeled compounds. Chemical purity of the product was confirmed to be below the accepted limits by polarography. [ 103 Pd]-labeled bis-thiosemicarbazones were prepared with a radiochemical yield of more than 80% at room temperature after 60-90 min by vortexing a mixture of thiosemicarbazones and Pd activity in ethanol. The purification of the labeled compounds performed by reverse phase column chromatography using C 18 plus Sep-Pak. Radiochemical purity of more than 99% specific activity of about 12500-13 000 Ci/mol was obtained. The stability of the complexes was checked in final product and presence of human serum at 37 C up to 48 h. The partition co-efficients of the final complexes were determined. The initial physico-chemical properties of the labeled compounds were compared to those of their copper homologues. (orig.)

40 CFR 721.10143 - Amines, bis (C11-14-branched and linear alkyl).

Science.gov (United States)

2010-07-01

... linear alkyl). 721.10143 Section 721.10143 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10143 Amines, bis (C11-14-branched and linear alkyl). (a) Chemical..., bis (C11-14-branched and linear alkyl) (PMN P-06-733; CAS No. 900169-60-0) is subject to reporting...

Molecular structure and conformation of two acyclic polythioethers: Implications for the design of heavy metal chelators

Energy Technology Data Exchange (ETDEWEB)

Desper, J.M.; Powell, D.R.; Gellman, S.H. (Univ. of Wisconsin, Madison (USA))

1990-05-23

The crystal structures of the 1,9-bis(p-tolyl)-2,5,8-trithianonane (1) and 1,12-bis(p-tolyl)-2,5,8,11-tetrathiadodecane (2) are reported. Previous studies of macrocyclic polythioethers have revealed a pronounced tendency for backbone CS-CC bonds to adopt gauche torsion angles. The same tendency is observed in the homologous acyclic polythioethers 1 and 2, demonstrating that the gauche preference is not simply the result of a macrocyclic constraint. Because of this gauche preference of CS-CC torsion units and the well-established anti preference of SC-CS torsion units, polythioethers constructed from ethylene sulfide subunits are generally far from preorganized for metal ion chelation.

Influence of body position, food and beverage consumption on BIS measurements

Science.gov (United States)

Medrano, G.; Eitner, F.; Ismail, A. H.; Pikkemaat, R.; Cordes, A.; Floege, J.; Leonhardt, S.

2010-04-01

Continuous monitoring of fluid changes using bioimpedance spectroscopy (BIS) during hemodialysis could help to predict hypotensive complications and extend the patient's life. Food and beverage consumption during the treatment may influence the measurements and the calculated fluid removal. In the present article the change observed in whole body and segmental (knee-to-knee, abdomen) BIS measurements following a sequence similar to the one of dialysis treatment (lying down, sitting and eating, lying down) on healthy subjects is presented. The measurements have been performed using a commercial bioimpedance device with a frequency range of 5 kHz to 1 MHz. Knee-to-knee measurements seem to be less sensitive to these influences, compared to the standard whole body and the alternative abdomen BIS measurements. The results indicate that the individual influence of both body posture and food and beverage consumption may be superposed when combined.

Thermodynamic and Kinetic Study of Zinc bis-(Dipalmithyl Dithiophosphate Activity as Anti-Corrosion Additive-Fatty Acid Based Through Potentiodynamic Polarization Technique

Directory of Open Access Journals (Sweden)

Komar Sutriah

2016-08-01

Full Text Available Zinc bis-(dipalmithyl dithiophosphate (ZDTP16 is one product variant of zinc dialkyl dithiophosphate (ZDTP-fatty acid based having function as corrosion inhibitor. By using 3% of effective dose for the application, its effectiveness of ZDTP16 corrosion inhibition will achieve 97% and it will be able to decrease Cu metal corrosion rate from 0.152 to 0.004 mm per year. Thermodynamic and kinetic parameter verification indicates the decreasing of spontaneity and corrosion rate by existence of ZDTP16 inhibitor. Gibbs free energy transition corrosion of Cu metal in electrolyte medium is measured in corrosion simulator increased from +85.22 to +91.77 kJ mol-1, while its activation energy increased from +16.66 to +33.68 kJ mol-1. Morphology observation of Cu metal substrate surface using SEM-EDX shows that the adsorption of ZDTP16 at substrate surface is able to protect surface from corrosion indicated by the existence of Zn, P, S, and C constituents representing composer atoms of ZDTP16, and the decreasing of Cl- corrosive constituent at substrate surface.

Spectrophotometric study of the complexation equilibria of uranium(VI) with 1,4-bis(4'-methylanilino)anthraquinone and determination of uranium(VI)

International Nuclear Information System (INIS)

Idriss, K.A.; Seleim, M.M.; Abu-Bakr, M.S.; Sedaira, H.

1985-01-01

The reaction of U(VI) with 1,4-bis(4'-methylanilino)anthraquinone (quinizarin green) in water-dimethylformamide medium was investigated spectrophotometrically. The complexation equilibria in solution were demonstrated. The study of the reaction in presence of equimolar concentrations or in solutions containing metal or ligand excess gave evidence for the formation of complexes with stoichiometric ratios of UO 2 :L = 1:1 and 1:2 in dependence on the pH of the medium. Their thermodynamic stabilities and the values of their molar absorption coefficients were determined. The optimum conditions for spectrophotometric determination of U(VI) with this reagent were found. (author)

Diaquabis[2,6-bis(4H-1,2,4-triazol-4-ylpyridine-κN2]bis(selenocyanato-κNcobalt(II

Directory of Open Access Journals (Sweden)

Yuan-Yuan Liu

2012-08-01

Full Text Available In the title compound, [Co(NCSe2(C9H7N72(H2O2], the Co2+ cation is coordinated by two selenocyanate anions, two 2,6-bis(4H-1,2,4-triazol-4-ylpyridine ligands and two water molecules within a slightly distorted N4O2 octahedron. The asymmetric unit consists of one Co2+ cation, which is located on a center of inversion, as well as one selenocyanate anion, one 2,6-bis(4H-1,2,4-triazol-4-ylpyridine ligand and one water molecule in general positions. Intermolecular O—H...N hydrogen bonds join the complex molecules into layers parallel to the bc plane. The layers are linked by C—H...N and C—H...Se hydrogen bonds into a three-dimensional supramolecular architecture.

Effect of substituents on polarizability and hyperpolarizability values of benzimidazole metal complexes

Energy Technology Data Exchange (ETDEWEB)

Praveen, P. A.; Babu, R. Ramesh, E-mail: rampap2k@yahoo.co.in [Crystal Growth and Thin films Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli - 620 024, Tamilnadu (India)

2016-05-23

In this report, the polarizability and first and second order hyperpolarizability values of bis benzimidazole Zn(II)-2R and bis benzimidazole Cd(II)-2R complexes, with different electron donating moieties R (R= Cl, Br, I, Acetate) were calculated using time dependent Hartree-Fock (TDHF) formalism embedded in MOPAC2012 package. Further the role of substituents on polarizability and hyperpolarizability values is investigated for the first time by analyzing the frontier molecular orbitals of the complexes with respect to the electronegativity of the substituents. It is found that the increase in electronegativity of the substituents correspondingly increases the energy gap of the molecules, which in turn reduces the polarizability values of both Zn and Cd benzimidazole complexes. Similarly, increase in electronegativity reduces the electric quadrupole moments of both the metal complexes, which in turn reduces the hyperpolarizability values.

Syntheses, structures and photoluminescent properties of Zn(Ⅱ)/Co(Ⅱ) coordination polymers based on flexible tetracarboxylate ligand of 5,5′-(butane-1,4-diyl)-bis(oxy)-di isophthalic acid

Energy Technology Data Exchange (ETDEWEB)

Gao, Yan-Peng [Inner Mongolia Key Lab Chem & Phys Rare Earth Mat, College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Department of Chemistry and Chemical Engineering, Ordos College of Inner Mongolia University, Ordos 017000 (China); Department of Chemistry and Chemical Engineering, Ordos Applied Technology College, Ordos 017000 (China); Guo, Le [Department of Chemistry and Chemical Engineering, Ordos College of Inner Mongolia University, Ordos 017000 (China); Department of Chemistry and Chemical Engineering, Ordos Applied Technology College, Ordos 017000 (China); Dong, Wei; Jia, Min; Zhang, Jing-Xue; Sun, Zhong [Inner Mongolia Key Lab Chem & Phys Rare Earth Mat, College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Chang, Fei, E-mail: ndchfei@imu.edu.cn [Inner Mongolia Key Lab Chem & Phys Rare Earth Mat, College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China)

2016-08-15

Three new mixed-ligand metal-organic frameworks based on 5,5′-(butane-1,4- diyl)-bis(oxy)-diisophthalic acid and transitional metal cations with the help of two ancillary bridging N-donor pyridyl and imidazole linkers, [Zn(L){sub 0.5}(4,4′-bpy)]·2(H{sub 2}O) (1), [M(L){sub 0.5}(bib)]·4(H{sub 2}O) (M = Zn (2), Co (3)), (4,4′-bpy=4,4′–bipyridine, bib=1,4-bis (1H-imidazol-1-yl)-butane), have been synthesized under solvothermal conditions. Their structures and properties were determined by single-crystal and powder X-ray diffraction analyses, IR spectra, elemental analyses and thermogravimetric analyses (TGA). Compounds 1–3 display a 3D 3-fold interpenetrated frameworks linked by the L{sup 4−} ligands, ancillary N-donor linkers and the free water molecules in the crystal lattice. Topological analysis reveals that 1–3 are a (4,4)-connected bbf topology net with the (6{sup 4}·8{sup 2})(6{sup 6}) topology. The effects of the L{sup 4−} anions, the N-donor ligands, and the metal ions on the structures of the coordination polymers have been discussed. Furthermore, luminescence properties and thermogravimetric properties of these compounds were investigated. - Graphical abstract: Three new compounds of MOFs have been prepared and characterized. The luminescence properties and thermogravimetric properties of compounds were investigated. Display Omitted.

Reductive Bis-addition of Aromatic Aldehydes to α,β-Unsaturated Esters via the Use of Sm/Cu(I) in Air: A Route to the Construction of Furofuran Lignans.

Science.gov (United States)

Liu, Yongjun; Tian, Guang; Li, Jingjing; Qi, Yan; Wen, Yonghong; Du, Feng

2017-06-02

The novel bis-addition of benzaldehydes to acrylates or maleates was achieved by the direct use of samarium metal with the assistance of CuI under mild conditions under dry air, and the useful 2-hydroxylalkyl-γ-butyrolactons and lignan derivatives were thus constructed with high efficiency. The key factors that influence the reaction efficiency were investigated. The use of potassium iodide and molecular sieves as additives can improve the reaction efficiency remarkably.

Reaction of urea thiourea and their derivatives with tertiary phosphine transition metal halides

International Nuclear Information System (INIS)

Adam, Eltayeb Mahala

2000-03-01

This thesis describes preparation characterization and some properties of a number of new compounds such as (ph 3 p)2 ML where M= cobalt (11), nickel (11), and copper (11), and L= urea, thiourea, phenylthiourea, sym diphenylurea and sym diphenylthiourea.These compounds have been prepared according according to the reaction of dichloro bis (triphenylphosphine) transition metal with urea, thiourea or some of their derivative ligands in 1:1 molar ratio.The work in this thesis is divided into three section firstly:- In the introduction chapter part one includes general definitions of coordination chemistry and related compounds and abroad definition of transition elements.Part two includes the theoretical back ground about transition metal complexes having urea, thiourea or some of their substituted derivative ligands.Part two also discusses the type of bonding between these ligands and the transition metal atom.Secondly: Chapter two describes the general techniques followed in this work such as purification of solvents recrystallization, preparation of starting materials and also gives full detailed procedures of the preparation of a number of new compounds.Thirdly: Discussion with detailed in chapter three, the results of the research are presented the preparation and characterization of a number of new compounds isolated from reaction between urea, thiourea or some of their substituted derivatives and dichloro bis (triphenyl phosphine) transition metal complex giving a general formula (ph 3 )2ML where M=cobalt, nickel, and copper, and urea, thiourea or some of their substituted derivatives ligands. The products of these experiments have been identified using infrared spectra, melting points and molar conductance. The results obtained indicated that all the compounds forming the nitrogen to metal bonds leading to the formation of a four- membered chelate ring, they are relatively thermally stable compounds, and also these compounds are non-electrolytes.(Author)

Preparation of 166 Dy/166 Ho DTPA-bis biotin as a system of In vivo generator

International Nuclear Information System (INIS)

Jimenez V, M.R.

2003-01-01

The objective of this work was to synthesize the complex 166 Dy/ 166 Ho - diethylen triamine pentaacetic-bis Biotin ( 166 Dy/ 166 Ho DTPA-bis Biotin) to evaluate its potential as a new radiopharmaceutical in directed radiotherapy. The Dysprosium-166 was obtained for neutron irradiation of 164 Dy 2 0 3 in the TRIGA Mark III reactor. The labelled was carried out in aqueous solution to p H 8.0 for addition of 166 Dy Cl 3 to the diethylen triamine pentaacetic-α, ω-bis Biotin (DTPA-bis Biotin). The radiochemical purity was determined for HPLC and ITLC. The biological integrity of the marked biotin is evaluated by the biological recognition of the avidin for HPLC - molecular exclusion with and without avidin addition. The studies of stability in vitro were made in dilutions of saline solution to 0.9% and with human serum at 37 C incubated 1 and 24 hours. The complex 166 Dy/ 166 Ho DTPA-bis Biotin was obtained with a radiochemical purity of 99.1 ± 0.6%. The biological recognition of the complex 166 Dy/ 166 Ho DTPA-bis Biotin for the avidin it doesn't affect the labelling procedure. The studies in vitro demonstrated that the 166 Dy/ 166 Ho DTPA-bis Biotin is stable after the dilution in saline solution and in human serum that there is not translocation of the one radionuclide subsequent son to the beta decay of the 166 Dy that could produce the 166 Ho 3+ liberation. The studies of Biodistribution in healthy mice demonstrated that the one complex 166 Dy/ 166 Ho DTPA-bis Biotin have a high renal distribution. In conclusion the radiolabelled biotin in this investigation has the appropriate properties to be used as an In vivo generator system stable for directed radiotherapy. (Author)

Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers

International Nuclear Information System (INIS)

Monier, M.; Ayad, D.M.; Sarhan, A.A.

2010-01-01

The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction.

Antimicrobial, thermoanalytical and viscometric studies of metal based schiff base polymer

International Nuclear Information System (INIS)

Mughal, M.A.; Mughal, A.

2013-01-01

This study examines the synthesis, characterization, viscosity, thermal behavior and antimicrobial studies of copper(II) and nickel(II), complexes of a synthesized monomer 5,5-methylene bis(2-pyridinecarboxaldehyde) (MBPC) and a Schiff base polymer poly-5,5-methylene bis (2-pyridinecarboxaldehyde) 1,3-propylenedimine (PMBPCPR). The monomer, polymeric ligand and poly metal complexes (PMBPCPRCu) and (PMBPCPRNi) were characterized by C.H.N analysis, FT-IR, UV - Vis spectroscopy, viscometery thermogravimetric (TGA) and differential thermogravimetry (DTA). The monomer MBPC was prepared by the reaction of 2-pyridinecarboxaldehyde with 1, 3, 5-trioxane in the presence of acetic acid and sulphuric acid. The polymeric ligand was prepared by polycondensation of monomer with 1,3-propylenediamine. The biological studies of compounds revealed that they possessed significant antibacterial and antifungal properties, against Micrococcus flavus, Staphylococcus aureus, Bacillus Cirroflgellosus, Shigella flexneri, Escherichia Coli, Candida albicans, Aspergillus flavus, and A. Niger. (author)

Luminescent Dinuclear Ruthenium Terpyridine Complexes with a Bis-Phenylbenzimidazole Spacer.

Science.gov (United States)

Mondal, Debiprasad; Biswas, Sourav; Paul, Animesh; Baitalik, Sujoy

2017-07-17

A conjugated bis-terpyridine bridging ligand, 2-(4-(2,6-di(pyridin-2-yl)pyridin-4-yl)phenyl)-6-(2-(4-(2,6-di(pyridin-2-yl)pyridin-4-yl)phenyl)-1H-benzo[d]imidazol-6-yl)-1H-benzo[d] imidazole (tpy-BPhBzimH 2 -tpy), was designed in this work by covalent coupling of 3,3'-diaminobenzidine and two 4'-(p-formylphenyl)-2,2':6',2″-terpyridine units to synthesize a new series of bimetallic Ru(II)-terpyridine light-harvesting complexes. Photophysical and electrochemical properties were modulated by the variation of the terminal ligands in the complexes. The new compounds were thoroughly characterized by 1 H NMR spectroscopy, high-resolution mass spectrometry, and elemental analysis. Absorption spectra of the complexes consist of very strong ligand-centered π-π* and n-π* transitions in the UV, metal-to-ligand, and intraligand charge transfer bands in the visible regions. Steady-state and time-resolved emission spectral measurements indicate that the complexes exhibit moderately intense luminescence at room temperature within the spectral domain of 653-687 nm having luminescence lifetimes in the range between 6.3 and 55.2 ns, depending upon terminal tridentate ligand and solvent. Variable-temperature luminescence measurements suggest substantial increase of the energy gap between luminescent 3 metal-to-ligand charge transfer state and nonluminescent 3 metal centered in the complexes compared to the parent [Ru(tpy) 2 ] 2+ . Each of the three bimetallic complexes exhibits only one reversible couple in the positive potential window with almost no detectable splitting corresponding to simultaneous oxidation of the two remote Ru centers. All the complexes possess a number of imidazole NH protons, which became sufficiently acidic upon metal ion coordination. By utilizing these NH protons, we thoroughly studied anion recognition properties of the complexes in pure organic as well as predominantly aqueous media through multiple optical channels and spectroscopic methods. Finally

Le principe non bis in idem et le droit communautaire

OpenAIRE

Hedabou, Aziz

2018-01-01

Le principe non bis in idem est une garantie fondamentale qui interdit que les mêmes faits soit poursuivi et puni deux fois. Il est reconnu par tous les droits internes et “appartient aux droit universel des nations”. Dès lors, sa lettre et son esprit ne sont plus cantonnés au droit interne et ont tendance à s’internationaliser. En droit communautaire, l’étude du principe non bis in idem peut être envisagée sous trois angles différents. D’abord en droit pénal international unilatéral où chaqu...

BIS-2 spectrometer for search and investigation of narrow resonances

International Nuclear Information System (INIS)

Aleev, A.N.; Aref'ev, V.A.; Balandin, V.P.

1989-01-01

The configuration and main characteristics of the BIS-2 spectrometer are described. The spectrometer was intended to search for and to investigate charmed particles and narrow resonances produced in neutron-nucleus interactions. It was placed on a neutron beam of the Serpukhov accelerator. The Monte-Carlo simulated and experimentally measured characteristics of individual elements and the spectrometer as a whole are described. A brief review of the principal results based on the analysis of more than 10 7 neutron-nucleus interactions registered by means of the BIS-2 spectrometer is given. 34 refs.; 8 figs.; 5 tabs

Behavioural Inhibition System (BIS) sensitivity differentiates EEG theta responses during goal conflict in a continuous monitoring task.

Science.gov (United States)

Moore, Roger A; Mills, Matthew; Marshman, Paul; Corr, Philip J

2012-08-01

Previous research has revealed that EEG theta oscillations are affected during goal conflict processing. This is consistent with the behavioural inhibition system (BIS) theory of anxiety (Gray & McNaughton, 2000). However, studies have not attempted to relate these BIS-related theta effects to BIS personality measures. Confirmation of such an association would provide further support for BIS theory, especially as it relates to trait differences. EEG was measured (32 electrodes) from extreme groups (low/high trait BIS) engaged in a target detection task. Goal conflicts were introduced throughout the task. Results show that the two groups did not differ in behavioural performance. The major EEG result was that a stepwise discriminant analysis indicated discrimination by 6 variables derived from coherence and power, with 5 of the 6 in the theta range as predicted by BIS theory and one in the beta range. Also, across the whole sample, EEG theta coherence increased at a variety of regions during primary goal conflict and showed a general increase during response execution; EEG theta power, in contrast, was primarily reactive to response execution. This is the first study to reveal a three-way relationship between the induction of goal conflict, the induction of theta power and coherence, and differentiation by psychometrically-defined low/high BIS status. Copyright © 2012 Elsevier B.V. All rights reserved.

Synthesis, characterization, and reactivity of furan- and thiophene-functionalized bis(n-heterocyclic carbene) complexes of iron(II)

KAUST Repository

Rieb, Julia

2014-09-15

The synthesis of iron(II) complexes bearing new heteroatom-functionalized methylene-bridged bis(N-heterocyclic carbene) ligands is reported. All complexes are characterized by single-crystal X-ray diffraction (SC-XRD), nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis. Tetrakis(acetonitrile)-cis-[bis(o-imidazol-2-ylidenefuran)methane]iron(II) hexafluorophosphate (2a) and tetrakis(acetonitrile)-cis-[bis(o-imidazol-2-ylidenethiophene)methane]iron(II) hexafluorophosphate (2b) were obtained by aminolysis of [Fe{N(SiMe3)2}2(THF)] with furan- and thiophene-functionalized bis(imidazolium) salts 1a and 1b in acetonitrile. The SC-XRD structures of 2a and 2b show coordination of the bis(carbene) ligand in a bidentate fashion instead of a possible tetradentate coordination. The four other coordination sites of these distorted octahedral complexes are occupied by acetonitrile ligands. Crystallization of 2a in an acetone solution by the slow diffusion of Et2O led to the formation of cisdiacetonitriledi[ bis(o-imidazol-2-ylidenefuran)methane]iron(II) hexafluorophosphate (3a) with two bis(carbene) ligands coordinated in a bidentate manner and two cis-positioned acetonitrile molecules. Compounds 2a and 2b are the first reported iron(II) carbene complexes with four coordination sites occupied by solvent molecules, and it was demonstrated that those solvent ligands can undergo ligand-exchange reactions.

CE of phytosiderophores and related metal species in plants.

Science.gov (United States)

Xuan, Yue; Scheuermann, Enrico B; Meda, Anderson R; Jacob, Peter; von Wirén, Nicolaus; Weber, Günther

2007-10-01

Phytosiderophores (PS) and the closely related substance nicotianamine (NA) are key substances in metal uptake into graminaceous plants. Here, the CE separation of these substances and related metal species is demonstrated. In particular, the three PS 2'-deoxymugineic acid (DMA), mugineic acid (MA), and 3-epi-hydroxymugineic acid (epi-HMA), and NA, are separated using MES/Tris buffer at pH 7.3. Moreover, three Fe(III) species of the different PS are separated without any stability problems, which are often present in chromatographic analyses. Also divalent metal species of Cu, Ni, and Zn with the ligands DMA and NA are separated with the same method. By using a special, zwitterionic CE capillary, even the separation of two isomeric Fe(III) chelates with the ligand ethylenediamine-N,N'-bis(o-hydroxyphenyl)acetic acid (EDDHA) is possible (i.e., meso-Fe(III)-EDDHA and rac-Fe(III)-EDDHA), and for fast separations of NA and respective divalent and trivalent metal species, a polymer CE microchip with suppressed EOF is described. The proposed CE method is applicable to real plant samples, and enables to detect changes of metal species (Cu-DMA, Ni-NA), which are directly correlated to biological processes.

Transferred metal electrode films for large-area electronic devices

International Nuclear Information System (INIS)

Yang, Jin-Guo; Kam, Fong-Yu; Chua, Lay-Lay

2014-01-01

The evaporation of metal-film gate electrodes for top-gate organic field-effect transistors (OFETs) limits the minimum thickness of the polymer gate dielectric to typically more than 300 nm due to deep hot metal atom penetration and damage of the dielectric. We show here that the self-release layer transfer method recently developed for high-quality graphene transfer is also capable of giving high-quality metal thin-film transfers to produce high-performance capacitors and OFETs with superior dielectric breakdown strength even for ultrathin polymer dielectric films. Dielectric breakdown strengths up to 5–6 MV cm −1 have been obtained for 50-nm thin films of polystyrene and a cyclic olefin copolymer TOPAS ® (Zeon). High-quality OFETs with sub-10 V operational voltages have been obtained this way using conventional polymer dielectrics and a high-mobility polymer semiconductor poly[2,5-bis(3-tetradecylthiophene-2-yl)thieno[3,2-b]thiophene-2,5-diyl]. The transferred metal films can make reliable contacts without damaging ultrathin polymer films, self-assembled monolayers and graphene, which is not otherwise possible from evaporated or sputtered metal films

Synthesis, DNA Binding, and Anticancer Properties of Bis-Naphthalimide Derivatives with Lysine-Modified Polyamine Linkers

Directory of Open Access Journals (Sweden)

Yu Huang

2018-01-01

Full Text Available A series of bis-naphthalimide derivatives with different diamine linkers were designed and synthesized. All of the synthesized bis-naphthalimide derivatives were characterized by NMR and HRMS spectra. The binding ability between the compounds and CT DNA was evaluated by using UV–Vis titration experiments. The bis-naphthalimide compound with an ethylenediamine linker showed the largest binding constant with CT DNA. Hence, it was used as the model compound to study the DNA binding selectivity by UV–Vis titration aiming at different DNA duplexes. As a result, this compound showed binding preference to AT-rich duplexes. The DNA binding modes of the compounds were also measured by viscosity titration. The cytotoxicity of the compounds was evaluated by MTT assay. Compounds with 1,6-diaminohexane or 1,4-phenylenedimethanamine linkers showed higher cytotoxicity compared with other bis-naphthalimide derivatives.

Convenient synthesis of bis(alkoxy)rhenium(VII) complexes

Energy Technology Data Exchange (ETDEWEB)

Zhu, Z.; Al-Ajlouni, A.M.; Espenson, J.H. [Iowa State Univ., Ames, IA (United States)

1996-02-28

The study of high-oxidation-state organorhenium compounds has been a field of continuing activity, thanks to the success of methylrhenium trioxide (CH{sub 3}ReO{sub 3} or MTO) in catalytic processes. This catalyst is effective in oxidations, olefin metathesis, the olefination of aldehydes, and the preparation of other compounds with three-membered rings. The syntheses of some rhenium compounds derived form MTO have been reported. Epoxide formation is a key reaction, and it bears directly on these findings reported here. Re(VII) complexes containing a chelated bis(diolate) ligand can be synthesized by refluxing MTO with 2,3-dimethyl-2,3-diol. Here, the authors report a more convenient method for this preparation. A different series of related compounds consists of chelated bis(diolates) of the Cp*Re-oxo series, Cp*ReO-(diolate).

Preparation of {sup 166} Dy/{sup 166} Ho DTPA-bis biotin as a system of In vivo generator; Preparacion de {sup 166} Dy/{sup 166} Ho DTPA-bis biotina como un sistema de generador In vivo

Energy Technology Data Exchange (ETDEWEB)

Jimenez V, M.R

2003-07-01

The objective of this work was to synthesize the complex {sup 166} Dy/{sup 166} Ho - diethylen triamine pentaacetic-bis Biotin ({sup 166} Dy/{sup 166} Ho DTPA-bis Biotin) to evaluate its potential as a new radiopharmaceutical in directed radiotherapy. The Dysprosium-166 was obtained for neutron irradiation of {sup 164} Dy{sub 2}0{sub 3} in the TRIGA Mark III reactor. The labelled was carried out in aqueous solution to p H 8.0 for addition of {sup 166} Dy Cl{sub 3} to the diethylen triamine pentaacetic-{alpha}, {omega}-bis Biotin (DTPA-bis Biotin). The radiochemical purity was determined for HPLC and ITLC. The biological integrity of the marked biotin is evaluated by the biological recognition of the avidin for HPLC - molecular exclusion with and without avidin addition. The studies of stability in vitro were made in dilutions of saline solution to 0.9% and with human serum at 37 C incubated 1 and 24 hours. The complex {sup 166} Dy/{sup 166} Ho DTPA-bis Biotin was obtained with a radiochemical purity of 99.1 {+-} 0.6%. The biological recognition of the complex {sup 166} Dy/{sup 166} Ho DTPA-bis Biotin for the avidin it doesn't affect the labelling procedure. The studies in vitro demonstrated that the {sup 166} Dy/{sup 166} Ho DTPA-bis Biotin is stable after the dilution in saline solution and in human serum that there is not translocation of the one radionuclide subsequent son to the beta decay of the {sup 166} Dy that could produce the {sup 166} Ho{sup 3+} liberation. The studies of Biodistribution in healthy mice demonstrated that the one complex {sup 166} Dy/{sup 166} Ho DTPA-bis Biotin have a high renal distribution. In conclusion the radiolabelled biotin in this investigation has the appropriate properties to be used as an In vivo generator system stable for directed radiotherapy. (Author)

Preparation of {sup 166} Dy/{sup 166} Ho DTPA-bis biotin as a system of In vivo generator; Preparacion de {sup 166} Dy/{sup 166} Ho DTPA-bis biotina como un sistema de generador In vivo

Energy Technology Data Exchange (ETDEWEB)

Jimenez V, M R

2003-07-01

The objective of this work was to synthesize the complex {sup 166} Dy/{sup 166} Ho - diethylen triamine pentaacetic-bis Biotin ({sup 166} Dy/{sup 166} Ho DTPA-bis Biotin) to evaluate its potential as a new radiopharmaceutical in directed radiotherapy. The Dysprosium-166 was obtained for neutron irradiation of {sup 164} Dy{sub 2}0{sub 3} in the TRIGA Mark III reactor. The labelled was carried out in aqueous solution to p H 8.0 for addition of {sup 166} Dy Cl{sub 3} to the diethylen triamine pentaacetic-{alpha}, {omega}-bis Biotin (DTPA-bis Biotin). The radiochemical purity was determined for HPLC and ITLC. The biological integrity of the marked biotin is evaluated by the biological recognition of the avidin for HPLC - molecular exclusion with and without avidin addition. The studies of stability in vitro were made in dilutions of saline solution to 0.9% and with human serum at 37 C incubated 1 and 24 hours. The complex {sup 166} Dy/{sup 166} Ho DTPA-bis Biotin was obtained with a radiochemical purity of 99.1 {+-} 0.6%. The biological recognition of the complex {sup 166} Dy/{sup 166} Ho DTPA-bis Biotin for the avidin it doesn't affect the labelling procedure. The studies in vitro demonstrated that the {sup 166} Dy/{sup 166} Ho DTPA-bis Biotin is stable after the dilution in saline solution and in human serum that there is not translocation of the one radionuclide subsequent son to the beta decay of the {sup 166} Dy that could produce the {sup 166} Ho{sup 3+} liberation. The studies of Biodistribution in healthy mice demonstrated that the one complex {sup 166} Dy/{sup 166} Ho DTPA-bis Biotin have a high renal distribution. In conclusion the radiolabelled biotin in this investigation has the appropriate properties to be used as an In vivo generator system stable for directed radiotherapy. (Author)

Inhibition of S-adenosylmethionine decarboxylase and diamine oxidase activities by analogues of methylglyoxal bis(guanylhydrazone) and their cellular uptake during lymphocyte activation.

OpenAIRE

Jänne, J; Morris, D R

1984-01-01

Several congeners of methylglyoxal bis(guanylhydrazone) were tested for their ability to inhibit eukaryotic putrescine-activated S-adenosylmethionine decarboxylase (EC 4.1.1.50) and intestinal diamine oxidase (EC 1.4.3.6). All the compounds tested, namely methylglyoxal bis(guanylhydrazone), ethylglyoxal bis(guanylhydrazone), dimethylglyoxal bis(guanylhydrazone) and the di-N"-methyl derivative of methylglyoxal bis(guanylhydrazone), were strong inhibitors of both yeast and mouse liver adenosylm...

Thermal decomposition of potassium bis-oxalatodiaqua- indate(III ...

Indian Academy of Sciences (India)

Unknown

32), temperature programmable thermal balance, with platinum crucible as container, is used for taking thermograms in air. The rate of heating is fixed at ... Thermal decomposition of pot. bis-oxalatodiaquaindate (III).H2O. 277. 3. Results and ...

Carbonate formation within a nickel dimer: synthesis of a coordinatively unsaturated bis(mu-hydroxo) dinickel complex and its reactivity toward carbon dioxide.

Science.gov (United States)

Wikstrom, Jeffrey P; Filatov, Alexander S; Mikhalyova, Elena A; Shatruk, Michael; Foxman, Bruce M; Rybak-Akimova, Elena V

2010-03-14

The tridentate aminopyridine ligand bearing a bulky tert-butyl substituent at the amine nitrogen, tert-butyl-dipicolylamine (tBuDPA), occupies three coordination sites in six-coordinate complexes of nickel(ii), leaving the remaining three sites available for additional ligand binding and activation. New crystallographically characterized complexes include two mononuclear species with 1:1 metal:ligand complexation: a trihydrate solvate (1.3H(2)O) and a monohydrate biacetonitrile solvate (1.H(2)O.2CH(3)CN). Complexation in the presence of sodium hydroxide results in a bis(mu-hydroxo) complex (2), the bridging hydroxide anions of which are labile and become displaced by methoxide anions in methanol solvent, affording bis-methoxo-bridged (4). Nickel(II) centers in 2 are five-coordinate and antiferromagnetically coupled (with J = -31.4(5) cm(-1), H = -2JS(1)S(2), in agreement with Ni-O-Ni angle of 103.7 degrees). Bridging hydroxide or alkoxide anions in coordinatively unsaturated dinuclear nickel(II) complexes with tBuDPA react as active nucleophiles. 2 readily performs carbon dioxide fixation, resulting in the formation of a bis(mu-carbonato) tetrameric complex (3), which features a novel binding geometry in the form of an inverted butterfly-type nickel-carbonate core. Temperature-dependent magnetic measurements of tetranuclear carbonato-bridged revealed relatively weak antiferromagnetic coupling (J(1) = -3.1(2) cm(-1)) between the two nickel centers in the core of the cluster, as well as weak antiferromagnetic pairwise interactions (J(2) = J(3) = -4.54(5) cm(-1)) between central and terminal nickel ions.

Habit modification of bis-thiourea zinc chloride (ZTC) semi organic crystals by impurities

Science.gov (United States)

Ruby Nirmala, L.; Thomas Joseph Prakash, J.

2013-06-01

Single crystals of bis-thiourea zinc chloride (ZTC) doped with metal ion (Li+) possess excellent nonlinear optical properties. These crystals were grown by slow evaporation solution growth technique. The effect of Li+ dopant on the growth and properties of ZTC single crystal were investigated and reported. The grown crystals were crystallized in orthorhombic structure with non-centro symmetric space group Pn21a through the parent compound. The amount of dopant incorporated in the parent crystal was revealed by the inductively coupled plasma (ICP-OES) studies. The FT-IR spectroscopy study was done for finding and confirming the functional groups present in the compound. The UV-Visible spectral study was carried out to find the optical behavior and transparency nature of the grown crystal. TG/DTA measurements and Vickers microhardness measurements were traced to find out the thermal and mechanical stability of the grown crystals respectively. Using Nd:YAG laser, the Second harmonic generation (SHG) for the grown crystals were confirmed.

INIBIÇÃO À CORROSÃO DE AÇO-CARBONO EM MEIO SALINO PELO HETEROCICLO ISATINA VEICULADO EM MICROEMULSÕES

Directory of Open Access Journals (Sweden)

Ádna Dornelles Nicácio de Souza

Full Text Available Polar microemulsion systems (SME based on saponified coconut oil (OCS as surfactant were prepared in order to increase the solubility of the heterocycle isatin (IST aiming at its application as corrosion inhibitor against AISI 1020 mild steel, in saline medium. The adsorptions phenomena of the tested SME systems (SME-OCS1-IST and SME-OCS2-IST in the liquid/gas interface were evaluated by surface tension measurements which do not show significant differences in the presence of ion Cl-. The free energy values of the micellization proved the occurrence of spontaneous process. The corrosion inhibition effectiveness of SME-OCS2, SME-OCS1-IST and SME-OCS2-IST samples was evaluated in 0.5% aqueous NaCl using voltammetry linear scan method (LPR. The maximum efficiency findings were 73.2% for SME-OCS2, 88.2% for SME-OCS2-IST and 97.6% for SME-OCS1-IST. The spontaneity of the adsorption phenomena was also observed in the liquid/metal interface by analyzes of the adsorption free energy. In addition, since computational calculations have been found as a very relevant tool in the corrosion field, a theoretical study was performed in attempt to give support to the observed experimental results, in which B3LYP and 6-311++G(d,p were applied aiming at investigation of geometry, electronic density aspects, HOMO-LUMO energy gap, as well as the binding between isatin and metal surface.

Trypanocidal 1,3-arylene diketone bis(guanylhydrazone)s. Structure-activity relationships among substituted and heterocyclic analogues.

Science.gov (United States)

Ulrich, P; Cerami, A

1984-01-01

Based on the antitrypanosomal activity of 1,3-diacetylbenzene bis(guanylhydrazone) (4) and 2,6-diacetylpyridine bis(guanylhydrazone) (17), a number of substituted and heterocyclic 1,3-arylene diketone bis(guanylhydrazone)s were prepared and tested against Trypanosoma brucei infections in mice. A wide range of ED50 values was observed among 5-substituted derivatives of 4. The 5-amino analogue 5 and 5-acetamido analogue 6 were about twice as active as 4. 1,3,5-Triacetylbenzene tris(guanylhydrazone) (12) was about 9 times as active as 4 and was approximately one-half as active as the currently used trypanocide diminazene aceturate in this test system. Other 5-derivatives had activity equivalent to or less than that of the parent compound 4. Three new heterocyclic analogues were all less active than 2,6-diacetylpyridine derivative 17 and benzene derivative 4. Ring substitution ortho to the guanylhydrazone side chains was invariably detrimental to activity. Side-chain homologues 1,3-dipentanoylbenzene bis(guanylhydrazone) and 1,3-diacetylbenzene bis(2-imidazolin-2-ylhydrazone) were essentially inactive.

Polymerization behavior of butyl bis(hydroxymethyl)phosphine oxide ...

Indian Academy of Sciences (India)

lenovo

Polymerization behavior of butyl bis(hydroxymethyl)phosphine oxide: Phosphorus containing polyethers for. Li‒ion conductivities. Heeralal Vignesh Babu, Billakanti Srinivas and Krishnamurthi Muralidharan*. School of Chemistry, University of Hyderabad, Hyderabad - 500046, India. Table of Contents. TGA plots of SPE2.

Conformational switching of ethano-bridged Cu,H2-bis-porphyrin induced by aromatic amines.

Science.gov (United States)

Bettini, Simona; Maglie, Emanuela; Pagano, Rosanna; Borovkov, Victor; Inoue, Yoshihisa; Valli, Ludovico; Giancane, Gabriele

2015-01-01

Cu,H2-bis-porphyrin (Cu,H2-Por2), in which copper porphyrin and free-base porphyrin are linked together by an ethano-bridge, was dissolved in chloroform and spread at the air/liquid subphase interface of a Langmuir trough. The bis-porphyrin derivative, floating film was characterized by reflection spectroscopy and the surface pressure of the floating film was studied as a function of the mean area per molecule. When aromatic amines are dissolved in the subphase, an evident interaction between the bis-porphyrin host and the aromatic amine guest is observed. A clear-cut variation of the profile of surface pressure vs area per molecule curve is observed. Reflection spectroscopy highlights that the aromatic amines dissolved in the subphase are able to induce the syn-to-anti conformational switching in the bis-porphyrin derivative. The Langmuir-Schaefer technique has been used to transfer the floating bis-porphyrin film (when using pure water as a subphase) to a surface plasmon resonance (SPR) substrate and the resulting device was able to detect the presence of aniline at concentrations as low as 1 nM in aqueous solution. The high selectivity of the SPR sensing device has been verified by checking the spectral response of the active layer towards other analytes dissolved in the aqueous solutions.

Conformational switching of ethano-bridged Cu,H2-bis-porphyrin induced by aromatic amines

Directory of Open Access Journals (Sweden)

Simona Bettini

2015-11-01

Full Text Available Cu,H2-bis-porphyrin (Cu,H2-Por2, in which copper porphyrin and free-base porphyrin are linked together by an ethano-bridge, was dissolved in chloroform and spread at the air/liquid subphase interface of a Langmuir trough. The bis-porphyrin derivative, floating film was characterized by reflection spectroscopy and the surface pressure of the floating film was studied as a function of the mean area per molecule. When aromatic amines are dissolved in the subphase, an evident interaction between the bis-porphyrin host and the aromatic amine guest is observed. A clear-cut variation of the profile of surface pressure vs area per molecule curve is observed. Reflection spectroscopy highlights that the aromatic amines dissolved in the subphase are able to induce the syn-to-anti conformational switching in the bis-porphyrin derivative. The Langmuir–Schaefer technique has been used to transfer the floating bis-porphyrin film (when using pure water as a subphase to a surface plasmon resonance (SPR substrate and the resulting device was able to detect the presence of aniline at concentrations as low as 1 nM in aqueous solution. The high selectivity of the SPR sensing device has been verified by checking the spectral response of the active layer towards other analytes dissolved in the aqueous solutions.

Effects of polyamines and methylglyoxal bis(guanylhydrazone) on hepatic nuclear structure and deoxyribonucleic acid template activity.

Science.gov (United States)

Brown, K B; Nelson, N F; Brown, D G

1975-12-01

1. The interaction of polyamines and methylglyoxal bis(guanythydrazone) (1, 1'-[(methylethanediylidene)-dinitrilo]diguanidine) with isolated rat liver nuclei was investigated by electron microscopy. 2. At 4mM, putrescine was without effect; however, spermidine, spermine or methylglyoxal bis(guanythydrazone) resulted in dispersed chromatin and alterations in nucleolar structure. In addition, spermidine or methylglyoxal bis(guanylhydrazone) caused marked aggregation of interchromatin granules. 3. The DNA template property of calf thymus DNA was examined by using DNA polymerases from Escherichia coli, Micrococcus lysodeikticus and calf thymus in the presence of 0-5 mM-amine. 4. In the presence of DNA polymerase, spermine or methylglyoxal bis(guanylhydrazone) inhibited activity, whereas putrescine or spermidine had much less effect or in some cases stimulated [3H]dTMP incorporation. 5. Template activity which was inhibited by spermine or methylglyoxal bis(guanylhydrazone) could be partially restored by additional DNA or enzyme. 6. When mixed with calf thymus DNA, calf thymus histone inhibited template activity as measured with E. coli DNA polymerase. The template activity of such a 'histone-nucleate' could not be restored by putrescine, spermidine, spermine or methylglyoxal bis(guanylhydrazone). 7. DNA template activity of isolated rat liver nuclei was tested by using E. coli DNA polymerase. None of the amines was able to increase the template activity of the nuclear DNA in vitro.

Four Mixed-Ligand Zn(II Three-Dimensional Metal-Organic Frameworks: Synthesis, Structural Diversity, and Photoluminescent Property

Directory of Open Access Journals (Sweden)

Chih-Chieh Wang

2017-11-01

Full Text Available Assemblies of four three-dimensional (3D mixed-ligand coordination polymers (CPs having formulas, {[Zn2(bdc2(4-bpdh]·C2H5OH·2H2O}n (1, [Zn(bdc(4-bpdh]n (2, {[Zn2(bdc2(4-bpdh2]·(4-bpdh}n (3, and {[Zn(bdc(4-bpdh]·C2H5OH}n (4 (bdc2− = dianion of 1,4-benzenedicarboxylic acid, 4-bpdh = 2,5-bis(4-pyridyl-3,4-diaza-2,4-hexadiene have been synthesized and structurally characterized by single-crystal X-ray diffraction method. Structural determination reveals that the coordination numbers (geometry of Zn(II ions in 1, 2, 3, and 4 are five (distorted square-pyramidal (SP, six (distorted octahedral (Oh, five (trigonal-bipyramidal (TBP, and four (tetrahedral (Td, respectively, and are bridged by 4-bpdh with bis-monodentate coordination mode and bdc2− ligands with bis-bidentate in 1, chelating/bidentate in 2, bis-monodentate and bis-bidentate in 3, and bis-monodentate in 4, to generate two-fold interpenetrating 3D cube-like metal-organic framework (MOF with pcu topology, non-interpenetrating 3D MOF, two-fold interpenetrating 3D rectangular-box-like MOF with pcu topology and five-fold interpenetrating diamondoid-like MOF with dia topology, respectively. These different intriguing architectures indicate that the coordination numbers and geometries of Zn(II ions, coordination modes of bdc2− ligand, and guest molecules play important roles in the construction of MOFs and the formation of the structural topologies and interpenetrations. Thermal stabilities, and photoluminescence study of 1–4 were also studied in detail. The complexes exhibit ligands based photoluminescence properties at room temperature.

Synthesis of peptide thioacids at neutral pH using bis(2-sulfanylethyl)amido peptide precursors.

Science.gov (United States)

Pira, Silvain L; Boll, Emmanuelle; Melnyk, Oleg

2013-10-18

Reaction of bis(2-sulfanylethyl)amido (SEA) peptides with triisopropylsilylthiol in water at neutral pH yields peptide thiocarboxylates. An alkylthioester derived from β-alanine was used to trap the released bis(2-sulfanylethyl)amine and displace the equilibrium toward the peptide thiocarboxylate.

An intramolecular inverse electron demand Diels–Alder approach to annulated α-carbolines

Directory of Open Access Journals (Sweden)

Zhiyuan Ma

2012-06-01

Full Text Available Intramolecular inverse electron demand cycloadditions of isatin-derived 1,2,4-triazines with acetylenic dienophiles tethered by amidations or transesterifications proceed in excellent yields to produce lactam- or lactone-fused α-carbolines. Beginning with various isatins and alkynyl dienophiles, a pilot-scale library of eighty-eight α-carbolines was prepared by using this robust methodology for biological evaluation.

Synthesis and Characterisation of Eight Isomeric Bis(2-pyridyloxynaphthalenes

Directory of Open Access Journals (Sweden)

Peter J. Steel

2006-09-01

Full Text Available Eight isomeric bis(2-pyridyloxynaphthalenes have been prepared from reactions of 2-bromopyridine with the appropriate dihydroxynaphthalene and the products fully characterised by 1- and 2-D NMR spectroscopy.

Bis[2,6-bis(trimethylsilylaminopyridine-κN1]{[6-bis(trimethylsilylaminopyridin-2-yl-κN1](trimethylsilylazanido-κN}lithium

Directory of Open Access Journals (Sweden)

Justin A. Rave

2016-03-01

Full Text Available The title complex, [Li(C11H22N3Si2(C11H23N3Si22], contains a single lithium cation coordinated to three ligands. This is the first reported example of the ligand 2,6-bis(trimethylsilylaminopyridine supporting a monometallic complex. One ligand is mono-anionic and forms a four-membered chelate ring with the lithium cation via the pyridine and silylamido N atoms. The other two ligands are neutral and bind via the pyridine nitrogen. The lithium cation is coordinated in a tetrahedral environment. No intra- or intermolecular hydrogen bonding is observed in the crystal structure, likely indicating that weak electrostatic interactions are the dominant feature of the crystal packing.

Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers

Energy Technology Data Exchange (ETDEWEB)

Monier, M., E-mail: monierchem@yahoo.com [Chemistry Department, Drexel University, Philadelphia, PA (United States); Chemistry Department, Faculty of Science, Mansoura University, Mansoura (Egypt); Ayad, D.M.; Sarhan, A.A. [Chemistry Department, Faculty of Science, Mansoura University, Mansoura (Egypt)

2010-04-15

The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction.

Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers.

Science.gov (United States)

Monier, M; Ayad, D M; Sarhan, A A

2010-04-15

The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction. 2009 Elsevier B.V. All rights reserved.

Bis(triisopropylsilylethynyl)pentacene/Au(111) interface: Coupling, molecular orientation, and thermal stability

KAUST Repository

Gnoli, Andrea; Ü stü nel, Hande; Toffoli, Daniele; Yu, Liyang; Catone, D.; Turchini, Stefano; Lizzit, Silvano; Stingelin, Natalie; Larciprê te, Rosanna

2014-01-01

The assembly and the orientation of functionalized pentacene at the interface with inorganics strongly influence both the electric contact and the charge transport in organic electronic devices. In this study electronic spectroscopies and theoretical modeling are combined to investigate the properties of the bis(triisopropylsilylethynyl)pentacene (TIPS-Pc)/Au(111) interface as a function of the molecular coverage to compare the molecular state in the gas phase and in the adsorbed phase and to determine the thermal stability of TIPS-Pc in contact with gold. Our results show that in the free molecule only the acene atoms directly bonded to the ligands are affected by the functionalization. Adsorption on Au(111) leads to a weak coupling which causes only modest binding energy shifts in the TIPS-Pc and substrate core level spectra. In the first monolayer the acene plane form an angle of 33 ± 2° with the Au(111) surface at variance with the vertical geometry reported for thicker solution-processed or evaporated films, whereas the presence of configurational disorder was observed in the multilayer. The thermal annealing of the TIPS-Pc/Au(111) interface reveals the ligand desorption at ∼470 K, which leaves the backbone of the decomposed molecule flat-lying on the metal surface as in the case of the unmodified pentacene. The weak interaction with the metal substrate causes the molecular dissociation to occur 60 K below the thermal decomposition taking place in thick drop-cast films.

Bis(triisopropylsilylethynyl)pentacene/Au(111) interface: Coupling, molecular orientation, and thermal stability

KAUST Repository

Gnoli, Andrea

2014-10-02

The assembly and the orientation of functionalized pentacene at the interface with inorganics strongly influence both the electric contact and the charge transport in organic electronic devices. In this study electronic spectroscopies and theoretical modeling are combined to investigate the properties of the bis(triisopropylsilylethynyl)pentacene (TIPS-Pc)/Au(111) interface as a function of the molecular coverage to compare the molecular state in the gas phase and in the adsorbed phase and to determine the thermal stability of TIPS-Pc in contact with gold. Our results show that in the free molecule only the acene atoms directly bonded to the ligands are affected by the functionalization. Adsorption on Au(111) leads to a weak coupling which causes only modest binding energy shifts in the TIPS-Pc and substrate core level spectra. In the first monolayer the acene plane form an angle of 33 ± 2° with the Au(111) surface at variance with the vertical geometry reported for thicker solution-processed or evaporated films, whereas the presence of configurational disorder was observed in the multilayer. The thermal annealing of the TIPS-Pc/Au(111) interface reveals the ligand desorption at ∼470 K, which leaves the backbone of the decomposed molecule flat-lying on the metal surface as in the case of the unmodified pentacene. The weak interaction with the metal substrate causes the molecular dissociation to occur 60 K below the thermal decomposition taking place in thick drop-cast films.

bis-NHC complexes of R-BINOL scaffold

Indian Academy of Sciences (India)

SONALI RAMGOPAL MAHULE

2017-09-04

Sep 4, 2017 ... The newly synthesized bis-NHC ligand precursor (1g) and its corresponding {[L(L -NHC)2]Ag}Cl (1h) and .... -binaphthyl (1f) (0.500 g, 1.21 mmol) and 1-i-propyl- ... chloride (1g) (0.250 g, 0.340 mmol) and Ag2O (0.078 g, 0.340.

SYNTHESIS OF BIS-QUINOXALINE DERIVATIVES USING TONSIL ...

African Journals Online (AJOL)

A convenient and efficient synthesis of new bis-quinoxaline is described, involving ... the following composition (in %): SiO2: 74.5, Al2O3: 9.3, MgO: 0.4, Fe2O3: 1.3, CaO: 4.0, K2O: 0.4 and .... Tonsil clay is a nanoparticle with layered structure.

Growth and characterization of nonlinear optical single crystals: bis ...

Indian Academy of Sciences (India)

Administrator

molecules have received great attention for NLO applica- tions. However ... Figure 3. Single crystals of bis(cyclohexylammonium) terephthalate (crystal a) and cyclohexylammo- .... from ground state to higher energy states.17 Optical window ...

Cytotoxicity, DNA binding and localisation of novel bis-naphthalimidopropyl polyamine derivatives.

Science.gov (United States)

Pavlov, V; Kong Thoo Lin, P; Rodilla, V

2001-07-31

Bis-naphthalimidopropyl spermidine (BNIPSpd), spermine (BNIPSpm) and oxa-spermine (BNIPOSpm) showed high in vitro cytotoxicity against human breast cancer MCF-7 cells with IC(50) values of 1.38, 2.91 and 8.45 microM, respectively. These compounds were found to effectively displace the intercalating agent ethidium bromide bound to the calf thymus DNA using fluorimetric methods (C(50) 0.08-0.12 microM) and their apparent equilibrium binding constants (K(app)) were calculated to be in the range of 10.5-18 x 10(7) M(-1). Furthermore, strong stabilisation of calf thymus DNA duplex in the presence of bis-naphthalimidopropyl polyamine derivatives (BNIPSpd, BNIPSpm and BNIPOSpm) was observed by UV spectrophotometric analysis (T(m)=93.3-97 degrees C compared with 75 degrees C for calf thymus DNA without drug). Because of their inherent fluorescence, these compounds were localised preferentially inside the nucleus as evidenced by their direct observation under the fluorescence microscope. The results obtained suggest that the cytotoxic activity of the bis-naphthalimidopropyl polyamines may be in part, caused by their effects on DNA.

Effects of phenylated compounds of methylglyoxal bis(guanylhydrazone) on diamine oxidase activity from rat small intestine.

Science.gov (United States)

Balaña-Fouce, R; Pulido, T G; Escudero, D O; Sanz-Sanchez, F

1986-01-01

Two phenylated compounds of methylglyoxal bis(guanylhydrazone), potentially inhibitors of diamine oxidase activity, have been synthesized: phenylglyoxal bis(guanylhydrazone) and diphenylglyoxal bis(guanylhydrazone). Their inhibitory capacity was tested: while PGBG was able to reduce the enzyme activity by 50% at 1.3 microM, DPGBG was only able to reduce diamine oxidase activity by less than 2% at a concentration 1000-fold higher. The inhibition of PGBG was non-competitive and the Ki calculated by a Dixon plot was estimated as 1.7 microM.

Metal and ligand K-edge XAS of organotitanium complexes: metal 4p and 3d contributions to pre-edge intensity and their contributions to bonding.

Science.gov (United States)

George, Serena DeBeer; Brant, Patrick; Solomon, Edward I

2005-01-19

Titanium cyclopentadienyl (Cp) complexes play important roles as homogeneous polymerization catalysts and have recently received attention as potential anticancer agents. To systematically probe the contribution of the Cp to bonding in organotitanium complexes, Ti K-edge XAS has been applied to TiCl(4) and then to the mono- and bis-Cp complexes, TiCpCl(3) and TiCp(2)Cl(2). Ti K-edge XAS is used as a direct probe of metal 3d-4p mixing and provides insight into the contribution of the Cp to bonding. These data are complimented by Cl K-edge XAS data, which provide a direct probe of the effect of the Cp on the bonding to the spectator chloride ligand. The experimental results are correlated to DFT calculations. A model for metal 3d-4p mixing is proposed, which is based on covalent interactions with the ligands and demonstrates that metal K-pre-edge intensities may be used as a measure of ligand-metal covalency in molecular Ti(IV) systems in noncentrosymmetric environments.

Ternary (liquid + liquid) equilibria of {bis(trifluoromethylsulfonyl)-amide based ionic liquids + butan-1-ol + water}

International Nuclear Information System (INIS)

Marciniak, Andrzej; Wlazło, Michał; Gawkowska, Joanna

2016-01-01

Highlights: • Ternary (liquid + liquid) equilibria for 3 ionic liquid + butanol + water systems. • The influence of ionic liquid structure on phase diagrams is discussed. • Influence of IL structure on S and β for butanol/water separation is discussed. - Abstract: Ternary (liquid + liquid) phase equilibria for 3 systems containing bis(trifluoromethylsulfonyl)-amide ionic liquids (1-buthyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)-amide, 1-(2-methoxyethyl)-1-methylpiperidinium bis(trifluoromethylsulfonyl)-amide, {1-(2-methoxyethyl)-1-methylpyrrolidinium bis(trifluorylsulfonyl)-amide) + butan-1-ol + water} have been determined at T = 298.15 K. The selectivity and solute distribution ratio were calculated for investigated systems and compared with literature data for other systems containing ionic liquids. In each system total solubility of butan-1-ol and low solubility of water in the ionic liquid is observed. The experimental results have been correlated using NRTL model. The influence of the structure of ionic liquid on phase equilibria, selectivity and solute distribution ratio is shortly discussed.

Comparison of specificity of inhibition of polyamine synthesis in bovine lymphocytes by ethylglyoxal bis(guanylhydrazone) and methylglyoxal bis(guanylhydrazone).

Science.gov (United States)

Igarashi, K; Porter, C W; Morris, D R

1984-11-01

Ethylglyoxal bis(guanylhydrazone) (EGBG) was compared as an inhibitor of polyamine biosynthesis with methylglyoxal bis(guanylhydrazone) (MGBG) in bovine small lymphocytes stimulated by concanavalin A. EGBG brought about a decrease in spermidine and spermine levels equal to that found with MGBG, but at a 5-fold lower intracellular drug concentration. Despite identical polyamine levels, the degree of inhibition of DNA and protein synthesis by EGBG was smaller than that observed with MGBG, in either the presence or absence of the ornithine decarboxylase inhibitor, alpha-difluoromethylornithine. It was found that in vitro protein synthesis and in vivo mitochondrial function were inhibited by concentrations of MGBG necessary to inhibit polyamine synthesis in cells (1 to 3 mM), but not by efficacious levels of EGBG (0.2 to 0.6 mM). These results suggest that EGBG is more suitable as a specific inhibitor of polyamine biosynthesis and that use of this drug, rather than MGBG, in combination with alpha-difluoromethylornithine may be useful for studying the physiological functions of polyamines in animal cells.

Enhancement of superconductivity near the pressure-induced semiconductor-metal transition in the BiS₂-based superconductors LnO₀.₅F₀.₅BiS₂ (Ln = La, Ce, Pr, Nd).

Science.gov (United States)

Wolowiec, C T; White, B D; Jeon, I; Yazici, D; Huang, K; Maple, M B

2013-10-23

Measurements of electrical resistivity were performed between 3 and 300 K at various pressures up to 2.8 GPa on the BiS2-based superconductors LnO0.5F0.5BiS2 (Ln=Pr, Nd). At lower pressures, PrO0.5F0.5BiS2 and NdO0.5F0.5BiS2 exhibit superconductivity with critical temperatures Tc of 3.5 and 3.9 K, respectively. As pressure is increased, both compounds undergo a transition at a pressure Pt from a low Tc superconducting phase to a high Tc superconducting phase in which Tc reaches maximum values of 7.6 and 6.4 K for PrO0.5F0.5BiS2 and NdO0.5F0.5BiS2, respectively. The pressure-induced transition is characterized by a rapid increase in Tc within a small range in pressure of ∼0.3 GPa for both compounds. In the normal state of PrO0.5F0.5BiS2, the transition pressure Pt correlates with the pressure where the suppression of semiconducting behaviour saturates. In the normal state of NdO0.5F0.5BiS2, Pt is coincident with a semiconductor-metal transition. This behaviour is similar to the results recently reported for the LnO0.5F0.5BiS2 (Ln=La, Ce) compounds. We observe that Pt and the size of the jump in Tc between the two superconducting phases both scale with the lanthanide element in LnO0.5F0.5BiS2 (Ln=La, Ce, Pr, Nd).

Four coordination polymers based on 5-tert-butyl isophthalic acid and rigid bis(imidazol-1yl)benzene linkers: Synthesis, luminescence detection of acetone and optical properties

International Nuclear Information System (INIS)

Arıcı, Mürsel; Zafer Yeşilel, Okan; Büyükgüngör, Orhan

2017-01-01

Four coordination polymers including, [Co(µ-Htbip) 2 (µ-dib)] n (1), [Co(µ-tbip)(µ-dmib) 0.5 ] n (2), [Zn 2 (µ-tbip)(µ 3 -tbip)(µ-dmib) 1.5 ] n (3) and [Cd(µ 3 -tbip)(µ-dib) 0.5 (H 2 O)] n (4) (tbip: 5-tert-butylisophthalate, dib: 1,4-bis(imidazol-1yl)benzene, dmib: 1,4-bis(imidazol-1yl)-2,5-dimethylbenzene), were hydrothermally synthesized and characterized by elemental analysis, IR spectra, single crystal and powder X-ray diffraction and thermal analysis (TG/DTA). The structural diversity is observed depending on ligands and coordination number of metal centers in the synthesized complexes. The tbip ligand displayed five different coordination modes in its complexes. In 1 and 2, complex 1 is 3D framework with the dia topology while complex 2 has 2D structure with the sql topology depending on coordination geometries of Co ions. Complex 3 is 3D framework with the fsh 4,6-conn topology and complex 4 has 2D 4-connected sql topology. Photoluminescent properties of complex 3 dispersed in various organic solvents were investigated and the results showed that 3 dispersed in methanol could be used as a fluorescent sensor for the detection of acetone. Moreover, thermal and optical properties of the complexes were also studied. - Graphical abstract: Four coordination polymers were hydrothermally synthesized and characterized by various techniques. The complexes showed the structural diversity depending on ligands and coordination number of metal centers. The tbip ligand displayed four different coordination modes in its complexes. In 1 and 2, complexes 1 and 2 are 3D and 2D structures with the dia and sql topologies depending on coordination geometries of Co ions, respectively. Complexes 3 and 4 are 3D and 2D structures with the fsh 4,6-conn and sql topology, respectively. Photoluminescent properties of complex 3 dispersed in various organic solvents were investigated and the results showed that 3 dispersed in methanol could be used as a fluorescent sensor for the

Flame atomic absorption spectrometric determination of zinc, nickel, iron and lead in different matrixes after solid phase extraction on sodium dodecyl sulfate (SDS)-coated alumina as their bis (2-hydroxyacetophenone)-1, 3-propanediimine chelates

International Nuclear Information System (INIS)

Ghaedi, M.; Tavallali, H.; Shokrollahi, A.; Zahedi, M.; Montazerozohori, M.; Soylak, M.

2009-01-01

A sensitive and simple solid phase extraction method for the simultaneous determination of trace and toxic metals in food samples has been reported. The method is based on the adsorption of zinc, nickel, iron and lead on sodium dodecyl sulfate (SDS)-coated alumina, which is also chelated with bis (2-hydroxyacetophenone)-1, 3-propanediimine (BHAPN). The retained analyte ions on modified solid phase were eluted using 8 mL of 4 mol L -1 HNO 3 . The analyte determinations were carried out by flame atomic absorption spectrometry. The influences of some metal ions and anions on the recoveries of understudy analyte ions were investigated. The proposed method has been successfully applied for the evaluation of these trace and toxic metals in some traditional food samples from Iran.

Regulatory behavior and frontal activity: Considering the role of revised-BIS in relative right frontal asymmetry.

Science.gov (United States)

Gable, Philip A; Neal, Lauren B; Threadgill, A Hunter

2018-01-01

Essential to human behavior are three core personality systems: approach, avoidance, and a regulatory system governing the two motivational systems. Decades of research has linked approach motivation with greater relative left frontal-cortical asymmetry. Other research has linked avoidance motivation with greater relative right frontal-cortical asymmetry. However, past work linking withdrawal motivation with greater relative right frontal asymmetry has been mixed. The current article reviews evidence suggesting that activation of the regulatory system (revised Behavioral Inhibition System [r-BIS]) may be more strongly related to greater relative right frontal asymmetry than withdrawal motivation. Specifically, research suggests that greater activation of the r-BIS is associated with greater relative right frontal activity, and reduced r-BIS activation is associated with reduced right frontal activity (greater relative left frontal activity). We review evidence examining trait and state frontal activity using EEG, source localization, lesion studies, neuronal stimulation, and fMRI supporting the idea that r-BIS may be the core personality system related to greater relative right frontal activity. In addition, the current review seeks to disentangle avoidance motivation and r-BIS as substrates of relative right frontal asymmetry. © 2017 Society for Psychophysiological Research.

7α-alkylation and 7,7-bis-alkylation of 20-hydroxyecdysone with propargyl bromide in a lithium-ammonia solution and catalytic reductive spirocyclization of 7,7-bis(2-propyn-1-yl)-14-deoxy-Δ(8(14))-20-hydroxyecdysone.

Science.gov (United States)

Galyautdinov, Ilgiz V; Khairullina, Zarema R; Sametov, Valery P; Muslimov, Zabir S; Khalilov, Leonard M; Odinokov, Victor N

2016-03-01

7α-Alkylation and 7,7-bis-alkylation of 20-hydroxyecdysone with propargyl bromide in a lithium-ammonia solution resulted in the formation of 7α-(2-propyn-1-yl)- and 7,7-bis(2-propyn-1-yl)-14-deoxy-Δ(8(14))-20-hydroxyecdysone in 92% and 75% yield respectively. Upon catalytic hydrogenation (10% Pd-C) of 7,7-bis(2-propyn-1-yl) derivative spirocyclization occurs by geminal 2-propyn-1-yl groups. Copyright © 2016 Elsevier Inc. All rights reserved.

E/Z-Photoisomerization of N,N'-Bis(4-dimethylaminobenzylidene1,2-diaminoethane and N,N'-Bis(4-dimethylaminobenzylidene1,3-diaminopropane in Chloroform

Directory of Open Access Journals (Sweden)

Asghar Samimi

2011-01-01

Full Text Available The E/Z-Photoisomerization of Schiff bases N,N'-bis(4-dimethylamino benzylidene1,2-diaminoethane (BDAE and N,N'-bis(4-dimethylaminobenzyli-dene1,3-diaminopropane (BDAP were studied by UV-Vis absorption spectroscopy and theoretical chemistry calculations. Photochemical investigations in solution depict the time resolved spectral changes, recorded before and after irradiation. The shift indicates the transformation from E to Z configuration of the C=N bond in solution for BDAE and BDAP. Spectra profiles and kinetic constants were evaluated using multivariate curve resolution and non-linear least squares curve fitting by toolbox of MATLAB program using the corresponding absorption spectra-time data. The experimental results show that BDAP can perform the photochromism easier than BDAE, may be due to the molecular topology difference.

Physiological effects in bovine lymphocytes of inhibiting polyamine synthesis with ethylglyoxal bis(guanylhydrazone).

Science.gov (United States)

Igarashi, K; Morris, D R

1984-11-01

Previous results have suggested that ethylglyoxal bis(guanylhydrazone) is a more specific inhibitor of polyamine biosynthesis than the widely used methylglyoxal bis(guanylhydrazone). The physiological effects on mitogenically activated lymphocytes of polyamine depletion with ethylglyoxal bis(guanylhydrazone) were examined. In the presence of ethylglyoxal bis(guanylhydrazone) and the ornithine decarboxylase inhibitor alpha-difluoromethylornithine, the cellular contents of putrescine, spermidine, and spermine were decreased by 75 to 90, 65 to 80, and 40 to 60%, respectively, compared with control cultures. Inhibition of DNA synthesis in these polyamine-deficient cells was always greater than that of protein synthesis. Upon addition of spermidine to the deficient cells, the cellular spermidine content was restored within 4 hr, but the complete recovery of macromolecular synthesis took 10 to 20 hr. Thymidine kinase and DNA polymerase alpha activities in polyamine-deficient cells were lower than those in normal cells, whereas RNA polymerase II and leucyl transfer RNA synthase activities were nearly equal to those in normal cells. These results and studies with 2-dimensional gel electrophoresis raise the possibility that polyamines may regulate the synthesis of specific proteins. Decreased synthesis of replication proteins in polyamine-deficient cells may be one reason for the reduced synthesis of DNA.

Species dependence of [64Cu]Cu-Bis(thiosemicarbazone) radiopharmaceutical binding to serum albumins

International Nuclear Information System (INIS)

Basken, Nathan E.; Mathias, Carla J.; Lipka, Alexander E.; Green, Mark A.

2008-01-01

Introduction: Interactions of three copper(II) bis(thiosemicarbazone) positron emission tomography radiopharmaceuticals with human serum albumin, and the serum albumins of four additional mammalian species, were evaluated. Methods: 64 Cu-labeled diacetyl bis(N 4 -methylthiosemicarbazonato)copper(II) (Cu-ATSM), pyruvaldehyde bis(N 4 -methylthiosemicarbazonato)copper(II) (Cu-PTSM) and ethylglyoxal bis(thiosemicarbazonato)copper(II) (Cu-ETS) were synthesized and their binding to human, canine, rat, baboon and porcine serum albumins quantified by ultrafiltration. Protein binding was also measured for each tracer in human, porcine, rat and mouse serum. Results: The interaction of these neutral, lipophilic copper chelates with serum albumin is highly compound- and species-dependent. Cu-PTSM and Cu-ATSM exhibit particularly high affinity for human serum albumin (HSA), while the albumin binding of Cu-ETS is relatively insensitive to species. At HSA concentrations of 40 mg/ml, '% free' (non-albumin-bound) levels of radiopharmaceutical were 4.0±0.1%, 5.3±0.2% and 38.6±0.8% for Cu-PTSM, Cu-ATSM and Cu-ETS, respectively. Conclusions: Species-dependent variations in radiopharmaceutical binding to serum albumin may need to be considered when using animal models to predict the distribution and kinetics of these compounds in humans

Electronic states of 1,4-bis(phenylethynyl)benzene

DEFF Research Database (Denmark)

Nguyen, Duy Duc; Jones, Nykola; Hoffmann, Søren Vrønning

2012-01-01

The electronic transitions of 1,4-bis(phenylethynyl)benzene (BPEB) were investigated by UV synchrotron radiation linear dichroism (SRLD) spectroscopy in the range 25,000 – 58,000 cm–1 (400 – 170 nm) on molecular samples aligned in stretched polyethylene. The investigation was supported by variable...

Faszinierende Physik ein bebilderter Streifzug vom Universum bis in die Welt der Elementarteilchen

CERN Document Server

Bahr, Benjamin; Riebe, Kristin

2013-01-01

Von den Rätseln der Quantenwelt bis zum Polarlicht - von Schwarzen Löchern bis zum GPS-System -von Teilchenbeschleunigern, dem Higgs und der Supersymmetrie bis zum Foucaultschen Pendel – dieses Buch bietet einen packenden Streifzug durch die spannendsten und aktuellsten Themen der modernen Physik! Auf jeweils einer Doppelseite wird dem Leser dabei mit vielen Bildern ein kompakter und klar verständlicher Einstieg in jeweils ein Thema und den Stand der Forschung geboten – und so insgesamt etwa 140 verschiedene Themen beleuchtet und jedes treffend erläutert. Dabei liegt die besondere Stärke des Buches in der klaren Sprache und den Erklärungen, die nahezu ganz ohne Formeln auskommen – begleitet von atemberaubenden und weltweit eingeholten Bildern renommierter Forscher und Institute, die uns die Schönheit unserer Welt vor Augen führen.

Isolation and Characterization of Bis (2 – Methoxyethyl) Phthalate ...

African Journals Online (AJOL)

Isolation and Characterization of Bis (2 – Methoxyethyl) Phthalate and Hexashydro-1 3 – Dimethyl – 4 – Phenyl – 1h – Azepine 4 – Carboxylic Acid from the Root of Cissampelos Owariensis (P. Beauv)

Polyamine metabolism in the kidneys of castrated and testosterone-treated mice after administration of methylglyoxal bis(guanylhydrazone).

Science.gov (United States)

Henningsson, S; Persson, L; Rosengren, E

1979-02-01

The effects of methylglyoxal bis(guanylhydrazone) on S-adenosyl-L-methionine decarboxylase (EC 4.1.1.50) activity were studied in the mouse kidney stimulated to growth by testosterone administration. The drug was found a potent inhibitor of the enzyme in vitrol Administration of methylglyoxal bis(guanylhydrazone) in vivo resulted in a transient inhibition followed by a strong enhancement of the enzyme activity. Dialysis of the kidney extract, to remove remaining methylglyoxal bis(guanylhydrazone), revealed a great and rapid increase in the activity of S-adenosyl-L-methionine decarboxylase. Injections of testosterone to castrated mice resulted in a marked increase in kidney weight and an accumulation of renal putrescine, spermidine and spermine. These effects of testosterone could not be blocked by simultaneous injections of methylglyoxal bis(guanylhydrazone). It appears that due to secondary effects by which the inhibition of methylglyoxal bis(guanylhydrazone) on S-adenosyl-L-methionine decarboxylase activity is circumvented the inhibitor seems to be of uncertain value in attempts to decrease selectively the in vivo levels of polyamines.

Effect of Annealing Temperature on Flowerlike Cu3BiS3 Thin Films Grown by Chemical Bath Deposition

Science.gov (United States)

Deshmukh, S. G.; Patel, S. J.; Patel, K. K.; Panchal, A. K.; Kheraj, Vipul

2017-10-01

For widespread application of thin-film photovoltaic solar cells, synthesis of inexpensive absorber material is essential. In this work, deposition of ternary Cu3BiS3 absorber material, which contains abundant and environmentally benign elements, was carried out on glass substrate. Flowerlike Cu3BiS3 thin films with nanoflakes as building block were formed on glass substrate by chemical bath deposition. These films were annealed at 573 K and 673 K in sulfur ambient for structural improvement. Their structure was characterized using Raman spectroscopy, as well as their surface morphological and optical properties. The x-ray diffraction profile of as-deposited Cu3BiS3 thin film revealed amorphous structure, which transformed to orthorhombic phase after annealing. The Raman spectrum exhibited a characteristic peak at 290 cm-1. Scanning electron microscopy of as-deposited Cu3BiS3 film confirmed formation of nanoflowers with diameter of around 1052 nm. Wettability testing of as-deposited Cu3BiS3 thin film demonstrated hydrophobic nature, which became hydrophilic after annealing. The measured ultraviolet-visible (UV-Vis) absorption spectra of the Cu3BiS3 thin films gave an absorption coefficient of 105 cm-1 and direct optical bandgap of about 1.42 eV after annealing treatment. Based on all these results, such Cu3BiS3 material may have potential applications in the photovoltaic field as an absorber layer.

Well-Defined Silica Grafted Molybdenum Bis(imido) Catalysts for Imine Metathesis Reactions

KAUST Repository

Barman, Samir

2017-04-06

Novel site-isolated tetracoordinated molybdenum complexes possessing bis(imido) ligands, [(≡Si–O)2Mo(═NR)2] (R = t-Bu, 2,6-C6H3-i-Pr2), were immobilized on partially dehydroxylated silica (SiO2-200) by a rigorous surface organometallic chemistry protocol. The newly developed materials adorned with bis(imido) functional units, which were previously exploited mainly as spectator ligands on silica-supported olefin metathesis molybdenum catalysts, are found to be efficient heterogeneous catalytic systems for imine cross metathesis under mild conditions.

Well-Defined Silica Grafted Molybdenum Bis(imido) Catalysts for Imine Metathesis Reactions

KAUST Repository

Barman, Samir; Merle, Nicolas; Minenkov, Yury; De Mallmann, Aimery; Samantaray, Manoja; Le Qué mé ner, Fré dé ric; Szeto, Kai C.; Abou-Hamad, Edy; Cavallo, Luigi; Taoufik, Mostafa; Basset, Jean-Marie

2017-01-01

Novel site-isolated tetracoordinated molybdenum complexes possessing bis(imido) ligands, [(≡Si–O)2Mo(═NR)2] (R = t-Bu, 2,6-C6H3-i-Pr2), were immobilized on partially dehydroxylated silica (SiO2-200) by a rigorous surface organometallic chemistry protocol. The newly developed materials adorned with bis(imido) functional units, which were previously exploited mainly as spectator ligands on silica-supported olefin metathesis molybdenum catalysts, are found to be efficient heterogeneous catalytic systems for imine cross metathesis under mild conditions.

Immunomodulatory effects of intravenous bis-1 f(ab')(2) administration in renal-cell cancer-patients

NARCIS (Netherlands)

Janssen, R. A. J.; Kroesen, B. J.; Mesander, G.; Sleijfer, D. T.; The, T. Hauw; Mulder, N. H.; de Leij, L

We report the immunomodulatory effects of an intravenous treatment with F(ab')(2) fragments of the bispecific monoclonal antibody BIS-1 during subcutaneous recombinant interleukin 2 (rIL-2) therapy of renal cell cancer (RCC) patients. BIS-1 is directed against both the CD3 antigen on T cells and the

Superconductivity in Layered Organic Metals

Directory of Open Access Journals (Sweden)

Jochen Wosnitza

2012-04-01

Full Text Available In this short review, I will give an overview on the current understanding of the superconductivity in quasi-two-dimensional organic metals. Thereby, I will focus on charge-transfer salts based on bis(ethylenedithiotetrathiafulvalene (BEDT-TTF or ET for short. In these materials, strong electronic correlations are clearly evident, resulting in unique phase diagrams. The layered crystallographic structure leads to highly anisotropic electronic as well as superconducting properties. The corresponding very high orbital critical field for in-plane magnetic-field alignment allows for the occurrence of the Fulde–Ferrell– Larkin–Ovchinnikov state as evidenced by thermodynamic measurements. The experimental picture on the nature of the superconducting state is still controversial with evidence both for unconventional as well as for BCS-like superconductivity.

Color stability and flexural strength of poly (methyl methacrylate) and bis-acrylic composite based provisional crown and bridge auto-polymerizing resins exposed to beverages and food dye: an in vitro study.

Science.gov (United States)

Gujjari, Anil K; Bhatnagar, Vishrut M; Basavaraju, Ravi M

2013-01-01

To evaluate the color stability and flexural strength of poly (methyl methacrylate) (PMMA) and bis-acrylic composite based provisional crown and bridge auto-polymerizing resins exposed to tea, coffee, cola, and food dye. Two provisional crown and bridge resins, one DPI self-cure tooth molding powder (PMMA) (Group A), and one Protemp 4 Temporization Material (bis-acrylic composite) (Group B) were used. Disk-shaped specimens for color stability testing (n = 30 for each material) and bar-shaped specimens for flexural strength testing (n = 30 for each material) were fabricated using a metal mold. The specimens were immersed in artificial saliva, artificial saliva + tea, artificial saliva + coffee, artificial saliva + cola, and artificial saliva + food dye solutions and stored in an incubator at 37°C. Color measurements were taken before immersion, and then after 3 and 7 days of immersion. Flexural strength was evaluated after 7 days of immersion. Group A showed significantly higher color stability as compared to Group B, and artificial saliva + coffee solution had the most staining capacity for the resins. Test solutions had no effect on the flexural strength of Group A, but Group B specimens immersed in artificial saliva + cola showed significantly lower flexural strength values as compared to the control group. The findings of the study showed that for materials used in the study, PMMA was more color stable than bis-acrylic composite based resin. Also, material based on PMMA was more resistant to damage from dietary beverages as compared to bis-acrylic composite based provisional crown and bridge resin.

Structural Insights into 2,2′-Azino-Bis(3-Ethylbenzothiazoline-6-Sulfonic Acid) (ABTS)-Mediated Degradation of Reactive Blue 21 by Engineered Cyathus bulleri Laccase and Characterization of Degradation Products

OpenAIRE

Kenzom, T.; Srivastava, P.; Mishra, S.

2014-01-01

Advanced oxidation processes are currently used for the treatment of different reactive dyes which involve use of toxic catalysts. Peroxidases are reported to be effective on such dyes and require hydrogen peroxide and/or metal ions. Cyathus bulleri laccase, expressed in Pichia pastoris, catalyzes efficient degradation (78 to 85%) of reactive azo dyes (reactive black 5, reactive orange 16, and reactive red 198) in the presence of synthetic mediator ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-...

Crystal structures of functional building blocks derived from bis(benzo[b]thiophen-2-yl)methane.

Science.gov (United States)

Katzsch, Felix; Gruber, Tobias; Weber, Edwin

2016-09-01

The syntheses of three bis(benzo[b]thiophen-2-yl)methane derivatives, namely bis(benzo[b]thiophen-2-yl)methanone, C17H10OS2, (I), 1,1-bis(benzo[b]thiophen-2-yl)-3-(trimethylsilyl)prop-2-yn-1-ol, C22H20OS2Si, (II), and 1,1-bis(benzo[b]thiophen-2-yl)prop-2-yn-1-ol, C19H12OS2, (III), are described and their crystal structures discussed comparatively. The conformation of ketone (I) and the respective analogues are rather similar for most of the compounds compared. This is true for the interplanar angles, the Caryl-Cbridge-Caryl angles and the dihedral angles. The best resemblance is found for a bioisotere of (I), viz. 2,2'-dinaphthyl ketone, (VII). By way of interest, the crystal packings also reveal similarities between (I) and (VII). In (I), the edge-to-face interactions seen between two napthyl residues in (VII) are substituted by S...π contacts between the benzo[b]thiophen-2-yl units in (I). In the structures of the bis(benzo[b]thiophen-2-yl)methanols, i.e. (II) and (III), the interplanar angles are also quite similar compared with analogues and related active pharmaceutical ingredients (APIs) containing the dithiophen-2-ylmethane scaffold, though the dihedral angles show a larger variability and produce unsymmetrical molecules.

Synthesis, spectral and structural properties of bis-imidazoline selones

Indian Academy of Sciences (India)

The solid state structures of bis-imidazoline selones were ... two biologically active selones are expected to function. ∗ .... The organic extract was washed with brine solution .... mentioned CH2 carbon and the quaternary carbon of benzene ...

Amino Acids Sequence Based in Silico Analysis of RuBisCO (Ribulose-1,5 Bisphosphate Carboxylase Oxygenase Proteins in Some Carthamus L. ssp.

Directory of Open Access Journals (Sweden)

Emre SEVİNDİK

2017-06-01

Full Text Available RuBisCO is an important enzyme for plants to photosynthesize and balance carbon dioxide in the atmosphere. This study aimed to perform sequence, physicochemical, phylogenetic and 3D (three-dimensional comparative analyses of RuBisCO proteins in the Carthamus ssp. using various bioinformatics tools. The sequence lengths of the RuBisCO proteins were between 166 and 477 amino acids, with an average length of 411.8 amino acids. Their molecular weights (Mw ranged from 18711.47 to 52843.09 Da; the most acidic and basic protein sequences were detected in C. tinctorius (pI = 5.99 and in C. tenuis (pI = 6.92, respectively. The extinction coefficients of RuBisCO proteins at 280 nm ranged from 17,670 to 69,830 M-1 cm-1, the instability index (II values for RuBisCO proteins ranged from 33.31 to 39.39, while the GRAVY values of RuBisCO proteins ranged from -0.313 to -0.250. The most abundant amino acid in the RuBisCO protein was Gly (9.7%, while the least amino acid ratio was Trp (1.6 %. The putative phosphorylation sites of RuBisCO proteins were determined by NetPhos 2.0. Phylogenetic analysis revealed that RuBisCO proteins formed two main clades. A RAMPAGE analysis revealed that 96.3%-97.6% of residues were located in the favoured region of RuBisCO proteins. To predict the three dimensional (3D structure of the RuBisCO proteins PyMOL was used. The results of the current study provide insights into fundamental characteristic of RuBisCO proteins in Carthamus ssp.

Biochemical and chemical characterization of trifluoromethylglyoxal bis(guanylhydrazone), a close analog of the antileukemic drug mitoguazone.

Science.gov (United States)

Elo, H; Mutikainen, I

1988-01-01

In order to study the structure-activity relationships of bis(guanylhydrazone) type polyamine antimetabolites, trifluoromethylglyoxal bis(guanylhydrazone) (CF3-GBG), a close analog of the antileukemic drug methylglyoxal bis(guanylhydrazone) (mitoguazone, MGBG) was synthesized according to a novel modification of previous methods, yielding single crystals. Single-crystal X-ray crystallography revealed the presence of an isomer different from the one detected in the case of MGBG and all other bis(guanylhydrazones) so far studied. In contrast to MGBG, CF3-GBG was shown to be a very weak inhibitor of yeast adenosylmethionine decarboxylase, being thus devoid of value as a polyamine antimetabolite. In addition, the compound did not have antiproliferative activity against mouse L1210 leukemia cells in vitro. As long as analogous isomers of the two compounds are not available, no conclusions can be drawn about the reasons lying behind the drastical differences between their biological properties.

Copper(II)-bis(thiosemicarbazonato) complexes as anti-chlamydial agents.

Science.gov (United States)

Marsh, James W; Djoko, Karrera Y; McEwan, Alastair G; Huston, Wilhelmina M

2017-09-29

Lipophilic copper (Cu)-containing complexes have shown promising antibacterial activity against a range of bacterial pathogens. To examine the susceptibility of the intracellular human pathogen Chlamydia trachomatis to copper complexes containing bis(thiosemicarbazone) ligands [Cu(btsc)], we tested the in vitro effect of CuII-diacetyl- and CuII-glyoxal-bis[N(4)-methylthiosemicarbazonato] (Cu(atsm) and Cu(gtsm), respectively) on C. trachomatis. Cu(atsm) and to a greater extent, Cu(gtsm), prevented the formation of infectious chlamydial progeny. Impacts on host cell viability and respiration were also observed in addition to the Chlamydia impacts. This work suggests that copper-based complexes may represent a new lead approach for future development of new therapeutics against chlamydial infections, although host cell impacts need to be fully explored. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The BIS and the Latin American debt crisis of the 1980s

OpenAIRE

Piet Clement; Ivo Maes

2013-01-01

The Latin American debt crisis, which broke out in August 1982, was the first global financial crisis in the postwar period. While the crisis started in the "periphery", it constituted a threat to the "core" of the world economy, as the banking system was under severe pressure. Alongside the IMF, the BIS played an important role in coordinating the international response to the crisis. Moreover, a lot of work at the BIS in the second half of the 1970s had aimed at restraining the debt build-u...

Synthesis and crystal structure of the rhodium(I) cyclooctadiene complex with bis(3-tert-butylimidazol-2-ylidene)borate ligand

Energy Technology Data Exchange (ETDEWEB)

Chen, F.; Shao, K.-J.; Xiao, Y.-C.; Pu, X.-J.; Zhu, B., E-mail: zhubao-999@126.com [Affiliated Wuxi Peoples Hospital, Department of Nuclear Medicine, Nanjing Medical University (China); Jiang, M.-J., E-mail: jmj16888@126.com [Affiliated Wuxi Peoples Hospital, Department of Clinical Laboratory Science, Nanjing Medical University (China)

2015-12-15

The rhodium(I) cyclooctadiene complex with the bis(3-tert-butylimidazol-2-ylidene)borate ligand [H{sub 2}B(Im{sup t}Bu){sup 2}]Rh(COD) C{sup 22}H{sup 36}BN{sup 4}Rh, has been prepared, and its crystal structure is determined by X-ray diffraction. Complex exhibits slightly distorted square planar configurations around the metal center, which is coordinated by the bidentate H{sup 2}B(Im{sup t}Bu){sub 2} and one cyclooctadiene group. The Rh–C{sub carbene} bond lengths are 2.043(4) and 2.074(4) Å, and the bond angle C–Rh1–C is 82.59°. The dihedral angle between two imidazol-2-ylidene rings is 67.30°.

Synthesis of novel bis(perfluorophenyl azides) coupling agents: Evaluation of their performance by crosslinking of poly(ethylene oxide)

KAUST Repository

Mehenni, Hakim

2011-11-01

Novel bis(perfluorophenyl azides) coupling agents, containing spacer arms from ethylene or ethylene glycol subunits, were successfully synthesized. Nitrenes photogenerated from these novel bis(PFPA) coupling agents were applied successfully to the cross-linking of poly(ethylene oxide) (PEO10,000) in either aqueous medium or at the solid state, thus, we demonstrated the potential of these bis(PFPA) molecules as promising coupling agents in surface engineering. © 2011 Elsevier Ltd. All rights reserved.

Ne bis in idem põhimõte Eesti karistusõiguses : [bakalaureusetöö] / Natalja Mogiljova ; Tartu Ülikool, õigusteaduskond ; juhendaja: Elina Elkind

Index Scriptorium Estoniae

Mogiljova, Natalja

2009-01-01

Ne bis in idem põhimõtte olemusest ja ajaloolisest arengust, horisontaalsest riigisisesest ne bis in idem-ist, rahvusvahelistest konventsioonidest, EIÕK praktikast, Riigikohtu praktikast, ne bis in idem Ameerika Ühendriikide õiguskorras

Psychometric Properties of the BIS/BAS Scales and the SPSRQ in Flemish Adolescents

Directory of Open Access Journals (Sweden)

Laura Vandeweghe

2016-12-01

Full Text Available Objective: Gray’s Reinforcement Sensitivity Theory (RST is a frequently used model of personality that is relevant to the period of adolescence. However, the psychometric properties of the most frequently used questionnaires to measure the RST-constructs, namely the Behavioural Inhibition System and Behavioural Activation System Scales (BIS/BAS Scales and the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ, are rarely examined in samples of adolescents. Therefore, the goal of the present study was to examine the two-factor structure, reliability and convergent validity of the BIS/BAS Scales and SPSRQ in a Flemish adolescent community sample.  Method: A sample of 579 adolescents (39.5% boys; 14–19 years was recruited. The proposed two-factor structure was assessed using Exploratory Structural Equation Modeling. Reliability was evaluated using internal consistency and construct validity was examined with the correlations between the two questionnaires and with the Temperament and Character Inventory–short form (TCI-SF.  Results: After the removal of problematic items, and the addition of correlated errors, all indices indicated a good fit for the two-factor structure of the modified BIS/BAS Scales. For the modified SPSRQ, three fit indices indicated a good model fit, while a fourth fit index was slightly below the cut-off score of an adequate model fit. Internal consistency of both questionnaires was sufficient. In general, the associations with scales of the TCI-SF were as expected, with positive correlations between BIS-related scales, and between BAS-related scales of all three instruments.  Discussion: In Flemish adolescents, the use of a two-factor model to analyze data gathered with the modified BIS/BAS Scales or modified SPSRQ seems appropriate.

Interactions between 2,4-bis-pteridine-1,5-benzodiazepine and group 12 dihalides: synthesis, spectral and XRD structural studies and theoretical calculations.

Science.gov (United States)

Illán-Cabeza, Nuria A; Jiménez-Pulido, Sonia B; Hueso-Ureña, Francisco; Peña-Ruiz, Tomás; Quirós-Olozábal, Miguel; Moreno-Carretero, Miguel N

2016-11-28

2,4-Bis(1,3,7-trimethyl-pteridine-2,4(1H,3H)-dione-6-yl)-2,3-dihydro-2-methyl-1H-1,5-benzodiazepine (DLMBZD) has been prepared and its molecular and crystal structures have been determined from spectral and XRD data. The benzodiazepine ligand was reacted with zinc(ii), cadmium(ii) and mercury(ii) chloride, bromide and iodide to give complexes with general formula [M(DLMBZD)X 2 ]. The complexes have been synthesized and characterized by IR, NMR and elemental analysis. The structure of seven complexes has been obtained by single crystal X-ray diffraction. In all the cases, the metal is (2 + 2 + 1)-five-coordinated by two halide ligands, two nitrogen atoms from pyrazine and diazepine rings and a carbonyl oxygen from a pteridine ring. The coordinated-metal environment is a square-based pyramid, with increasing trigonality from Hg(ii) to Zn(ii) complexes. To coordinate the metals, the ligand folds itself, establishing four intramolecular σ-π interactions with the pyrimidine and pyrazine rings. A topological analysis of the electron density using the Quantum Theory of Atoms in Molecules and the complexes stability has been performed.

BIS impulsivity and acute nicotine exposure are associated with discounting global consequences in the Harvard game.

Science.gov (United States)

Hogarth, Lee; Stillwell, David J; Tunney, Richard J

2013-01-01

The Barratt Impulsivity Scale (BIS) provides a transdiagnostic marker for a number of psychiatric conditions and drug abuse, but the precise psychological trait(s) tapped by this questionnaire remain obscure. To address this, 51 smokers completed in counterbalanced order the BIS, a delay discounting task and a Harvard game that measured choice between a response that yielded a high immediate monetary payoff but decreased opportunity to earn money overall (local choice) versus a response that yielded a lower immediate payoff but afforded a greater opportunity to earn overall (global choice). Individual level of BIS impulsivity and self-elected smoking prior to the study were independently associated with increased preference for the local over the global choice in the Harvard game, but not delay discounting. BIS impulsivity and acute nicotine exposure reflect a bias in the governance of choice by immediate reward contingencies over global consequences, consistent with contemporary dual-process instrumental learning theories. Copyright © 2013 John Wiley & Sons, Ltd.

177Lu-DTPA-BIS-BIOTIN Binding of Octreotide-dextran-avidinated PANC-1 Cell Lines in Vitro

International Nuclear Information System (INIS)

Deng Xinrong; Zhai Shizhen; Shen Yijia; Luo Zhifu; Du Jin

2011-01-01

Tyr3-octreotide, dextran-40 and avidin were used to prepare octreotide-dextran-avidin (TOC-Dx 40 -Av). DTPA-BIS-BIOTIN was labelled with 177 Lu. The in vitro somatostatin receptor binding study was carried out by pretargeted method using TOC-Dx 40 -Av and 177 Lu-DTPA-BIS-BIOTIN. The 24 well cell culture plates were prepared with PANC-1 cell monolayer and then incubated with TOC-Dx 40 -Av. After two washed with PBS, the cells were incubated with different concentration of 177 Lu-DTPA-BIS-BIOTIN (48.8 ∼ 391 pmol). Cells uptake was evaluated with γ counter. The results showed that the chemical purity of TOC-Dx 40 -Av was over 99%. The results also showed that TOC-Dx 40 -Av remained high receptor binding affinity to somatostatin receptor which indicated that TOC- Dx 40 -Av could bind to 177 Lu-DTPA-BIS-BIOTIN with the molar ratio of 1 : 1 on the cell surface. (authors)

Synthesis of novel bis(perfluorophenyl azides) coupling agents: Evaluation of their performance by crosslinking of poly(ethylene oxide)

KAUST Repository

Mehenni, Hakim; Bakr, Osman

2011-01-01

Novel bis(perfluorophenyl azides) coupling agents, containing spacer arms from ethylene or ethylene glycol subunits, were successfully synthesized. Nitrenes photogenerated from these novel bis(PFPA) coupling agents were applied successfully

Dehalogenation of vicinal dihalo compounds by 1,1'-bis(trimethylsilyl)-1H,1'H-4,4'-bipyridinylidene for giving alkenes and alkynes in a salt-free manner.

Science.gov (United States)

Rej, Supriya; Pramanik, Suman; Tsurugi, Hayato; Mashima, Kazushi

2017-12-07

We report a transition metal-free dehalogenation of vicinal dihalo compounds by 1,1'-bis(trimethylsilyl)-1H,1'H-4,4'-bipyridinylidene (1) under mild conditions, in which trimethylsilyl halide and 4,4'-bipyridine were generated as byproducts. The synthetic protocol for this dehalogenation reaction was effective for a wide scope of dibromo compounds as substrates while keeping the various functional groups intact. Furthermore, the reduction of vicinal dichloro alkanes and vicinal dibromo alkenes also proceeded in a salt-free manner to afford the corresponding alkenes and alkynes.

Separation of alkali metals by extraction chromatography using polyethers

International Nuclear Information System (INIS)

Smulek, W.; Lada, W.

1977-01-01

Separation of alkali metals by means of acyclic polyether 1,13 bis(8-chinolinyl)1, 4, 7, 10, 13 pentaoxatridecane (CPOD) and cyclic polyether dibenzo-18-crown-6 (DBC) using extraction chromatography is described. Solutions of NaSCN were used as eluting agents. The separation ability of the polyether columns strongly depends on pH and temperature. The following radioisotopes were used in the experiments: Na-22, K-42, Rb-86 and Cs-137. The radionuclide purity of the tracers was examined by γ-ray spectrometry using a Ge(Li) detector and a multichannel γ-ray spectrometer. (T.I.)

Studies of (3-mercaptopropyl)trimethoxylsilane and bis(trimethoxysilyl)ethane sol-gel coating on copper and aluminum.

Science.gov (United States)

Li, Ying-Sing; Lu, Weijie; Wang, Yu; Tran, Tuan

2009-09-01

Bis(trimethoxysilyl)ethane (BTMSE) and (3-mercaptopropyl)trimethoxysilane (MPTMS) have been used as precursors to prepare sol-gels and hybrid sol-gel under acidic condition. From the X-ray photoelectron spectroscopy data on MPTMS sol-gel coated aluminum and copper, it has been shown that the silane film is covalently bonded to Al surface through the interfacial condensation. There is no evidence of bonding interaction between the thiol group and the Cu. The recorded reflection adsorption IR (RAIR) spectrum has provided evidence that the coating BTMSE film covalently interacts with Al. Vibrational assignments have been suggested for pure BTMSE, BTMSE sol-gel, BTMSE xerogel, and BTMSE coated Al panel based on the group frequencies and the variation of frequencies with the sample treatment conditions. The progression of condensation reaction has been observed from the IR spectra of the BTMSE sol-gel and the sol-gel coated film after the treatments at different temperatures with different lengths of time. The corrosion protection of the sol-gel coated Al and Cu has been characterized in NaCl solutions by cyclic voltammetric, potentiodynamic polarization and impedance spectroscopy methods. All these electrochemical measurements indicate that the sol-gel coated metals have better corrosion protection than the corresponding uncoated metals.

Synthesis and DNA cleavage activity of Bis-3-chloropiperidines as alkylating agents.

Science.gov (United States)

Zuravka, Ivonne; Roesmann, Rolf; Sosic, Alice; Wende, Wolfgang; Pingoud, Alfred; Gatto, Barbara; Göttlich, Richard

2014-09-01

Nitrogen mustards are an important class of bifunctional alkylating agents routinely used in chemotherapy. They react with DNA as electrophiles through the formation of highly reactive aziridinium ion intermediates. The antibiotic 593A, with potential antitumor activity, can be considered a naturally occurring piperidine mustard containing a unique 3-chloropiperidine ring. However, the total synthesis of this antibiotic proved to be rather challenging. With the aim of designing simplified analogues of this natural product, we developed an efficient bidirectional synthetic route to bis-3-chloropiperidines joined by flexible, conformationally restricted, or rigid diamine linkers. The key step involves an iodide-catalyzed double cyclization of unsaturated bis-N-chloroamines to simultaneously generate both piperidine rings. Herein we describe the synthesis and subsequent evaluation of a series of novel nitrogen-bridged bis-3-chloropiperidines, enabling the study of the impact of the linker structure on DNA alkylation properties. Our studies reveal that the synthesized compounds possess DNA alkylating abilities and induce strand cleavage, with a strong preference for guanine residues. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Aggregation-enhanced emission and piezochromic luminescence of 9,10-bis(p-dibutylaminostyryl)-2,6-bis(p-t-butylstyryl)anthracene

Energy Technology Data Exchange (ETDEWEB)

Sun, Mingxiao; Zhang, Deteng; Li, Yiping; Wang, Jianfeng; Gao, Yangyang; Yang, Wenjun, E-mail: ywjph2004@qust.edu.cn

2014-04-15

A cruciform 9,10-distyrylanthracene-containing luminogen, 9,10-bis(p-dibutylaminostyryl)-2,6-bis(p-t-butylstyryl)anthracene (DDC), has been synthesized and the optical properties investigated. The results show that DDC is an aggregation-induced enhanced emission (AIEE) and piezofluorochromic (PFC) dye. The fluorescence quantum yield in THF/water=1/9 (18.1%) is about 12-fold over that in THF (1.53%). PFC experiment shows that the fluorescence colors (emission spectra) of DDC solid change reversibly between orange-red (602 nm) and red (632 nm) emissions upon pressing and annealing. Wide-angle X-ray diffraction and differential scanning calorimetric analyses reveal that the grinding has induced the phase transition of DDC solid from pristine crystalline to ground amorphous states, and annealing could cause the re-crystallization of amorphized DDC solid. This transformation between crystalline and amorphous states is responsible for the reversible PFC behavior upon external stimuli. Highlights: • A two-dimensional cross-conjugated luminogen (DDC) was synthesized. • DDC exhibits aggregation-enhanced emission and piezofluorochromic behaviors. • DDC emits bluer light in the crystalline phase than in the amorphous phase. • The PFC mechanism is ascribed to grinding-induced amorphization.

(μ-Acetato-κ2O:O′[μ-2,6-bis({bis[(pyridin-2-yl-κNmethyl]amino-κN}methyl-4-methylphenolato-κ2O:O](methanol-κOdizinc bis(perchlorate

Directory of Open Access Journals (Sweden)

Biswanath Das

2014-04-01

Full Text Available The binuclear title complex, [Zn2(C33H33N6O(CH3COO2(CH3OH](ClO42, was synthesized by the reaction between 2,6-bis({[bis(pyridin-2-ylmethyl]amino}methyl-4-methylphenol (H-BPMP, Zn(OAc2 and NaClO4. The two ZnII ions are bridged by the phenolate O atom of the octadentate ligand and the acetate group. An additional methanol ligand is terminally coordinated to one of the ZnII ions, rendering the whole structure unsymmetric. Other symmetric dizinc complexes of BPMP have been reported. However, to the best of our knowledge, the present structure, in which the two ZnII ions are distinguishable by the number of coordinating ligands and the coordination geometries (octahedral and square-pyramidal, is unique. The dizinc complex is a dication, and two perchlorate anions balance the charge. The –OH group of the coordinating methanol solvent molecule forms a hydrogen bond with a perchlorate counter-anion. One of the anions is disordered over two sets of sites with an occupancy ratio of 0.734 (2:0.266 (2.

Crystal structure of bis{μ2-2,2′-[(4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diylbis(methylene]bis(4-oxo-4H-pyran-3-olato}dicobaltcalcium bis(perchlorate 1.36-hydrate

Directory of Open Access Journals (Sweden)

Patrizia Rossi

2017-12-01

Full Text Available The title compound, [CaCo2(C22H30N4O62](ClO42·1.36H2O or {Ca[Co(H–2L1]2}·2ClO4·1.36H2O {where L1 is 4,10-bis[(3-hydroxy-4-pyron-2-ylmethyl]-1,7-dimethyl-1,4,7,10-tetraazacyclododecane}, is a trinuclear complex whose asymmetric unit comprises a quarter of the {Ca[Co(H–2L1]2}2+ trinuclear complex, half of a perchlorate ion and 0.34-water molecules. In the neutral [Co(H–2L1] moiety, the cobalt ion is hexacoordinated in a trigonal–prismatic fashion by the surrounding N4O2 donor set. A Ca2+ cation holds together two neutral [Co(H–2L1] moieties and is octacoordinated in a distorted trigonal–dodecahedral fashion by the surrounding O atoms belonging to the deprotonated oxide and carbonyl groups of two [Co(H–2L1] units. The coordination of the CoII cation preorganizes L1 and an electron-rich area forms, which is able to host hard metal ions. The comparison between the present structure and the previously published ones suggests a high versatility of this ligand; indeed, hard metal ions with different nature and dimensions lead to complexes having different stoichiometry (mono- and dinuclear monomers and trinuclear dimers or even a polymeric structure. The heterotrinuclear CoII–CaII–CoII complexes are connected in three dimensions via weak C—H...O hydrogen bonds, which are also responsible for the interactions with the perchlorate anions and the lattice water molecules. The perchlorate anion is disordered about a twofold rotation axis and was refined giving the two positions a fixed occupancy factor of 0.5. The crystal studied was refined as a two-component inversion twin [BASF parameter = 0.14 (4].

Improvements/Experience derived from wiring 10% of BIS MDTs

CERN Document Server

Fassouliotis, D; Kourkoumelis, C; Pancheluga, V; Pappas, D P; Stefanidis, S; Birioukov, V

2001-01-01

This note describes the improvements performed to the University of Athens Muon Drift Tube assembly line. All implemented QA/QC tests are described. Experience and results of the performance are extracted from the assembly of more than 10% of the BIS tubes.

Combinatorial Libraries of Bis-Heterocyclic Compounds with Skeletal Diversity

OpenAIRE

Soural, Miroslav; Bouillon, Isabelle; Krchňák, Viktor

2008-01-01

Combinatorial solid-phase synthesis of bis-heterocyclic compounds, characterized by the presence of two heterocyclic cores connected by a spacer of variable length/structure, provided structurally heterogeneous libraries with skeletal diversity. Both heterocyclic rings were assembled on resin in a combinatorial fashion.

Synthesis, spectra and electrochemistry of dinitro-bis- {2-(phenylazo ...

Indian Academy of Sciences (India)

Unknown

2006-09-18

Sep 18, 2006 ... Synthesis, spectra and electrochemistry of dinitro-bis-. {2-(phenylazo)pyrimidine} ruthenium(II). Nitro–nitroso derivatives and reactivity of the electrophilic nitrosyl centre. PRITHWIRAJ BYABARTTA. Department of Chemistry, The University of Burdwan, Burdwan 713 104. Present address: Departmento de ...

Binuclear complexes of technetium. Evidence for bis(terdentate)bidentate coordination by the bridging ligand 2,3,5,6-tetrakis(2-pyridyl)pyrazine to technetium(V)

International Nuclear Information System (INIS)

Du Preez, J.G.H.; Gerber, T.I.A.; Gibson, M.L.; Geyser, R.

1990-01-01

The authors have used the potentially bis(terdentate) nitrogen aromatic heterocyclic ligand 2,3,5,6-tetrakis(2-pyridyl)pyrazine (tppz) to prepare mono- and bimetallic technetium(V) complexes bound to tppz. The stimulus for the development of the coordination chemistry of the man-made element technetium is provided by the use of complexes of this element as anatomical imaging agents in nuclear medicine. Although the chemistry of technetium(V) with nitrogen donor ligands is well understood, no complexes have been prepared using potentially terdentate neutral nitrogen donor ligands of this metal in the +5 oxidation state

Stabilization of N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)benzidine thin film morphology with UV light

Energy Technology Data Exchange (ETDEWEB)

Tomović, A.Ž.; Markešević, N. [Institute of Physics, University of Belgrade, Pregrevica 118, 11000 Belgrade (Serbia); Scarpellini, M.; Bovio, S. [Interdisciplinary Centre for Nanostructured Materials and Interfaces (CIMAINA), Università di Milano, Via Celoria 16, 20133 Milan (Italy); Lucenti, E. [Interdisciplinary Centre for Nanostructured Materials and Interfaces (CIMAINA), Università di Milano, Via Celoria 16, 20133 Milan (Italy); Institute of Molecular Science and Technology of CNR, via Golgi 19, 20133 Milan (Italy); Milani, P. [Interdisciplinary Centre for Nanostructured Materials and Interfaces (CIMAINA), Università di Milano, Via Celoria 16, 20133 Milan (Italy); Zikic, R. [Institute of Physics, University of Belgrade, Pregrevica 118, 11000 Belgrade (Serbia); Jovanović, V.P., E-mail: vladimir.jovanovic@ipb.ac.rs [Institute of Physics, University of Belgrade, Pregrevica 118, 11000 Belgrade (Serbia); Srdanov, V.I. [Interdisciplinary Centre for Nanostructured Materials and Interfaces (CIMAINA), Università di Milano, Via Celoria 16, 20133 Milan (Italy)

2014-07-01

Owing to their low glass transition temperature, T{sub g}, amorphous thin films of N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)benzidine (TPD) undergo morphological changes even at room temperature. It has been noticed previously that exposure to UV light can increase apparent T{sub g} of TPD films and thus stabilize their morphology. However, the reason behind increase in structural stability was not examined at the time. Here we present evidence that TPD molecules undergo photo-oxidation in air when exposed to λ ≈ 350 nm radiation and that less than 5% of the photo-oxidized species are needed to prevent dewetting of thin TPD films. We propose that photo-oxidized TPD species bind strongly to both ordinary TPD molecules and to terminal hydroxyl groups at the substrate surface, which decreases mobility of TPD molecules and makes thin TPD film less prone to morphology changes. - Highlights: • We made variable thickness TPD films and exposed them to UV light under ambient conditions. • Mass spectroscopy and proton NMR measurements of irradiated and pristine TPD films • TPD molecules undergo oxidation process under UV light irradiation. • Dipole–dipole interactions may be responsible for stabilization of morphological changes.

Inhibition of S-adenosylmethionine decarboxylase and diamine oxidase activities by analogues of methylglyoxal bis(guanylhydrazone) and their cellular uptake during lymphocyte activation.

Science.gov (United States)

Jänne, J; Morris, D R

1984-03-15

Several congeners of methylglyoxal bis(guanylhydrazone) were tested for their ability to inhibit eukaryotic putrescine-activated S-adenosylmethionine decarboxylase (EC 4.1.1.50) and intestinal diamine oxidase (EC 1.4.3.6). All the compounds tested, namely methylglyoxal bis(guanylhydrazone), ethylglyoxal bis(guanylhydrazone), dimethylglyoxal bis(guanylhydrazone) and the di-N"-methyl derivative of methylglyoxal bis(guanylhydrazone), were strong inhibitors of both yeast and mouse liver adenosylmethionine decarboxylase activity in vitro. The enzyme from both sources was most powerfully inhibited by ethylglyoxal bis(guanylhydrazone). All the diguanidines likewise inhibited diamine oxidase activity in vitro. The maximum intracellular concentrations of the ethyl and dimethylated analogues achieved in activated lymphocytes were only about one-fifth of that of the parent compound. However, both derivatives appeared to utilize the polyamine-carrier system, as indicated by competition experiments with spermidine.

Simultaneous spectrophotometric determination of copper, cobalt, nickel and iron in foodstuffs and vegetables with a new bis thiosemicarbazone ligand using chemometric approaches.

Science.gov (United States)

Rohani Moghadam, Masoud; Poorakbarian Jahromi, Sayedeh Maria; Darehkordi, Ali

2016-02-01

A newly synthesized bis thiosemicarbazone ligand, (2Z,2'Z)-2,2'-((4S,5R)-4,5,6-trihydroxyhexane-1,2-diylidene)bis(N-phenylhydrazinecarbothioamide), was used to make a complex with Cu(2+), Ni(2+), Co(2+) and Fe(3+) for their simultaneous spectrophotometric determination using chemometric methods. By Job's method, the ratio of metal to ligand in Ni(2+) was found to be 1:2, whereas it was 1:4 for the others. The effect of pH on the sensitivity and selectivity of the formed complexes was studied according to the net analyte signal (NAS). Under optimum conditions, the calibration graphs were linear in the ranges of 0.10-3.83, 0.20-3.83, 0.23-5.23 and 0.32-8.12 mg L(-1) with the detection limits of 2, 3, 4 and 10 μg L(-1) for Cu(2+), Co(2+), Ni(2+) and Fe(3+) respectively. The OSC-PLS1 for Cu(2+) and Ni(2+), the PLS1 for Co(2+) and the PC-FFANN for Fe(3+) were selected as the best models. The selected models were successfully applied for the simultaneous determination of elements in some foodstuffs and vegetables. Copyright © 2015 Elsevier Ltd. All rights reserved.

Side chain effect on electronic structure of spin-coated films of [6,6]-phenyl-C61-butyric acid methyl ester and its bis-adduct

International Nuclear Information System (INIS)

Akaike, Kouki; Kanai, Kaname; Ouchi, Yukio; Seki, Kazuhiko

2013-01-01

Highlights: ► Electronic structure of spin-coated films of PCBM and bis-PCBM was investigated. ► Ionization energy and electron affinity of bis-PCBM are smaller than those of PCBM. ► Electron donation from the side chain to C 60 -backbone raises the HOMO and LUMO. ► Open circuit voltages of PCBM-based solar cells relates to electron affinities. - Abstract: We investigated the electronic structure of spin-coated films of two soluble fullerenes; [6,6]-phenyl-C 61 -butyric acid methyl ester (PCBM) and its bis-adduct (bis-PCBM) using ultraviolet photoelectron spectroscopy, inverse photoemission spectroscopy and molecular orbital calculations. The ionization energy and electron affinity of spin-coated films of bis-PCBM were determined to be 6.01 eV and 3.4 eV, respectively. Analysis of electron density suggested the stronger electron donation from the two side chains to fullerene-backbone in a bis-PCBM molecule, compared with PCBM. The electron donation raises the energies of the frontier orbitals of bis-PCBM, which mainly consist of π-orbitals of fullerene-backbone. As a result, the ionization energy and electron affinity of bis-PCBM are smaller than those of PCBM. Moreover, we also concluded that the larger open circuit voltage observed for bis-PCBM based organic photovoltaics was explained by the higher-lying unoccupied molecular orbital of bis-PCBM

Species dependence of [{sup 64}Cu]Cu-Bis(thiosemicarbazone) radiopharmaceutical binding to serum albumins

Energy Technology Data Exchange (ETDEWEB)

Basken, Nathan E. [Division of Nuclear Pharmacy, Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47907 (United States)], E-mail: nbasken@purdue.edu; Mathias, Carla J. [Division of Nuclear Pharmacy, Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47907 (United States); Lipka, Alexander E. [Department of Statistics, Purdue University, West Lafayette, IN 47907 (United States); Green, Mark A. [Division of Nuclear Pharmacy, Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47907 (United States)], E-mail: magreen@purdue.edu

2008-04-15

Introduction: Interactions of three copper(II) bis(thiosemicarbazone) positron emission tomography radiopharmaceuticals with human serum albumin, and the serum albumins of four additional mammalian species, were evaluated. Methods: {sup 64}Cu-labeled diacetyl bis(N{sup 4}-methylthiosemicarbazonato)copper(II) (Cu-ATSM), pyruvaldehyde bis(N{sup 4}-methylthiosemicarbazonato)copper(II) (Cu-PTSM) and ethylglyoxal bis(thiosemicarbazonato)copper(II) (Cu-ETS) were synthesized and their binding to human, canine, rat, baboon and porcine serum albumins quantified by ultrafiltration. Protein binding was also measured for each tracer in human, porcine, rat and mouse serum. Results: The interaction of these neutral, lipophilic copper chelates with serum albumin is highly compound- and species-dependent. Cu-PTSM and Cu-ATSM exhibit particularly high affinity for human serum albumin (HSA), while the albumin binding of Cu-ETS is relatively insensitive to species. At HSA concentrations of 40 mg/ml, '% free' (non-albumin-bound) levels of radiopharmaceutical were 4.0{+-}0.1%, 5.3{+-}0.2% and 38.6{+-}0.8% for Cu-PTSM, Cu-ATSM and Cu-ETS, respectively. Conclusions: Species-dependent variations in radiopharmaceutical binding to serum albumin may need to be considered when using animal models to predict the distribution and kinetics of these compounds in humans.

Effective remediation of phenol,2,4-bis(1,1-dimethylethyl) and bis(2-ethylhexyl) phthalate in farm effluent using Guar gum--A plant based biopolymer.

Science.gov (United States)

Kee, Yang Ling; Mukherjee, Sumona; Pariatamby, Agamuthu

2015-10-01

This study was carried out to evaluate the efficiency of Guar gum in removing Persistent Organic Pollutants (POPs), viz. phenol,2,4-bis(1,1-dimethylethyl) and bis(2-ethylhexyl) phthalate (DEHP), from farm effluent. The removal efficiency was compared with alum. The results indicated that 4.0 mg L(-1) of Guar gum at pH 7 could remove 99.70% and 99.99% of phenol,2,4-bis(1,1-dimethylethyl) and DEHP, respectively. Box Behnken design was used for optimization of the operating parameters for optimal POPs removal. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy studies were conducted on the flocs. SEM micrographs showed numerous void spaces in the flocs produced by Guar gum as opposed to those produced by alum. This indicated why Guar gum was more effective in capturing and removal of suspended particles and POPs as compared to alum. FTIR spectra indicated a shift in the bonding of functional groups in the flocs produced by Guar gum as compared to raw Guar gum powder signifying chemical attachment of the organics present in the effluent to the coagulant resulting in their removal. Guar gum is highly recommended as a substitute to chemical coagulant in treating POPs due to its non-toxic and biodegradable characteristics. Copyright © 2015 Elsevier Ltd. All rights reserved.

EL CRITERIO DE INTERPRETACIÓN DEL PRINCIPIO NON BIS IN ÍDEM PREVISTO EN EL ARTÍCULO 45.3 DE LA CONSTITUCIÓN ESPAÑOLA The Interpretation Criterium of the "Non Bis Idem" Principle Provided in Article 45.3 of Spain Constitution

Directory of Open Access Journals (Sweden)

Ramírez Torrado María Lourdes

2010-01-01

Full Text Available Respecto a la lectura constitucional del principio se propone una interpretación complementaria y diversa a la hasta ahora presentada por la doctrina constitucional y científica que insisten en derivar el sustento constitucional del postulado non bis in ídem del artículo 25. Desconociendo lo anterior, una disposición constitucional que prevé tácitamente el non bis in ídem al establecer un criterio para determinar cuál es la sanción o el procedimiento a imponer sin quebrantar la prohibición bis in ídem.Con ello nos referimos a la presencia de un cláusula de interpretación del principio non bis in ídem, prevista en el artículo 45.3, que contempla en su texto la prevalencia del Derecho Penal sobre el Administrativo.With respect to the constitutional reading of the principle we propose a complementary and diverse reading different from what has been presented to date by constitutional and scientific doctrine, which insist on deriving constitutional support from article 25.Setting the former aside, there is a constitutional disposition which considers tacitly the "non bis in idem" by establishing a criterion to determine what the sanction or the procedure is to be imposed without violating prohibition "bis in idem". We refer to the presence of an interpretation clause of the "bis in idem" principle provided in article 45.3, which considers the prevalence of Penal Law over Administrative Law.

Synthesis and Antitumor Evaluation of Novel Bis-Triaziquone Derivatives

Directory of Open Access Journals (Sweden)

Yuh-Ling Lin

2009-06-01

Full Text Available Aziridine-containing compounds have been of interest as anticancer agents since late 1970s. The design, synthesis and study of triaziquone (TZQ analogues with the aim of obtaining compounds with enhanced efficacy and reduced toxicity are an ongoing research effort in our group. A series of bis-type TZQ derivatives has been prepared and their cytotoxic activities were investigated. The cytotoxicity of these bis-type TZQ derivatives were tested on three cancer lines, including breast cancer (BC-M1, oral cancer (OEC-M1, larynx epidermal cancer (Hep2 and one normal skin fibroblast (SF. Most of these synthetic derivatives displayed significant cytotoxic activities against human carcinoma cell lines, but weak activities against SF. Among tested analogues the bis-type TZQ derivative 1a showed lethal effects on larynx epidermal carcinoma cells (Hep2, with an LC50 value of 2.02 mM, and also weak cytotoxic activity against SF cells with an LC50 value over 10 mM for 24 hr treatment. Comparing the viability of normal fibroblast cells treated with compound 1a and TZQ, the LC50 value of the latter was 2.52 mM, indicating more toxicity than compound 1a. This significantly decreased cytotoxicity of compound 1a towards normal SF cells, while still maintaining the anticancer activity towards Hep2 cells is an interesting feature. Among the seven compounds synthesized, compound 1c has similar toxicity effects on the three cancer cell lines and SF normal cells as the TZQ monomer.

Characterization of Anthraquinone-DerivedRedox Switchable Ionophores and Their Complexes with Li+, Na+, K+, Ca+, and Mg+ Metal Ions

Directory of Open Access Journals (Sweden)

Vaishali Vyas

2011-01-01

Full Text Available Anthraquinone derived redox switchable ionophores 1,5 bis (2-(2-(2-ethoxy ethoxy ethoxyanthracene-9,10-dione (V1 and 1,8-bis(2-(2-(2-ethoxyethoxyethoxy anthracene—9,10-dione (V2 have been used for isolation, extraction and liquid membrane transport studies of Li+, Na+, K+, Ca2+ and Mg2+ metal ions. These isolated complexes were characterized by melting point determination, CV and IR, 1H NMR spectral analysis. Ionophore V2 shows maximum shift in reduction potential (ΔE with Ca(Pic2. The observed sequence for the shifting in reduction potential (ΔE between V2 and their complexes is V2 calcium picrate (42 mV > V2 potassium picrate (33 mV > V2 lithium picrate (25 mV > V2 sodium picrate (18 mV > V2 magnesium picrate (15 mV. These findings are also supported by results of extraction, back extraction and transport studies. Ionophore V2 complexed with KPic and showed much higher extractability and selectivity towards K+ than V1. These synthetic ionophores show positive and negative cooperativity towards alkali and alkaline earth metal ions in reduced and oxidized state. Hence, this property can be used in selective separation and enrichment of metal ions using electrochemically driven ion transport.

Bis[(lprolinate-N,O]Zn: A water-soluble and recycle catalyst for various organic transformations

Directory of Open Access Journals (Sweden)

Roona Poddar

2017-05-01

Full Text Available Under the green chemistry perspective, bis[(lprolinate-N,O]Zn (also called zinc–proline or Zn[(l-pro]2 has proven its competence as a promising alternative in a plethora of applications such as catalyst or promoter. Owing to its biodegradable and non-toxic nature of bis[(lprolinate-N,O]Zn, it is being actively investigated as a water soluble green catalyst for synthetic chemistry. Bis[(lprolinate-N,O]Zn are readily utilized under mild conditions and have high selectivity and reactivity with broad range of substrate acceptance to make it better reaction medium for a wide variety of organic transformations. This Review summarizes the till date literature on its synthesis, characterization, and its catalytic role in various organic reactions.

Five new Zn(II) and Cd(II) coordination polymers constructed by 3,5-bis-oxyacetate-benzoic acid: Syntheses, crystal structures, network topologies and luminescent properties

International Nuclear Information System (INIS)

Jiang Xianrong; Yuan Hongyan; Feng Yunlong

2012-01-01

Five Zn(II) and Cd(II) coordination polymers, [Zn 2 (BOABA)(bpp)(OH)]·0.5H 2 O (1), [Cd 3 (BOABA) 2 (bpp) 2 (H 2 O) 6 ]·2H 2 O (2), [Cd 3 (BOABA) 2 (2,2′-bipy) 3 (H 2 O) 4 ]·5.5H 2 O (3), [CdNa(BOABA)(H 2 O)] 2 ·H 2 O (4) and [Cd 2 (BOABA)(bimb)Cl(H 2 O) 2 ]·H 2 O (5) (H 3 BOABA=3,5-bis-oxyacetate-benzoic acid, bpp=1,3-bi(4-pyridyl)propane, 2,2′-bipy=2,2′-bipyridine, bimb=1,4-bis(imidazol-1′-yl)butane), have been solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and TG analyses. 1 is an uninodal 4-connected 2D square grid network based on binuclear zinc clusters. 2 is 2D wavelike layer structure and further linked by hydrogen bonds into the final 3D (5,6,6)-connected topology network. 3 is 3-connected 2D topology network and the 2,2′-bipy ligands decorate in two different types. 4 is a (4,8)-connected 2D topology network with heterocaryotic {Cd 2 Na 2 } clusters and BOABA 3– ligands. 5 can be rationalized as a (3,10)-connected 3D topology network with tetranuclear {Cd 4 Cl 2 } clusters and BOABA 3– ligands. Meanwhile, photoluminescence studies revealed that these five coordination polymers display strong fluorescent emission bands in the solid state at room temperature. - Graphical abstract: Five new d 10 metal(II) coordination polymers based on H 3 BOABA ligand were obtained and characterized. They display different topological structures and luminescent properties. Highlights: ► Five d 10 metal(II) polymers based on 3,5-bis-oxyacetate-benzoic acid were obtained. ► The polymers were structurally characterized by single-crystal X-ray diffraction. ► Polymers 1–5 display different topological structures. ► They show strong fluorescent emission bands in the solid state.

Combinatorial Libraries of Bis-Heterocyclic Compounds with Skeletal Diversity

Science.gov (United States)

Soural, Miroslav; Bouillon, Isabelle; Krchňák, Viktor

2009-01-01

Combinatorial solid-phase synthesis of bis-heterocyclic compounds, characterized by the presence of two heterocyclic cores connected by a spacer of variable length/structure, provided structurally heterogeneous libraries with skeletal diversity. Both heterocyclic rings were assembled on resin in a combinatorial fashion. PMID:18811208

Conversion of diphosphatidylglycerol to bis(monoacylglyceryl)phosphate by lysosomes

NARCIS (Netherlands)

Poorthuis, B. J.; Hostetler, K. Y.

1978-01-01

Diphosphatidyl[1',2',3'-14C]glycerol (cardiolipin) is converted to bis(monoacylglyceryl)phosphate when incubated in vitro with rat lysosomes at pH 4.4. The stereochemical configuration of the product is unknown. This reaction probably takes place via lysophosphatidylglycerol, one of the major

A study of the removal of heavy metals from aqueous solutions by Moringa oleifera seeds and amine-based ligand 1,4-bis[N,N-bis(2-picoyl)amino]butane

International Nuclear Information System (INIS)

Obuseng, Veronica; Nareetsile, Florence; Kwaambwa, Habauka M.

2012-01-01

Highlights: ► Materials are effective and selective in simultaneous removal of heavy metal ions. ► Use of composite adsorbent of both materials may result in more effective material. ► Seeds biomass has various functional groups involves in metal removal. ► Attainment of sorption equilibrium is rapid for the seeds biomass. ► Seeds biomass effectiveness is not affected over wide effective pH range. - Abstract: Uptake for lead, copper, cadmium, nickel and manganese from aqueous solution using the Moringa oleifera seeds biomass (MOSB) and amine-based ligand (ABL) was investigated. Experiments on two synthetic multi-solute systems revealed that MOSB performed well in the biosorption and followed the decreasing orders Pb(II) > Cu(II) > Cd(II) > Ni(II) > Mn(II) and Zn(II) > Cu(II) > Ni(II). The general trend of the heavy metal ions uptake by the amine-based ligand followed decreased in the order Mn > Cd > Cu > Ni > Pb, which is the reverse trend for what was observed for MOSB. Comparing the single- and multi-metal solutions, there was no clear effect in the biosorption capacity of MOSB suggesting the presence of sufficient active binding sites for all metal ions studied. The MOSB performance is also not affected by pH in the range 3.5–8.

catena-Poly[[copper(II-bis[μ-bis(3,5-dimethyl-1H-pyrazol-4-yl selenide

Directory of Open Access Journals (Sweden)

Maksym Seredyuk

2009-11-01

Full Text Available In the title compound, {[Cu(C10H14N4Se2](ClO42}n, the CuII ion is located on a twofold rotation axis and has a tetragonally distorted square-planar geometry constituted by four N atoms. A pair of bis(3,5-dimethyl-1H-pyrazol-4-yl selenide (L ligands bridges the copper centers into a polymeric chain extending along [001]. The perchlorate anions are involved in intermolecular N—H...O hydrogen bonding, which links the chains into layers parallel to the bc plane.

Pharmacological characterization and modeling of the binding sites of novel 1,3-bis(pyridinylethynyl)benzenes as metabotropic glutamate receptor 5-selective negative allosteric modulators

DEFF Research Database (Denmark)

Mølck, Christina; Harpsøe, Kasper; Gloriam, David E

2012-01-01

)pyridine (MPEP)-derived negative allosteric modulators, 2-, 3-, and 4-BisPEB, have been characterized. 2-, 3-, and 4-BisPEB are 1,3-bis(pyridinylethynyl)-benzenes and differ only by the position of the nitrogen atoms in the pyridine rings. Despite their high structural similarity, 2-BisPEB [1,3-bis(pyridin-2......-ylethynyl)-benzene, nitrogen atoms in ortho positions], with an IC(50) value in the nanomolar range, is significantly more potent than the 3- and 4-pyridyl analogs. Mutational analysis, directed by a previously published mGluR5 homology model, was used to determine key residues for the ligand...... that the higher potency of 2-BisPEB is due to hydrogen bonding to Ser809 because the S809A mutation made 2-BisPEB equipotent to 3- and 4-BisPEB (IC(50), 1-2.5 µM). The potency of MPEP was also greatly affected by S809A (52-fold), suggesting that a Ser809-mediated hydrogen bond is also a key interaction between...

Color stability and flexural strength of poly (methyl methacrylate and bis-acrylic composite based provisional crown and bridge auto-polymerizing resins exposed to beverages and food dye: An in vitro study

Directory of Open Access Journals (Sweden)

Anil K Gujjari

2013-01-01

Full Text Available Aim: To evaluate the color stability and flexural strength of poly (methyl methacrylate (PMMA and bis-acrylic composite based provisional crown and bridge auto-polymerizing resins exposed to tea, coffee, cola, and food dye. Materials and Methods: Two provisional crown and bridge resins, one DPI self-cure tooth molding powder (PMMA (Group A, and one Protemp 4 Temporization Material (bis-acrylic composite (Group B were used. Disk-shaped specimens for color stability testing (n = 30 for each material and bar-shaped specimens for flexural strength testing (n = 30 for each material were fabricated using a metal mold. The specimens were immersed in artificial saliva, artificial saliva + tea, artificial saliva + coffee, artificial saliva + cola, and artificial saliva + food dye solutions and stored in an incubator at 37°C. Color measurements were taken before immersion, and then after 3 and 7 days of immersion. Flexural strength was evaluated after 7 days of immersion. Results: Group A showed significantly higher color stability as compared to Group B, and artificial saliva + coffee solution had the most staining capacity for the resins. Test solutions had no effect on the flexural strength of Group A, but Group B specimens immersed in artificial saliva + cola showed significantly lower flexural strength values as compared to the control group. Conclusion: The findings of the study showed that for materials used in the study, PMMA was more color stable than bis-acrylic composite based resin. Also, material based on PMMA was more resistant to damage from dietary beverages as compared to bis-acrylic composite based provisional crown and bridge resin.

Rhenium(V) and technetium(V) complexes of bis(o-hydroxyphenyl)phenylphosphine (PO22-) and (o-hydroxyphenyl)diphenylphosphine (PO-) ligands

International Nuclear Information System (INIS)

Luo, Hongyan; Setyawati, Ika; Rettig, S.J.; Orvig, C.

1995-01-01

The synthesis of several phosphine-based chelating compounds and chelates formed between these compounds and rhenium or technetium is discussed. Four categories of products result, (i) bis-(o-hydroxyphenyl) diphenylphosphine (PO) complexes, (ii) mono- (PO) complexes, (iii) bis-bis(o-hydroxyphenyl)-phenylphosphine (PO 2 ) complexes, and mixed-(PO) and (PO 2 ) complexes. Molecular structures of these compounds (including isomers) were probed by NMR, MS, and IR spectroscopies and by X-ray crystallography

2,6-Bis(9-ethyl-9H-carbazolylmethylenecyclohexanone

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Abdullah M. Asiri

2009-10-01

Full Text Available The title compound, 2,6-bis(ethyl-9-ethyl-9H-carbazolylmethylenecyclohexanone has been synthesized by condensation of 9-ethylcarbazole-3-aldehyde and cyclohexanone in ethanol in the presence of pyridine. The structure of this new compound was confirmed by elemental analysis, IR, 1H NMR, 13C NMR and EI-MS spectral analysis.

Non-covalent interactions between {N,N′-bis[(2-pyridinyl)methylene]-1, 2-benzenediamine]-bis(nitrato)}Cu(II) with pyridoxine hydrochloride in methanol at T = (298.15, 308.15 and 318.15) K

International Nuclear Information System (INIS)

Brahman, Dhiraj; Sinha, Biswajit

2014-01-01

Highlights: • Methanolic solution of pyridoxine hydrochloride used as solvent. • {N,N′-bis[(2-pyridinyl)methylene]-1, 2-benzenediamine]-bis(nitrato)}Cu(II) used as solute. • Partial molar volumes and viscosity B-coefficients of the solute were determined. • Weak 1:1 association between the complex and pyridoxine hydrochloride found. • Non-covalent interactions and Cu(II) complex acts as a net structure maker in the ternary solutions. - Abstract: Non-covalent interactions between of {N,N′-bis[(2-pyridinyl)methylene]-1, 2-benzenediamine]-bis(nitrato)}Cu(II) with pyridoxine hydrochloride in methanol were investigated by a combination of physico-chemical and spectrophotometric methods at T = (298.15, 308.15 and 318.15) K under ambient pressure. From measured density and viscosity data the apparent molar volume (ϕ V ), the slope (S V ∗ ), standard partial molar volume (ϕ V 0 ), standard transfer volume (Δ t ϕ V 0 ), isobaric apparent molar expansibility (ϕ E ), standard isobaric partial molar expansibility (ϕ E 0 ), the viscosity B-coefficient, its temperature derivative (∂B/∂T), solvation number (S n ) were calculated and discussed on the basis of specific or non-specific (solute + cosolute) and (solute + solvent) interactions. Thermodynamics of viscous flow were discussed on the basis of the transition state theory. Spectrophotometric results indicated 1:1 (solute + cosolute) interaction between the complex and pyridoxine hydrochloride

Equatorenes: synthesis and properties of chiral naphthalene, phenanthrene, chrysene, and pyrene possessing bis(1-adamantyl) groups at the peri-position.

Science.gov (United States)

Yamamoto, Koji; Oyamada, Naohiro; Xia, Sheng; Kobayashi, Yuta; Yamaguchi, Masahiko; Maeda, Hiroaki; Nishihara, Hiroshi; Uchimaru, Tadafumi; Kwon, Eunsang

2013-11-06

Chiral polycyclic aromatic hydrocarbons containing bis(1-adamantyl) groups at the peri-positions, named equatorenes, were synthesized in optically pure form starting from optically pure 4,5-bis(1-adamantyl)-8-methoxy-1-naphthol. A sequential Diels-Alder reaction of furan and arynes generated from 1,2-bromotriflates provided tricyclic and tetracyclic epoxides, and acid-catalyzed aromatization gave phenanthrol and chrysenol. Deoxygenation reactions involving the hydrogenolysis of triflates gave 1,8-bis(1-adamantyl)naphthalene, 1,10-bis(1-adamantyl)phenanthrene, and 1,12-bis(1-adamantyl)chrysene. 3,4-Bis(1-adamantyl)pyrene was synthesized from phenanthrol by Sonogashira coupling and Pt-catalyzed cyclization. Essentially no racemization occurred during the synthesis. X-ray analysis indicated the distorted naphthalene moiety possessing the peri-diadamantyl groups and the flat structure of the other benzene rings. UV-vis analysis of the equatorenes showed considerable redshifts compared with that of the corresponding achiral arenes. Electrochemical analysis of the naphthalene and pyrene indicated that the distortion decreased the highest occupied molecular orbital stability with no marked effect on the lowest unoccupied molecular orbital energy level, and the origin was discussed on the basis of calculation results.

Bis(trialkylsilyl) peroxides as alkylating agents in the copper-catalyzed selective mono-N-alkylation of primary amides.

Science.gov (United States)

Sakamoto, Ryu; Sakurai, Shunya; Maruoka, Keiji

2017-06-13

The copper-catalyzed selective mono-N-alkylation of primary amides with bis(trialkylsilyl) peroxides as alkylating agents was reported. The results of a mechanistic study suggest that this reaction should proceed via a free radical process that includes the generation of alkyl radicals from bis(trialkylsilyl) peroxides.

Complementarity and completed trials: reforming the Ne bis in idem ...

African Journals Online (AJOL)

Nnamdi Azikiwe University Journal of International Law and Jurisprudence ... This paper is concerned with the question whether article 20(3) of the Rome Statute is ... Rome Statute, Ne bis in idem, double jeopardy, International Criminal Court ...

A study of the removal of heavy metals from aqueous solutions by Moringa oleifera seeds and amine-based ligand 1,4-bis[N,N-bis(2-picoyl)amino]butane

Energy Technology Data Exchange (ETDEWEB)

Obuseng, Veronica; Nareetsile, Florence [Department of Chemistry, University of Botswana, Private Bag UB 00704, Gaborone (Botswana); Kwaambwa, Habauka M., E-mail: hmkwaambwa@yahoo.com [Department of Chemistry, University of Botswana, Private Bag UB 00704, Gaborone (Botswana)

2012-06-12

Highlights: Black-Right-Pointing-Pointer Materials are effective and selective in simultaneous removal of heavy metal ions. Black-Right-Pointing-Pointer Use of composite adsorbent of both materials may result in more effective material. Black-Right-Pointing-Pointer Seeds biomass has various functional groups involves in metal removal. Black-Right-Pointing-Pointer Attainment of sorption equilibrium is rapid for the seeds biomass. Black-Right-Pointing-Pointer Seeds biomass effectiveness is not affected over wide effective pH range. - Abstract: Uptake for lead, copper, cadmium, nickel and manganese from aqueous solution using the Moringa oleifera seeds biomass (MOSB) and amine-based ligand (ABL) was investigated. Experiments on two synthetic multi-solute systems revealed that MOSB performed well in the biosorption and followed the decreasing orders Pb(II) > Cu(II) > Cd(II) > Ni(II) > Mn(II) and Zn(II) > Cu(II) > Ni(II). The general trend of the heavy metal ions uptake by the amine-based ligand followed decreased in the order Mn > Cd > Cu > Ni > Pb, which is the reverse trend for what was observed for MOSB. Comparing the single- and multi-metal solutions, there was no clear effect in the biosorption capacity of MOSB suggesting the presence of sufficient active binding sites for all metal ions studied. The MOSB performance is also not affected by pH in the range 3.5-8.

Four coordination polymers based on 5-tert-butyl isophthalic acid and rigid bis(imidazol-1yl)benzene linkers: Synthesis, luminescence detection of acetone and optical properties

Energy Technology Data Exchange (ETDEWEB)

Arıcı, Mürsel, E-mail: marici@ogu.edu.tr [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Zafer Yeşilel, Okan [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Büyükgüngör, Orhan [Department of Physics, Faculty of Arts and Sciences, Ondokuz Mayıs University, 55139 Samsun (Turkey)

2017-05-15

Four coordination polymers including, [Co(µ-Htbip){sub 2}(µ-dib)]{sub n} (1), [Co(µ-tbip)(µ-dmib){sub 0.5}]{sub n} (2), [Zn{sub 2}(µ-tbip)(µ{sub 3}-tbip)(µ-dmib){sub 1.5}]{sub n} (3) and [Cd(µ{sub 3}-tbip)(µ-dib){sub 0.5} (H{sub 2}O)]{sub n} (4) (tbip: 5-tert-butylisophthalate, dib: 1,4-bis(imidazol-1yl)benzene, dmib: 1,4-bis(imidazol-1yl)-2,5-dimethylbenzene), were hydrothermally synthesized and characterized by elemental analysis, IR spectra, single crystal and powder X-ray diffraction and thermal analysis (TG/DTA). The structural diversity is observed depending on ligands and coordination number of metal centers in the synthesized complexes. The tbip ligand displayed five different coordination modes in its complexes. In 1 and 2, complex 1 is 3D framework with the dia topology while complex 2 has 2D structure with the sql topology depending on coordination geometries of Co ions. Complex 3 is 3D framework with the fsh 4,6-conn topology and complex 4 has 2D 4-connected sql topology. Photoluminescent properties of complex 3 dispersed in various organic solvents were investigated and the results showed that 3 dispersed in methanol could be used as a fluorescent sensor for the detection of acetone. Moreover, thermal and optical properties of the complexes were also studied. - Graphical abstract: Four coordination polymers were hydrothermally synthesized and characterized by various techniques. The complexes showed the structural diversity depending on ligands and coordination number of metal centers. The tbip ligand displayed four different coordination modes in its complexes. In 1 and 2, complexes 1 and 2 are 3D and 2D structures with the dia and sql topologies depending on coordination geometries of Co ions, respectively. Complexes 3 and 4 are 3D and 2D structures with the fsh 4,6-conn and sql topology, respectively. Photoluminescent properties of complex 3 dispersed in various organic solvents were investigated and the results showed that 3 dispersed in

Side chain effect on electronic structure of spin-coated films of [6,6]-phenyl-C{sub 61}-butyric acid methyl ester and its bis-adduct

Energy Technology Data Exchange (ETDEWEB)

Akaike, Kouki, E-mail: akaike@riken.jp [Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan); Kanai, Kaname [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, Yamazaki 2641, Noda 278-8510 (Japan); Ouchi, Yukio; Seki, Kazuhiko [Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

2013-03-29

Highlights: ► Electronic structure of spin-coated films of PCBM and bis-PCBM was investigated. ► Ionization energy and electron affinity of bis-PCBM are smaller than those of PCBM. ► Electron donation from the side chain to C{sub 60}-backbone raises the HOMO and LUMO. ► Open circuit voltages of PCBM-based solar cells relates to electron affinities. - Abstract: We investigated the electronic structure of spin-coated films of two soluble fullerenes; [6,6]-phenyl-C{sub 61}-butyric acid methyl ester (PCBM) and its bis-adduct (bis-PCBM) using ultraviolet photoelectron spectroscopy, inverse photoemission spectroscopy and molecular orbital calculations. The ionization energy and electron affinity of spin-coated films of bis-PCBM were determined to be 6.01 eV and 3.4 eV, respectively. Analysis of electron density suggested the stronger electron donation from the two side chains to fullerene-backbone in a bis-PCBM molecule, compared with PCBM. The electron donation raises the energies of the frontier orbitals of bis-PCBM, which mainly consist of π-orbitals of fullerene-backbone. As a result, the ionization energy and electron affinity of bis-PCBM are smaller than those of PCBM. Moreover, we also concluded that the larger open circuit voltage observed for bis-PCBM based organic photovoltaics was explained by the higher-lying unoccupied molecular orbital of bis-PCBM.

Effects of bis(guanylhydrazones) on the activity and expression of ornithine decarboxylase.

Science.gov (United States)

Nikula, P; Alhonen-Hongisto, L; Jänne, J

1985-01-01

Derivatives of glyoxal bis(guanylhydrazone) (GBG), such as methylglyoxal bis(guanylhydrazone) and ethylglyoxal bis(guanylhydrazone), are potent inhibitors of S-adenosylmethionine decarboxylase (EC 4.1.1.50), the key enzyme required for the synthesis of spermidine and spermine. These compounds, but not the parent compound, induce a massive accumulation of putrescine, partly by blocking the conversion of putrescine into spermidine, but also by strikingly stimulating ornithine decarboxylase (ODC; EC 4.1.1.17) activity. The mechanism of the stimulation of ODC activity and enhanced accumulation of the enzyme protein apparently involved a distinct stabilization of the enzyme against intracellular degradation. However, although the parent compound GBG also stabilized ODC, it powerfully inhibited the enzyme activity and the accumulation of immunoreactive protein in cultured L1210 leukaemia cells. Kinetic considerations indicated that, in addition to the stabilization, all three compounds, GBG in particular, inhibited the expression of ODC. It is unlikely that the decreased rate of synthesis of ODC was attributable to almost unaltered amounts of mRNA in drug-treated cells, thus supporting the view that especially GBG apparently depressed the expression of ODC at some post-transcriptional level. Images PMID:4062886

Simultaneous determination of octylphenol, nonylphenol, Bis(2-ethylehxyl) phathalate in biological samples

Energy Technology Data Exchange (ETDEWEB)

Kim, J.H. [Jeonju University, Chonju (Korea)

2001-04-01

A comprehensive analytical method of endocrine disruptors[i.e., nonylphenol (NP), octylphenol (OP), bis (2-ethylhexyl) phthalate (BEHP) in meat or pork samples was developed. The method employed closed culture tube extraction with dichloromethane and solvent exchange to iso-hexane and SPE 92g) aminopropyl column, followed by determination on gas chromatography linked to mass spectrometry (GC/MS) operated in the single ion monitoring (SIM) mode. For the multipoint recovery of nonylphenol, octylphenol and bis (2-ethylhexyl) phthalate OP, NP were shown good recoveries in 0.125 {approx} 1.25 {mu}g/g range of concentration, and BEHP more good recoveries on 0.0125 {approx} 12.5 {mu}g/g wide range of concentration. The present method was applied to beef or pork samples of mart and butcher in Cheonju city and near cheonju. The range of concentrations was respectively, 0.06 {approx} 0.24 {mu}g/g in bis (2-ethylhexyl)phthalate (BEHP), but octylphenol (OP) was not dec ted in any samples. This method provides a powerful analytical tool to investigate a wide range of endocrine disruptors in biological samples of limited quantity. (author). 24 refs., 5 tabs., 3 figs.

The first example of intensive luminescence of LMCT state based on metal complexes in solution

International Nuclear Information System (INIS)

Lukova, G.V.; Vasil'ev, V.P.; Smirnov, V.A.; Huhn, W.

2007-01-01

A bridge complex rac-C 6 H 10 (IndH 4 ) 2 ZrC 2 , featuring a unique long-living luminescence in liquid solutions at 20 deg C, has been prepared for the first time by catalytic hydrogenation of bis-indinyl complex C 6 H 10 (Ind) 2 Zr 2 Cl 2 . It has been identified that quantum yields of luminescence of the complex solutions at room temperature are the greatest ones for the known compounds possessing emission states of charge transfer from ligand to metal. Linear correlations of quantum yield of metal complex luminescence in a solution with steric features of the solvent molecules have been detected for the first time [ru

Crystal structure of 1,4-bis(3-ammoniopropylpiperazine-1,4-diium bis[dichromate(VI

Directory of Open Access Journals (Sweden)

S. Vetrivel

2016-05-01

Full Text Available The asymmetric unit of the organic–inorganic title salt, (C10H28N4[Cr2O7]2, comprises one half of an 1,4-bis(3-ammoniopropylpiperazinediium cation (the other half being generated by the application of inversion symmetry and a dichromate anion. The piperazine ring of the cation adopts a chair conformation, and the two CrO4 tetrahedra of the anion are in an almost eclipsed conformation. In the crystal, the cations and anions form a layered arrangement parallel to (001. N—H...O hydrogen bonds between the cations and anions and additional C—H...O interactions lead to the formation of a three-dimensional network structure.

Non bis in idem : De ontwikkeling van een beginsel

NARCIS (Netherlands)

van Hattum, W.F.

2012-01-01

Non bis in idem. The development of a principle The double jeopardy rule forbids a second prosecution for the same offence. The rule is applicable after irrevocable judgments: condemnations as well as acquittals. If a conviction is subsequently found to be wrong, it is annulled. But what if an

The btp [2,6-bis(1,2,3-triazol-4-yl)pyridine] binding motif: a new versatile terdentate ligand for supramolecular and coordination chemistry.

Science.gov (United States)

Byrne, Joseph P; Kitchen, Jonathan A; Gunnlaugsson, Thorfinnur

2014-08-07

Ligands containing the btp [2,6-bis(1,2,3-triazol-4-yl)pyridine] motif have appeared with increasing regularity over the last decade. This class of ligands, formed in a one pot ‘click’ reaction, has been studied for various purposes, such as for generating d and f metal coordination complexes and supramolecular self-assemblies, and in the formation of dendritic and polymeric networks, etc. This review article introduces btp as a novel and highly versatile terdentate building block with huge potential in inorganic supramolecular chemistry. We will focus on the coordination chemistry of btp ligands with a wide range of metals, and how it compares with other classical pyridyl and polypyridyl based ligands, and then present a selection of applications including use in catalysis, enzyme inhibition, photochemistry, molecular logic and materials, e.g. polymers, dendrimers and gels. The photovoltaic potential of triazolium derivatives of btp and its interactions with anions will also be discussed.

Contrary interfacial exciton dissociation at metal/organic interface in regular and reverse configuration organic solar cells

Energy Technology Data Exchange (ETDEWEB)

Wu, Bo; Wu, Zhenghui; Tam, Hoi Lam; Zhu, Furong, E-mail: frzhu@hkbu.edu.hk [Department of Physics, Institute of Advanced Materials, and Institute of Research and Continuing Education (Shenzhen), Hong Kong Baptist University, 224 Waterloo Road, Kowloon Tong, NT (Hong Kong)

2014-09-08

An opposite interfacial exciton dissociation behavior at the metal (Al)/organic cathode interface in regular and inverted organic solar cells (OSCs) was analyzed using transient photocurrent measurements. It is found that Al/organic contact in regular OSCs, made with the blend layer of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl] -[3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]-thiophenediyl

Bis-polymer lipid-peptide conjugates and nanoparticles thereof

Energy Technology Data Exchange (ETDEWEB)

Xu, Ting; Dong, He; Shu, Jessica; Dube, Nikhil

2018-04-24

The present invention provides bis-polymer lipid-peptide conjugates containing a hydrophobic block and headgroup containing a helical peptide and two polymer blocks. The conjugates can self-assemble to form helix bundle subunits, which in turn assemble to provide micellar nanocarriers for drug cargos and other agents. Particles containing the conjugates and methods for forming the particles are also disclosed.

Crystal structures of three co-crystals of 1,2-bis-(pyridin-4-yl)ethane with 4-alk-oxy-benzoic acids: 4-eth-oxy-benzoic acid-1,2-bis-(pyridin-4-yl)ethane (2/1), 4-n-propoxybenzoic acid-1,2-bis(pyridin-4-yl)ethane (2/1) and 4-n-but-oxy-benzoic acid-1,2-bis-(pyridin-4-yl)ethane (2/1).

Science.gov (United States)

Tabuchi, Yohei; Gotoh, Kazuma; Ishida, Hiroyuki

2015-11-01

The crystal structures of three hydrogen-bonded co-crystals of 4-alk-oxy-benzoic acid-1,2-bis-(pyridin-4-yl)ethane (2/1), namely, 2C9H10O3·C12H12N2, (I), 2C10H12O3·C12H12N2, (II), and 2C11H14O3·C12H12N2, (III), have been determined at 93, 290 and 93 K, respectively. In (I), the asymmetric unit consists of one 4-eth-oxy-benzoic acid mol-ecule and one half-mol-ecule of 1,2-bis-(pyridin-4-yl)ethane, which lies on an inversion centre. In (II) and (III), the asymmetric units each comprise two crystallographically independent 4-alk-oxy-benzoic acid mol-ecules and one 1,2-bis-(pyridin-4-yl)ethane mol-ecule. In each crystal, the two components are linked by O-H⋯N hydrogen bonds, forming a linear hydrogen-bonded 2:1unit of the acid and the base. Similar to the structure of 2:1 unit of (I), the units of (II) and (III) adopt nearly pseudo-inversion symmetry. The 2:1 units of (I), (II) and (III) are linked via C-H⋯O hydrogen bonds, forming tape structures.

Blades and discs in gas turbines. Behaviour of material and components. Project department A-C. Final report; Schaufeln und Scheiben in Gasturbinen. Werkstoff- und Bauteilverhalten. Projektbereiche A bis C. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-04-01

The special research area 339 `Blades and discs in gas turbines, behaviour of material and components` was carried on from 1988 to the end of 1196. This final report deals with the work in the years 1994, 1995 and 1996. In the project area A `Development of material` manufacturing processes both for metallic and ceramic high temperature materials were developed, tested and optimised. In the area of optimising casting structure, it was shown that the making grains finer up to the medium temperature range can be a suitable means for significantly raising the resistance to LCF loading with nearly unchanged heat and creep strength properties. Another main point was the characterisation and optimisation of sprayed ceramic layers on metallic substrates (heat insulating layers) and compound ceramic materials. In project area B `Material behaviour` the mechanisms were studied, which, particularly in metallic high temperature materials such as nickel-based superalloys, lead to failure of the material under thermo-mechanical stresses. In project area C `Component design`, on the one hand models for estimating service life for metallic high temperature materials under different thermo-mechanical stresses were developed. [Deutsch] Der Sonderforschungsbereich 339, `Schaufeln und Scheiben in Gasturbinen - Werkstoff- und Bauteilverhalten` wurde von 1988 bis Ende 1996 gefoerdert. Dieser Abschlussbericht behandelt die Arbeiten der Jahre 1994, 1995 und 1996. Im Projektbereich A `Werkstoffentwicklung` wurden Herstellungsverfahren sowohl fuer metallische als auch fuer keramische Hochtemperaturwerkstoffe entwickelt, erprobt und optimiert. Auf dem Gebiet der Gussgefuegeoptimierung konnte gezeigt werden, dass die Kornfeinung bis in den mittleren Temperaturbereich ein geeignetes Mittel sein kann, um den Widerstand gegen LCF-Belastung bei annaehernd unveraenderten Warm- und Kriechfestigkeitseigenschaften signifikant zu erhoehen. Einen weiteren Schwerpunkt bildete die Charakterisierung und

Impulsivity components measured by the Brazilian version of the Barratt Impulsiveness Scale (BIS-11)

OpenAIRE

Vasconcelos,Alina Gomide; Teodoro,Maycoln Leôni Martins; Malloy-Diniz,Leandro; Correa,Humberto

2015-01-01

The main purpose of this study was to investigate the psychometric properties of the Barratt Impulsiveness Scale (BIS-11). Content item analysis was conducted by seven doctoral students. A convenience sample of 897 students was submitted to BIS-11 and they also filled self-reports about Minor Mental Disorder and ADHD symptoms, alcohol use and cigarette smoking. Mean age was 27.32 (SD=8.69) years, 56% were female and 52% had incomplete college degree. Content and factorial analyses revealed th...

The Influence of Substituents on the Tautomerism of Symmetrically Substituted 2,2'-Bis-benzimidazoles

Directory of Open Access Journals (Sweden)

Dall'Oglio Evandro

2002-01-01

Full Text Available The tautomerism of five symmetrically substituted 2,2'-bis-benzimidazoles [5(6,5'(6'-tetramethyl- (1; 5(6,5'(6'-dimethyl-(2; 5(6,5'(6'-dichloro- (3; 5(6,5'(6'-dimethoxy- (4 and 4(7,4'(7'-dimethyl-2,2'-bis-benzimidazole (5], was studied by means of ¹H NMR spectroscopy at variable temperatures, and the influence of the substituents on the energy barriers for tautomeric interconversion was interpreted with the aid of theoretical calculations.

Review: Holger Stoecker: Afrikawissenschaften in Berlin von 1919 bis 1945. Zur Geschichte und Topographie eines wissenschaftlichen Netzwerkes (2008 Buchbesprechung: Holger Stoecker: Afrikawissenschaften in Berlin von 1919 bis 1945. Zur Geschichte und Topographie eines wissenschaftlichen Netzwerkes

Directory of Open Access Journals (Sweden)

Katrin Bromber

2009-05-01

Full Text Available Review of the monograph: Holger Stoecker: Afrikawissenschaften in Berlin von 1919 bis 1945. Zur Geschichte und Topographie eines wissenschaftlichen Netzwerkes, Stuttgart: Franz Steiner Verlag 2008, ISBN 978-3-515-09161-9, 359 pages. Besprechung der Monographie: Holger Stoecker: Afrikawissenschaften in Berlin von 1919 bis 1945. Zur Geschichte und Topographie eines wissenschaftlichen Netzwerkes, Stuttgart: Franz Steiner Verlag 2008, ISBN 978-3-515-09161-9, 359 Seiten.

Bis[N,N-bis(1-allyl-1H-benzimidazol-2-ylmethyl-κN3benzylamine-κN]cadmium dipicrate

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Jing-Kun Yuan

2011-06-01

Full Text Available The crystal structure of the title compound, [Cd(C29H29N52](C6H2N3O72, consists of CdII complex cations and picrate anions. In the complex cation, the CdII ion is chelated by two bis(1-allylbenzimidazol-2-ylmethylbenzylamine (babb ligands in a distorted octahedral geometry. Extensive C—H...O hydrogen bonding occurs between cations and anions in the crystal structure.

Spectroscopic studies on Isatin-3-Semicarbazone and Isatin-3 ...

African Journals Online (AJOL)

... bombardment (FAB) and negative ion chemical ionization (NICI) mass spectra are also reported. Fragmentation of molecular and pseudomolecular ions are tabulated and rationalized. KEY WORDS: IH NMR, 13C NMR, Semicarbazone thiosemicarbazone, mass spectra, negative ion chemical ionization, fragmentation.

catena-Poly[[bis[[bis(3-aminopropylamine-κ3N,N′,N′′](thiocyanato-κNcadmium]-μ4-sulfato-κ4O,O:O′,O′] methanol hemisolvate

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Jan Boeckmann

2011-09-01

Full Text Available The asymmetric unit of the title compound, {[Cd2(NCS2(SO4(C6H17N32]·0.5CH3OH}n, consists of two Cd2+ cations, two thiocyanate and one sulfate anion, two bis(3-aminopropylamine co-ligands and one methanol molecule with half-occupancy. Each Cd2+ cation is coordinated by four N atoms of one terminal N-bonded thiocyanate anion and one bis(3-aminopropylamine co-ligand, and by two O atoms of two symmetry-related sulfate anions, defining a slightly distorted octahedral coordination polyhedron. Each two Cd2+ cations are connected into dimers, which are located on centres of inversion and which are further μ-1,1:3,3-bridged via the sulfate anions into polymeric zigzag chains along the a axis.

The transnational ne bis in idem principle in the EU. Mutual recognition and equivalent protection of human rights

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John A.E. Vervaele

2005-12-01

Full Text Available The deepening and widening of European integration has led to an increase in transborder crime. Concurrent prosecution and sanctioning by several Member States is not only a problem in inter-state relations and an obstacle in the European integration process, but also a violation of the ne bis in idem principle, defined as a transnational human right in a common judicial area. This article analyzes whether and to what extent the ECHR has contributed and may continue to contribute to the development of such a common ne bis in idem standard in Europe. It is also examined whether the application of the ne bis in idem principle in classic inter-state judicial cooperation in criminal matters in the framework of the Council of Europe may make such a contribution as well. The transnational function of the ne bis in idem principle is discussed in the light of the Court of Justice’s case law on ne bis in idem in the framework of the area of Freedom, Security and Justice. Finally the inherent tension between mutual recognition and the protection of human rights in transnational justice is analyzed by looking at the insertion of the ne bis in idem principle in the Framework Decision on the European arrest warrant.

Bis-Porphyrin Racks with Space-Separated Co-Planar Porphyrin Rings

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Martin R. Johnston

2001-03-01

Full Text Available A porphyrin appended norbornenyl building block 8 has been isolated and coupled, using a 1,3-dipolar ACE reaction, to yield bis-porphyrin compounds in which the porphyrin moietes are angled upward relative to the norbornane backbone.

Tradução e adaptação cultural da Barratt Impulsiveness Scale (BIS-11 para aplicação em adultos brasileiros Translation and cultural adaptation of Barratt Impulsiveness Scale (BIS-11 for administration in Brazilian adults

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Leandro Fernandes Malloy-Diniz

2010-01-01

Full Text Available OBJETIVOS: Os objetivos deste estudo foram traduzir, adaptar culturalmente e verificar a equivalência literal, semântica e idiomática da Barratt Impulsiveness Scale (BIS-11, que avalia a presença de manifestações da impulsividade tendo como base o modelo teórico proposto por Ernst Barratt. MÉTODOS: Inicialmente, a versão original em inglês da BIS-11 foi traduzida para o português por seis pesquisadores bilíngues. Em seguida, foi realizada uma tradução reversa para o inglês por uma tradutora de origem norte-americana. As versões original, traduzida e retraduzida foram avaliadas por um comitê de juízes especialistas, os quais emitiram pareceres com as observações pertinentes, o que culminou em uma versão final traduzida da BIS-11. As versões original e traduzida foram aplicadas em duas amostras da população geral com proficiência na língua inglesa, a fim de investigar a equivalência literal, semântica e idiomática da versão traduzida por meio de análises de correlação. CONCLUSÃO: Os resultados das análises quantitativas indicaram que a versão final do instrumento é satisfatória.OBJECTIVES: The objective of this study was to translate, make transcultural adaptation and assess the semantic, idiomatic and literal equivalence of the Barratt Impulsiveness Scale (BIS-11. METHODS:This scale assesses the presence of impulsive manifestations from the theoretical model proposed by Ernst Barratt. Firstly, the BIS-11 original version in English was translated to Portuguese by six bilingual researches. After this, was made the back-translation to English by a translator that was born in United States. Then, the three versions (original, translated and back-translated were assessed by a specialists committee which made and analyze and comments about the process and then we reach the final translated version of BIS-11. The original and translated version of BIS-11 was applied in two samples from general population with

catena-Poly[[copper(II)-bis[μ-bis(3,5-dimethyl-1H-pyrazol-4-yl) selenide

Science.gov (United States)

Seredyuk, Maksym; Haukka, Matti; Pavlenko, Vadim A.; Fritsky, Igor O.

2009-01-01

In the title compound, {[Cu(C10H14N4Se)2](ClO4)2}n, the CuII ion is located on a twofold rotation axis and has a tetra­gonally distorted square-planar geometry constituted by four N atoms. A pair of bis(3,5-dimethyl-1H-pyrazol-4-yl) selenide (L) ligands bridges the copper centers into a polymeric chain extending along [001]. The perchlorate anions are involved in inter­molecular N—H⋯O hydrogen bonding, which links the chains into layers parallel to the bc plane. PMID:21578140

Impulsivity components measured by the Brazilian version of the Barratt Impulsiveness Scale (BIS-11

Directory of Open Access Journals (Sweden)

Alina Gomide Vasconcelos

2015-03-01

Full Text Available The main purpose of this study was to investigate the psychometric properties of the Barratt Impulsiveness Scale (BIS-11. Content item analysis was conducted by seven doctoral students. A convenience sample of 897 students was submitted to BIS-11 and they also filled self-reports about Minor Mental Disorder and ADHD symptoms, alcohol use and cigarette smoking. Mean age was 27.32 (SD=8.69 years, 56% were female and 52% had incomplete college degree. Content and factorial analyses revealed that impulsivity was best represented by two latent factors labeled non-planning and inhibition behaviors. Test retest agreement tended to produce similar score patterns seven months after the first evaluation. Additionally, BIS-11 scores discriminated subjects in terms of cigarette smoking and psychopathological symptoms, which indicated evidences regarding criterion-related validity. The theoretical discussion was present based on the neuropsychological model of hot and cool aspects of executive function.

Molecular structure and vibrational spectra of Bis(melaminium) terephthalate dihydrate: A DFT computational study

Science.gov (United States)

Tanak, Hasan; Marchewka, Mariusz K.; Drozd, Marek

2013-03-01

The experimental and theoretical vibrational spectra of Bis(melaminium) terephthalate dihydrate were studied. The Fourier transform infrared (FT-IR) spectra of the Bis(melaminium) terephthalate dihydrate and its deuterated analogue were recorded in the solid phase. The molecular geometry and vibrational frequencies of Bis(melaminium) terephthalate dihydrate in the ground state have been calculated by using the density functional method (B3LYP) with 6-31++G(d,p) basis set. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The molecule contains the weak hydrogen bonds of Nsbnd H⋯O, Nsbnd H⋯N and Osbnd H⋯O types, and those bonds are calculated with DFT method. In addition, molecular electrostatic potential, frontier molecular orbitals and natural bond orbital analysis of the title compound were investigated by theoretical calculations. The lack of the second harmonic generation (SHG) confirms the presence of macroscopic center of inversion.

Interest of bone scintigraphy in the care of maxillary osteo-necroses induced by bis-phosphonates

International Nuclear Information System (INIS)

Agossa, Kevimy

2012-01-01

First cases of bis-phosphonates related osteonecrosis of jaws (BRONJ) have been described in 2003. Since then, this subject is one of the central concerns of several scientific communities, well beyond the oral sphere. The prevalence of BRONJ is evolving. Their etiology is not well established and the results of the treatments are inconstant. So many points that make the care to patients under bis-phosphonates really complex. Early diagnosis is essential in treatment outcome. So nuclear imaging including scintigraphy with technetium 99m seems to be helpful. It may allow detection before the onset of symptoms, facilitate localization of necrosis and it may be useful for the monitoring of such lesions after surgery. These are new applications for oncologist and dentist, in order to improve the management of patients treated by bis-phosphonates. (author) [fr

Marine Natural Product Bis-indole Alkaloid Caulerpin: Chemistry and Biology.

Science.gov (United States)

Lunagariya, Jignesh; Bhadja, Poonam; Zhong, Shenghui; Vekariya, Rohit; Xu, Shihai

2017-09-27

Marine bis-indole alkaloids comprise a large and increasingly growing class of secondary metabolites, and continue to deliver a great variety of structural templates. The alkaloids derived from marine resources play a crucial role in medicinal chemistry and as chemical agents. In particular, bis-indole alkaloid caulerpin isolated from marine green algae Caulerpa and a red algae Chondria armata at various places around the world, and tested against several therapeutic areas such as anti-diabetic, antinociceptive, anti-inflammatory, anti-tumor, anti-larvicidal, anti-herpes, anti-tubercular, anti-microbial and immunostimulating activity as well as means of other chemical agents. Herein, we summarized discovery of caulerpin, and its potential medicinal and chemical applications in chronological order with various aspects. Additionally, synthesis of caulerpin, its functional analogues, and structural isomer have also been reviewed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Utilizing bi-spectral index (BIS) for the monitoring of sedated adult ICU patients: a systematic review.

Science.gov (United States)

Bilgili, Beliz; Montoya, Juan C; Layon, A J; Berger, Andrea L; Kirchner, H L; Gupta, Leena K; Gloss, David S

2017-03-01

The ideal level of sedation in the ICU is an ongoing source of scrutiny. At higher levels of sedation, the current scoring systems are not ideal. BIS may be able to improve both. We evaluated literature on effectiveness of BIS monitoring in sedated mechanically ventilated (MV) ICU patients compared to clinical sedation scores (CSS). For this systematic review, full text articles were searched in OVID, MEDLINE, EMBASE, and Cochrane databases from 1986 - 2014. Additional studies were identified searching bibliographies/abstracts from national/international Critical Care Medicine conferences and references from searched articles retrieved. Search terms were: 'Clinical sedation scale, Bi-spectral Index, Mechanical ventilation, Intensive care Unit'. Included were prospective, randomized and non-randomized studies comparing BIS monitoring with any CSS in MV adult (>18 yr old) ICU patients. Studies were graded for quality of evidence based on bias as established by the GRADE guidelines. Additional sources of bias were examined. There were five studies which met inclusion criteria. All five studies were either unclear or high risk for blinding of participants and blinding of outcome assessment. All papers had at least one source of additional high risk, or unclear/unstated. BIS monitoring in the mechanically ventilated ICU patient may decrease sedative drug dose, recall, and time to wake-up. The studies suggesting this are severely limited methodologically. BIS, when compared to subjective CSSs, is not, at this time, clearly indicated. An appropriately powered randomized, controlled study is needed to determine if this monitoring modality is of use on the ICU.

Heterobimetallic gadolinium(III)-iron(III) complex of DTPA-bis(3-hydroxytyramide)

International Nuclear Information System (INIS)

Parac-Vogt, Tatjana N.; Kimpe, Kristof; Binnemans, Koen

2004-01-01

A derivative of diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA), carrying two catechol functional groups has been synthesised by the reaction between DTPA-bis(anhydride) and 3-hydroxytyramine (dopamine). The ligand DTPA-bis(3-hydroxytyramide), [DTPA(HTA) 2 ], is able to form stable heterobimetallic complexes with gadolinium(III) and iron(III) ions. The gadolinium(III) occupies the internal coordination cage of DTPA formed by three nitrogens, two carboxylate and two amide oxygens, while the [Fe(NTA)(H 2 O) 2 ] (nitrilotriacetic acid, NTA) binds to catechol units by the substitution of two water ligands. The formation of polymeric species was avoided by using the tripodal NTA ligand. The heterobimetallic complex was characterised by means of visible absorption spectroscopy, electron spray ionisation-mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR) spectroscopy

Quantitation of methylglyoxal bis(guanylhydrazone) in blood plasma and leukemia cells of patients receiving the drug.

Science.gov (United States)

Seppänen, P; Alhonen-Hongisto, L; Siimes, M; Jänne, J

1980-11-15

Methylglyoxal bis(guanylhydrazone), a cytostatic compound which apparently interferes with the metabolism and/or functions of the natural polyamines (spermidine and spermine), was effectively taken up by cultured human lymphocytic leukemia cells, rapidly resulting in the formation of a concentration gradient of up to 1,000-fold across the cell membrane in cells grown in the presence of micromolar concentrations of the drug. For an anti-proliferative effect on the leukemia cells, an intracellular concentration of more than 0.5 mM was required. The uptake of methylglyoxal bis(guanylhydrazone) was critically dependent on the growth rate of the leukemia cells. Low intracellular concentrations of the drug were present in cells growing slowly, whereas in rapidly dividing cells the intracellular concentration of the drug approached 5mM. When given as repeated intravenous infusions to two leukemic children, methylglyoxal bis(guanylhydrazone) exhibited sharp and transient peaks of plasma concentration, the drug having an apparent half-life in plasma of only 1-2 h. However, as in cultured cells, the drug was rapidly concentrated in the leukemia cells, reaching concentrations that were distinctly anti-proliferative. In contrast to the rapid disappearance of methylglyoxal bis(guanylhydrazone) from plasma, the circulation leukemia cells retained the drug for a period of several days with only minimal decrease in the initial concentrations. Methylglyoxal bis(guanylhydrazone) was given to the patients for 1 to 2 months as intravenous infusions, the timing of which was determined by regular assays of the drug concentrations in the leukemia cells. In agreement with the results obtained with the cultured cells, and intracellular concentration of about 0.5 to 1mM was apparently required for growth-inhibitory action to occur. Regular determination of the cellular drug concentrations indicated that methylglyoxal bis(quanylhydrazone) could be given as weekly infusions. This treatment

From polyethylene waxes to HDPE using an α,α'-bis(arylimino)-2,3:5,6-bis(pentamethylene)pyridyl-chromium(iii) chloride pre-catalyst in ethylene polymerisation.

Science.gov (United States)

Huang, Chuanbing; Du, Shizhen; Solan, Gregory A; Sun, Yang; Sun, Wen-Hua

2017-05-30

Five examples of α,α'-bis(arylimino)-2,3:5,6-bis(pentamethylene)pyridyl-chromium(iii) chlorides (aryl = 2,6-Me 2 Ph Cr1, 2,6-Et 2 Ph Cr2, 2,6-i-Pr 2 Ph Cr3, 2,4,6-Me 3 Ph Cr4, 2,6-Et 2 -4-MePh Cr5) have been synthesized by the one-pot template reaction of α,α'-dioxo-2,3:5,6-bis(pentamethylene)pyridine, CrCl 3 ·6H 2 O and the corresponding aniline. The molecular structures of Cr1 and Cr4 reveal distorted octahedral geometries with the N,N,N-ligand adopting a mer-configuration. On activation with an aluminium alkyl co-catalyst, Cr1-Cr5 exhibited high catalytic activities in ethylene polymerization and showed outstanding thermal stability operating effectively at 80 °C with activities up to 1.49 × 10 7 g of PE (mol of Cr) -1 h -1 . Significantly, the nature of the co-catalyst employed had a dramatic effect on the molecular weight of the polymeric material obtained. For example, using diethylaluminium chloride (Et 2 AlCl) in combination with Cr4 gave high density/high molecular weight polyethylene with broad molecular weight distributions (30.9-39.3). By contrast, using modified methylaluminoxane (MMAO), strictly linear polyethylene waxes of lower molecular weight and narrow molecular weight distribution (1.6-2.0) were obtained with vinyl end-groups.

Layered Metal Nanoparticle Structures on Electrodes for Sensing, Switchable Controlled Uptake/Release, and Photo-electrochemical Applications.

Science.gov (United States)

Tel-Vered, Ran; Kahn, Jason S; Willner, Itamar

2016-01-06

Layered metal nanoparticle (NP) assemblies provide highly porous and conductive composites of unique electrical and optical (plasmonic) properties. Two methods to construct layered metal NP matrices are described, and these include the layer-by-layer deposition of NPs, or the electropolymerization of monolayer-functionalized NPs, specifically thioaniline-modified metal NPs. The layered NP composites are used as sensing matrices through the use of electrochemistry or surface plasmon resonance (SPR) as transduction signals. The crosslinking of the metal NP composites with molecular receptors, or the imprinting of molecular recognition sites into the electropolymerized NP matrices lead to selective and chiroselective sensing interfaces. Furthermore, the electrosynthesis of redox-active, imprinted, bis-aniline bridged Au NP composites yields electrochemically triggered "sponges" for the switchable uptake and release of electron-acceptor substrates, and results in conductive surfaces of electrochemically controlled wettability. Also, photosensitizer-relay-crosslinked Au NP composites, or electrochemically polymerized layered semiconductor quantum dot/metal NP matrices on electrodes, are demonstrated as functional nanostructures for photoelectrochemical applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of alkyl chain length and substituent pattern of fullerene bis-adducts on film structures and photovoltaic properties of bulk heterojunction solar cells.

Science.gov (United States)

Tao, Ran; Umeyama, Tomokazu; Kurotobi, Kei; Imahori, Hiroshi

2014-10-08

A series of alkoxycarbonyl-substituted dihydronaphthyl-based [60]fullerene bis-adduct derivatives (denoted as C2BA, C4BA, and C6BA with the alkyl chain of ethyl, n-butyl, and n-hexyl, respectively) have been synthesized to investigate the effects of alkyl chain length and substituent pattern of fullerene bis-adducts on the film structures and photovoltaic properties of bulk heterojunction polymer solar cells. The shorter alkyl chain length caused lower solubility of the fullerene bis-adducts (C6BA > C4BA > C2BA), thereby resulting in the increased separation difficulty of respective bis-adduct isomers. The device performance based on poly(3-hexylthiophene) (P3HT) and the fullerene bis-adduct regioisomer mixtures was enhanced by shortening the alkyl chain length. When using the regioisomerically separated fullerene bis-adducts, the devices based on trans-2 and a mixture of trans-4 and e of C4BA exhibited the highest power conversion efficiencies of ca. 2.4%, which are considerably higher than those of the C6BA counterparts (ca. 1.4%) and the C4BA regioisomer mixture (1.10%). The film morphologies as well as electron mobilities of the P3HT:bis-adduct blend films were found to affect the photovoltaic properties considerably. These results reveal that the alkyl chain length and substituent pattern of fullerene bis-adducts significantly influence the photovoltaic properties as well as the film structures of bulk heterojunction solar cells.

Cis-[RuCl(BzCN)(N-N)(P-P)]PF6 complexes: Synthesis and in vitro antitumor activity: (BzCN=benzonitrile; N-N=2,2'-bipyridine; 1,10-phenanthroline; P-P=1,4-bis(diphenylphosphino) butane, 1,2-bis(diphenylphosphino)ethane, or 1,1'-(diphenylphosphino)ferrocene).

Science.gov (United States)

Pereira, Flávia de C; Lima, Benedicto A V; de Lima, Aliny P; Pires, Wanessa C; Monteiro, Thallita; Magalhães, Lorena F; Costa, Wanderson; Graminha, Angélica E; Batista, Alzir A; Ellena, Javier; Siveira-Lacerda, Elisângela de P

2015-08-01

The motivation to use ruthenium complexes in cancer treatment has led our research group to synthesize complexes with this metal and test them against several types of tumor cells, yielding promising results. In this paper the results of biological tests, assessed by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, were carried out on the complexes cis-[RuCl(BzCN)(bipy)(dppe)]PF6 (1), cis-[RuCl(BzCN)(bipy)(dppb)]PF6 (2), cis-[RuCl(BzCN)(bipy)(dppf)]PF6 (3) and cis-[RuCl(BzCN)(phen)(dppb)]PF6 (4) which are described [BzCN = b enzonitrile; bipy = 2,2'-bipyridine; phen = 1,10-phenanthroline; dppe = 1,2-bis(diphenylphosphino) ethane; dppb = 1,4-bis-(diphenylphosphino)butane; dppf = 1,1'-bis(diphenylphosphino)ferrocene]. The present study is focused on the cytotoxic activity of complexes (1)-(4) against four tumor cell lines and on the apoptosis and changes in the cell cycle and gene expression observed in the sarcoma 180 (S180) tumor cell line treated with complex (1). The results demonstrated that this complex inhibits S180 cell growth, with an IC50 of 17.02 ± 8.21 μM, while exhibiting lower cytotoxicity (IC50 = 53.73 ± 5.71 μM) towards lymphocytes (normal cells). Flow cytometry revealed that the complex inhibits the growth of tumor cells by inducing apoptosis as evidenced by an increase in the proportion of cells positive for annexin V staining and G0/G1 phase cell-cycle arrest. Further investigation showed that complex (1) induces a drop in the mitochondrial membrane potential and provokes a decrease in Bcl-2 protein expression and increase in caspase 3 activation, while the increased activation of caspase 8 caused a decrease in the gene expression in caspases 3 and 9. Increases in Tp53 and Bax expressions were also observed. Copyright © 2015 Elsevier Inc. All rights reserved.

Thermodynamic investigation of the MOCVD of copper films from bis ...

Indian Academy of Sciences (India)

Equilibrium concentrations of various condensed and gaseous phases have been thermodynamically calculated, using the free energy minimization criterion, for the metalorganic chemical vapour deposition (MOCVD) of copper films using bis(2,2,6,6-tetramethyl-3,5-heptadionato)copper(II) as the precursor material.

Synthesis, Characterization and Thermal Decomposition Studies of Cr(III, Mn(II and Fe(III Complexes of N, N '-Bis[1,3-benzodioxol-5-ylmethylene]butane-1,4-diamine

Directory of Open Access Journals (Sweden)

Prasad M. Alex

2009-01-01

Full Text Available A bidentate Schiff base ligand namely, N,N'-bis-1,3-benzodioxol-5-ylmethylene]butane-1,4-diamine was synthesised by condensing piperonal (3,4-dioxymethylenebenzaldehyde with butane-1,4-diamine. Cr(III, Mn(II, Fe(III complexes of this chelating ligand were synthesised using acetates, chlorides, bromides, nitrates and perchlorates of these metals. The ligand and the complexes were characterised by elemental analysis, 1H NMR, UV-Vis and IR spectra, conductance and magnetic susceptibility measurements and thermogravimetric analysis. The thermograms of three complexes were analysed and the kinetic parameters for the different stages of decompositions were determined.

Structure-dependent photophysical properties of singlet and triplet metal-to-ligand charge transfer states in copper(I) bis(diimine) compounds.

Science.gov (United States)

Siddique, Zainul Abedin; Yamamoto, Yuichi; Ohno, Takeshi; Nozaki, Koichi

2003-10-06

The photophysical properties of singlet and triplet metal-to-ligand charge transfer (MLCT) states of [Cu(I)(diimine)(2)](+), where diimine is 2,9-dimethyl-1,10-phenanthroline (dmphen), 2,9-dibutyl-1,10-phenanthroline (dbphen), or 6,6'-dimethyl-2,2'-bipyridine (dmbpy), were studied. On 400 nm laser excitation of [Cu(dmphen)(2)](+) in CH(2)Cl(2) solution, prompt (1)MLCT fluorescence with a quantum yield of (2.8 +/- 0.8) x 10(-5) was observed using a picosecond time-correlated single photon counting technique. The quantum yield was dependent on the excitation wavelength, suggesting that relaxation of the Franck-Condon state to the lowest (1)MLCT competes with rapid intersystem crossing (ISC). The fluorescence lifetime of the copper(I) compound was 13-16 ps, unexpectedly long despite a large spin-orbit coupling constant of 3d electrons in copper (829 cm(-1) ). Quantum chemical calculations using a density functional theory revealed that the structure of the lowest (1)MLCT in [Cu(dmphen)(2)](+) (1(1)B(1)) was flattened due to the Jahn-Teller effect in 3d(9) electronic configuration, and the dihedral angle between the two phenanthroline planes (dha) was about 75 degrees with the dha around 90 degrees in the ground state. Intramolecular reorganization energy for the radiative transition of 1(1)B(1) was calculated as 2.1 x 10(3) cm(-1), which is responsible for the large Stokes shift of the fluorescence observed (5.4 x 10(3) cm(-1)). To understand the sluggishness of the intersystem crossing (ISC) of (1)MLCT of the copper(I) compounds, the strength of the spin-orbit interaction between the lowest (1)MLCT (1(1)B(1)) and all (3)MLCT states was calculated. The ISC channels induced by strong spin-orbit interactions (ca. 300 cm(-1)) between the metal-centered HOMO and HOMO - 1 were shown to be energetically unfavorable in the copper(I) compounds because the flattening distortion caused large splitting (6.9 x 10(3) cm(-1)) between these orbitals. The possible ISC is therefore

Synthesis and Characterization of Tetrakis-aqua-bis-isonicotin-amide(itmd)nickel(II) Sulfate

Science.gov (United States)

Rahardjo, S. B.; Hastuti, S.; Amanati, N.; Syaima, H.

2018-03-01

The complex of Tetrakis-aqua-bis-(isonicotinamide)nickel(II) sulfate has been synthesized in 1:2 mole ratio of metal to ligands in methanol. The formula of the complex predicted from analysis nickel content in the complex by Atomic Absorption Spectroscopy (AAS) was Ni(itmd)2SO4(H2O)4. The conductivity of the complex in methanol was measured by conductivity meter correspond to 1:1 electrolyte. Thermal analysis of the complex was determined by Differential Thermal Analyzer (DTA) indicating that the complex contains four H2O molecules as ligands. The magnetic susceptibility measurement showed that the complex was paramagnetic with μeff = 3.02 BM. The electronic spectra of the complex appear due to two transition peak on λ = 398 nm and 664 nm. The Infrared spectra showed a shift of NH2 stretching vibration of Ni(itmd)2SO4(H2O)4. These facts indicated that these functional groups were coordinated to the center ion of the complexes. The proposed structure of the complex was octahedral therefore the possibility formula of this complex was [Ni(itmd)2(H2O)4]SO4.

Cd(II)-coordination polymers based on tetracarboxylic acid and diverse bis(imidazole) ligands: Synthesis, structural diversity and photoluminescence properties

Energy Technology Data Exchange (ETDEWEB)

Arıcı, Mürsel, E-mail: marici@ogu.edu.tr [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Yeşilel, Okan Zafer [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Taş, Murat [Department of Science Education, Education Faculty, Ondokuz Mayıs University, 55139 Samsun (Turkey)

2017-01-15

Three new Cd(II)-coordination polymers, namely, ([Cd{sub 2}(μ{sub 6}-ao{sub 2}btc)(μ-1,5-bipe){sub 2}]·2H{sub 2}O){sub n} (1), ([Cd{sub 2}(μ{sub 6}-ao{sub 2}btc)(μ-1,4-bix){sub 2}]{sub n}·2DMF) (2) and ([Cd{sub 2}(μ{sub 8}-abtc)(μ-1,4-betix)]·DMF·H{sub 2}O){sub n} (3) (ao{sub 2}btc=di-oxygenated form of 3,3′,5,5′-azobenzenetetracarboxylate, 1,5-bipe: 1,5-bis(imidazol-1yl)pentane, 1,4-bix=1,4-bis(imidazol-1ylmethyl)benzene, 1,4-betix=1,4-bis(2-ethylimidazol-1ylmethyl)benzene) were synthesized with 3,3′,5,5′-azobenzenetetracarboxylic acid and flexible, semi-flexible and semi-flexible substituted bis(imidazole) linkers. They were characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction, powder X-ray diffractions (PXRD) and thermal analyses (TG/DTA). Complexes 1–3 exhibited structural diversities depending on flexible, semi-flexible and semi-flexible substituted bis(imidazole) ligands. Complex 1 was 2D structure with 3,6L18 topology. Complex 2 had a 3D pillar-layered framework with the rare sqc27 topology. When semi-flexible substituted bis(imidazole) linker was used, 3D framework of complex 3 was obtained with the paddlewheel Cd{sub 2}(CO{sub 2}){sub 4}-type binuclear SBU. Moreover, thermal and photoluminescence properties of the complexes were determined in detailed. - Graphical abstract: In this study, three novel Cd(II)-coordination polymers were synthesized with 3,3′,5,5′-azobenzenetetracarboxylic acid and flexible, semi-flexible and semi-flexible substituted bis(imidazole) linkers. They were characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction, powder X-ray diffractions (PXRD) and thermal analyses (TG/DTA). Complexes 1–3 exhibited structural diversities depending on flexible, semi-flexible and semi-flexible substituted bis(imidazole) ligands. Complex 1 was 2D structure with 3,6L18 topology. Complex 2 had a 3D pillar-layered framework with the rare sqc27 topology. When semi

Relation of the antiproliferative action of methylglyoxal-bis(guanylhydrazone) to the natural polyamines.

Science.gov (United States)

Seppänen, P; Alhonen-Hongisto, L; Jänne, J

1980-09-01

Enzymic determinations of intracellular concentrations of methylglyoxal-bis(guanylhydrazone), an anticancer drug which inhibits the synthesis of the polyamines spermidine and spermine, in cultured tumor cells revealed that the drug was remarkably effectively concentrated inside the cell. A concentration gradient across the cell membrane as great as 500--1000-fold was formed in cells exposed to the drug for 1-2 days. An exposure of cultured Ehrlich ascites carcinoma cells to increasing concentrations of the drug indicated that the cells could tolerate intracellular concentrations up to 1 mM with only slight changes in their proliferation rate. Micromolar concentrations of spermidine or spermine, but not putrescine, effectively blocked the uptake of methylglyoxal-bis(guanylhydrazone) and reduced the intracellular concentration of the drug below the levels required for growth inhibition. Analysis of cellular polyamine contents in Ehrlich ascites cells exposed to rising concentrations of methylglyoxal-bis(guanylhydrazone) gave little support to the view that the drug-induced growth inhibition was solely produced by an intracellular polyamine deprivation. Not only was the uptake of the drug inhibited in the presence of spermidine and spermine, but it was likewise washed out by polyamines from the cells that had been previously exposed to the drug and then transferred into drug-free medium in the presence of polyamines. For the inhibition of methylglyoxal-bis(guanylhydrazone) uptake by amines, three or more amino/imino groups were apparently required, since low concentrations of aliphatic diamines were either without any effect (short-chain diamines) or only marginally prevented (long-chain diamines) the uptake of the drug. High concentrations of Mg2+ ions, however, markedly inhibited the transport of the drug into Ehrlich ascites tumor cells.

REFORMING THE NE BIS IN IDEM CLAUSE OF ARTICLE 20(3)

African Journals Online (AJOL)

Fr. Ikenga

deal with all perpetrators of the crimes that come under its jurisdiction wherever such crimes are ... KAYITANA: Complementarity and Completed Trials: Reforming the Ne Bis in Idem Clause of Article 20(3) of ..... exchange for lenient sentences.

Isolation and Characterization of Stigmasterol and Bis-(5, 7-diacetyl ...

African Journals Online (AJOL)

Nigerian Journal of Basic and Applied Sciences ... from the hexane fraction and a catechin glycoside, Bis-(5,7-diacetyl-catechin-4'-α- rhamnopyranoside) was isolated from the ethylacetate soluble fraction using a combination of silica gel column, gel filtration (sephadex LH-20) and preparative thin layer chromatography.

Molecular modeling in the development of metal radiopharmaceuticals

International Nuclear Information System (INIS)

Green, M.A.

1993-10-01

We began this project with a compilation of a structural library to serve as a data base containing descriptions of the molecular features of metal-labeled radiopharmaceuticals known to efficiently cross the blood-brain barrier. Such a data base is needed in order to identify structural features (size, shape, molecular surface areas and volumes) that are critical in allowing blood-brain barrier penetration. Nine metal complexes have been added to this structural library. We have completed a detailed comparison of four molecular mechanics computer programs QUANTA, SYBYL, BOYD, and MM2DREW to assess their applicability to modeling the structures of low molecular weight metal complexes. We tested the ability of each program to reproduce the crystallographic structures of 38 complexes between nickel(II) and saturated N-donor ligands. The programs were evaluated in terns of their ability to reproduce structural features such as bond lengths, bond angles, and torsion angles. Recently, we investigated the synthesis and characterization of lipophilic cationic gallium complexes with hexadentate bis(salicylaldimine) ligands. This work identified the first gallium-68 radiopharrnaceuticals that can be injected intravenously and that subsequently exhibit significant myocardial uptake followed by prolonged myocardial retention of 68 Ga radioactivity. Tracers of this type remain under investigation as agents for evaluation of myocardial perfusion with positron emission tomography

Biochemical properties and crystal structure of ethylmethylglyoxal bis(guanylhydrazone) sulfate--an extremely powerful novel inhibitor of adenosylmethionine decarboxylase.

Science.gov (United States)

Elo, H; Mutikainen, I; Alhonen-Hongisto, L; Laine, R; Jänne, J; Lumme, P

1986-01-01

Ethylmethylglyoxal bis(guanylhydrazone) (EMGBG) sulfate, an analog of the well-known anti-leukemic drug methylglyoxal bis(guanylhydrazone), was synthesized. It was shown to be an extremely powerful competitive inhibitor of eukaryotic S-adenosylmethionine decarboxylase, with an apparent Ki value 12 nM. Thus, it appears to be the most powerful known inhibitor of the enzyme, being almost an order of magnitude more powerful than the corresponding ethylglyoxal derivative. It neither inhibited the proliferation of mouse L1210 leukemia cells in vitro, nor did it potentiate the growth inhibition produced by alpha-difluoromethyl ornithine. In this respect, its properties are closely related to those of dimethylglyoxal, ethylglyoxal and propylglyoxal bis(guanylhydrazones), while in striking contrast to those of the antiproliferative glyoxal and methylglyoxal analogs. EMGBG also inhibited intestinal diamine oxidase activity (Ki 0.7 microM). EMGBG sulfate was crystallized from water, giving orthorhombic crystals (space group Pbcn). Their crystal and molecular structure was determined by X-ray diffraction methods. The carbon-nitrogen double bonds between the ethylmethylglyoxal part and the aminoguanidine moieties were found to have the same configuration as they are known to have in the salts of glyoxal, methylglyoxal and propylglyoxal bis(guanylhydrazones). The glyoxal bis(guanylhydrazone) chain of the EMGBG cation deviated strongly from planarity, thus differing dramatically from the corresponding chains of the glyoxal, methylglyoxal and propylglyoxal analogs.

CFA-4 - a fluorinated metal-organic framework with exchangeable interchannel cations.

Science.gov (United States)

Fritzsche, J; Grzywa, M; Denysenko, D; Bon, V; Senkovska, I; Kaskel, S; Volkmer, D

2017-05-23

The syntheses and crystal structures of the fluorinated linker 1,4-bis(3,5-bis(trifluoromethyl)-1H-pyrazole-4-yl)benzene (H 2 -tfpb; 1) and the novel metal-organic framework family M[CFA-4] (Coordination Framework Augsburg University-4), M[Cu 5 (tfpb) 3 ] (M = Cu(i), K, Cs, Ca(0.5)), are described. The ligand 1 is fully characterized by single crystal X-ray diffraction, photoluminescence-, NMR-, IR spectroscopy, and mass spectrometry. The copper(i)-containing MOF crystallizes in the hexagonal crystal system within the chiral space group P6 3 22 (no. 182) and the unit cell parameters are as follows: a = 23.630(5) Å, c = 41.390(5) Å, V = 20 015(6) Å 3 . M[CFA-4] features a porous 3-D structure constructed from pentanuclear copper(i) secondary building units {Cu(pz) 6 } - (pz = pyrazolate). Cu(I)[CFA-4] is fully characterized by synchrotron single crystal X-ray diffraction, thermogravimetric analysis, variable temperature powder X-ray diffraction, IR spectroscopy, photoluminescence and gas sorption measurements. Moreover, thermal stability and gas sorption properties of K[CFA-4] and Cu(I)[CFA-4] are compared.

Hydrothermal synthesis, crystal structures, and enantioselective adsorption property of bis(L-histidinato)nickel(II) monohydrate

Science.gov (United States)

Ramos, Christian Paul L.; Conato, Marlon T.

2018-05-01

Despite the numerous researches in metal-organic frameworks (MOFs), there are only few reports on biologically important amino acids, histidine in particular, on its use as bridging ligand in the construction of open-framework architectures. In this work, hydrothermal synthesis was used to prepare a compound based on Ni2+ and histidine. The coordination assembly of imidazole side chain of histidine with divalent nickel ions in aqueous condition yielded purple prismatic solids. Single crystal X-ray diffraction (XRD) analysis of the product revealed structure for Ni(C6H8N3O2)2 • H2O that has a monoclinic (C2) structure with lattice parameters, a = 29.41, b = 8.27, c = 6.31 Å, β = 90.01 ˚. Circular dichroism - optical rotatory dispersion (CD-ORD), Powder X-ray diffraction (PXRD) and Fourier transform - infrared spectroscopy (FT-IR) analyses are conducted to further characterize the crystals. Enantioselective adsorption analysis using racemic mixture of 2-butanol confirmed bis(L-histidinato)nickel(II) monohydrate MOF crystal's enantioselective property preferentially favoring the adsorption of (S)-2-butanol isomer.

Five new Zn(II) and Cd(II) coordination polymers constructed by 3,5-bis-oxyacetate-benzoic acid: Syntheses, crystal structures, network topologies and luminescent properties

Energy Technology Data Exchange (ETDEWEB)

Jiang Xianrong; Yuan Hongyan [Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, Zhejiang 321004 (China); Feng Yunlong, E-mail: sky37@zjnu.edu.cn [Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, Zhejiang 321004 (China)

2012-07-15

Five Zn(II) and Cd(II) coordination polymers, [Zn{sub 2}(BOABA)(bpp)(OH)]{center_dot}0.5H{sub 2}O (1), [Cd{sub 3}(BOABA){sub 2}(bpp){sub 2}(H{sub 2}O){sub 6}]{center_dot}2H{sub 2}O (2), [Cd{sub 3}(BOABA){sub 2}(2,2 Prime -bipy){sub 3}(H{sub 2}O){sub 4}]{center_dot}5.5H{sub 2}O (3), [CdNa(BOABA)(H{sub 2}O)]{sub 2}{center_dot}H{sub 2}O (4) and [Cd{sub 2}(BOABA)(bimb)Cl(H{sub 2}O){sub 2}]{center_dot}H{sub 2}O (5) (H{sub 3}BOABA=3,5-bis-oxyacetate-benzoic acid, bpp=1,3-bi(4-pyridyl)propane, 2,2 Prime -bipy=2,2 Prime -bipyridine, bimb=1,4-bis(imidazol-1 Prime -yl)butane), have been solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and TG analyses. 1 is an uninodal 4-connected 2D square grid network based on binuclear zinc clusters. 2 is 2D wavelike layer structure and further linked by hydrogen bonds into the final 3D (5,6,6)-connected topology network. 3 is 3-connected 2D topology network and the 2,2 Prime -bipy ligands decorate in two different types. 4 is a (4,8)-connected 2D topology network with heterocaryotic {l_brace}Cd{sub 2}Na{sub 2}{r_brace} clusters and BOABA{sup 3-} ligands. 5 can be rationalized as a (3,10)-connected 3D topology network with tetranuclear {l_brace}Cd{sub 4}Cl{sub 2}{r_brace} clusters and BOABA{sup 3-} ligands. Meanwhile, photoluminescence studies revealed that these five coordination polymers display strong fluorescent emission bands in the solid state at room temperature. - Graphical abstract: Five new d{sup 10} metal(II) coordination polymers based on H{sub 3}BOABA ligand were obtained and characterized. They display different topological structures and luminescent properties. Highlights: Black-Right-Pointing-Pointer Five d{sup 10} metal(II) polymers based on 3,5-bis-oxyacetate-benzoic acid were obtained. Black-Right-Pointing-Pointer The polymers were structurally characterized by single-crystal X-ray diffraction. Black-Right-Pointing-Pointer Polymers 1-5 display different

Pharmacokinetic behaviour of phenylglyoxal bis(guanylhydrazone) (PGBG) after intravenous administration in rabbits.

Science.gov (United States)

Rodríguez, C; San Andrés, M I; San Andrés, M D; Encinas, T; González, F; Ballesteros, E

2001-04-01

Phenylglyoxal bis(guanylhydrazone) (PGBG) is a synthesized analogue of methylglyoxal bis(guanylhydrazone) (MGBG), which has demonstrated anti-parasitic activity in rabbits. The pharmacokinetic behaviour of PGBG after intravenous administration (10 mg/kg bodyweight) was studied in five rabbits. Plasma concentrations of PGBG were measured by high-performance liquid chromatography. Plasma PGBG concentrations decreased rapidly and were not detectable beyond 90 min after treatment. The mean [+/- standard deviation (SD)] volume of distribution at steady state (Vdss) was 2.19 +/- 0.47 l/kg and the mean plasma clearance value (Cl) was 29.99 +/- 3.98 ml/min kg. This drug is rapidly eliminated from the body in rabbits, having a short elimination half-life (0.93 h) and mean residence time (1.21 h).

Fluorimetric determination of yttrium by methyl-bis(8-hydraxy--- 2-quinolyl)amine

International Nuclear Information System (INIS)

Golovina, A.P.; Kachin, S.V.; Runov, V.K.; Fakeeva, O.A.

1982-01-01

Using a method of mathematical Box-Wilson experiment planning the optimum conditions of yttrium fluorimetric determination by methyl-bis (8-hydroxy-2-quinolyl) amine (pH 7.5, csub(R)=1.4x10sup(-5) M) with the determination limit=0.05 μg/ml are found. An extraction-fluorimetric method of yttrium determination by methyl-bis (8-hydroxy-2-quinolyl) amine is developed. The extraction has been realized with aliphatic alcohols at pH > 11. The method is characteristic of the lowest determination limit (0.01 μg/ml) as compared with the known ones. The possibility is shown of yttrium determination in the presence of 5000-multiple aluminium contents, stoichiometric contents of La, Lu, Fe (3), U (6), tartrates, citrates

One-pot, Facile Synthesis of Quinoxaline Derivatives from Bis-aryl a ...

African Journals Online (AJOL)

NICO

Bis-aryl a-Hydroxyketones and o-Arenediamines using. KMnO. 4. /CuSO. 4 ... Faculty of Chemistry, Bu-Ali Sina University, Hamedan 65174, Iran. Received 31 ... cent materials,6 organic semiconductors,7 building blocks for the synthesis of ...

Ionochromic effects and structures of metalated poly(p-phenylenevinylene) polymers incorporating 2,2'-bipyridines

International Nuclear Information System (INIS)

Chen, L.X.; Jager, W.J.H.; Gosztola, D.J.; Niemczyk, M.P.; Wasielewski, M.R.

2000-01-01

The effects of metal ion chelation to the 2,2'-bipyridine (bpy) groups on the photophysics and exciton dynamics of two conjugated polymers 1 and 2 in solution are investigated. The structures of polymers 1 and 2 have 2,2'-bipyridyl-5-vinylene units that alternate with one and three 2,5-bis(n-decyloxy)-1,4-phenylenevinylene monomer units, respectively. The photophysics and exciton dynamics of metalated polymers 1 and 2 are compared to those of the metal-free polymers (Chen et al. J. Phys. Chem. A 1999, 103, 4341-4351). The origins of ionochromic effects due the metal ion chelation were studied using both steady-state and transient optical spectroscopy, and the results indicate that both conformational flattening and participation of Jr electrons from the metal in the π-conjugation of the polymer backbone play important roles in metal ion binding induced red shifts in absorption and photoluminescence spectra. The photoluminescence properties of the metalated polymers are determined by the metal ion electronic structures, where the closed shell Zn 2+ -bound polymer 2 has an increased photoluminescence quantum yield and the corresponding open shell Ni 2+ - or Fe 3+ -bound polymers have quenched photoluminescence due to spin-orbit coupling. The dual character of metalated polymer 2 as a conjugated polymer and as a metal-bpy complex is discussed. In addition, the structures of metal ion binding sites are studied via X-ray absorption fine structure (XAFS) and are related to the photophysical properties of the metalated polymers

Ligand and Metal Based Multielectron Redox Chemistry of Cobalt Supported by Tetradentate Schiff Bases.

Science.gov (United States)

Andrez, Julie; Guidal, Valentin; Scopelliti, Rosario; Pécaut, Jacques; Gambarelli, Serge; Mazzanti, Marinella

2017-06-28

We have investigated the influence of bound cations on the reduction of cobalt complexes of redox active ligands and explored the reactivity of reduced species with CO 2 . The one electron reduction of [Co II ( R salophen)] with alkali metals (M = Li, Na, K) leads to either ligand-centered or metal-centered reduction depending on the alkali ion. It affords either the [Co I ( R salophen)K] complexes or the [Co II 2 (bis-salophen)M 2 ] (M = Li, Na) dimers that are present in solution in equilibrium with the respective [Co I (salophen)M] complexes. The two electron reduction of [Co II ( OMe salophen)] results in both ligand centered and metal centered reduction affording the Co(I)-Co(II)-Co(I) [Co 3 (tris- OMe salophen)Na 6 (THF) 6 ], 6 complex supported by a bridging deca-anionic tris- OMe salophen 10- ligand where three OMe salophen units are connected by two C-C bonds. Removal of the Na ion from 6 leads to a redistribution of the electrons affording the complex [(Co( OMe salophen)) 2 Na][Na(cryptand)] 3 , 7. The EPR spectrum of 7 suggests the presence of a Co(I) bound to a radical anionic ligand. Dissolution of 7 in pyridine leads to the isolation of [Co I 2 (bis- OMe salophen)Na 2 Py 4 ][Na(cryptand)] 2 , 8. Complex 6 reacts with ambient CO 2 leading to multiple CO 2 reduction products. The product of CO 2 addition to the OMe salophen ligand, [Co( OMe salophen-CO 2 )Na] 2 [Na(cryptand)] 2 , 9, was isolated but CO 3 2- formation in 53% yield was also detected. Thus, the electrons stored in the reversible C-C bonds may be used for the transformation of carbon dioxide.

Bis-ligated Ti and Zr complexes of chelating N-heterocyclic carbenes

KAUST Repository

El-Batta, Amer; Waltman, Andrew W.; Grubbs, Robert H.

2011-01-01

In this communication we report the synthesis of novel titanium and zirconium complexes ligated by bidentate "salicylaldimine-like" N-heterocyclic carbenes (NHC). Double addition of the NHC chelate to either TiCl4(thf)2 or ZrCl4 forms bis

Degradation of bis- p -nitrophenyl phosphate using zero-valent iron nanoparticles

International Nuclear Information System (INIS)

Valle-Orta, Maiby; Guerrero, Rubén Saldivar; Díaz, David; Dubé, Inti Zumeta; Quiñonez, José Luis Ortiz

2017-01-01

Phosphate esters are employed in some agrochemical formulations and have long life time in the Environment. They are neurotoxic to mammals and it is very difficult to hydrolyze them. It is easy to find papers in the literature dealing with transition metal complexes used in the hydrolysis processes of organophosphorous compounds. However, there are few reports related with degradation of phosphate esters with inorganic nanoparticles. In this work bis-4-nitrophenyl phosphate (BNPP) was used as an agrochemical agent model. The BNPP interaction with zero-valent iron nanoparticles (ZVI NPs), in aqueous media, was searched. The concentration of BNPP was 1000 times higher than the ZVI NPs concentration. The average size of the used iron nanoparticles was 10.2 ± 3.2 nm. The BNPP degradation process was monitored by means of UV-visible method. Initially, the BNPP hydrolysis happens through the P-O bonds breaking-off under the action of the ZVI NPs. Subsequently, the nitro groups were reduced to amine groups. The overall process takes place in 10 minutes. The reaction products were identified employing standard substances in adequate concentrations. The iron by-products were isolated and characterized by X-RD. These iron derivatives were identified as magnetite (Fe 3 O 4 ) and/or maghemite (γ-Fe 2 O 3 ) and lepidocrocite (γ-FeOOH). A suggested BNPP degradation mechanism will be discussed. (paper)

Tax penalty payment and the “non bis in idem” principle

Directory of Open Access Journals (Sweden)

Marie Karfíková

2017-01-01

Full Text Available The subject. This paper deals with problems related to tax law with a special focus on legalregulation of the tax procedure contained in the Czech Tax Procedure Code. Attention ispaid in particular to tax penalty payments and the “non bis in idem” principle.The purpose to identify ratio between penalty payments in tax procedure and in criminalprocedure in context of “non bis in idem” principle.The methodological basis of the article is analysis of legislation and court practice of Czechrepublic, Austria, European Union, including formal legal analysis, comparative analysis,synthesis, systematic approach.The results and scope of application. The existing case law of the Czech criminal courts andof the Supreme Court was based on the legal opinion that a penalty payment imposed bythe tax administration in a tax procedure constitutes no punishment, i.e. it is no sanction ofcriminal nature, so that even the final (enforceable decision of the tax administration doesnot create a “ne bis in idem”1 barrier in relation to criminal sanctions for the same taxesrelatednon-compliant action (tax evasion in respect of the penalty payment imposed bythe tax administration.Conclusions. It would probably be advisable for the legislation to amend the relevant provisionsof the Tax Procedure Code in a way that the tax authorities concentrate within thelimits of their powers on proper tax collection and that the law enforcement authorities areauthorized to punishments for deliberate tax evasion. A suggested amendment may thereforebe the removal of the penalty payments from the Tax Procedure Code as the defaultinterest itself is sufficient instrument enough to penalize the taxpayers. Another option is to keep the tax penalty payment in the Tax Procedure Code, but its imposition would only be considered after making sure that the result of any criminal proceedings does not constitute a “ne bis in idem” prohibition within the meaning of Art. 40 (5 of the

Comparative Study of Structure-Property Relationships in Polymer Networks Based on Bis-GMA, TEGDMA and Various Urethane-Dimethacrylates

Directory of Open Access Journals (Sweden)

Izabela Barszczewska-Rybarek

2015-03-01

Full Text Available The effect of various dimethacrylates on the structure and properties of homo- and copolymer networks was studied. The 2,2-bis-[4-(2-hydroxy-3- methacryloyloxypropoxyphenyl]-propane (Bis-GMA, triethylene glycol dimethacrylate (TEGDMA and 1,6-bis-(methacryloyloxy-2-ethoxycarbonylamino-2,4,4-trimethylhexane (HEMA/TMDI, all popular in dentistry, as well as five urethane-dimethacrylate (UDMA alternatives of HEMA/TMDI were used as monomers. UDMAs were obtained from mono-, di- and tri(ethylene glycol monomethacrylates and various commercial diisocyanates. The chemical structure, degree of conversion (DC and scanning electron microscopy (SEM fracture morphology were related to the mechanical properties of the polymers: flexural strength and modulus, hardness, as well as impact strength. Impact resistance was widely discussed, being lower than expected in the case of poly(UDMAs. It was caused by the heterogeneous morphology of these polymers and only moderate strength of hydrogen bonds between urethane groups, which was not high enough to withstand high impact energy. Bis-GMA, despite having the highest polymer morphological heterogeneity, ensured fair impact resistance, due to having the strongest hydrogen bonds between hydroxyl groups. The TEGDMA homopolymer, despite being heterogeneous, produced the smoothest morphology, which resulted in the lowest brittleness. The UDMA monomer, having diethylene glycol monomethacrylate wings and the isophorone core, could be the most suitable HEMA/TMDI alternative. Its copolymer with Bis-GMA and TEGDMA had improved DC as well as all the mechanical properties.

Bis[N-(3-aminopropylpropane-1,3-diamine-κ3N,N′,N′′]cadmium nitrate perchlorate

Directory of Open Access Journals (Sweden)

Václav Eigner

2012-03-01

Full Text Available The title complex, [Cd(C6H17N32](ClO4(NO3, was synthesized by the reaction of Cd(NO32·4H2O, bis(3-aminopropylamine and sodium perchlorate in methanol. The asymmetric unit of the title complex consists of one Cd2+ cation, two tridentate bis(3-aminopropylamine ligands, one nitrate anion and one perchlorate anion. The Cd2+ cation is coordinated by six N atoms of the bis(3-aminopropylamine ligands in a slightly distorted octahedral coordination geometry. In the crystal, molecules are held together by an intricate network of N—H...O interactions. One of the two amine ligands was found to be disordered over two sets of sites, with a ratio of 0.802 (3:0.198 (3, similarly to the nitrate anion, with a ratio of 0.762 (10:0.238 (10.

Thermal studies on a mechanical prototype of A BIS MDT chamber

CERN Document Server

Petridou, C; Wotschack, J; Zisis, A

1998-01-01

The deformations of a BIS MDT chamber owing to temperature gradients between the two multilayers and between the two Faraday cages were studied on a mechanical prototype. The influence of thermal insulation on the thermal behaviour of the chamber is also reported.

Adhesion of Streptococcus Mutans to Glass Ionomer, BisCem Cement and Enamel: An In Vitro Study

Directory of Open Access Journals (Sweden)

Ezzatollah Jalalian

2016-05-01

Full Text Available Objectives: Considering the adhesion of some microorganisms such as Streptococcus mutans (S. mutans to restorative materials and the unrecognized consequences of this phenomenon, and due to the controversies in this regard, it is important to discover the materials to which the lowest adhesion of S. mutans occurs. The objective of this study was to assess the level of adhesion of S. mutans to glass ionomer (GI, BisCem Cement and enamel.Materials and Methods:In this in vitro experimental study, 12 specimens including five GI blocks (GC America Inc., Alsip, IL, USA, five BisCem blocks (Bisco Inc., Schaumburg, IL, USA and two enamel blocks were exposed to a bacterial suspension (1×106 mg/mL. After incubation for one hour at 37˚C, the swab samples were taken and cultured in blood agar. The S. mutans colonies were counted by unaided vision after 48 hours of incubation. The results were analyzed using ANOVA followed by the Tukey’s test.Results:The number of colonies attributed to enamel, GI, and BisCem blocks was 24±2, 24.2±2.7 and 14.8±1.7 colonies/mm2, respectively. There was no difference between enamel and GI in terms of adhesion of S. mutans (P=0.08 and P>0.001, respectively; however, the difference between these two and BisCem was statistically significant (P= 0.00075 and P<0.001, respectively.Conclusion:Within the limitations of this study, BisCem cement is superior to GI for the cementation of indirect restorations.  Normal 0 false false false EN-US JA AR-SA Modulation of the conflict monitoring intensity: the role of aversive reinforcement, cognitive demand, and trait-BIS.

Science.gov (United States)

Leue, Anja; Lange, Sebastian; Beauducel, André

2012-06-01

According to Botvinick's (2007) integrative account, conflict monitoring is aversive because individuals anticipate cognitive demand, whereas the revised reinforcement sensitivity theory (rRST) predicts that conflict processing is aversive because individuals anticipate aversive reinforcement of erroneous responses. Because these accounts give different reasons for the aversive aspects of conflict, we manipulated cognitive demand and the aversive reinforcement as a consequence of wrong choices in a go/no-go task. Thereby, we also aimed to investigate whether individual differences in conflict sensitivity (i.e., in trait anxiety, linked to high sensitivity of the behavioral inhibition system [trait-BIS]) represent the effects of aversive reinforcement and cognitive demand in conflict tasks. We expected that these manipulations would have effects on the frontal N2 component representing activity of the anterior cingulate cortex. Moreover, higher-trait-BIS individuals should be more sensitive than lower-trait-BIS individuals to aversive effects in conflict situations, resulting in a more negative frontal N2 for higher-trait-BIS individuals. In Study 1, with N = 104 students, and Study 2, with N = 47 students, aversive reinforcement was manipulated in three levels (within-subjects factor) and cognitive demand in two levels (between-subjects factor). The behavioral findings from the go/no-go task with noncounterbalanced reinforcement levels (Study 1) could be widely replicated in a task with counterbalanced reinforcement levels (Study 2). The frontal mean no-go N2 amplitude and the frontal no-go N2 dipole captured predicted reinforcement-related variations of conflict monitoring, indicating that the anticipation of aversive reinforcement induces variations in conflict monitoring intensity in frontal brain areas. The aversive nature of conflict was underlined by the more pronounced conflict monitoring in higher- than in lower-trait-BIS individuals.

Next-generation bis-locked nucleic acids with stacking linker and 2'-glycylamino-LNA show enhanced DNA invasion into supercoiled duplexes

DEFF Research Database (Denmark)

Geny, Sylvain; Moreno, Pedro M D; Krzywkowski, Tomasz

2016-01-01

Targeting and invading double-stranded DNA with synthetic oligonucleotides under physiological conditions remain a challenge. Bis-locked nucleic acids (bisLNAs) are clamp-forming oligonucleotides able to invade into supercoiled DNA via combined Hoogsteen and Watson-Crick binding. To improve the b...

Layer silicates modified with 1,4-bis(3-aminopropyl)piperazine for the removal of Th(IV), U(VI) and Eu(III) from aqueous media

International Nuclear Information System (INIS)

Guerra, Denis L.; Pinto, Alane A.; Viana, Rubia R.; Airoldi, Claudio

2009-01-01

Natural montmorillonite (M) and synthetic kanemite (K) have been functionalized with 1,4-bis(3-aminopropyl)piperazine reacted with methylacrylate to yield new inorganic-organic chelating materials. The original and modified materials were characterized by X-ray diffractometry, textural analysis, SEM and nuclear magnetic nuclei of carbon-13 and silicon-29. The chemically modified clay samples (M-APPMA and K-APPMA) showed modification of its physical-chemical properties including: specific area 45.0 m 2 g -1 (M) to 978.8 m 2 g -1 (M-APPMA) and 23.5 m 2 g -1 (K) to 898.9 m 2 g -1 (K-APPMA). The ability of these materials to remove thorium(IV), uranyl(VI) and europium(III) from aqueous solution was followed by a series of adsorption isotherms, which were fitted to non-linear Sips adsorption isotherm model. To achieve the best adsorption conditions the influence of pH and variation of metal concentration were investigated. The energetic effects (Δ int H o , Δ int G o and Δ int S o ) caused by metal ions adsorption were determined through calorimetric titrations.

[Karin Hallas. Das Tallinner Mietshaus. Vom Historismus bis zum Jugendstil] / Paul Kaegbein

Index Scriptorium Estoniae

Kaegbein, Paul

2006-01-01

Arvustus: Karin Hallas. Das Tallinner Mietshaus. Vom Historismus bis zum Jugendstil. In: Architektur und bildende Kunst im Baltikum um 1900. Frankfurt am Main, Berlin, Bern, Bruxelles, New York, Wien: Lang 1999. S. 173-192.

Approaches to lung cancer treatment using the CD3E x GP-2-directed bispecific monoclonal antibody BIS-1

NARCIS (Netherlands)

Kroesen, BJ; Nieken, J; Sleijfer, DT; Molema, G; deVries, EGE; Groen, HJM; Helfrich, W; The, TH; Mulder, NH; deLeij, L

1997-01-01

The bispecific monoclonal antibody (bsAb) BIS-1 combines a monoclonal-antibody(mAb)-defined specificity for the CD3 complex, as present on all T lymphocytes, with a mAb-defined specificity for the pancarcinoma/epithelium associated glycoprotein EGP-2. In vitro studies indicate that BIS-1 can direct

Diminished excretion of polyamines from BHK-21/C13 cells exposed to methylglyoxal bis(guanylhydrazone).

Science.gov (United States)

Melvin, M A; Keir, H M

1978-01-01

Methylglyoxal bis(guanylhydrazone) (1,1'-[methylethanediylidine)dinitrilo]diguanidine) inhibited the growth of BHK-21/C13 cells in monolayer cultures. Accumulation of spermidine and spermine was inhibited, whereas the accumulation of putrescine was increased. The intracellular spermidine/spermine molar ratio decreased conly slightly after exposure of the cells to 20 micrometer-methylglyoxal bis(guanylhydrazone) for 1 day. Cells incubated in the presence of the drug released less polyamine into the culture medium that did control cells, the polyamine released consisting almost exclusively of spermidine, both free and as a conjugated form. PMID:697761

Translation and cultural adaptation of Barratt Impulsiveness Scale (BIS-11) for administration in Brazilian adults

OpenAIRE

Malloy-Diniz, Leandro Fernandes; Mattos, Paulo; Leite, Wellington Borges; Abreu, Neander; Coutinho, Gabriel; Paula, Jonas Jardim de; Tavares, Hermano; Vasconcelos, Alina Gomide; Fuentes, Daniel

2010-01-01

OBJETIVOS: Os objetivos deste estudo foram traduzir, adaptar culturalmente e verificar a equivalência literal, semântica e idiomática da Barratt Impulsiveness Scale (BIS-11), que avalia a presença de manifestações da impulsividade tendo como base o modelo teórico proposto por Ernst Barratt. MÉTODOS: Inicialmente, a versão original em inglês da BIS-11 foi traduzida para o português por seis pesquisadores bilíngues. Em seguida, foi realizada uma tradução reversa para o inglês por uma tradutora ...

Bis-spirochromanones as potent inhibitors of Mycobacterium tuberculosis: synthesis and biological evaluation.

Science.gov (United States)

Dongamanti, Ashok; Aamate, Vikas Kumar; Devulapally, Mohan Gandhi; Gundu, Srinivas; Balabadra, Saikrishna; Manga, Vijjulatha; Yogeeswari, Perumal; Sriram, Dharmarajan; Balasubramanian, Sridhar

2017-11-01

On the basis of reported antimycobacterial property of chroman-4-one pharmacophore, a series of chemically modified bis-spirochromanones were synthesized starting from 2-hydroxyacetophenone and 1,4-dioxaspiro[4.5] decan-8-one using a Kabbe condensation approach. The synthesized bis-spirochromanones were established based on their spectral data and X-ray crystal structure of 6e. All synthesized compounds were evaluated against Mycobacterium tuberculosis H37Rv (ATCC 27294) strain, finding that some products exhibited good antimycobacterial activity with minimum inhibitory concentration as low as [Formula: see text]. Docking studies were carried out to identify the binding interactions of compounds II, 6a and 6n with FtsZ. Compounds exhibiting good in vitro potency in the MTB MIC assay were further evaluated for toxicity using the HEK cell line.

Bis(pyrrolo)tetrathiafulvalene - An Efficient Pi-Donor in Supramolecular Chemistry

DEFF Research Database (Denmark)

Lau, Jesper; Nielsen, Mogens Brøndsted; Thorup, Niels

1999-01-01

The synthesis of three novel macrocycles 3-5 based on the two electron donors bis(2,5-dimethyl- pyrrolo)[3,4-d]tetrathiafulvalene (1) and 1,4-hydroquinone is presented. Their abilities to include the electron acceptor paraquat (6) have been investigated by UV/Vis and sup 1 H NMR spectroscopy and ...

The differences of saliva pH before and after application of Bis-GMA resin based-pit and fissure sealant

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Ayub Irmadani Anwar

2016-06-01

Full Text Available Pit and fissure sealant applications is one way to prevent caries. One of the effective ingredient as a pit and fissure sealant is a Bis-GMA resin. One of the active components  of  Bis-GMA  resin  is  sodium  fluoride,  which is capable  of releasing fluoride ions to the tooth surface and able to improve the repair and remineralization process through the replacement  of  calcium and phosphate ions found in saliva to increase the pH of saliva. This study was to determine the effect of pit and fissure sealant applications made from Bis-GMA resin to pH of saliva in children aged 6-12 years. The study design is pre and post test with control group design. Saliva samples were derived from 15 pediatric patients has met the criteria. The pH of saliva were taken before and after the application of pit and fissure sealant made from Bis-GMA and measured with pH meter. This study used a non-parametric test, the Wilcoxon Signed Rank test. The results of this study are also supported by the results of statistical tests showed p-: 0.005 (p<0.05 value, which means that there are significant differences in pH of saliva before and after the application of pit and fissure sealant made from Bis-GMA resin.

Crystal structures of bis(phenoxysilicon phthalocyanines: increasing π–π interactions, solubility and disorder and no halogen bonding observed

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Benoît H. Lessard

2016-07-01

Full Text Available We report the syntheses and characterization of three solution-processable phenoxy silicon phthalocyanines (SiPcs, namely bis(3-methylphenoxy(phthalocyaninesilicon [(3MP2-SiPc], C46H30N8O2Si, bis(2-sec-butylphenoxy(phthalocyaninesilicon [(2secBP2-SiPc], C44H24I2N8O2Si, and bis(3-iodophenoxy(phthalocyaninesilicon [(3IP2-SiPc], C52H42N8O2Si. Crystals grown of these compounds were characterized by single-crystal X-ray diffraction and the π–π interactions between the aromatic SiPc cores were studied. It was determined that (3MP2-SiPc has similar interactions to previously reported bis(3,4,5-trifluorophenoxysilicon phthalocyanines [(345 F2-SiPc] with significant π–π interactions between the SiPc groups. (3IP2-SiPc and (2secBP2-SiPc both experienced a parallel stacking of two of the peripheral aromatic groups. In all three cases, the solubility of these molecules was increased by the addition of phenoxy groups while maintaining π–π interactions between the aromatic SiPc groups. The solubility of (2secBP2-SiPc was significantly higher than other bis-phenoxy-SiPcs and this was exemplified by the higher observed disorder within the crystal structure.

Superconductivity in REO0.5F0.5BiS2 with high-entropy-alloy-type blocking layers

Science.gov (United States)

Sogabe, Ryota; Goto, Yosuke; Mizuguchi, Yoshikazu

2018-05-01

We synthesized new REO0.5F0.5BiS2 (RE: rare earth) superconductors with high-entropy-alloy-type (HEA-type) REO blocking layers. The lattice constant a systematically changed in the HEA-type samples with the RE concentration and the RE ionic radius. A sharp superconducting transition was observed in the resistivity measurements for all the HEA-type samples, and the transition temperature of the HEA-type samples was higher than that of typical REO0.5F0.5BiS2. The sharp superconducting transition and the enhanced superconducting properties of the HEA-type samples may indicate the effectiveness of the HEA states of the REO blocking layers in the REO0.5F0.5BiS2 system.

77 FR 66951 - Proposed Information Collection; Comment Request; BIS Program Evaluation

Science.gov (United States)

2012-11-08

... feedback from seminar participants. This information helps BIS determine the effectiveness of its programs... collection). Affected Public: Business or other for-profit organizations. Estimated Number of Respondents: 3... Total Annual Cost to Public: $0. IV. Request for Comments Comments are invited on: (a) Whether the...

Gold(III) bis(thiosemicarbazonate) compounds in breast cancer cells: Cytotoxicity and thioredoxin reductase targeting.

Science.gov (United States)

Rodríguez-Fanjul, Vanessa; López-Torres, Elena; Mendiola, M Antonia; Pizarro, Ana María

2018-03-25

Gold(III) compounds have received increasing attention in cancer research. Three gold complexes of general formula [Au III L]Cl, where L is benzil bis(thiosemicarbazonate), compound 1, benzil bis(4-methyl-3-thiosemicarbazonate), compound 2, or benzil bis(4-cyclohexyl-3-thiosemicarbazonate), compound 3, have been synthesized and fully characterized, including the X-ray crystal structure of compound 3, confirming square-planar geometry around the gold(III) centre. Compound 1 showed moderate cytotoxicity and accumulation in MCF7 breast cancer cells but did not inhibit thioredoxin reductase (TrxR) activity and did not induce reactive oxygen species (ROS) production. Compound 2, the least cytotoxic, was found to be capable of modestly inhibiting TrxR activity and produced low levels of ROS in the MCF7 cell line. The most cytotoxic compound, 3, had the highest cellular accumulation and its distribution pattern showed a clear preference for the cytosol and mitochondria of MCF7 cells. It readily hampered intracellular TrxR activity leading to a dramatic alteration of the cellular redox state and to the induction of cell death. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Preoperative and postoperative agreement in fat free mass (FFM) between bioelectrical impedance spectroscopy (BIS) and dual-energy X-ray absorptiometry (DXA) in patients undergoing cardiac surgery.

Science.gov (United States)

van Venrooij, Lenny M W; Verberne, Hein J; de Vos, Rien; Borgmeijer-Hoelen, Mieke M M J; van Leeuwen, Paul A M; de Mol, Bas A J M

2010-12-01

To measure undernutrition in terms of fat free mass (FFM), there are several options. The aim of this study was to assess agreement in FFM between the portable, bedside bioelectrical impedance spectrometry (BIS) and relatively expensive, non-portable dual-energy X-ray absorptiometry (DXA) in patients undergoing cardiac surgery. In a prospective study, body composition measurements by BIS and DXA were performed two weeks prior and two months after cardiac surgery. Preoperative and postoperative agreement in FFM between BIS and DXA were analyzed with Bland and Altman plots. Twenty-six patients were analyzed. BIS overestimated preoperative and postoperative FFM by 2 kg compared to DXA (2.3 kg (95%CI: -3.5-8.1 kg) and 2.1 kg (95%CI: -4.5-8.7 kg), respectively). BIS underestimated FFM change by -0.5% (95%CI: -8.4-7.5%). There is a large inter-individual variation between BIS and DXA. This hinders the interchange-ability of BIS and DXA in routine clinical practice and may lead to misclassifications and thereby inappropriate nutritional treatment and possible postoperative complications. To evaluate nutritional therapy in patients undergoing cardiac surgery, we advocate the use of DXA assessed FFM in parallel to BIS assessed extracellular and intracellular water and FFM. Copyright © 2010 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Carnitine prevents the early mitochondrial damage induced by methylglyoxal bis(guanylhydrazone) in L1210 leukaemia cells.

Science.gov (United States)

Nikula, P; Ruohola, H; Alhonen-Hongisto, L; Jänne, J

1985-06-01

We previously found that the anti-cancer drug methylglyoxal bis(guanylhydrazone) (mitoguazone) depresses carnitine-dependent oxidation of long-chain fatty acids in cultured mouse leukaemia cells [Nikula, Alhonen-Hongisto, Seppänen & Jänne (1984) Biochem. Biophys. Res. Commun. 120, 9-14]. We have now investigated whether carnitine also influences the development of the well-known mitochondrial damage produced by the drug in L1210 leukaemia cells. Palmitate oxidation was distinctly inhibited in tumour cells exposed to 5 microM-methylglyoxal bis(guanylhydrazone) for only 7 h. Electron-microscopic examination of the drug-exposed cells revealed that more than half of the mitochondria were severely damaged. Similar exposure of the leukaemia cells to the drug in the presence of carnitine not only abolished the inhibition of fatty acid oxidation but almost completely prevented the drug-induced mitochondrial damage. The protection provided by carnitine appeared to depend on the intracellular concentration of methylglyoxal bis(guanylhydrazone), since the mitochondria-sparing effect disappeared at higher drug concentrations.

An efficient and facile synthesis of divergent C-3/C-5 bis ...

Indian Academy of Sciences (India)

extensive attention in organic synthesis and also serve as potential synthons for the ... plays an important role in synthetic chemistry, because they also serve as ...... scope, rate acceleration and selective formation of bis-. MBH adduct with ...

μ-Oxalato-bis[(2,2′-bipyridylcopper(II] bis(perchlorate dimethylformamide disolvate monohydrate

Directory of Open Access Journals (Sweden)

Alexander N. Boyko

2010-09-01

Full Text Available The title compound, [Cu2(C2O4(C10H8N24](ClO42·2C3H7NO·H2O, contains doubly charged centrosymmetric dinuclear oxalato-bridged copper(II complex cations, perchlorate anions, and DMF and water solvate molecules. In the complex cation, the oxalate ligand is coordinated in a bis-bidentate bridging mode to the Cu atoms. Each Cu atom has a distorted tetragonal-bipyramidal environment, being coordinated by two N atoms of the two chelating bipy ligands and two O atoms of the doubly deprotonated oxalate anion. Pairs of perchlorate anions and water molecules are linked into rectangles by O—H...O bonds in which the perchlorate O atoms act as acceptors and the water molecules as donors. Methyl groups of the DMF solvent molecule are disordered over two sites with occupancies of 0.453 (7:0.547 (7, and the water molecule is half-occupied.

Synthesis, Characterization and Antibacterial Activity of Novel 1,3-Diethyl-1,3-bis(4-nitrophenylurea and Its Metal(II Complexes

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Hoda Pasdar

2017-12-01

Full Text Available A bioactive ligand and its dinuclear metal(II complexes were synthesized and characterized by Fourier-transform infrared spectroscopy (FT-IR, ultraviolet-visible (UV-Visible, nuclear magnetic resonance (1H-NMR, mass spectroscopy and molar conductance measurements. The ligand has been crystalized in the monoclinic system with a P21/c space group. The biological activities of metal complexes were evaluated using disc diffusion and broth dilution methods. In vitro antibacterial activities of the ligand and their metal complexes were examined against two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus and two Gram-negative bacteria (Escherichia coli and Serratia marcescens and compared to the standard drugs. It was found that metal complexes displayed much higher antibacterial activities and better inhibitory effects than that of the ligand and standard drugs. Among these complexes, the compound having Zn-metal showed greater antibacterial activity against all four tested bacteria and was more effective against Serratia marcescens with the zone inhibition diameter of 26 mm and MIC value of 31.25 µg/mL.

4,4’-Bis(4-octylphenoxy)-2,2’-bipyridine

OpenAIRE

Zhen-Ting Du; Jun-Ru Wang; Ru Liu; Yan Xu

2009-01-01

4,4’-Bis(4-octylphenoxy)-2,2’-bipyridine which can be used in complexes of ruthenium was synthesized. This ligand bears a long chain for the purpose of increasing the solubility of the final complex. The synthesis was achieved through a nucleophilic aromatic substitution reaction of 4,4’-bromo-2,2’-bipyridine and 4-octylphenol.

Polymerization of methyl methacrylate by diphenylamido bis (methylcyclopentadienyl) ytterbium complex

Institute of Scientific and Technical Information of China (English)

WANG, Yao-Rong(王耀荣); SHEN, Qi(沈琪); MA, Jia-Le(马家乐); ZHAO, Qun(赵群)

2000-01-01

Methyl methacrylate (MMA) was effectively polymerized by diphenylamido bis(methyicyclopentadienyl) ytterbium complex (MeCp)2YbNPh2(THF). Tne reaction can be carried out over a range of polymerization temperature from - 40℃ to 40℃ and gives the polyMMA with high molecular weights.The initiation mechanism was demonstrated by diphenylamidoterminated methyl methacrylate oligomer.

Piperidinium tethered nanoparticle-hybrid electrolyte for lithium metal batteries

KAUST Repository

Korf, Kevin S.

2014-06-23

We report on the synthesis of novel piperidinium-based ionic liquid tethered nanoparticle hybrid electrolytes and investigate their physical and electrochemical properties. Hybrid electrolytes based on the ionic liquid 1-methyl-1-propylpiperidinium bis(trifluoromethanesulfone) imide covalently tethered to silica nanoparticles (SiO2-PP-TFSI) were blended with propylene carbonate-1 M lithium bis(trifluoromethanesulfone) imide (LiTFSI). We employed NMR analysis to confirm the successful creation of the hybrid material. Dielectric and rheological measurements show that these electrolytes exhibit exceptional room-temperature DC ionic conductivity (10-2 to 10 -3 S cm-1) as well as high shear mechanical moduli (105 to 106 Pa). Lithium transference numbers were found to increase with particle loading and to reach values as high as 0.22 at high particle loadings where the particle jam to form a soft glassy elastic medium. Analysis of lithium electrodeposits obtained in the hybrid electrolytes using SEM and EDX spectra show that the SiO2-PP-TFSI nanoparticles are able to smooth lithium deposition and inhibit lithium dendrite proliferation in Li metal batteries. LTOSiO2-PP-TFSI/PC in 1 M LiTFSILi half-cells based on the SiO2-PP-TFSI hybrid electrolytes exhibit attractive voltage profiles and trouble-free extended cycling behavior over more than 1000 cycles of charge and discharge. This journal is © the Partner Organisations 2014.

Low Band Gap Donor–Acceptor Type Polymers Containing 2,3-Bis(4-(decyloxyphenylpyrido[4,3-b]pyrazine as Acceptor and Different Thiophene Derivatives as Donors

Directory of Open Access Journals (Sweden)

Yan Zhang

2016-10-01

Full Text Available Four donor–acceptor type conducting polymers, namely poly(2,3-bis(4-decyloxyphenyl-5,8-bis(4-thiophen-2-ylpyrido[4,3-b]pyrazine (P1, poly(2,3-bis(4-decyloxyphenyl-5,8-bis(4-butylthiophen-2-ylpyrido[4,3-b]pyrazine (P2, poly(2,3-bis(4-(decyloxyphenyl-5,8-bis(4-hexyloxythiophen-2-ylpyrido[4,3-b]pyrazine (P3 and poly(2,3-bis(4-(decyloxyphenyl-5,8-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-7-ylpyrido[4,3-b]pyrazine (P4, containing thiophene or its derivative as the donor and pyrido[4,3-b]pyrazine as the acceptor were prepared and characterized by cyclic voltammetry, scanning electron microscopy, and UV-Vis spectroscopy to detect the influence of the donor units’ strength on the electrochromic performances. The results demonstrated that all of the polymers could be reversibly reduced and oxidized by p-type doping and n-type doping, and showed near-infrared activities and different color changes in p-type doping process. Especially, P3 and P4 showed lower optical band gap than P1 and P2 due to the strong electron-donating hexyloxythiophen group of P3 and ethylenedioxythiophene group of P4. Besides, P3 and P4 displayed the saturated green color at the neutral state and the desirable transparency at the oxidized state. All the polymers displayed desirable optical contrasts, satisfactory coloration efficiency, excellent stability and short switching time, which made the polymers fascinating candidates in the electrochromic device applications.