Synthesis, crystal structure and thermal decomposition mechanism of the complex [Sm(p-BrBA)3bipy.H2O]2.H2O

International Nuclear Information System (INIS)

Zhang Haiyan; Zhang Jianjun; Ren Ning; Xu Suling; Tian Liang; Bai Jihai

2008-01-01

A new binuclear samarium (III) complex [Sm(p-BrBA) 3 bipy.H 2 O] 2 .H 2 O (p-BrBA = p-bromobenzoic acid; bipy = 2,2'-bipyridine) has been synthesized and characterized by elemental analysis, UV, IR, molar conductance and TG-DTG techniques. The structure of the complex was established by single crystal X-ray diffraction. It crystallizes in triclinic, space group P1-bar with a = 8.2476(7) A, b = 13.3483(10) A, c = 15.9035(13) A, α 73.9160(10) o , β = 78.9630(10) o , γ = 74.4770(10) o , Z = 1, D c 1.947 g cm -3 , F(000) = 910. The carboxylic groups are bonded to the samarium ion in two modes: bidentate bridging, monodentate. Each center Sm 3+ ion is eight-coordinated by one 2,2'-bipyridine molecular, four bidentate bridging and a monodentate carboxylic group, as well as one water molecular. The coordination polyhedron around each Sm 3+ ion can be described as bi-capped triangular prism geometry. The thermal decomposition behavior of the title complex in a static air atmosphere was investigated by TG-DTG and IR techniques

Influence of the Torsion Angle in 3,3'-Dimethyl-2,2'-bipyridine on the Intermediate Valence of Yb in (C5Me5)2 Yb(3,3'-Me2-bipy)

Energy Technology Data Exchange (ETDEWEB)

Nocton, Gr& #233; gory; Booth, Corwin H.; Maron, Laurent; Andersen, Richard A.

2014-06-26

The synthesis and X-ray crystal structures of Cp-2*Yb(3,3'-Me(2)bipy) and [Cp-2 Yb(3,3'-Me(2)bipy)][Cp-2 YbCl1.6I0.4]center dot CH2Cl2 are described. In both complexes, the NCCN torsion angles are approximately 40 degrees. The temperature-independent value of n(f) of 0.17 shows that the valence of ytterbium in the neutral adduct is multiconfigurational, in reasonable agreement with a CASSCF calculation that yields a n(f) value of 0.27; that is, the two configurations in the wave function are f(13)(pi(1))(1) and f(14)(pi(1))(0) in a ratio of 0.27:0.73, respectively, and the open-shell singlet lies 0.28 eV below the triplet state (n(f) accounts for f-hole occupancy; that is, n(f) = 1 when the configuration is f(13) and n(f) = 0 when the configuration is f(14)). A correlation is outlined between the value of nf and the individual ytterbocene and bipyridine fragments such that, as the reduction potentials of the ytterbocene cation and the free x,x'-R-2-bipy ligands approach each other, the value of nf and therefore the f(13):f(14) ratio reaches a maximum; conversely, the ratio is minimized as the disparity increases.

Mixed diphosphine/diamine ruthenium (II) isomers: Synthesis, structural characterization and catalytic hydrogenation of ketones

Science.gov (United States)

Nascimento, Rebecca D.; Silva, Andressa K.; Lião, Luciano M.; Deflon, Victor M.; Ueno, Leonardo T.; Dinelli, Luis R.; Bogado, André L.

2018-01-01

The complexes trans-[RuCl2(dppb)(cydn)] (1), trans-[RuCl2(dppb)(opda)] (2) and cis-[RuCl2(dppb)(cydn)] (3) were synthesized from [{RuCl2(dppb)}2-μ-(dppb)] {where: dppb = 1,4-bis(diphenylphosphino)butane; cydn = cis and trans (±) 1,2-diaminocyclohexane, and opda = o-phenylenediamine}. The complexes were characterized by nuclear magnetic resonance of phosphorus (31P{1H} NMR), cyclic voltammetry (CV), infrared and ultraviolet/visible spectra (IR and UV/vis) as well as elemental analyses (CHN). The X-ray structures of (1) and (3) were determined and they are presented here. DFT calculations and experimental data showed that the trans isomers are obtained as thermodynamic products while the cis isomers are kinetic products. This behavior is different than described in the literature for similar complexes, where the cis isomer is obtained from the trans isomer. Additionally, the catalytic activity of the complexes (1), (2) and (3) was investigated, as pre-catalysts, in the reduction of the acetophenone and 4-methylacetophenone by transfer-hydrogenation.

Establishing the anion recognition correlation of the 2-(2-methoxyphenyl)-1H-imidazo [4, 5-f][1,10] phenanthroline and its Ru(bipy){sub 2}{sup 2+} complex via fluorimetry

Energy Technology Data Exchange (ETDEWEB)

Alreja, Priya; Kaur, Navneet, E-mail: neet_chem@yahoo.co.in

2016-11-15

2-(2-methoxyphenyl)-1H-imidazo [4, 5-f][1, 10] phenanthroline (1) and its Ru(bipy){sub 2}{sup 2+} complex (2) were synthesized and the anion sensing properties of the two were well evaluated and compared by fluorescence titration experiments. Both 1 and 2 were fluorescent in DMSO solution and possessed an anion binding imidazole N–H site to interact with the anions. 1 did not exhibit any fluorescent changes with even most basic anions in DMSO solution but on introduction of Ru metal center via synthesis of its Ru(bipy){sub 2}{sup 2+} complex (2), the N–H acidity enhanced appreciably and it could detect acetate even at very low concentrations (LOD=5.25×10{sup −7}). The fluorescence intensity of 2 was almost completely quenched and its fluorescent red orange color disappeared with the addition of acetate ions. The spatial arrangement of receptor 2 fits well for the triangular shape of AcO{sup −} ion, hence making it the most preferred anion for binding. Both {sup 1}H NMR titrations and DFT computational calculations supported the deprotonation mechanism.

[Ru(bipy)3]2+ nanoparticle-incorporate dental light cure resin to promote photobiomodulation therapy for enhanced vital pulp tissue repair

Science.gov (United States)

Mosca, Rodrigo C.; Young, Nicholas; Zeituni, Carlos A.; Arany, Praveen R.

2018-02-01

The use of nanoparticle on dental light cure resin is not new, currently several compounds (nanoadditives) are used to promote better communication between the restorative material and biological tissues. The interest for this application is growing up to enhance mechanical proprieties to dental tissue cells regeneration. Bioactive nanoparticles and complex compounds with multiple functions are the major target for optimizing the restorative materials. In this work, we incorporate [Ru(bipy)3]2+ nanoparticles, that absorbs energy at 450 nm (blue-light) and emits strongly at 620 nm (red-light), in PLGA Microspheres and insert it in Dental Light Cure Resin to promote the Photobiomodulation Therapy (PBM) effects to accelerate dental pulp repair by in vitro using cytotoxicity and proliferation assay.

Novel piplartine-containing ruthenium complexes: synthesis, cell growth inhibition, apoptosis induction and ROS production on HCT116 cells.

Science.gov (United States)

D'Sousa Costa, Cinara O; Araujo Neto, João H; Baliza, Ingrid R S; Dias, Rosane B; Valverde, Ludmila de F; Vidal, Manuela T A; Sales, Caroline B S; Rocha, Clarissa A G; Moreira, Diogo R M; Soares, Milena B P; Batista, Alzir A; Bezerra, Daniel P

2017-11-28

Piplartine (piperlongumine) is a plant-derived molecule that has been receiving intense interest due to its anticancer characteristics that target the oxidative stress. In the present paper, two novel piplartine-containing ruthenium complexes [Ru(piplartine)(dppf)(bipy)](PF 6 ) 2 (1) and [Ru(piplartine)(dppb)(bipy)](PF 6 ) 2 (2) were synthesized and investigated for their cellular and molecular responses on cancer cell lines. We found that both complexes are more potent than metal-free piplartine in a panel of cancer cell lines on monolayer cultures, as well in 3D model of cancer multicellular spheroids formed from human colon carcinoma HCT116 cells. Mechanistic studies uncovered that the complexes reduced the cell growth and caused phosphatidylserine externalization, internucleosomal DNA fragmentation, caspase-3 activation and loss of the mitochondrial transmembrane potential on HCT116 cells. Moreover, the pre-treatment with Z-VAD(OMe)-FMK, a pan-caspase inhibitor, reduced the complexes-induced apoptosis, indicating cell death by apoptosis through caspase-dependent and mitochondrial intrinsic pathways. Treatment with the complexes also caused a marked increase in the production of reactive oxygen species (ROS), including hydrogen peroxide, superoxide anion and nitric oxide, and decreased reduced glutathione levels. Application of N-acetyl-cysteine, an antioxidant, reduced the ROS levels and apoptosis induced by the complexes, indicating activation of ROS-mediated apoptosis pathway. RNA transcripts of several genes, including gene related to the cell cycle, apoptosis and oxidative stress, were regulated under treatment. However, the complexes failed to induce DNA intercalation. In conclusion, the complexes are more potent than piplartine against different cancer cell lines and are able to induce caspase-dependent and mitochondrial intrinsic apoptosis on HCT116 cells by ROS-mediated pathway.

A Linear trans-Bis(imido) Neptunium(V) Actinyl Analog: Np(V)(NDipp)2((t)Bu2bipy)2Cl (Dipp = 2,6-(i)Pr2C6H3).

Science.gov (United States)

Brown, Jessie L; Batista, Enrique R; Boncella, James M; Gaunt, Andrew J; Reilly, Sean D; Scott, Brian L; Tomson, Neil C

2015-08-05

The discovery that imido analogs of actinyl dioxo cations can be extended beyond uranium into the transuranic elements is presented. Synthesis of the Np(V) complex, Np(NDipp)2((t)Bu2bipy)2Cl (1), is achieved through treatment of a Np(IV) precursor with a bipyridine coligand and lithium-amide reagent. Complex 1 has been structurally characterized, analyzed by (1)H NMR and UV-vis-NIR spectroscopies, and the electronic structure evaluated by DFT calculations.

Cold snare polypectomy reduced delayed postpolypectomy bleeding compared with conventional hot polypectomy: a propensity score-matching analysis

Science.gov (United States)

Yamashina, Takeshi; Fukuhara, Manabu; Maruo, Takanori; Tanke, Gensho; Marui, Saiko; Sada, Ryota; Taki, Mio; Ohara, Yoshiaki; Sakamoto, Azusa; Henmi, Shinichiro; Sawai, Yugo; Saito, Sumio; Nishijima, Norihiro; Nasu, Akihiro; Komekado, Hideyuki; Sekikawa, Akira; Asada, Masanori; Tumura, Takehiko; Kita, Ryuichi; Kimura, Toru; Osaki, Yukio

2017-01-01

Background and study aims  Cold snare polypectomy (CSP) for small colorectal polyps has lower incidence of adverse events, especially delayed postpolypectomy bleeding (DPPB). However, few data are available on comparisons of the incidence of DPPB of CSP and hot polypectomy (HP). The aim of this study was to evaluate the incidence of DPPB after CSP and compare it with that of HP. A propensity score model was used as a secondary analysis. Patients and methods  This was a retrospective cohort study conducted in a single municipal hospital. We identified 539 patients with colorectal polyps from 2 mm to 11 mm in size who underwent CSP (804 polyps in 330 patients) or HP (530 polyps in 209 patients) between July 2013 and June 2015. Results  There were no cases of DPPB in the CSP group. Conversely, DPPB occurred in 4 patients (1.9 %) after HP, resulting in a significant difference between the CSP and HP groups (0.008 % vs 0 %, P  = 0.02). Propensity score-matching analysis created 402 matched pairs, yielding a significantly higher DPPB rate in the HP group than CSP group (0.02 % vs 0 %, P  = 0.04). However, significantly more patients in the CSP group had unclear horizontal margins that precluded assessment (83 vs 38 cases, P  < 0.001). The retrieval failure rate was significantly higher in the CSP group than in the HP group (3 % vs 0.7 %, P  = 0.01). Conclusions  DPPB was less frequent with CSP than HP, as selected by the propensity score-matching model. Our findings indicate that CSP is recommended polypectomy in daily clinical setting. However, special care should be taken during polyp retrieval and horizontal margin assessment, and these issues could be taken into account in follow-up after CSP. PMID:28670615

Three extracellular dipeptidyl peptidases found in Aspergillus oryzae show varying substrate specificities.

Science.gov (United States)

Maeda, Hiroshi; Sakai, Daisuke; Kobayashi, Takuji; Morita, Hiroto; Okamoto, Ayako; Takeuchi, Michio; Kusumoto, Ken-Ichi; Amano, Hitoshi; Ishida, Hiroki; Yamagata, Youhei

2016-06-01

Three extracellular dipeptidyl peptidase genes, dppB, dppE, and dppF, were unveiled by sequence analysis of the Aspergillus oryzae genome. We investigated their differential enzymatic profiles, in order to gain an understanding of the diversity of these genes. The three dipeptidyl peptidases were expressed using Aspergillus nidulans as the host. Each recombinant enzyme was purified and subsequently characterized. The enzymes displayed similar optimum pH values, but optimum temperatures, pH stabilities, and substrate specificities varied. DppB was identified as a Xaa-Prolyl dipeptidyl peptidase, while DppE scissile substrates were similar to the substrates for Aspergillus fumigatus DPPV (AfDPPV). DppF was found to be a novel enzyme that could digest both substrates for A. fumigatus DPPIV and AfDPPV. Semi-quantitative PCR revealed that the transcription of dppB in A. oryzae was induced by protein substrates and repressed by the addition of an inorganic nitrogen source, despite the presence of protein substrates. The transcription of dppE depended on its growth time, while the transcription of dppF was not affected by the type of the nitrogen source in the medium, and it started during the early stage of the fungal growth. Based on these results, we conclude that these enzymes may represent the nutrition acquisition enzymes. Additionally, DppF may be one of the sensor peptidases responsible for the detection of the protein substrates in A. oryzae environment. DppB may be involved in nitrogen assimilation control, since the transcription of dppB was repressed by NaNO3, despite the presence of protein substrates.

Reactivity of the parent amido complexes of iridium with olefins: C-NH2 bond formation versus C-H activation.

Science.gov (United States)

Mena, Inmaculada; García-Orduña, Pilar; Polo, Víctor; Lahoz, Fernando J; Casado, Miguel A; Oro, Luis A

2017-08-29

Herein we report on the different chemical reactivity displayed by two mononuclear terminal amido compounds depending on the nature of the coordinated diene. Hence, treatment of amido-bridged iridium complexes [{Ir(μ-NH 2 )(tfbb)} 3 ] (1; tfbb = tetrafluorobenzobarrelene) with dppp (dppp = bis(diphenylphosphane)propane) leads to the rupture of the amido bridges forming the mononuclear terminal amido compound [Ir(NH 2 )(dppp)(tfbb)] (3) in the first stage. On changing the reaction conditions, the formation of a C-NH 2 bond between the amido moiety and the coordinated diene is observed and a new dinuclear complex [{Ir(1,2-η 2 -4-κ-C 12 H 8 F 4 N)(dppp)} 2 (μ-dppp)] (4) has been isolated. On the contrary, the diiridium amido-bridged complex [{Ir(μ-NH 2 )(cod)} 2 ] (2; cod = 1,5-cyclooctadiene) in the presence of dppb (dppb = bis(diphenylphosphane)butane) allows the isolation of a mononuclear complex [Ir(1,2,3-η 3 -6-κ-C 8 H 10 )H(dppb)] (5), as a consequence of the extrusion of ammonia. The monitoring of the reaction of 2 with dppb (and dppp) allowed us to detect terminal amido complexes [Ir(NH 2 )(P-P)(cod)] (P-P = dppb (6), dppp (7)) in solution, as confirmed by an X-ray analysis of 7. Complex 7 was observed to evolve into hydrido species 5 at room temperature. DFT studies showed that C-H bond activation occurs through the deprotonation of one methylene fragment of the cod ligand by the highly basic terminal amido moiety instead of C-H oxidative addition to the Ir(i) center.

Study of ruthenium complexation by 22' bipyridine in nitric aqueous solutions

International Nuclear Information System (INIS)

Alozy, J.P.

1982-01-01

Substitution of the NO 3- , NO + ions of RuNO(NO 3 )x.yH 2 Osup((3-x)+) complexes by 22'bipyridine (bipy) in nitric aqueous solution was studied by spectrophotometry. In the absence of reducing agent we observe the species RuNO(bipy)(NO3)sub(z)sup((3-z)+) and RuNO(bipy) 2 NO 3 2 + . Most reducing agents give rise to the RuNO(bipy) 2 NO 3 2 + + e → RuNO(bipy) 2 NO 3+ reaction. The oxydation potential of the reversible couple RuNO(bipy) 2 NO 3 2 + /RuNO(bipy) 2 NO 3+ was measured by cyclic voltamperometry at the platinum electrode. Its value is + 1.02 V/NHE. Substitution of NO + ions by a (bipy) molecule is only possible in the presence of reducing agents of apparent formal potential below + 0.5 V/NHE, and anti-nitrite agents are also needed; these two functions can be fulfilled by hydrazine and ascorbic acid. The presence of HSO 3 NH 2 was necessary to obtain the substitution of NO + and NO 3- by bipy during electrochemical reductions. The intermediate complexes RuNO(bipy) 2 NO 3 2 + and RuNO(bipy) 2 NO 3+ probably include two bipy molecules in the trans position whereas RuNO(bipy) 2 2 + complexes, where the sixth coordination position is occupied by π donors stronger than NO 3- , have two bipy molecules in the cis position [fr

A novel highly efficient adsorbent {[Co4(L)2(μ3-OH)2(H2O)3(4,4‧-bipy)2]·(H2O)2}n: Synthesis, crystal structure, magnetic and arsenic (V) absorption capacity

Science.gov (United States)

Zhang, Chong; Xiao, Yu; Qin, Yan; Sun, Quanchun; Zhang, Shuhua

2018-05-01

A novel highly efficient adsorbent-microporous tetranuclear Co(II)-based polymer, {[Co4(L)2(μ3-OH)2(H2O)3(4,4‧-bipy)2]·(H2O)2}n (1, H3L = 4-(N,N‧-bis(4-carboxybenzyl)amino) benzenesulfonic acid, 4,4‧-bipy = 4,4‧-bipyridine), was hydrothermally synthesized. The complex 1 is a metal-organic framework (MOF) material which was characterized by single-crystal X-ray diffraction, BET and platon software. Co-MOF (complex 1) reveals excellent adsorption property. The capacity of Co-MOF to remove arsenic As(V) from sodium arsenate aqueous solutions was investigated (The form of As(V) is AsO43-). The experimental results showed that Co-MOF had a higher stable and relatively high As(V) removal rate (> 98%) at pH 4-10. The adsorption kinetics followed a pseudo-second-order kinetic model, and the adsorption isotherm followed the Langmuir equation. Co-MOF exhibits a very high adsorption capacity of As(V) in aqueous solution (Qmax of 96.08 mg/g). Finally, the optimal adsorption conditions for the model were obtained through a Box-Behnken response surface experiment which was designed with adsorption time, dose, temperature and rotational speed of the shaker as the influencing factors to determine two-factor interaction effects. Co-MOF was further characterized using FTIR, PXRD, X-ray photoelectron spectroscopy before and after adsorption As (V). The magnetism of Co-MOF was also discussed.

Hydrothermal synthesis and characterization of a new three-dimensional hybrid zinc phosphate [Zn2(HPO4)2(4,4'-bipy)].3H2O with neutral porous framework

International Nuclear Information System (INIS)

Wang Lei; Yang Ming; Li Guanghua; Shi Zhan; Feng Shouhua

2006-01-01

Employing 4,4'-bipyridine as a bridged ligand, a new three-dimensional (3-D) hybrid zinc phosphate [Zn 2 (HPO 4 ) 2 (4,4'-bipy)].3H 2 O has been prepared under hydrothermal conditions and characterized by single crystal X-ray diffraction. This compound crystallizes in the monoclinic space group C2/c, with cell parameters, a=21.188(4)A, b=10.229(2)A, c=9.0656(18)A, β=90.21(3) o , V=1964.8(7)A 3 and Z=4. The connectivity of the ZnO 3 N and HPO 4 tetrahedra results in a 2-D neutral layer that with interesting 4,8 2 net along the bc plane. Furthermore, the 4,4'-bipyridine molecule links the 4,8 2 net into a 3-D structure. The water molecules sit in the middle of the channels and interact with the framework via hydrogen bonds. The compound exhibits intense photoluminescence at room temperature

Coordination compounds of the nitrate salts of oxycation uranyl (UO22+) and praseodymium(III), neodymium(III) and erbium(III) with 2,2'-bipyridine-1,1'-dioxide

International Nuclear Information System (INIS)

Madan, S.; Chan, K.S.

1977-01-01

Coordination compounds with 2,2'-bipyridine-1,1'-dioxide (bipyO 2 ) having the composition [UO 2 (bipyO 2 ) 2 (NO 3 ) 2 ].4H 2 O, [Pr(bipyO 2 ) 4 (NO 3 ) 2 ]NO 3 .2H 2 O, [Dy(bipyO 2 ) 4 (NO 3 ) 2 ]NO 3 .4H 2 O and [Er(bipyO 2 ) 4 (NO 3 ) 2 ]NO 3 .4H 2 O have been synthesized. These new complexes have been characterized by electrical conductance, X-ray powder patterns and IR spectral measurements. (author)

Syntheses, structures and characterizations of three novel vanadium selenites with organically bonded copper/nickel complex

Science.gov (United States)

Qian, Cheng; Kong, Fang; Mao, Jiang-Gao

2016-06-01

A series of vanadium selenites covalently bonded with metal-organic complex, namely, Ni(2,2-bipy)2V2O4(SeO3)2 (1), Cu(2,2-bipy)V2O4(SeO3)2·0.5H2O (2) and Cu2(2,2-bipy)2V5O12(SeO3)2 (3) (2,2-bipy=2,2-bipyridine) have been hydrothermally synthesized and structurally characterized. They exhibit three different structural dimensions, from 0D cluster, 1D chain to 2D layer. Compound 1 features a 0D {Ni(2,2-bipy)2V2O4(SeO3)2}2 dimeric cluster composed of two {Ni(2,2-bipy)2}2+ moieties connected by the {V4O8(SeO3)4}4- cluster. Compound 2 shows a 1D {Cu(2,2-bipy)V2O4(SeO3)2}n chain in which the {Cu2(2,2-bipy)2}4+ moieties are bridged by the {V4O8(SeO3)4}4- clusters. Compound 3 displays a 2D structure consisted of mixed valence vanadium selenites layers {VIVVV4SeIV2O18}n4- and {Cu(2,2-bipy)}2+ complex moieties. The adjacent layers are further interconnected via π-π interactions between the 2,2-bipy ligands exhibiting an interesting 3D supramolecular architecture. Both compound 1 and 2 contain a new {V4O8(SeO3)4}4- cluster and compound 3 exhibits the first 2D vanadate polyhedral layer in vanadium selenites/tellurites with organic moieties.

Dinuclear NHC-palladium complexes containing phosphine spacers: synthesis, X-ray structures and their catalytic activities towards the Hiyama coupling reaction.

Science.gov (United States)

Yang, Jin; Li, Pinhua; Zhang, Yicheng; Wang, Lei

2014-05-21

Six dinuclear N-heterocyclic carbene (NHC) palladium complexes, [PdCl2(IMes)]2(μ-dppe) (1), [PdCl2(IPr)]2(μ-dppe) (2), [PdCl2(IMes)]2(μ-dppb) (3), [PdCl2(IPr)]2(μ-dppb) (4), [PdCl2(IMes)]2(μ-dpph) (5), and [PdCl2(IPr)]2(μ-dpph) (6) [IMes = N,N'-bis-(2,4,6-trimethylphenyl)imidazol-2-ylidene; IPr = N,N'-bis-(2,6-di(iso-propyl)phenyl)imidazol-2-ylidene; dppe = 1,2-bis(diphenylphosphino)ethane, dppb = 1,4-bis(diphenylphosphino)butane; and dpph = 1,6-bis(diphenylphosphino)hexane], have been synthesized through bridge-cleavage reactions of chloro-bridged dimeric compounds, [Pd(μ-Cl)(Cl)(NHC)]2, with the corresponding diphosphine ligands. The obtained compounds were fully characterized by (1)H NMR, (13)C NMR and (31)P NMR spectroscopy, FT-IR, elemental analysis and single-crystal X-ray crystallography. Moreover, further explorations of the catalytic potential of the dinuclear carbene palladium complexes as catalysts for the Pd-catalyzed transformations have been performed under microwave irradiation conditions, and the complexes exhibited moderate to good catalytic activity in the Hiyama coupling reaction of trimethoxyphenylsilane with aryl chlorides.

Experimental studies on the nature of bonding of DNA/bipyridyl-(ethylenediamine)platinum(II) and DNA/netropsin complexes in solution and oriented wet-spun films

Science.gov (United States)

Marlowe, R. L.; Szabo, A.; Lee, S. A.; Rupprecht, A.

2002-03-01

The stability of complexes of NaDNA with bipyridyl-(ethylenediamine)platinum(II) (abbreviated [(bipy)Pt(en)]) and with netropsin has been studied using two techniques: (i) ultraviolet melting experiments were done on NaDNA/[(bipy)Pt(en)], showing that the [(bipy)Pt(en)] ligand stabilizes the DNA double helix structure; and (ii) swelling measurements (via optical microscopy) as a function of relative humidity were done on wet-spun oriented films of NaDNA/[(bipy)Pt(en)] and of NaDNA/netropsin. The swelling data shows that an irreversible transition of the films occurs at high relative humidity, first for the NaDNA/netropsin, then for pure NaDNA, and lastly for the NaDNA/[(bipy)Pt(en)]. These results are indicative that the [(bipy)Pt(en)] complex stabilizes the intermolecular bonds which mediate the film swelling characteristics. A model is suggested for the binding of [(bipy)Pt(en)] to DNA to explain why the swelling experiments show this ligand as increasing the intermolecular bond strength between the DNA double helices, while netropsin decreases this degree of stabilization.

Synthesis and Near IR Photoluminescence of Os(II) Bis(2,2'-bipyridine) (3,8-Diarylethynyl-1,10-phemanthroline) Complexes: Anomalous Behavior of the 3,8-Dinitrophenylethynyl-substituted Homologue

Science.gov (United States)

Yang, Jinhua; Dass, Amala; Sotiriou-Leventis, Chariklia; Tyson, Daniel S.; Leventis, Nicholas

2005-01-01

A large bathochromic shift (50 nm) and emission in the near infrared is observed by attaching arylethynyl groups at the 3,8-positions of the 1,10-phenanthroline ligand (phen) of [Os(bipy)2(phen)]2+ (where bipy = 2,2'-bipyridine). Thus [Os(bipy)2(3,8-di-4-methoxyphenylethynyl-1,10-phenathroline)]2+ emits at 795 nm, while [Os(bipy)2(3,8-diphenylethynyl-1,10-phenanthroline)]2+ emits at 815 nm. According to this trend it would have been expected that [Os(bipy)2(3,8-di-4-nitrophenylethynyl-1,10-phenathroline)]2+ emits farther in the near infrared. Nevertheless, this complex is not photoluminescent because of intramolecular electron transfer quenching of the MLCT excited state by the nitroaromatic group. These results set structural and redox potential standards in the design of near infrared emitters based on [Os(bipy)2(phen)]2+ type complexes.

Hybrid compounds of Keggin polyoxotungstate with transition metal ion as the central atom. Synthesis, structure and properties

Science.gov (United States)

Li, Xiao-Min; Chen, Ya-Guang; Shi, Tian

2016-02-01

The compounds (Hbipy)2[Co(bipy)2(H2O)4]2(CoW12O40)·2bipy·7H2O (1) and [Ni2(Hbipy)2(bipy)(H2O)4(H2W12O40)]·5H2O (2) (bipy = 4,4-bipyridine) were synthesized hydrothermally and characterized by elemental analysis, IR spectroscopy, TG analyses, solid ultraviolet diffuse spectroscopy and single crystal X-ray diffraction method. In 1 the complex ions, [Co(bipy)2(H2O)4]2+, construct a supramolecular layer through π-π stacking interaction. The heteropolyanions with central Co atom and supramolecular layers are linked by hydrogen bonds. In 2 a 2D structure is formed from metatungstate anions and binuclear Ni-bipy complexes through the coordination of metatungstate anions and bipy to Ni ions. Between the layers and bipyridine molecules are the hydrogen bond interactions. The formation of 1 and 2 shows that the solution acidity and metal ions influence greatly the structure of the compounds. Solid ultraviolet diffusion results indicate that the compounds 1 and 2 are potential semiconductor materials. In 1 and 2 there exists a weak antiferromagnetic interaction.

Ligand field and intermolecular interactions tuning the magnetic properties of spin-crossover Fe(II) polymer with 4,4′-bipyridine

Energy Technology Data Exchange (ETDEWEB)

Luo, Yang-Hui; Liu, Qing-Ling; Yang, Li-Jing; Ling, Yang; Wang, Wei; Sun, Bai-Wang, E-mail: chmsunbw@seu.edu.cn

2015-02-15

A new spin crossover coordination polymer (SCO-CPs) of Fe(II)-4,4′-bipyridine (4,4′-bipy) family: (Fe(4,4′-bipy){sub 2}(H{sub 2}O){sub 2})·(4,4′-bipy)· 8(H{sub 2}O)·2(ClO{sub 4}) (3), which displays half spin transitions between 100 and 300 K, has been synthesized and structurally characterized. Compound 3 featured with two-dimensional (2-D) grids connected by hydrogen bonds and π…π packing between one-dimensional (1-D) chains, the 2-D grids expand to three-dimensional (3-D) architecture supported by a “S-shaped holder” involving lattice 4-4′-bipy, water molecules and perchlorate anion. We compared 3 with the other two analogous complexes: ((Fe(4,4′-bipy) (H{sub 2}O){sub 2} (NCS){sub 2})·4,4′-bipy, 1 and (Fe(4,4′-bipy){sub 2}(NCS){sub 2})·mSolv, 2) through Hirshfeld surfaces analysis, which revealed that the low ligand field strength (NCS{sup −}) and lone-pair…H contacts contribute to the stabilization of HS (high-spin) state of the Fe(II) ion, while the high ligand field strength (4,4′-bipy) and strong intermolecular contacts (hydrogen bonds and π…π packing interactions) make for the LS (low-spin) state. - Highlights: ●A new member of Fe(||)-4,4′-bipy family has been prepared. ●It displays half spin transitions tuned by ligand field and intermolecular interactions. ●We have made a detailed comparison of this new member with two other analogous complexes.

Syntheses, structures and characterizations of three novel vanadium selenites with organically bonded copper/nickel complex

International Nuclear Information System (INIS)

Qian, Cheng; Kong, Fang; Mao, Jiang-Gao

2016-01-01

A series of vanadium selenites covalently bonded with metal-organic complex, namely, Ni(2,2-bipy) 2 V 2 O 4 (SeO 3 ) 2 (1), Cu(2,2-bipy)V 2 O 4 (SeO 3 ) 2 ·0.5H 2 O (2) and Cu 2 (2,2-bipy) 2 V 5 O 12 (SeO 3 ) 2 (3) (2,2-bipy=2,2-bipyridine) have been hydrothermally synthesized and structurally characterized. They exhibit three different structural dimensions, from 0D cluster, 1D chain to 2D layer. Compound 1 features a 0D {Ni(2,2-bipy) 2 V 2 O 4 (SeO 3 ) 2 } 2 dimeric cluster composed of two {Ni(2,2-bipy) 2 } 2+ moieties connected by the {V 4 O 8 (SeO 3 ) 4 } 4- cluster. Compound 2 shows a 1D {Cu(2,2-bipy)V 2 O 4 (SeO 3 ) 2 } n chain in which the {Cu 2 (2,2-bipy) 2 } 4+ moieties are bridged by the {V 4 O 8 (SeO 3 ) 4 } 4− clusters. Compound 3 displays a 2D structure consisted of mixed valence vanadium selenites layers {V IV V V 4 Se IV 2 O 18 } n 4− and {Cu(2,2-bipy)} 2+ complex moieties. The adjacent layers are further interconnected via π-π interactions between the 2,2-bipy ligands exhibiting an interesting 3D supramolecular architecture. Both compound 1 and 2 contain a new {V 4 O 8 (SeO 3 ) 4 } 4− cluster and compound 3 exhibits the first 2D vanadate polyhedral layer in vanadium selenites/tellurites with organic moieties. - Graphical abstract: We got three new vanadium selenites with organically linked copper/nickel complex, namely, Ni(2,2-bipy) 2 V 2 O 4 (SeO 3 ) 2 (1), Cu(2,2-bipy)V 2 O 4 (SeO 3 ) 2 ·0.5H 2 O (2) and Cu 2 (2,2-bipy) 2 V 5 O 12 (SeO 3 ) 2 (3) by hydrothermally syntheses. They display three different structural dimensions, from 0D cluster, to 1D chain and 2D layer. Display Omitted - Highlights: • Three new compounds display three different structural dimensions, from 0D cluster, to 1D chain and 2D layer. • The Tetranuclear {V 4 O 8 (SeO 3 ) 4 } 4− cluster and the vanadate {V 5 O 17 } n 2D layer are observed firstly. • Optical Properties and Magnetic Properties of three compounds are reported.

Construction of Insulin 18-mer Nanoassemblies Driven by Coordination to Iron(II) and Zinc(II) Ions at Distinct Sites

DEFF Research Database (Denmark)

Munch, Henrik K.; Nygaard, Jesper; Christensen, Niels Johan

2016-01-01

coordination with two different metal ions. Selective attachment of an abiotic 2,2′-bipyridine (bipy) ligand to HI, yielding HI–bipy, enabled ZnII-binding hexamers to SA into trimers of hexamers, [[HI–bipy]6]3, driven by octahedral coordination to a FeII ion. The structures were studied in solution by small...

Synthesis, structure, terahertz spectroscopy and luminescent properties of copper (I) complexes with bis(diphenylphosphino)methane and N-donor ligands

Science.gov (United States)

Fan, Wei-Wei; Li, Zhong-Feng; Li, Jiao-Bao; Yang, Yu-Ping; Yuan, Yuan; Tang, Han-Qin; Gao, Ling-Xiao; Jin, Qiong-Hua; Zhang, Zhen-Wei; Zhang, Cun-Lin

2015-11-01

The reactions of copper(I) salts CuX [X = Cl, OTf (OTf = CF3SO3) and ClO4] and bis(diphenylphosphino)methane (dppm) with 4,4-bipyridine (4,4-bipy), 2,2-bipyridine (2,2-bipy), isoquinoline (i-C9H7N) and 1,10-phenanthroline (phen) lead to five new copper(I) complexes: [CuCl(dppm)(i-C9H7N)]2 (1), {[CuCl(dppm)(phen)]2•5H2O}n (2), [Cu2Cl2(dppm)2(4,4-bipy)]•4CH3CN (3), [Cu(dppm)(2,2-bipy)]2(OTf)2 (4), {[Cu2Cl(dppm)2(4,4-bipy)](ClO4)}n (5). Complexes 1, 3 and 4 are of dinuclear structure with eight-membered Cu2P4C2 rings. The structure of compound 2 can be simplified as three-dimensional topology. Complex 5 is of infinite chain structure linked by 4,4-bipy. All these complexes are characterized by IR, elemental analyses, single-crystal X-ray diffraction analysis, luminescence, NMR and terahertz time-domain spectroscopy.

Synthesis, spectroscopic characterization, crystallographic studies and antibacterial assays of new copper(II) complexes with sulfathiazole and nimesulide

Science.gov (United States)

Nunes, Julia Helena Bormio; de Paiva, Raphael Enoque Ferraz; Cuin, Alexandre; da Costa Ferreira, Ana Maria; Lustri, Wilton Rogério; Corbi, Pedro Paulo

2016-05-01

New ternary copper(II) complexes of sulfathiazole (SFT, C9H8N3O2S2) or nimesulide (NMS, C13H11N2O5S) and 2,2‧-bipyridine (bipy) were synthesized, and characterized by chemical and spectroscopic techniques. Elemental analyses indicated a 2:1:1 sulfonamide/copper/bipy composition for both complexes. Mass spectrometric measurements permitted identifying the molecular ions [Cu(SFT)2(bipy)+H]+ and [Cu(NMS)2(bipy)+H]+ at m/z 728 and 835, respectively, confirming the proposed compositions. Crystal structure of the [Cu(SFT)2(bipy)] complex was solved by powder X-ray diffraction analysis (PXRD), attesting that the Cu(II) ion is hexacoordinated in a distorted octahedral geometry. Each SFT molecule coordinates to the metal ion by the nitrogen atoms of the SO2-N group and of the heterocyclic ring. The coordination sphere is completed by a bipyridine. Electronic paramagnetic resonance (EPR) studies were carried out for the [Cu(NMS)2(bipy)] complex, indicating a tetragonal environment around the metal ion. It was suggested that NMS coordinates to Cu(II) by the nitrogen and oxygen atoms of the SO2-N group, which was confirmed by infrared spectroscopic studies. Biological studies showed the antibacterial activity of both Cu-SFT and Cu-NMS complexes, with the minimum inhibitory concentration (MIC) values ranging from 0.10 to 0.84 mmol L-1 against Gram-negative bacteria for [Cu(SFT)2(bipy)], and from 1.50 to 3.00 mmol L-1 against Gram-positive and -negative bacteria for [Cu(NMS)2(bipy)].

Synthesis, Structure, and Fluorescence of a Novel Cadmium Compound

Science.gov (United States)

Yao, Zhong-Liang; Chen, Wen-Tong

2017-12-01

A novel cadmium compound, [(CdI3)2(μ2-I)]2(Me2-4,4'-H2bipy)3 (1) (Me = methyl; 4,4'-bipy = 4,4'-bipyridine) with the Me2-4,4'-H2bipy moiety generated in situ, has been prepared through a solvothermal reaction and structurally characterized by X-ray single crystal diffraction analysis. Compound 1 is characterized by an isolated structural motif, consisting of [(CdI3)2(μ2-I)]3- anions and Me2-4,4'-H2bipy2+ cations. The [(CdI3)2(μ2-I)]3- anions and Me2-4,4'-H2bipy2+ cations interconnect together via C-H···I hydrogen-bonding interactions to complete a three-dimensional (3D) supramolecular network. Solid state fluorescent spectrum reveals an emission band in the violet region.

Electrochemical and spectroscopic studies of tungstencarbonyl complexes containing nitrogen and phosphorous ligands

Directory of Open Access Journals (Sweden)

Haddad Paula S.

2000-01-01

Full Text Available The present work deals with the synthesis, spectroscopic investigation and electrochemical behaviour of the compounds [W(CO4(bipy] (1, [W(CO3(bipy(dppm] (2 and [W(CO3(bipy(dppf] (3, bipy = 2,2'-bipyridine; dppm = bis(diphenylphosphinomethane; dppf = 1,1'-bis(diphenylphosphinoferrocene. The IR and 31P{¹H} NMR spectroscopic data have shown an octahedral coordination geometry for the tungsten atom with the diphosphines acting as monodentate ligands. The electrochemical behaviour of the complexes was investigated by cyclic voltammetry and controlled potential coulometry. Cyclic voltammograms have indicated that the compounds containing diphosphines ligands are more stable towards oxidation than compound (1.

Photochemistry of framework-supported M(diimine)(CO)3X complexes in three-dimensional lithium carboxylate metal–organic frameworks: monitoring the effect of framework cations

OpenAIRE

Reade, Thomas J.; Murphy, Thomas S.; Calladine, James A.; Horvath, Raphael; Clark, Ian P.; Greetham, Gregory M.; Towrie, Michael; Lewis, William; George, Michael W.; Champness, Neil R.

2017-01-01

The structures and photochemical behaviour of two new metal–organic frameworks (MOFs) are reported. Reaction of Re(2,2′-bipy-5,5′-dicarboxylic acid)(CO)3Cl or Mn(2,2′-bipy-5,5′-dicarboxylic acid)(CO)3Br with LiCl or LiBr, respectively, produces single crystals of {Li2(DMF)2 [(2,2′-bipy-5,5′-dicarboxylate)Re(CO)3Cl]}n (ReLi) or {Li2(DMF)2[(2,2′-bipy-5,5′-dicarboxylate)Mn(CO)3Br]}n (MnLi). The structures formed by the two MOFs comprise one-dimensional chains of carboxylate-bridged Li(I) cations...

Syntheses, structures and characterizations of three novel vanadium selenites with organically bonded copper/nickel complex

Energy Technology Data Exchange (ETDEWEB)

Qian, Cheng [College of Chemistry, Fuzhou University, Fuzhou, Fujian 350002 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Kong, Fang [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Mao, Jiang-Gao, E-mail: mjg@fjirsm.ac.cn [College of Chemistry, Fuzhou University, Fuzhou, Fujian 350002 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China)

2016-06-15

A series of vanadium selenites covalently bonded with metal-organic complex, namely, Ni(2,2-bipy){sub 2}V{sub 2}O{sub 4}(SeO{sub 3}){sub 2} (1), Cu(2,2-bipy)V{sub 2}O{sub 4}(SeO{sub 3}){sub 2}·0.5H{sub 2}O (2) and Cu{sub 2}(2,2-bipy){sub 2}V{sub 5}O{sub 12}(SeO{sub 3}){sub 2} (3) (2,2-bipy=2,2-bipyridine) have been hydrothermally synthesized and structurally characterized. They exhibit three different structural dimensions, from 0D cluster, 1D chain to 2D layer. Compound 1 features a 0D {Ni(2,2-bipy)_2V_2O_4(SeO_3)_2}{sub 2} dimeric cluster composed of two {Ni(2,2-bipy)_2}{sup 2+} moieties connected by the {V_4O_8(SeO_3)_4}{sup 4-} cluster. Compound 2 shows a 1D {Cu(2,2-bipy)V_2O_4(SeO_3)_2}{sub n} chain in which the {Cu_2(2,2-bipy)_2}{sup 4+} moieties are bridged by the {V_4O_8(SeO_3)_4}{sup 4−} clusters. Compound 3 displays a 2D structure consisted of mixed valence vanadium selenites layers {V"I"VV"V_4Se"I"V_2O_1_8}{sub n}{sup 4−} and {Cu(2,2-bipy)}{sup 2+} complex moieties. The adjacent layers are further interconnected via π-π interactions between the 2,2-bipy ligands exhibiting an interesting 3D supramolecular architecture. Both compound 1 and 2 contain a new {V_4O_8(SeO_3)_4}{sup 4−} cluster and compound 3 exhibits the first 2D vanadate polyhedral layer in vanadium selenites/tellurites with organic moieties. - Graphical abstract: We got three new vanadium selenites with organically linked copper/nickel complex, namely, Ni(2,2-bipy){sub 2}V{sub 2}O{sub 4}(SeO{sub 3}){sub 2} (1), Cu(2,2-bipy)V{sub 2}O{sub 4}(SeO{sub 3}){sub 2}·0.5H{sub 2}O (2) and Cu{sub 2}(2,2-bipy){sub 2}V{sub 5}O{sub 12}(SeO{sub 3}){sub 2} (3) by hydrothermally syntheses. They display three different structural dimensions, from 0D cluster, to 1D chain and 2D layer. Display Omitted - Highlights: • Three new compounds display three different structural dimensions, from 0D cluster, to 1D chain and 2D layer. • The Tetranuclear {V_4O_8(SeO_3)_4}{sup 4−} cluster and the vanadate {V

Synthesis and Crystal Structure of a Five-Coordinate Complex of Copper(II) with 4-Nitrobenzenesulfonate and 2, 2'-Bipyridine.

Science.gov (United States)

Sharif, Mahboubeh A; Tabatabaee, Masoumeh; Beik, Vahideh; Khavasi, Hamid Reza

2012-06-01

[Cu(bipy)2Cl](nbs) (1) (bipy = 2,2'-bipyridine, nbs = 4-nitrobenzenesulfonate) was obtained from the reaction of 4-nitrobenzenesulfonyl chloride and 2-amine-4-methylopyridine with CuCl2 in the presence of 2,2'-bipyridine and characterized by elemental analysis, IR spectra and X-ray single-crystal diffraction. The asymmetric unit of (1) contains the cationic complex [Cu(bipy)2Cl]+ and, in the outer coordination sphere, an (nbs)- counter ion.

Is the bipyridyl thorium metallocene a low-valent thorium complex? A combined experimental and computational study

Energy Technology Data Exchange (ETDEWEB)

Ren, Wenshan; Lukens, Wayne W.; Zi, Guofu; Maron, Laurent; Walter, Marc D.

2012-01-12

Bipyridyl thorium metallocenes [5-1,2,4-(Me3C)3C5H2]2Th(bipy) (1) and [5-1,3-(Me3C)2C5H3]2Th(bipy) (2) have been investigated by magnetic susceptibility and computational studies. The magnetic susceptibility data reveal that 1 and 2 are not diamagnetic, but they behave as temperature independent paramagnets (TIPs). To rationalize this observation, density functional theory (DFT) and complete active space SCF (CASSCF) calculations have been undertaken, which indicated that Cp2Th(bipy) has indeed a Th(IV)(bipy2-) ground state (f0d0 2, S = 0), but the open-shell singlet (f0d1 1, S = 0) (almost degenerate with its triplet congener) is lying only 9.2 kcal/mol higher in energy. Complexes 1 and 2 react cleanly with Ph2CS to give [ 5-1,2,4-(Me3C)3C5H2]2Th[(bipy)(SCPh2)] (3) and [ 5-1,3-(Me3C)2C5H3]2Th[(bipy)(SCPh2)] (4), respectively, in quantitative conversions. Since no intermediates were observed experimentally, this reaction was also studied computationally. Coordination of Ph2CS to 2 in its S = 0 ground state is not possible, but Ph2CS can coordinate to 2 in its triplet state (S = 1) upon which a single electron transfer (SET) from the (bipy2-) fragment to Ph2CS followed by C-C coupling takes place.

Hydrothermal synthesis, crystal structure, luminescent and magnetic properties of a new mononuclear GdIII coordination complex

Science.gov (United States)

Coban, Mustafa Burak

2018-06-01

A new GdIII coordination complex, {[Gd(2-stp)2(H2O)6].2(4,4'-bipy).4(H2O)}, complex 1, (2-stp = 2-sulfoterephthalate anion and 4,4'-bipy = 4,4'-bipyridine), has been synthesized by hydrothermal method and characterized by elemental analysis, solid state UV-Vis and FT-IR spectroscopy, single-crystal X-ray diffraction, solid state photoluminescence and variable-temperature magnetic measurements. The crystal structure determination shows that GdIII ions are eight coordinated and adopt a distorted square-antiprismatic geometry. Molecules interacting through intra- and intermolecular (O-H⋯O, O-H⋯N) hydrogen bonds in complex 1, give rise to 3D hydrogen bonded structure and the discrete lattice 4,4'-bipy molecules occupy the channel of the 3D structure. π-π stacking interactions also exist 4,4'-bipy-4,4'-bipy and 4,4'-bipy-2-stp molecule rings in 3D structures. Additionally, solid state photoluminescence properties of complex 1 at room temperature have been investigated. Under the excitation of UV light (at 349 nm), the complex 1 exhibited green emissions (at 505 nm) of GdIII ion in the visible region. Furthermore, Variable-temperature magnetic susceptibility and isothermal magnetization as function of external magnetic field studies reveal that complex 1 displays possible antiferromagnetic interaction.

Integration of a semi-rigid proline ligand and 4,4'-bipyridine in the synthesis of homochiral metal-organic frameworks with helices.

Science.gov (United States)

Xu, Zhong-Xuan; Kang, Yao; Han, Min-Le; Li, Dong-Sheng; Zhang, Jian

2015-06-28

A pair of 3-D homochiral metal-organic frameworks (HMOFs) based on a mixed semi-rigid 5-(2-carboxypyrrolidine-1-carbonyl)isophthalate (PIA) ligand and rigid 4,4'-bipyridine (bipy), [Co3((R)-PIA)2(bipy)3]·6H2O (1-D) and [Co3((S)-PIA)2(bipy)3]·6H2O (1-L) are synthesized and structurally characterized. They are enantiomers and exhibit three-dimensional open frameworks. In each structure, the PIA ligands link the Co centers into homochiral frameworks with large open channels that are occupied by the bipy ligands. Interesting helical chains built from the connectivity between PIA ligands and Co centers are presented. Antiferromagnetic coupling is observed in 1-D. These results demonstrated that the mixed ligand approach is successful for the construction of HMOFs.

A series of Cadmium(II) complexes with 2-substituted terephthalate building block and N-Donor co-ligands: Structural diversity and fluorescence properties

Science.gov (United States)

Ren, Yixia; Zhou, Shanhong; Wang, Zhixiang; Zhang, Meili; Wang, Jijiang; Cao, Jia

2017-11-01

Four new Cd(II) complexes have been prepared based on 1,2,4-trimellitic acid (H3tma) and monosodium 2-sulfoterephthalate (2-NaH2stp), formulated as [Cd2(Htma)2 (dpp)2(H2O)] (1), [Cd3 (tma)2 (2,4-bipy)4(H2O)2] (2), [Cd (2-Hstp) (2,2'-bipy)2]·2H2O (3) and [Cd (2-Hstp) (2,4-bipy) (H2O)2] (4) (dpp = dipyrido [3,2-a:2‧,3'-c] phenazine, 2,4-bipy = 2,4-bipyridine, 2,2'-bipy = 2,2'- bipyridine) by hydrothermal method. X-ray diffraction structural analyses show all these complexes crystallized in triclinic crystal system of Pī space group, but their structures are diverse. Complex 1 exhibits an infinite one-dimensional chain featuring the left- and right-handed stranded chains interweaved each other. For 2, the two-dimensional network is constructed by one-dimensional ladder-like chain linked by Cd2 ions. In complex 3, the cadmium ion is surrounded with one 2-Hstp2- anion and two 2,2'-bipy molecules. Complex 4 is also a discrete structure based on a metallic dimer unit. In all these complexes, the N-donor co-ligands take the important roles in the assembly of three-dimensional supramolecular structures. The fluorescence properties of complexes 1-4 could be assigned to the π - π* transition of organic ligands.

Magneto, spectral and thermal studies of lanthanum and lanthanide(3) bromide and nitrate complexes of 2,2'bipyridine mono N-oxide

International Nuclear Information System (INIS)

Agarwal, R.K.

1988-01-01

Lanthanide(3) bromide and nitrate complexes of 2,2'-bipyridine mono N-oxide (BipyNO) having the composition Ln(BipyNO) 3 Br 3 and Ln(BipyNO) 2 (NO 3 ) 3 (Ln=La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Yb) have been prepared and characterized by means of conductance, molecular weight, magnetic and spectral studies. The ligand acts as a bidentate O,N-chelating agent. The coordination number nine or ten for lanthanide ions has been assigned to these complexes. 3 tabs., 25 refs. (author)

Intermediate-Valence Tautomerism in Decamethylytterbocene Complexes of Methyl-Substituted Bipyridines

Energy Technology Data Exchange (ETDEWEB)

Booth, Corwin H.; Kazhdan, Daniel; Werkema, Evan L.; Walter, Marc D.; Lukens, Wayne W.; Bauer, Eric D.; Hu, Yung-Jin; Maron, Laurent; Eisenstein, Odile; Head-Gordon, Martin; Andersen, Richard A.

2011-01-25

Multiconfigurational, intermediate valent ground states are established in several methyl-substituted bipyridine complexes of bispentamethylcyclopentadienylytterbium, Cp*{sub 2} Yb(Me{sub x}-bipy). In contrast to Cp*{sub 2} Yb(bipy) and other substituted-bipy complexes, the nature of both the ground state and the first excited state are altered by changing the position of the methyl or dimethyl substitutions on the bipyridine rings. In particular, certain substitutions result in multiconfigurational, intermediate valent open-shell singlet states in both the ground state and the first excited state. These conclusions are reached after consideration of single-crystal x-ray diffraction (XRD), the temperature dependence of x-ray absorption near-edge structure (XANES), extended x-ray absorption fine-structure (EXAFS), and magnetic susceptibility data, and are supported by CASSCF-MP2 calculations. These results place the various Cp*{sub 2}Yb(bipy) complexes in a new tautomeric class, that is, intermediate-valence tautomers.

Diverse Cd(II) compounds based on N-benzoyl-L-glutamic acid and N-donor ligands: Structures and photoluminescent properties

Science.gov (United States)

Ma, Ning; Guo, Wei-Ying; Song, Hui-Hua; Yu, Hai-Tao

2016-01-01

Five new Cd(II) coordination polymers with N-benzoyl-L-glutamic acid (H2bzgluO) and different N-donor ligands, [Cd(bzgluO)(2,2‧-bipy)(H2O)]n (1), [Cd(bzgluO)(2,4‧-bipy)2(H2O)·3H2O]n (2), [Cd(bzgluO)(phen)·H2O]n (3), [Cd(bzgluO)(4,4‧-bipy)(H2O)]n (4), [Cd(bzgluO)(bpp)(H2O)·2H2O]n (5) were synthesized (2,2‧-bipy=2,2‧-bipyridine, 2,4‧-bipy=2,4‧-bipyridine, phen=1,10-phenanthroline, 4,4‧-bipy=4,4‧-bipyridine, bpp=1,3-di(4-pyridyl)propane). Compounds 1-2 exhibit a 1D single-chain structure. Compound 1 generates a 2D supramolecular structure via π-π stacking and hydrogen bonding, 3D architecture of compound 2 is formed by hydrogen bonding. Compound 3 features a 1D double-chain structure, which are linked by π-π interactions into a 2D supramolecular layer. Compounds 4-5 display a 2D network structure. Neighboring layers of 4 are extended into a 3D supramolecular architecture through hydrogen bonding. The structural diversity of these compounds is attributed to the effect of ancillary N-donor ligands and coordination modes of H2bzgluO. Luminescent properties of 1-5 were studied at room temperature. Circular dichroism of compounds 1, 2 and 5 were investigated.

Synthesis, spectral and single crystal X-ray structural studies on bis(2,2’-bipyridinesulphidoM(II (M = Cu or Zn and diaqua 2,2’-bipyridine zinc(IIsulphate dihydrate

Directory of Open Access Journals (Sweden)

ARUMUGAM MANOHAR

2010-08-01

Full Text Available Reaction of bis(diethanoldithiocarbamatocopper(II, [Cu(deadtc2] and bis(di-n-propyldithiocarbamatozinc(II, [Zn(dnpdtc2] complexes with 2,2’-bipyridine (2,2’-bipy (1:1 ratio in ethanol was investigated. Simple mixing of the reactants in 1:1 ratio resulted in five-coordinated [Cu(2,2’--bipy2S]•CH3CH2OSO3H (1 and [Zn(2,2’-bipy2S]•CH3CH2OSO3H·2H2O (2. Refluxing the reactants and cooling the contents result in the formation of [Zn(2,2’-bipy(H2O2]SO4 (3 and [Cu(2,2’-bipy(H2O2]SO4 (4. Complexes 1 and 2 are monomeric with trigonal bipyramidal geometry. A distorted octahedral environment was observed in complexes 3 and 4. The crystal structure of 4 has already been reported in the literature. Crystal structures of 1, 2 and 3 are reported in this paper. The M–S distances in 1 and 2 are 2.318(1 Å and 2.323 Å, respectively. The N–M–S angles are larger than the N–M–N angles due to the steric requirements.

Supramolecular compounds of indium sulfates with nitrogen-containing cations

International Nuclear Information System (INIS)

Petrosyants, S.P.; Ilyukhin, A.B.; Ketsko, V.A.

2006-01-01

Compounds with a general formula [Cat][In(H 2 O) n (SO 4 ) 2 ] x · mH 2 O (where Cat = C(NH 2 ) 3 , H(2,2'-Bipy), H 2 (4,4'-Bipy), H 2 [Py(CH 2 ) 3 Py], and H 3 N(CH 2 ) 6 NH 3 ) were synthesized and identified from the elemental analysis, IR, and thermogravimetric analysis data. X-ray diffraction analysis of crystalline [C(NH 2 ) 3 ][In(H 2 O) 2 (SO 4 ) 2 ] complex has shown that the polymer chains of In aqua sulfate form ensembles with guanidinium ions. The structure of [H 2 (4,4'-Bipy)][In 2 (H 2 O) 6 (SO 4 ) 4 ] · 2H 2 O consists of the dimeric anions of indium sulfate. The coordination sphere of In includes three O atoms of three SO 4 groups and three O atoms of water molecules. The dimers are united into framework by diprotonated Bipy cations [ru

Coordination polymers with the chiral ligand N-p-tolylsulfonyl-L-glutamic acid: Influence of metal ions and different bipyridine ligands on structural chirality

International Nuclear Information System (INIS)

He Rong; Song Huihua; Wei Zhen; Zhang Jianjun; Gao Yuanzhe

2010-01-01

Four new polymers, namely [Ni(-tsgluO)(2,4'-bipy) 2 (H 2 O) 2 ] n .5nH 2 O (1), [Co(-tsgluO)(2,4'-bipy) 2 (H 2 O) 2 ] n .5nH 2 O (2), [Ni(-tsgluO)(4,4'-bipy)] n .0.5nH 2 O (3), and [Co(-tsgluO)(4,4'-bipy)] n .0.5nH 2 O (4), where tsgluO 2- =(+)-N-p-tolylsulfonyl-L-glutamate dianion, 2,4'-bipy=2,4'-bipyridine, and 4,4'-bipy=4,4'-bipyridine, have been prepared and structurally characterized. Compounds 1 and 2 are isostructural and mononuclear, and crystallize in the acentric monoclinic space group Cc, forming 1D chain structures. Compound 3 is also mononuclear, but crystallizes in the chiral space group P2 1 , forming a homochiral 2D architecture. In contrast to the other complexes, compound 4 crystallizes in the space group P-1 and is composed of binuclear [Co 2 O 6 N 2 ] n 4- units, which give rise to a 2D bilayer framework. Moreover, compounds 1, 2, and 4 self-assemble to form 3D supramolecular structures through π-π stacking and hydrogen-bonding interactions, while compound 3 is further hydrogen-bonded to form 3D frameworks. We have demonstrated the influence of the central metal and bipyridine ligands on the framework chirality of the coordination complexes. - Graphical abstract: Four novel polymers based on a chiral ligand were prepared and structurally characterized; it represents the first series of investigations about the effect of central metals and bipyridine ligands on framework chirality.

Specificity of the second binding protein of the peptide ABC-transporter (Dpp) of Lactococcus lactis IL1403

NARCIS (Netherlands)

Sanz, Y; Toldra, F; Renault, P; Poolman, B

2003-01-01

The genome sequence of Lactococcus lactis IL1403 revealed the presence of a putative peptide-binding protein-dependent ABC-transporter (Dpp). The genes for two peptide-binding proteins (dppA and dppP) precede the membrane components, which include two transmembrane protein genes (dppB and dppC) and

Uranyl citrate dimers as guests in a copper-bipyridine framework: a novel hetero-metallic inorganic-organic hybrid compound

International Nuclear Information System (INIS)

Thuery, P.

2007-01-01

Reaction of uranyl nitrate with citric acid (H 4 cit) in the presence of copper(II) bis(tri-fluoro-methane-sulfonate) and 4,4'-bipyridine (bipy) under hydrothermal conditions gave the mixed complex[Cu(bipy) 2 (H 2 O) 2 ][UO 2 (Hcit)(H 2 O)] 2 .5H 2 O, in which di-anionic uranyl citrate dimers are incorporated in the interlayer spaces of the [Cu(bipy) 2 (H 2 O) 2 ] n 2n+ square grid assemblage. An extended hydrogen bonding network links the uranyl complex units together and also to the grid framework, resulting in the formation of a 3-D assemblage held by weak interactions. (author)

Synthesis and electrochemistry of tri- and tetranuclear polypyridine derivations of ruthenium

International Nuclear Information System (INIS)

Francis, A.M.A.

1990-01-01

The synthesis of clusters of ruthenium is the focus of this work. The electrochemistry of metal cluster derivatives of ruthenium, iron and osmium are reviewed. The ability of these compounds to undergo more than one electron transfer reaction and to act as electron reservoirs is evident. The synthesis and characterisation of a range of polypyridine derivatives of [Ru 3 (CO) 12 ]; [Ru 3 (CO) 10 (napy)]; [Ru 3 (CO) 10 (bipy)]; [Ru 4 H 4 (CO) 12 ]; [Ru 4 H 4 (CO) 8 (bipy) 2 ] and [Ru 4 H 4 (CO) 10 (bipy)] were dealt with. The crystal structures of [Ru 3 (CO) 10 (napy)] and [Ru 4 H 4 (CO) 10 (bipy)] were also determined. The six compounds were fully investigated and a mechanism for their electrochemical reduction was postulated based on their observed experimental data, and that of the relevant compounds. The techniques used are also described and a brief introduction to the actual theory and practise of these techniques is discussed. 132 refs., 33 figs., 22 tabs

Thorium(IV) and zirconium(IV) complexes of oxygen donor ligands. Pt. 12

International Nuclear Information System (INIS)

Agarwal, R.K.; Jain, P.C.; Kapur, V.; Sharma, S.; Srivastava, A.K.

1980-01-01

Crystalline thorium (IV) chelates with mono N-oxides of 2,2'-bipyridine (bipyNO) and 1,10-phenanthroline (phenNO), ThX 4 x 2L(X = Cl,Br,NO 3 or NCS) and ThX 4 x 3L(X = I or ClO 4 and L = bipyNO or phenNO) have been synthesised and characterized on the basis of i.r. spectra, molar conductance, molecular weights, t.g.a. and d.t.a. data. All the complexes are weakly diamagnetic and contain bipyNO and phenNO bonded to thorium(IV) through nitrogen and oxygen. The coordination number of thorium(IV) varies from six to twelve depending on the nature of the anions. (orig.) [de

New dinuclear palladium(II) complexes: Studies of the nucleophilic substitution reactions, DNA/BSA interactions and cytotoxic activity.

Science.gov (United States)

Ćoćić, Dušan; Jovanović, Snežana; Nišavić, Marija; Baskić, Dejan; Todorović, Danijela; Popović, Suzana; Bugarčić, Živadin D; Petrović, Biljana

2017-10-01

Six new dinuclear Pd(II) complexes, [{Pd(2,2'-bipy)Cl} 2 (μ-pz)](ClO 4 ) 2 (Pd1), [{Pd(dach)Cl} 2 (μ-pz)](ClO 4 ) 2 (Pd2), [{Pd(en)Cl} 2 (μ-pz)](ClO 4 ) 2 (Pd3), [{Pd(2,2'-bipy)Cl} 2 (μ-4,4'-bipy)](ClO 4 ) 2 (Pd4), [{Pd(dach)Cl} 2 (μ-4,4'-bipy)](ClO 4 ) 2 (Pd5) and [{Pd(en)Cl} 2 (μ-4,4'-bipy)](ClO 4 ) 2 (Pd6) (where 2,2'-bipy=2,2'-bipyridyl, pz=pyrazine, dach=trans-(±)-1,2-diaminocyclohexane, en=ethylenediamine, 4,4'-bipy=4,4'-bipyridyl) have been synthesized and characterized by elemental microanalysis, IR, 1 H NMR and MALDI-TOF mass spectrometry. The pK a values of corresponding diaqua complexes were determined by spectrophotometric pH titration. Substitution reactions with thiourea (Tu), l-methionine (l-Met), l-cysteine (l-Cys), l-histidine (l-His) and guanosine-5'-monophosphate (5'-GMP) were studied under the pseudo-first order conditions at pH7.2. Reactions of Pd1 with Tu, l-Met and l-Cys were followed by decomposition of complexes, while structures of dinuclear complexes were preserved during the substitution with nitrogen donors. Interactions with calf-thymus DNA (CT-DNA) were followed by absorption spectroscopy and fluorescence quenching measurements. All complexes can bind to CT-DNA exhibiting high intrinsic binding constants (K b =10 4 -10 5 M -1 ). Competitive studies with ethidium bromide (EB) have shown that complexes can displace DNA-bound EB. High values of binding constants towards bovine serum albumin protein (BSA) indicate good binding affinity. Finally, all complexes showed moderate to high cytotoxic activity against HeLa (human cervical epithelial carcinoma cell lines) and MDA-MB-231 (human breast epithelial carcinoma cell lines) tumor cell lines inducing apoptotic type cell death, whereas normal fibroblasts were significantly less sensitive. The impact on cell cycle of these cells was distinctive, where Pd4, Pd5 and Pd6 showed the most prominent effect arresting MDA-MB-231 (human lung fibroblast cell lines) cell in G1/S phase of cell

Synthesis and Reactivity of a Cerium(III Scorpionate Complex Containing a Redox Non-Innocent 2,2′-Bipyridine Ligand

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Fabrizio Ortu

2015-11-01

Full Text Available The Ce(III hydrotris(3,5-dimethylpyrazolylborate complex [Ce(TpMe22(κ2-dmpz] (1 (TpMe2 = {HB(dmpz3}−; dmpz = 3,5-dimethylpyrazolide was isolated in fair yield from the reaction of [Ce(I3(THF4] with two equivalents of [K(TpMe2] via the facile decomposition of TpMe2. [Ce(TpMe22(bipy] (2 was synthesized in poor yield by the “one-pot” reaction of [Ce(I3(THF4], bipy (bipy = 2,2′-bipyridine, KC8 and two equivalents of [K(TpMe2] in tetrahydrofuran (THF. The reaction of 2 with N-methylmorpholine-N-oxide produced the known decomposition product [Ce(TpMe2(μ-BOpMe2]2 (3 (BOpMe2 = {HBO(dmpz2}2− in poor yield, presumably by N–O and B–N bond cleavage of a reactive intermediate. The reaction of 2 with trimethylsilylazide gave [Ce(TpMe22(N3] (4 in poor yield; the fate of bipy and the trimethylsilyl group is unknown. Complexes 1–4 were characterized by single crystal XRD, NMR and FTIR spectroscopy and elemental analysis. Complex 2 was additionally probed by UV/Vis/NIR and Electron Paramagnetic Resonance (EPR spectroscopies, Cyclic Voltammetry (CV and magnetometry, which together indicate a formal 4f1 Ce(III center coordinated by a bipy·− radical anion in this system.

Synthesis and characterization of μ-hydroxido- and μ-polycarboxylato-bridged iron(III complexes with 2,2’-bipyridine

Directory of Open Access Journals (Sweden)

Tasić Nikola

2014-01-01

Full Text Available Four novel polymeric iron(III complexes with 2,2’-bipyridine (bipy and different aromatic polycarboxylato ligands as anions of phthalic (pht, isophthalic (ipht, terephthalic (tpht and pyromellitic (pyr acid were synthesized by ligand exchange reaction. The complexes were characterized by elemental and TG/DSC analysis, FTIR and diffuse reflectance UV-VIS-NIR spectroscopy and magnetic susceptibility measurements. Based on analytical and spectral data the formulae of the complexes are {[Fe4(bipy2 (H2O2(OH6(pht3]•2H2O}n (1, {[Fe4(bipy2(Hipht2(ipht2(OH6]•4H2O}n (2, {[Fe4(bipy2(Htpht2(OH6(tpht2]•4H2O}n (3 and {[Fe4(bipy(H2O8(OH4 (pyr2]•H2O}n (4. All complexes are red brown and low-spin with a distorted octahedral geometry and FeO6 or FeN2O4 chromophore. Polycarboxylato ligands have a bridging role in all cases, whereas monodentate COO groups are present in 2 and 3, bridging and chelate COO groups are established in 1 and 4. The thermal behaviour of 1-4 was investigated in detail and the molar dehydration enthalpies were calculated. According to the all those results, the structural formulae of the complexes 1-4 were proposed. [Projekat Ministarstva nauke Republike Srbije, br. III45007

Towards Behaviorally Informed Public Interventions

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Karol Olejniczak

2015-06-01

Full Text Available Purpose: This article informs readers about the theoretical and practical origins of the behaviorally informed interventions (BIPI, analyzes examples of the BIPI from different policy sectors and strategies they offer for policy and regulatory design, and discusses applications and implications of BIPI for public interventions Methodology: This paper is based on a review of literature, as well as an inspection of administrative practices in OECD countries. It encompasses a systematic analysis of scientific papers fromthe SCOPUS database and a query carried out at the library of George Washington University. Findings: The traditional approach to public policy research is based on rational choice theory. It offers limited support, because by assuming perfect rationality of policy decisions, it overlooks existence of systematic errors and biases of human decision-making. The authors argue that behaviorally informed public interventions (BIPI might contribute to improving the effectiveness of a number of public measures – regulation, projects, programs, and even entire policies. Practical implications: The behavioral approach allows decision-makers to better understand the decisions and behaviors of citizens, as well as to design more effective interventions with minimum effort by adapting the existing solutions to real decision mechanisms of citizens. Originality: By combining the concepts of traditional approach with the growing behavioral approach, the authors aim to propose a new theoretical framework (BIPI to be used as a tool for policy design, delivery and evaluation.

Electropolymerized supramolecular tetraruthenated porphyrins applied as a voltammetric sensor

Energy Technology Data Exchange (ETDEWEB)

Silva, Monize M. da; Ribeiro, Gabriel H.; Faria, Anizio M. de; Bogado, Andre L.; Dinelli, Luis R., E-mail: dinelli@pontal.ufu.br [Universidade Federal de Uberlandia (UFU), Ituiutaba, MG (Brazil). Faculdade de Ciencias Integradas do Pontal; Batista, Alzir A. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica

2013-11-15

Porphyrin 5,10,15,20-Tetra(4-pyridyl)manganese(III), [Mn-TPyP(H{sub 2}O){sub 2}]PF{sub 6}, and electropolymerized supramolecular porphyrins (ESP), {l_brace}Mn-TPyP(H{sub 2}O){sub 2}[RuCl{sub 3}(dppb)]{sub 4}{r_brace}PF{sub 6} (dppb = 1,4-bis(diphenylphosphine)butane), were synthesized and characterized. A thin solid film of ESP was obtained on a glass carbon electrode surface by a cyclic voltammetry method. The peak current increased with the number of voltammetric cycles, which shows a typical behavior of the species being adsorbed on the surface of the electrode. Cyclic voltammetry was also employed for acetaminophen quantification using an ESP modified electrode. The modified electrode shows a linear relationship between the anodic peak current and the concentration of acetaminophen (in the rage 0.05 to 0.7 mmol L{sup -1}. The performance of the modified electrode was verified by the determination of acetaminophen in a commercial pharmaceutical product and the results were in good agreement with those obtained by a control HPLC method. (author)

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

The activity of the [Mn(bipy)2]2+/HMS catalyst differs with the type of the solvent and in this case, acetonitrile gives the best conversion results. The kinetic of benzyl alcohol oxidation was investigated at temperatures of 27, 46, 60, 75 and 90°C using [Mn(bipy)2]2+/HMS and excess TBHP. The order of reaction with respect to ...

Preparation and properties of a calcium(II)-based molecular chain decorated with manganese(II) butterfly-like complexes.

Science.gov (United States)

Benniston, A C; Melnic, S; Turta, C; Arauzo, A B; Bartolomé, J; Bartolomé, E; Harrington, R W; Probert, M R

2014-09-21

The room temperature reaction of [Mn2O2(bipy)4](ClO4)3 (bipy = 2,2'-bipyridine) with Ca(CHCl2COO)2 in methanol produced a yellow crystalline material. The X-ray determined structure comprises of a multiple calcium(II) carboxylate bridged chain-like structure which is decorated with [Mn(bipy)2(OH2)](2+) subunits. The redox behaviour for the complex in H2O and MeCN is reported. In the latter solvent the oxidation of the manganese ions appears to be facilitated by the presence of the calcium ions. Magnetic susceptibility and low temperature magnetization measurements show that the Mn moment is isotropic, with g = 1.99(1) and S = 5/2, confirming it is in the 2+ oxidation state. A very weak antiferromagnetic interaction is also detected. Frequency-dependent ac measurements evidence slow magnetic relaxation of the Mn(bipy)2 units. Two relaxation mechanisms are identified: a very slow direct process and a faster one caused by the Resonant Phonon Trapping mechanism. This is the first example of field-induced single ion magnet (SIM) behavior in a mononuclear Mn(II) complex.

Hydrothermal synthesis and characterization of a binuclear complex and a coordination

Directory of Open Access Journals (Sweden)

Reza Mohamadinasab

2010-06-01

Full Text Available Two new copper complexes [(bipy(pydcCu(μ-OCO-pydcCu(bipy(H2O].3.5H¬2O (1 and {[(μ2-C2O4(2,2'-bipyCu].2H2O}n (2 (pydcH2 = pyridine-2,6-dicarboxylilic acid, bipy = 2,2'-bipyridine have been hydrothermally synthesized. Both complexes were characterized by IR spectroscopy, elemental analysis and single crystal X-ray diffraction studies. Complex 1 consists of two independent neutral molecules. In every moiety, metal ion center is in a distorted octahedral geometry. Coordination polymer (2 has been prepared from the reaction of bis-(cyclohexanone-oxal-dihydrazone,2,2'-bipyridine and Cu(NO32 in basic solution and under hydrothermal condition. The results showed that the bis-(cyclohexanone-oxal-dihydrazone was converted to oxalate ion under heating and basic pH. Each metal ion center in 2 is in a distorted octahedral geometry and is coordinated by four oxygen atoms of two bridged oxalate ions and two nitrogen atoms of 2,2'-bipyridine molecules. In the crystal structure of 2, some H-bonds and π-π interaction cause formation of a 3D network.

Lanthanide modification of CdSe/ZnS core/shell quantum dots

DEFF Research Database (Denmark)

Dethlefsen, Johannes Rytter; Mikhailovsky, Alexander A.; Burks, Peter T.

2012-01-01

Lanthanide-modified CdSe quantum dots (CdSe(Ln) QDs) have been prepared by heating a solution of Cd(oleate)(2), SeO2, and Ln(bipy)(S2CNEt2)(3) (bipy = 2,2'-bipyridine) to 180-190 degrees C for 10-15 min. The elemental compositions of the resulting CdSe(Ln) cores and CdSe(Ln)/ZnS core/shell QDs show...

Crystal structures of tetramethylammonium (2,2′-bipyridinetetracyanidoferrate(III trihydrate and poly[[(2,2′-bipyridine-κ2N,N′di-μ2-cyanido-dicyanido(μ-ethylenediamine(ethylenediamine-κ2N,N′cadmium(IIiron(II] monohydrate

Directory of Open Access Journals (Sweden)

Songwuit Chanthee

2016-05-01

Full Text Available The crystal structures of the building block tetramethylammonium (2,2′-bipyridine-κ2N,N′tetracyanidoferrate(III trihydrate, [N(CH34][Fe(CN4(C10H8N2]·3H2O, (I, and a new two-dimensional cyanide-bridged bimetallic coordination polymer, poly[[(2,2′-bipyridine-κ2N,N′di-μ2-cyanido-dicyanido(μ-ethylenediamine-κ2N:N′(ethylenediamine-κ2N,N′cadmium(IIiron(II] monohydrate], [CdFe(CN4(C10H8N2(C2H8N22]·H2O, (II, are reported. In the crystal of (I, pairs of [Fe(2,2′-bipy(CN4]− units (2,2′-bipy is 2,2′-bipyridine are linked together through π–π stacking between the pyridyl rings of the 2,2′-bipy ligands to form a graphite-like structure parallel to the ab plane. The three independent water molecules are hydrogen-bonded alternately with each other, forming a ladder chain structure with R44(8 and R66(12 graph-set ring motifs, while the disordered [N(CH34]+ cations lie above and below the water chains, and the packing is stabilized by weak C—H...O hydrogen bonds. The water chains are further linked with adjacent sheets into a three-dimensional network via O—H...O hydrogen bonds involving the lattice water molecules and the N atoms of terminal cyanide groups of the [Fe(2,2′-bipy(CN4]− building blocks, forming an R44(12 ring motif. Compound (II features a two-dimensional {[Fe(2,2′-bipy(CN4Cd(en2]}n layer structure (en is ethylenediamine extending parallel to (010 and constructed from {[Fe(2,2′-bipy(CN4Cd(en]}n chains interlinked by bridging en ligands at the Cd atoms. Classical O—H...N and N—H...O hydrogen bonds involving the lattice water molecule and N atoms of terminal cyanide groups and the N—H groups of the en ligands are observed within the layers. The layers are further connected via π–π stacking interactions between adjacent pyridine rings of the 2,2′-bipy ligands, completing a three-dimensional supramolecular structure.

Bis(2,2'-bipyridyl-κN,N')(carbonato-κO,O')cobalt(III) bromide trihydrate.

Science.gov (United States)

Ma, Peng-Tao; Wang, Yu-Xia; Zhang, Guo-Qian; Li, Ming-Xue

2007-12-06

The title complex, [Co(CO(3))(C(10)H(8)N(2))(2)]Br·3H(2)O, is isostructural with the chloride analogue. The six-coordinated octahedral [Co(2,2'-bipy)(2)CO(3)](+) cation (2,2'-bipy is 2,2'-bipyrid-yl), bromide ion and water mol-ecules are linked together via O-H⋯Br and O-H⋯O hydrogen bonds, generating a one-dimensional chain.

Synthesis and Crystal Structure of a 4,4'-bipyridine Linked Dinuclear Copper(II) Complex Derived from 2-{[2-(2-hydroxyethylamino)ethylimino]methyl}-6-methylphenol.

Science.gov (United States)

Zhang, Xiu-Zhen; Gu, Yitong; Li, Yuntong; Liu, Andong; Liu, Fuyao; You, Zhonglu; Zhu, Hai-Liang

2016-12-01

A novel 4,4'-bipyridine linked dinuclear copper(II) complex, [Cu2L2(bipy)](NO3)2·bipy (L = 2-[2-(2-hydroxyethylamino) ethylimino]methyl-6-methylphenol; bipy = 4,4'-bipyridine), was prepared and characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction. The Cu···Cu distance is 11.129(2) Å. The CuII atom is coordinated by one phenolate O, one imine N, and one amine N atoms of a Schiff base ligand, and one N atom of the bridging 4,4'-bipyridine ligand, forming a square planar geometry. In the crystal structure of the complex, the dinuclear copper complex cations are linked by 4,4'-bipyridine molecules through intermolecular O-H···N hydrogen bonds, to form 1D chains running in the [2 0 -1] direction.

A tristable [2]pseudo[2]rotaxane

KAUST Repository

Trabolsi, Ali

2010-01-01

A strategy towards increasing the lifetime of the metastable state of a [2]rotaxane incorporating tetrathiafulvalene, 1,5-dioxynaphthalene and bipyridinium (BIPY 2+) is presented. Incorporation of BIPY 2+ served multiple roles as an electrostatic barrier to relaxation, a supramolecular recognition site for bis-1,5-dioxynaphthalene[38]crown-10 macrocycle, and upon reduction a recognition site for the mechanically bonded cyclobis(paraquat-p-phenylene) ring. © The Royal Society of Chemistry 2010.

(PSNP) to Household Asset Building in Selected Kebeles of K

African Journals Online (AJOL)

user

resources in cash and in kind have been transferred to the beneficiaries for .... and micro-credit programs. ... Since the latter is the major factor, SNNP-DPPB further grouped ... data of a typical household in each wealth group for the year ...... N. P im p act o n h o u seh o ld assets. a b. In creased. M ain tain ed. 8. 1. (4. 0 .5. ).

Bis(2,2′-bipyridyl-κ2 N,N′)(carbonato-κ2 O,O′)cobalt(III) bromide trihydrate

Science.gov (United States)

Ma, Peng-Tao; Wang, Yu-Xia; Zhang, Guo-Qian; Li, Ming-Xue

2008-01-01

The title complex, [Co(CO3)(C10H8N2)2]Br·3H2O, is isostructural with the chloride analogue. The six-coordinated octahedral [Co(2,2′-bipy)2CO3]+ cation (2,2′-bipy is 2,2′-bipyrid­yl), bromide ion and water mol­ecules are linked together via O—H⋯Br and O—H⋯O hydrogen bonds, generating a one-dimensional chain. PMID:21200495

Poly[[(μ4-benzene-1,3,5-tricarboxylato-κ4O1:O1′:O2:O3bis(2,2-bipyridine-κ2N,N′(μ2-hydroxidodicopper(II] trihydrate

Directory of Open Access Journals (Sweden)

Mohamed N. El-kaheli

2014-07-01

Full Text Available In the title two-dimensional coordination polymer, {[Cu2(C9H3O6(OH(C10H8N22]·3H2O}n, each of the two independent CuII atoms is coordinated by a bridging OH group, two O atoms from two benzene-1,3,5-tricarboxylate (L ligands and two N atoms from a 2,2- bipyridine (bipy ligand in a distorted square-pyramidal geometry. Each L ligand coordinates four CuII atoms, thus forming a polymeric layer parallel to the bc plane with bipy molecules protruding up and down. The lattice water molecules involved in O—H...· O hydrogen bonding are situated in the inner part of each layer. The crystal packing is consolidated by π–π interactions between the aromatic rings of bipy ligands from neigbouring layers [intercentroid distance = 3.762 (3 Å].

Design and construction of diverse structures of coordination polymers: Photocatalytic properties

Energy Technology Data Exchange (ETDEWEB)

Wu, Yu, E-mail: wuyuhlj@163.com [College of Chemistry and Environmental Engineering, Sichuan University of Science & Engineering, Zigong 643000 (China); Institute of Functional Materials, Sichuan University of Science & Engineering, Zigong 643000 (China); Lu, Lu [College of Chemistry and Environmental Engineering, Sichuan University of Science & Engineering, Zigong 643000 (China); Institute of Functional Materials, Sichuan University of Science & Engineering, Zigong 643000 (China); Feng, Jianshen [Institute of Functional Materials, Sichuan University of Science & Engineering, Zigong 643000 (China); Li, Yulong; Sun, Yanchun [College of Chemistry and Environmental Engineering, Sichuan University of Science & Engineering, Zigong 643000 (China); Institute of Functional Materials, Sichuan University of Science & Engineering, Zigong 643000 (China); Ma, Aiqing, E-mail: maqandght@126.com [School of Pharmacy, Guangdong Medical University, Dongguan 523808 (China)

2017-01-15

The reaction of Cu(NO{sub 3}){sub 2}·3H{sub 2}O/Ni(NO{sub 3}){sub 2}·6H{sub 2}O with 4′-(4-(3,5-dicarboxylphenoxy)phenyl)-4,2′:6′,4′′-terpyridine (H{sub 2}dbp) gave [Cu{sub 0.5}(Hdbp)]{sub n} (1) and [Ni(dbp)(H{sub 2}O)]{sub n} (2), while the reactions of Co(NO{sub 3}){sub 2}·6H{sub 2}O with H{sub 2}dbp in the presence of 4,4′-bipy and 2,2′-bpy generated [Co(dbp)(4,4′-bipy)]{sub n} (3) and ([Co(dbp)(2,2′-bipy)]{sub n}·H{sub 2}O) (4), respectively (4,4′-bipy=4.4′-pyridine and 2,2′-bipy=2,2′-bipyridine). X-Ray single-crystal analyses reveal that 1 contains a 1D double chain. 2 possesses a 3D architecture with (4.6{sup 2}0.8{sup 3}){sub 2} topology that is interpenetrated with each other to form a 2-fold network. In 3, the 2D [Co(dbp)]n sheets are pillared by 4,4′-bpy to form a 3D framework with 1D open channel. Compound 4 consists of a 1D ladder-like chain. The results showed that the structural diversity of the coordination polymers resulted from the different geometries of metal ions and effect of assistant ligands. Furthermore, the photocatalytic properties of 1–4 for degradation of the methyl violet (MV) have been examined. - Graphical abstract: The photocatalytic activity and selectivity of complexes 1–4 prove that they may be good and stable photocatalysts for degradation of organic dyes.

Entangled zinc-ditetrazolate frameworks involving in situ ligand synthesis and topological modulation by various secondary N-donor ligands

International Nuclear Information System (INIS)

Li Yunwu; Chen Weilin; Wang Yonghui; Li Yangguang; Wang Enbo

2009-01-01

The introduction of various secondary N-donor ligands into an in situ ditetrazolate-ligand synthesis system of terephthalonitrile, NaN 3 and ZnCl 2 led to the formation of three new entangled frameworks Zn(pdtz)(4,4'-bipy).3H 2 O (1), [Zn(pdtz)(bpp)] 2 .3H 2 O (2) and Zn(pdtz) 0.5 (N 3 )(2,2'-bipy) (3) (4,4'-bipy=4,4'-bipyridine; bpp=1,3-bis(4-pyridyl)propane; 2,2'-bipy=2,2'-bipyridine; H 2 pdtz=5,5'-1,4-phenylene-ditetrazole). The formation of pdtz 2- ligand involves the Sharpless [2+3] cycloaddition reaction between terephthalonitrile and NaN 3 in the presence of Zn 2+ ion as a Lewis-acid catalyst under hydrothermal conditions. Compound 1 exhibits a fivefold interpenetrating 3D framework based on the diamondoid topology. Compound 2 displays a twofold parallel interpenetrating framework based on the wavelike individual network. Compound 3 possesses a 2D puckered network. These new Zn-ditetrazolate frameworks are highly dependent on the modulation of different secondary N-donor ligands. Their luminescent properties were investigated. - Graphical abstract: Three new entangled frameworks were prepared by an in situ ditetrazolate-ligand synthesis system assisted with various auxiliary N-donor ligands. The entangled structures can be modulated by different secondary ligands.

Efficient tetracycline adsorption and photocatalytic degradation of rhodamine B by uranyl coordination polymer

Science.gov (United States)

Ren, Ya-Nan; Xu, Wei; Zhou, Lin-Xia; Zheng, Yue-Qing

2017-07-01

Two mixed uranyl-cadmium malonate coordination polymers [(UO2)2Cd(H-bipy)2(mal)4(H2O)2]·4H2O 1 and [(UO2)Cd(bipy)(mal)2]·H2O 2 (H2mal = malonic acid, bipy =4,4‧-bipyridine) have been synthesized in room temperature. Compound 1 represents a one-dimensional (1D) chain assembly of Cd(II) ions, uranyl centers and malonate ligands. Compound 2 exhibits a two-dimensional (2D) 2D +2D → 3D polycatenated framework based on inclined interlocked 2D 44 sql grids. The two compounds have been characterized by elemental analysis, IR and UV-vis spectroscopy, thermal analysis, powder X-ray diffraction and photoluminescence spectroscopy. And the ferroelectric property of 2 also has been studied. Moreover, compound 2 exhibits good photocatalytic activity for dye degradation under UV light and is excellent adsorbent for removing tetracycline antibiotics in the aqueous solution.

Synthesis, crystal structure and applications of palladium thiosalicylate complexes

Directory of Open Access Journals (Sweden)

S.B. Moosun

2017-05-01

Full Text Available Three palladium thiosalicylate complexes [Pd(tb(bipy]·3H2O (1, [Pd2(tb2(bipy2]·(dtdb2 (2 and [Pd2(tb2(phen2]·dtdb·H2O (3 (bipy = bipyridine; phen = phenanthroline were prepared from the reaction of PdCl2(CH3CN2 with dithiosalicylic acid (dtdb which underwent cleavage to form thiobenzoate anion (tb in DMF/MeOH. Square planar geometries of the complexes with a N2SO coordination type were proposed on the basis of single crystal X-ray structural study. The presence of trapped and uncoordinated dtdb was observed in complexes 2 and 3. Complexes 1–3 were evaluated as catalysts for Heck coupling reactions of methyl acrylate with iodobenzene, and showed moderate activities at a very low catalyst loading. Complex 1 was found to inhibit the growth of bacteria and scavenge free radicals efficiently.

Diverse Cd(II) compounds based on N-benzoyl-L-glutamic acid and N-donor ligands: Structures and photoluminescent properties

International Nuclear Information System (INIS)

Ma, Ning; Guo, Wei-Ying; Song, Hui-Hua; Yu, Hai-Tao

2016-01-01

Five new Cd(II) coordination polymers with N-benzoyl-L-glutamic acid (H_2bzgluO) and different N-donor ligands, [Cd(bzgluO)(2,2′-bipy)(H_2O)]_n (1), [Cd(bzgluO)(2,4′-bipy)_2(H_2O)·3H_2O]_n (2), [Cd(bzgluO)(phen)·H_2O]_n (3), [Cd(bzgluO)(4,4′-bipy)(H_2O)]_n (4), [Cd(bzgluO)(bpp)(H_2O)·2H_2O]_n (5) were synthesized (2,2′-bipy=2,2′-bipyridine, 2,4′-bipy=2,4′-bipyridine, phen=1,10-phenanthroline, 4,4′-bipy=4,4′-bipyridine, bpp=1,3-di(4-pyridyl)propane). Compounds 1–2 exhibit a 1D single-chain structure. Compound 1 generates a 2D supramolecular structure via π–π stacking and hydrogen bonding, 3D architecture of compound 2 is formed by hydrogen bonding. Compound 3 features a 1D double-chain structure, which are linked by π–π interactions into a 2D supramolecular layer. Compounds 4-5 display a 2D network structure. Neighboring layers of 4 are extended into a 3D supramolecular architecture through hydrogen bonding. The structural diversity of these compounds is attributed to the effect of ancillary N-donor ligands and coordination modes of H_2bzgluO. Luminescent properties of 1–5 were studied at room temperature. Circular dichroism of compounds 1, 2 and 5 were investigated. - Graphical abstract: Five new Cd(II) metal coordination compounds with H_2bzgluO and different N-donor ligands were synthesized and characterized. Compounds 1, 2 and 3 present 1D structures, compounds 4 and 5 display 2D networks. Results indicate that auxiliary ligands and coordination modes of H_2bzgluO play an important role in governing the formation of final frameworks, and the hydrogen-bonding and π–π stacking interactions contribute the formation of the diverse supramolecular architectures. Furthermore, the different crystal structures influence the emission spectra significantly. - Highlights: • It is rarely reported that complexes prepared with N-benzoyl-L-glutamic acid. • Each complex displays diverse structures and different supramolecular

A chemical approach toward low temperature alloying of immiscible iron and molybdenum metals

Energy Technology Data Exchange (ETDEWEB)

Nazir, Rabia [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Applied Chemistry Research Centre, Pakistan Council of Scientific and Industrial Research Laboratories Complex, Lahore 54600 (Pakistan); Ahmed, Sohail [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Mazhar, Muhammad, E-mail: mazhar42pk@yahoo.com [Department of Chemistry, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Akhtar, Muhammad Javed; Siddique, Muhammad [Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); Khan, Nawazish Ali [Material Science Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Shah, Muhammad Raza [HEJ Research Institute of Chemistry, University of Karachi, Karachi 75270 (Pakistan); Nadeem, Muhammad [Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)

2013-11-15

Graphical abstract: - Highlights: • Low temperature pyrolysis of [Fe(bipy){sub 3}]Cl{sub 2} and [Mo(bipy)Cl{sub 4}] homogeneous powder. • Easy low temperature alloying of immiscible metals like Fe and Mo. • Uniform sized Fe–Mo nanoalloy with particle size of 48–68 nm. • Characterization by EDXRF, AFM, XRPD, magnetometery, {sup 57}Fe Mössbauer and impedance. • Alloy behaves as almost superparamagnetic obeying simple –R(CPE)– circuit. - Abstract: The present research is based on a low temperature operated feasible method for the synthesis of immiscible iron and molybdenum metals’ nanoalloy for technological applications. The nanoalloy has been synthesized by pyrolysis of homogeneous powder precipitated, from a common solvent, of the two complexes, trisbipyridineiron(II)chloride, [Fe(bipy){sub 3}]Cl{sub 2}, and bipyridinemolybedenum(IV) chloride, [Mo(bipy)Cl{sub 4}], followed by heating at 500 °C in an inert atmosphere of flowing argon gas. The resulting nanoalloy has been characterized by using EDXRF, AFM, XRD, magnetometery, {sup 57}Fe Mössbauer and impedance spectroscopies. These results showed that under provided experimental conditions iron and molybdenum metals, with known miscibility barrier, alloy together to give (1:1) single phase material having particle size in the range of 48–66 nm. The magnetism of iron is considerably reduced after alloy formation and shows its trend toward superparamagnetism. The designed chemical synthetic procedure is equally feasible for the fabrication of other immiscible metals.

Insertion reactions into Pd[bond]O and Pd[bond]N bonds: preparation of alkoxycarbonyl, carbonato, carbamato, thiocarbamate, and thioureide complexes of palladium(II).

Science.gov (United States)

Ruiz, José; Martínez, M Teresa; Florenciano, Félix; Rodríguez, Venancio; López, Gregorio; Pérez, José; Chaloner, Penny A; Hitchcock, Peter B

2003-06-02

Mononuclear palladium hydroxo complexes of the type [Pd(N[bond]N)(C(6)F(5))(OH)] [(N[bond]N = 2,2'-bipyridine (bipy), 4,4'-dimethyl-2,2'-bipyridine (Me(2)bipy), 1,10-phenanthroline (phen), or N,N,N',N'-tetramethylethylenediamine (tmeda)] have been prepared by reaction of [Pd(N[bond]N)(C(6)F(5))(acetone)]ClO(4) with KOH in methanol. These hydroxo complexes react, in methanol, with CO (1 atm, room temperature) to yield the corresponding methoxycarbonyl complexes [Pd(N[bond]N)(C(6)F(5))(CO(2)Me)]. Similar alkoxycarbonyl complexes [Pd(N[bond]N)(C(6)F(5))(CO(2)R)] (N[bond]N = bis(3,5-dimethylpyrazol-1-yl)methane); R = Me, Et, or (i)Pr) are obtained when [Pd(N[bond]N)(C(6)F(5))Cl] is treated with KOH in the corresponding alcohol ROH and CO is bubbled through the solution. The reactions of [Pd(N[bond]N)(C(6)F(5))(OH)] (N[bond]N = bipy or Me(2)bipy) with CO(2), in tetrahydrofuran, lead to the formation of the binuclear carbonate complexes [(N[bond]N)(C(6)F(5))Pd(mu-eta(2)-CO(3))Pd(C(6)F(5))(N[bond]N)]. Complexes [Pd(N[bond]N)(C(6)F(5))(OH)] react in alcohol with PhNCS to yield the corresponding N-phenyl-O-alkylthiocarbamate complexes [Pd(N[bond]N)(C(6)F(5))[SC(OR)NPh

One pot synthesis, structure and magnetic property of a pseudo-interpenetrated 2D copper framework based on coordinated 1,1‧-biphenyl-3,3‧,5,5‧-tetracarboxylate and synthon

Science.gov (United States)

Su, Feng; Lu, Liping; Zhu, Miaoli; Feng, Sisi

2016-03-01

A mixture of 1,1‧-biphenyl-3,3‧,5,5‧-tetracarboxylate acid (abbreviated as H4bpta), 4,4‧-bipyridine (abbreviated as 4,4‧-bipy), and CuCl2·2H2O generates co-crystallization supramolecular solids [Cu2(cis-H2bpta)2(4,4‧-bipy)2]n·nH4bpta·2nH2O (I) under hydrothermal condition and form of partly deprotonated cis-H2bpta2- firstly emerges in this work. Crystallographically, a 1:1 co-crystal is formed by co-crystallization of [Cu2(cis-H2bpta)2(4,4‧-bipy)2] and H4bpta in self-assembled process. Structurally, the compound (I) exhibits two-dimensional (2D) double-layered nets with a pseudo-interpenetrated skeleton, one layer is characteristic of metal-organic moiety linked via cis-H2bpta2- and 4,4‧-bipy spaces, and the other formed by O-H···O H-bonds presented in neutral H4bpta ligands. Interestingly, its mechanically interlocked structure is formed by hydrogen bonds, which results in an interesting interweaving framework with a new (3,4,5)-connected topological structure. Magnetic couplings between adjacent Cu(II) centers are mediated through double syn-syn carboxylate bridges. Magnetic susceptibility measurement indicates that (I) exhibits a dinuclear Cu(II) behavior with antiferromagnetic coupling (J = -35.69(1) cm-1).

A chemical approach toward low temperature alloying of immiscible iron and molybdenum metals

International Nuclear Information System (INIS)

Nazir, Rabia; Ahmed, Sohail; Mazhar, Muhammad; Akhtar, Muhammad Javed; Siddique, Muhammad; Khan, Nawazish Ali; Shah, Muhammad Raza; Nadeem, Muhammad

2013-01-01

Graphical abstract: - Highlights: • Low temperature pyrolysis of [Fe(bipy) 3 ]Cl 2 and [Mo(bipy)Cl 4 ] homogeneous powder. • Easy low temperature alloying of immiscible metals like Fe and Mo. • Uniform sized Fe–Mo nanoalloy with particle size of 48–68 nm. • Characterization by EDXRF, AFM, XRPD, magnetometery, 57 Fe Mössbauer and impedance. • Alloy behaves as almost superparamagnetic obeying simple –R(CPE)– circuit. - Abstract: The present research is based on a low temperature operated feasible method for the synthesis of immiscible iron and molybdenum metals’ nanoalloy for technological applications. The nanoalloy has been synthesized by pyrolysis of homogeneous powder precipitated, from a common solvent, of the two complexes, trisbipyridineiron(II)chloride, [Fe(bipy) 3 ]Cl 2 , and bipyridinemolybedenum(IV) chloride, [Mo(bipy)Cl 4 ], followed by heating at 500 °C in an inert atmosphere of flowing argon gas. The resulting nanoalloy has been characterized by using EDXRF, AFM, XRD, magnetometery, 57 Fe Mössbauer and impedance spectroscopies. These results showed that under provided experimental conditions iron and molybdenum metals, with known miscibility barrier, alloy together to give (1:1) single phase material having particle size in the range of 48–66 nm. The magnetism of iron is considerably reduced after alloy formation and shows its trend toward superparamagnetism. The designed chemical synthetic procedure is equally feasible for the fabrication of other immiscible metals

Spin crossover studies in cationic complexes of iron by using Moessbauer spectroscopy

International Nuclear Information System (INIS)

Vadera, S.R.; Kumar, N.

1990-01-01

The spin transition in two new cationic complexes of iron, i.e. iron bipyridine formate, [Fe(bipy) 3 ](HCOO) 2 .5(HCOOH) and iron bipyridine tetrafluoro borate, [Fe(bipy) 3 ](BF 4 ) 2 .2H 2 O were studied by Moessbauer spectroscopy. From quadrupole splitting values, it was established that at different temperatures both complexes show the coexistence of both high spin state and low spin state at 300 K, while complete transformation to low spin state occurs at 77 K. Both compounds were prepared by electrochemical technique. (author) 12 refs.; 1 fig.; 1 tab

Homochiral coordination polymers constructed from aminocarboxylate derivates: Effect of bipyridine on the amidation reaction

International Nuclear Information System (INIS)

Chen Jianshan; Sheng Tianlu; Hu Shengmin; Xiang Shengchang; Fu Ruibiao; Zhu Qilong; Wu Xintao

2012-01-01

Using aminocarboxylate derivates (S)-N-(4-cyanobenzoic)-glutamic acid (denoted as cbg, 1a) and (S)-N-(4-nitrobenzoic)-glutamic acid (denoted as nbg, 1b) as chiral ligands, five new homochiral coordination polymers formulated as [Cu(cbg)(H 2 O) 2 ] n (3), [Cu(cbop) 2 (4,4′-bipy)(H 2 O)] n (4) (cbop=(S)-N-(4-cyanobenzoic)-5-oxoproline, 4,4′-bipy=4,4′-bipyridine), {[Cu(nbop) 2 (4,4′-bipy)]·4H 2 O} n (5) (nbop=(S)-N-(4-nitrobenzoic)-5-oxoproline), {[Cd(nbop) 2 (4,4′-bipy)]·2H 2 O} n (6), and [Ni(nbop) 2 (4,4′-bipy)(H 2 O) 2 ] n (7) have been hydrothermally synthesized and structurally characterized. Single-crystal X-ray diffraction study reveals that the original chirality of aminocarboxylate derivates is maintained in all these complexes. Complexes 3, 4, and 7 are one-dimensional infinite chain coordination polymers, while complexes 5 and 6 possess two-dimensional network structures. In situ cyclization of 1a and 1b was taken place in the formation of complexes 4–7, which may be due to the competition of 4,4′-bipyridine with chiral ligands during the coordination process. Preliminary optical behavior investigation indicates that ligands 1a, 1b, and complexes 6, 7 are nonlinear optical active. - Graphical abstract: Using aminocarboxylate derivates as chiral ligands, five new homochiral coordination polymers possessing second harmonic generation activities have been hydrothermally synthesized. Highlights: ► Two new chiral aminocarboxylate derivates were firstly synthesized. ► Five new homochiral metal organic complexes were obtained hydrothermally based on these ligands. ► Intramolecular amidation was taken place on the aminocarboxylate derivates during the formation of these complexes. ► In situ amidation may be due to the impact of 4,4′-bipyridine. ► The homochiral complexes are nonlinear optical active.

Syntheses, structures, and magnetic properties of cobalt(II) and nickel(II) coordination polymers based on a V-shaped ligand

Energy Technology Data Exchange (ETDEWEB)

Yao, Shuang [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022 (China); Yi, Fei-Yan [The School of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211 (China); Li, Guanghua [State Key Laboratory of Inorganic Synthesis & Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012 (China); Yu, Yang [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022 (China); Wang, Jing-yuan, E-mail: jywang@mail.ipc.ac.cn [Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences, 29 Zhongguancun East Road, Haidian District, Beijing 100190 (China); Liu, Dan, E-mail: liudan2007@ciac.ac.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022 (China); Song, Shu-Yan [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022 (China)

2017-06-15

Two coordination polymers [Co{sub 2}(TA)(4,4′-bipy){sub 2}(H{sub 2}O){sub 2}]·H{sub 2}O (1) and [Ni{sub 2}(TA)(4,4′-bipy){sub 2}(H{sub 2}O){sub 4}]·3H{sub 2}O (2) were prepared by hydrothermal reactions of MCl{sub 2}·6H{sub 2}O (M = Co, Ni) with a V-shaped ligand TDPA (3,3′,4,4′-thiodiphthalic anhydride) and a I-shaped N-donor co-ligand (4,4′-bipy). They were characterized by elemental analyses, thermogravinetric analyses, and magnetic behavior. As is expected, TDPA hydrolyzes into the corresponding tetra-carboxylate acid H{sub 4}TA (3,3′,4,4′-thiodiphthalic acid) during the reactions. Co{sub 2} dimer and Ni mononuclear center are connected into two-dimensional (2D) layers by H{sub 4}TA and 4,4′-bipy bridge in 1 and 2, respectively. The most amazing feature is that 1 and 2 exhibit interesting spin-canting metamagnetism and weak ferromagnetic behavior, respectively, with the critical Néel temperature of T{sub N} =4 K for 1 and T{sub N} =13 K for 2, based on variable temperature magnetic susceptibility measurements. In low mono- or dinuclear metal system, such magnetic behaviors have rare been observed. Furthermore, complex 1 will be a potential metamagnet material. - Graphical abstract: Two Co(II) and Ni(II) coordination polymers were synthesized by hydrothermal reactions from a V-shape ligand (3,3′,4,4′-thiodiphthalic anhydride) and a I-shape ligand (4,4′-bipy), which were characterized by single crystal X-ray diffraction, elemental analyses, thermogravinetric analyses, and magnetic behavior, and exhibit interesting spin-canting metamagnetism and weak ferromagnetic behavior, respectively. - Highlights: • Two Co(II) and Ni(II) coordination polymers were successfully synthesized. • Co(II) coordination polymer shows an interesting spin-canting metamagnetism. • Ni(II) coordination polymer exhibits a weak ferromagnetic behavior.

Complexation of uranyl ion with sulfonates. One- to three-dimensional assemblies with 1,5- and 2,7-naphthalenedisulfonates

Energy Technology Data Exchange (ETDEWEB)

Thuery, Pierre [NIMBE, CEA, CNRS, Universite Paris-Saclay, CEA Saclay, Gif-sur-Yvette (France); Harrowfield, Jack [ISIS, Universite de Strasbourg (France)

2017-02-03

Uranyl nitrate was treated with the sodium salt of either 1,5- or 2,7-naphthalenedisulfonate (1,5-ndsNa{sub 2} or 2,7-ndsNa{sub 2}, respectively) under (solvo)-hydrothermal conditions, in the presence of additional coligands and/or metal cations, to give six new complexes, which were characterized by determination of their crystal structures. Complex [UO{sub 2}(1,5-nds)(H{sub 2}O)] (1) crystallizes as a three-dimensional (3D) framework, with both sulfonate groups coordinated in the O,O{sup '}-bridging mode. In the presence of the N-chelating species 2,2{sup '}-bipyridine (bipy) or 1,10-phenanthroline (phen), the three complexes [(UO{sub 2}){sub 2}(1,5-nds)(OH){sub 2}(bipy){sub 2}].H{sub 2}O (2), [(UO{sub 2}){sub 2}(1,5-nds)(OH){sub 2}(bipy){sub 2}].bipy (3) and [(UO{sub 2}){sub 2}(1,5-nds)(OH){sub 2}(phen){sub 2}] (4) were obtained, in which doubly hydroxide-bridged uranyl dimers are assembled into one-dimensional (1D) chains by bis(unidentate) disulfonate ligands. Complex [Cu(bipy){sub 2}Cl][UO{sub 2}(2,7-nds)(OH)].H{sub 2}O (5) displays anionic, two-dimensional (2D) sheets in which unidentate/O,O{sup '}-bridging disulfonate ligands link hydroxide-bridged uranyl dimers. In the additional presence of cucurbit[6]uril (CB6), complex [(UO{sub 2}){sub 4}Na{sub 4}(2,7-nds){sub 2}(CB6)Cl{sub 4}O{sub 2}(H{sub 2}O){sub 10}].5H{sub 2}O (6) crystallizes as a 3D framework of intricate architecture, with bis(μ{sub 3}-oxo)-bridged uranyl tetranuclear moieties connected to CB6-bound sodium cations by doubly O,O{sup '}-bridging disulfonates. Complexes 2 and 4 display intense and well-resolved uranyl emission in the solid state, while nearly complete quenching is observed in 3 and 5. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Hydrothermal synthesis and crystal structure of a europium(III) coordination polymer with 5-sulfoisophthalate trivalent anions and free 4, 4'-bipyridine molecules

International Nuclear Information System (INIS)

Lin Humao; Qing Caixiao; Qian Miao; Ping Xiaohong

2005-01-01

A novel europium(III) coordination polymer [Eu(Sip)(H 2 O) 5 ] n · nH 2 O · 1.5 n(Bipy) (I) (Sip is 5-sulfoisophthalate trivalent anion and Bipy is 4,4'-bipyridine) is hydrothermally synthesized and determined by the single crystal X-ray diffraction method. Polymer I crystallizes in the monoclinic system, space group C2/c with a = 30.7515(6), b = 10.9577(2), c = 17.5545(4) A, β = 112.040(1) deg, Z = 4. In I, each Eu 3+ ion is coordinated by four oxygen atoms from two carboxylate groups of two different Sip anions and five oxygen atoms from five coordinated water molecules to complete a deformed mono-cap square antiprism. Moreover, each Sip anion acts as a tetradentate ligand to connect two adjacent Eu 3+ ions through its two chelating carboxylate groups, resulting in one-dimensional linear chains. In addition, fifteen different kinds of hydrogen-bonding interactions link the chains, lattice water molecules, and free Bipy molecules to engender a complicated hydrogen-bonding network [ru

Uranyl Ion Complexes with Long-Chain Aliphatic α,ω-Dicarboxylates and 3d-Block Metal Counterions.

Science.gov (United States)

Thuéry, Pierre; Harrowfield, Jack

2016-03-07

Twelve new complexes were obtained from reaction of uranyl ions with the aliphatic dicarboxylic acids HOOC-(CH2)n-2-COOH (H2Cn; n = 7-10 and 12) under solvo-hydrothermal conditions, in the presence of 3d-block metal ions (Mn(2+), Fe(3+), Co(2+), Ni(2+), and Cu(2+)) and 2,2'-bipyridine (bipy) or 1,10-phenanthroline (phen). In contrast to previously reported triple-stranded helicates obtained with C9(2-) and C12(2-), all these complexes crystallize as polymeric one-dimensional (1D) or two-dimensional (2D) species. [Fe(bipy)3][(UO2)2(C7)3]·3H2O (1), [Cu(phen)2]2[(UO2)3(C7)4(H2O)2]·2H2O (2), and [Cu(bipy)2]2[(UO2)2(C9)3] (6), in which the 3d cation was reduced in situ, are 1D ladderlike polymers displaying tetra- or hexanuclear rings, of sufficient width to encompass two counterions in 2 and 6. The three complexes [Co(phen)3][(UO2)3(C8)3(O)]·H2O (3), [Ni(phen)3][(UO2)3(C8)3(O)]·H2O (4) and [Co(phen)3][(UO2)3(C9)3(O)]·H2O (5) contain bis(μ3-oxo)-bridged tetranuclear secondary building units, and they crystallize as deeply furrowed 2D assemblies. Depending on the nature of the counterion, C10(2-) gives [Ni(bipy)3][(UO2)2(C10)3]·2H2O (7), a 2D network displaying elongated decanuclear rings containing the counterions, or [Mn(phen)3][(UO2)2(C10)3]·6H2O (8), [Co(phen)3][(UO2)2(C10)3]·7H2O (9), and [Ni(phen)3][(UO2)2(C10)3]·7H2O (10), which consist of 2D assemblies with honeycomb topology; the hexanuclear rings in 8-10 are chairlike and occupied by one counterion and two uranyl groups from neighboring layers. Two complexes of the ligand with the longest chain, C12(2-), are reported. [UO2(C12)(bipy)] (11) is a neutral 1D species in which bipy chelates the uranyl ion and plays an important role in the packing through π-stacking interactions. Two polymeric units, 1D and 2D, coexist in the complex [Ni(bipy)3][(UO2)2(C12)3][UO2(C12)(H2O)2]·H2O (12); the 2D network has the honeycomb topology, but the hexanuclear rings are markedly convoluted, with local features akin to

Synthesis, structures, spectroscopy and antimicrobial properties of complexes of copper(II) with salicylaldehyde N-substituted thiosemicarbazones and 2,2'-bipyridine or 1,10-phenanthroline.

Science.gov (United States)

Lobana, Tarlok S; Indoria, Shikha; Jassal, Amanpreet Kaur; Kaur, Harpreet; Arora, Daljit S; Jasinski, Jerry P

2014-04-09

Among the biometals (Cu, Co, Ni-cofactors in many enzymes), copper derivatives of O, N, S-donor salicylaldehyde thiosemicarbazones have received considerable attention owing to their potential biological applications. Eight new complexes of salicylaldehyde-N-substituted thiosemicarbazones [5-MeO-2-HO-C₆H₄-C(2)(H)N(3)-N(2)H-C(1)(S)-N(1)HR; R = Me, H2L(1); Et, H₂L(1), Ph, H₂L(3), H, H₂L(4)] with copper(II), namely, [Cu(κ(3)-O,N,S-L)( κ(2)-N,N-L')] {(L)(2-) = (L(1))(2-), L' = bipy, 1, phen, 2; (L)(2-) = (L(2))(2-), L' = bipy, 3, phen, 4; (L)(2-) = (L(3))(2-), L' = bipy, 5, phen, 6; (L)(2-) = (L(4))(2-), L' = bipy, 7, phen, 8} have been isolated. Complexes have slightly distorted square pyramidal geometry around the metal center (τ parameter = 0.243-0.357) and display weak to intense fluorescence in the region, 375-475 nm. These copper complexes have shown significant growth inhibitory activity (antimicrobial activity) against Staphylococcus aureus (MTCC740), methicillin resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae 1 (MTCC109), Shigella flexneri (MTCC1457), Pseudomonas aeruginosa (MTCC741) and Candida albicans (MTCC227). The activity against MRSA is an interesting observation as the commercially available gentamycin is found to be inactive against this bacterial strain. Specifically complex 5 formed by 5-methoxysalicylaldehyde-N-phenylthiosemicatbazone has shown novel antimicrobial activity against various bacteria and yeast investigated. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

A low frequency infrared study of ruthenium(II) complexes with 1,8-naphthyridines and 2,2'-bipyridine

International Nuclear Information System (INIS)

Staniewicz, R.J.; Hendricker, D.G.; Griffiths, P.R.

1977-01-01

A report is presented on the synthesis and characterization of [Ru(napy) 4 ](PF 6 ) 2 , [Ru(2-mnapy) 4 ] (PF 6 ) 2 , [Ru(2,7-dmnapy) 3 ] (PF 6 ) 2 and [Ru(bipy) 3 ] (PF 6 ) 2 ; where (napy) = 1,8-naphthyridine; (2,7-dmnapy) = 2,7-dimethyl-1, 8-naphthyridine; (2-mnapy) = 2-methyl-1, 8-naphthyridine, and (bipy) = bipyridine. The complexes were prepared as previously reported (Staniewicz et al., (J.Am.Chem.Soc., in the press)). Low frequency infrared spectra were measured using a Digilab FTS-14 Fourier transform spectrophotometer. The results are discussed. Molecular structures are proposed. (U.K.)

Ruthenium(II) chloro-bis(bipyridyl) complexes with substituted pyridine ligands: interpretation of their electronic absorption spectra

International Nuclear Information System (INIS)

Sizova, O.V.; Ershov, A.Yu.; Ivanova, N.V.; Shashko, A.D.; Kutejkina-Teplyakova, A.V.

2003-01-01

A number of complexes cis-[Ru(Bipy) 2 (L)(Cl)](BF 4 ), where Bipy-2,2'-bipyridine, L-pyridine, 4-aminopyridine, 4-picoline, nicotinamide, isonicotinamide, 3- and 4-cyanopyridine, 4,4'-bipyridine, trans-1,2-bis(4-pyridyl)ethylene, 4,4'-azopyridine, pyrazine, imidazole and NH 3 , were prepared. Using the CINDO-CI semiempirical method the energies and intensities of transition in electronic absorption spectra (EAS) of the complexes were calculated. It is shown that major differences in EAS of the compounds stem from position of transitions with charge transfer d π (Ru)→π*(L) [ru

Diverse Cd(II) compounds based on N-benzoyl-L-glutamic acid and N-donor ligands: Structures and photoluminescent properties

Energy Technology Data Exchange (ETDEWEB)

Ma, Ning; Guo, Wei-Ying; Song, Hui-Hua, E-mail: songhuihua@mail.hebtu.edu.cn; Yu, Hai-Tao, E-mail: haitaoyu@mail.hebtu.edu.cn

2016-01-15

Five new Cd(II) coordination polymers with N-benzoyl-L-glutamic acid (H{sub 2}bzgluO) and different N-donor ligands, [Cd(bzgluO)(2,2′-bipy)(H{sub 2}O)]{sub n} (1), [Cd(bzgluO)(2,4′-bipy){sub 2}(H{sub 2}O)·3H{sub 2}O]{sub n} (2), [Cd(bzgluO)(phen)·H{sub 2}O]{sub n} (3), [Cd(bzgluO)(4,4′-bipy)(H{sub 2}O)]{sub n} (4), [Cd(bzgluO)(bpp)(H{sub 2}O)·2H{sub 2}O]{sub n} (5) were synthesized (2,2′-bipy=2,2′-bipyridine, 2,4′-bipy=2,4′-bipyridine, phen=1,10-phenanthroline, 4,4′-bipy=4,4′-bipyridine, bpp=1,3-di(4-pyridyl)propane). Compounds 1–2 exhibit a 1D single-chain structure. Compound 1 generates a 2D supramolecular structure via π–π stacking and hydrogen bonding, 3D architecture of compound 2 is formed by hydrogen bonding. Compound 3 features a 1D double-chain structure, which are linked by π–π interactions into a 2D supramolecular layer. Compounds 4-5 display a 2D network structure. Neighboring layers of 4 are extended into a 3D supramolecular architecture through hydrogen bonding. The structural diversity of these compounds is attributed to the effect of ancillary N-donor ligands and coordination modes of H{sub 2}bzgluO. Luminescent properties of 1–5 were studied at room temperature. Circular dichroism of compounds 1, 2 and 5 were investigated. - Graphical abstract: Five new Cd(II) metal coordination compounds with H{sub 2}bzgluO and different N-donor ligands were synthesized and characterized. Compounds 1, 2 and 3 present 1D structures, compounds 4 and 5 display 2D networks. Results indicate that auxiliary ligands and coordination modes of H{sub 2}bzgluO play an important role in governing the formation of final frameworks, and the hydrogen-bonding and π–π stacking interactions contribute the formation of the diverse supramolecular architectures. Furthermore, the different crystal structures influence the emission spectra significantly. - Highlights: • It is rarely reported that complexes prepared with N-benzoyl-L-glutamic acid

Bis(2,2′-bipyridine-κ2N,N′(3-methylbenzoato-κ2O,O′zinc 3-methylbenzoate–3-methylbenzoic acid–water (1/1/2

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Qiu-qi Ye

2012-09-01

Full Text Available The title compound, [Zn(C8H7O2(C10H8N22](C8H7O2·C8H8O2·2H2O, is comprised of a Zn2+ cation, two 2,2′-bipydine (bipy ligands and one 3-methylbenzoate anion (L− together with one uncoordinating L− anion, one uncoordinating HL molecule and two lattice water molecules. The ZnII atom is coordinated by four N atoms of two bipy ligands and two O atoms from one L− ligand in a distorted octahedral geometry. Pairs of centrosymmetrically related complex molecules form dimers via slipped π-stacking interactions between bipy ligands with an interplanar distance of 3.470 (4 Å. The dimers are linked into supramolecular chains along [111], via C—H...O hydrogen bonds. The uncoordinated L− anions, HL molecules and water molecules are connected with each other via O—H...O hydrogen bonds, forming chains between the metal complex chains and binding them together via C—H...O contacts. The resulting layers parallel to (010 are further assembled into a three-dimensional supramolecular architecture through additional C—H...O interactions.

Synthesis, spectroscopy and biological investigations of manganese(III) Schiff base complexes derived from heterocyclic β-diketone with various primary amine and 2,2'-bipyridyl

Science.gov (United States)

Surati, Kiran R.

2011-06-01

The mixed ligand mononuclear complex [Mn(bipy)(HPMFP)(OAc)]ClO 4 was synthesized by reaction of Mn(OAc) 3·2H 2O with HPMFP and 2,2'-bipyridyl. The corresponding Schiff base complexes were prepared by condensation of [Mn(bipy)(HPMFP)(OAc)]ClO 4 with ethylenediamine, ethanolamine and glycine (where HPMFP = 1-phenyl-3methyl-4-formyl-2-pyrazolin-5one, bipy = 2,2'-bipyridyl). All the compounds have been characterized by elemental analysis, magnetic susceptibility, conductometry measurements and 1H and 13C NMR, FT-IR, mass spectrometry. Electronic spectral and magnetic susceptibility measurements indicate square pyramidal geometry around manganese(III) ion. The thermal stabilities, activation energy E*, entropy change Δ S*, enthalpy change Δ H* and heat capacity of thermal degradation for these complexes were determined by TGA and DSC. The in vitro antibacterial and antifungal activity of four coordination compounds and ligand HPMFP were investigated. In vitro activates of Bacillus subtillis (MTCC-619), Staphylococcus aureus (MTCC-96), Escherichia coli (MTCC-722) and Klebsiella pneumonia (MTCC-109) bacteria and the fungus Candida albicans (ATCC-90028) were determined. All the compounds showed good antimicrobial activity. The antimicrobial activities increased as formation of Schiff base.

Insertion of molecular oxygen into a palladium(II) methyl bond: a radical chain mechanism involving palladium(III) intermediates.

Science.gov (United States)

Boisvert, Luc; Denney, Melanie C; Hanson, Susan Kloek; Goldberg, Karen I

2009-11-04

The reaction of (bipy)PdMe(2) (1) (bipy = 2,2'-bipyridine) with molecular oxygen results in the formation of the palladium(II) methylperoxide complex (bipy)PdMe(OOMe) (2). The identity of the product 2 has been confirmed by independent synthesis. Results of kinetic studies of this unprecedented oxygen insertion reaction into a palladium alkyl bond support the involvement of a radical chain mechanism. Reproducible rates, attained in the presence of the radical initiator 2,2'-azobis(2-methylpropionitrile) (AIBN), reveal that the reaction is overall first-order (one-half-order in both [1] and [AIBN], and zero-order in [O(2)]). The unusual rate law (half-order in [1]) implies that the reaction proceeds by a mechanism that differs significantly from those for organic autoxidations and for the recently reported examples of insertion of O(2) into Pd(II) hydride bonds. The mechanism for the autoxidation of 1 is more closely related to that found for the autoxidation of main group and early transition metal alkyl complexes. Notably, the chain propagation is proposed to proceed via a stepwise associative homolytic substitution at the Pd center of 1 with formation of a pentacoordinate Pd(III) intermediate.

Exploration of spectroscopic properties of solvated tris(thenoyltrifluoroacetonate)(2,2′-bipyridine)europium(III)red hybrid organic complex for solution processed OLEDs and displays

International Nuclear Information System (INIS)

Chitnis, Dipti; Thejokalyani, N.; Dhoble, S.J.

2017-01-01

In order to explore the spectroscopic properties of a novel europium activated hybrid organic tris(thenoyltrifluoroacetonate)(2,2′-bipyridine)europium(III), Eu(TTA) 3 bipy phosphor in various solvents at different pH and molar concentrations, UV–vis optical absorption and photoluminescence spectra were carried out. With a variation in the solvent from basic (chloroform, toluene, tetrahydrofuran) to acidic (acetic acid, formic acid) media, staggering differences in optical absorptions and optical densities were noticed with hypsochromic shift in the absorption peaks. The optical density was found to be maximum for the complex with pH= 7.0 and the intensity as well as optical density gradually decreased when pH is lowered to 6.0 or raised to 8.0 (at an interval of 0.5), proving that the complex is pH sensitive. It's optical energy gap and stokes shift values in various organic solvents were also calculated on the basis of Lippert-Mataga plot. The exploration of spectroscopic properties of solvated Eu(TTA) 3 bipy complex demonstrates its prospective for solution processed OLEDs and display devices. - Graphical abstract: Pictorial depiction of photoluminescence in solvated Eu(TTA) 3 bipy complex under UV light.

Superparamagnetic bimetallic iron-palladium nanoalloy: synthesis and characterization

Energy Technology Data Exchange (ETDEWEB)

Nazir, Rabia; Mazhar, Muhammad [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Akhtar, M Javed; Nadeem, M; Siddique, Muhammad [Physics Division, PINSTECH, PO Nilore, Islamabad 44000 (Pakistan); Shah, M Raza [HEJ Research Institute of Chemistry, University of Karachi, Karachi 75270 (Pakistan); Khan, Nawazish A [Material Science Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Mehmood, Mazhar [National Centre for Nanotechnology, PIEAS, Islamabad 45650 (Pakistan); Butt, N M [Pakistan Science Foundation, Islamabad 44000 (Pakistan)], E-mail: mazhar42pk@yahoo.com

2008-05-07

Iron-palladium nanoalloy in the particle size range of 15-30 nm is synthesized by the relatively low temperature thermal decomposition of coprecipitated [Fe(Bipy){sub 3}]Cl{sub 2} and [Pd(Bipy){sub 3}]Cl{sub 2} in an inert ambient of dry argon gas. The silvery black Fe-Pd alloy nanoparticles are air-stable and have been characterized by EDX-RF, XRD, AFM, TEM, magnetometry, {sup 57}Fe Moessbauer and impedance spectroscopy. This Fe-Pd nanoalloy is in single phase and contains iron sites having up to 11 nearest-neighboring atoms. It is superparamagnetic in nature with high magnetic susceptibility, low coercivity and hyperfine field.

Synthesis, structural modelling and luminescence of a novel erbium(III) complex with 2,4-nonanedione and 2,2‧-bipyridine ligands for chitosan matrices doping

Science.gov (United States)

Martín-Ramos, P.; Chamorro-Posada, P.; Ramos Silva, M.; Pereira da Silva, P. S.; Martín, I. R.; Lahoz, F.; Lavín, V.; Martín-Gil, J.

2015-03-01

We report the synthesis, the Sparkle/PM7 semi-empirical quantum model for the ground state geometry and the absorption/luminescent properties of the Er3+ ternary complex [Er(nd)3(bipy)] (where Hnd is 2,4-nonanedione and bipy is 2,2‧-bipyridine). The solid-state electronic absorption spectra and the photoluminescent spectra show long-wavelength 4f-4f transitions which provide a potential use of the compound as a NIR-emitting material for the doping of polymer-based matrices for waveguides or for bio-analytical applications. The dispersion of the novel complex in a biocompatible chitosan film has been assessed.

Synthesis, structures and Helicobacter pylori urease inhibitory activity of copper(II) complexes with tridentate aroylhydrazone ligands.

Science.gov (United States)

Pan, Lin; Wang, Cunfang; Yan, Kai; Zhao, Kedong; Sheng, Guihua; Zhu, Hailiang; Zhao, Xinlu; Qu, Dan; Niu, Fang; You, Zhonglu

2016-06-01

A series of new copper(II) complexes were prepared. They are [CuL(1)(NCS)] (1), [CuClL(1)]·CH3OH (2), [CuClL(2)]·CH3OH (3), [CuL(3)(NCS)]·CH3OH (4), [CuL(4)(NCS)]·0.4H2O (5), and [CuL(5)(bipy)] (6), where L(1), L(2), L(3) and L(4) are the deprotonated form of N'-(2-hydroxybenzylidene)-3-methylbenzohydrazide, 4-bromo-N'-(2-hydroxy-5-methoxybenzylidene)benzohydrazide, N'-(2-hydroxy-5-methoxybenzylidene)-3-methylbenzohydrazide and 2-chloro-N'-(2-hydroxy-5-methoxybenzylidene)benzohydrazide, respectively, L(5) is the dianionic form of N'-(2-hydroxybenzylidene)-3-methylbenzohydrazide, and bipy is 2,2'-bipyridine. The complexes were characterized by infrared and UV-Vis spectra and single crystal X-ray diffraction. The Cu atoms in complexes 1, 2, 3, 4 and 5 are coordinated by the NOO donor set of the aroylhydrazone ligands, and one Cl or thiocyanate N atom, forming square planar coordination. The Cu atom in complex 6 is in a square pyramidal coordination, with the NOO donor set of L(1), and one N atom of bipy defining the basal plane, and with the other N atom of bipy occupying the apical position. Complexes 1, 2, 3, 4 and 5 show effective urease inhibitory activities, with IC50 values of 5.14, 0.20, 4.06, 5.52 and 0.26μM, respectively. Complex 6 has very weak activity against urease, with IC50 value over 100μM. Molecular docking study of the complexes with the Helicobacter pylori urease was performed. The relationship between structures and urease inhibitory activities indicated that copper complexes with square planar coordination are better models for urease inhibition. Copyright © 2016 Elsevier Inc. All rights reserved.

Ru/Fe bimetallic complexes: Synthesis, characterization, cytotoxicity and study of their interactions with DNA/HSA and human topoisomerase IB.

Science.gov (United States)

Takarada, Jessica E; Guedes, Adriana P M; Correa, Rodrigo S; Silveira-Lacerda, Elisângela de P; Castelli, Silvia; Iacovelli, Federico; Deflon, Victor Marcelo; Batista, Alzir Azevedo; Desideri, Alessandro

2017-12-15

Three ruthenium/iron-based compounds, 1: [Ru(MIm)(bipy)(dppf)]PF 6 (MIm = 2-mercapto-1-methylimidazole anion), 2: [RuCl(Im)(bipy)(dppf)]PF 6 (Im = imidazole), and 3: [Ru(tzdt)(bipy)(dppf)]PF 6 (tzdt = 1,3-thiazolidine-2-thione anion) (dppf = 1,1'-bis(diphenylphosphine)ferrocene and bipy = 2,2'-bipyridine), were synthesized, and characterized by elemental analyses, conductivity, UV/Vis, IR, 1 H, 13 C and 31 P{1H} NMR spectroscopies, and by electrochemical technique. The complex 3 was also characterized by single-crystal X-ray. The three ruthenium(II) complexes show cytotoxicity against DU-145 (prostate carcinoma cells) and A549 (lung carcinoma cells) tumor cells. The free ligands do not exhibit any cytotoxic activity, such as evident by the IC 50 values higher than 200 μM. UV/Vis and viscosity experiments showed that the complexes interact weakly with the DNA molecule, via electrostatic forces. The interaction of the complexes 1-3 with the HSA is moderate, with K b values in range of 10 5 -10 7  M -1 , presenting a static mechanism of interaction stabilized by hydrophobic. Complexes 2 and 3 showed high affinity for the FA7 HSA site as evidenced by fluorescence spectroscopy and molecular docking. Complexes 1-3 were tested as potential human Topoisomerase IB inhibitors by analysing the different steps of the enzyme catalytic cycle. The results indicate that all compounds efficiently inhibit the DNA relaxation and the cleavage reaction, in which the effect increases upon pre-incubation. Complexes 1 and 2 are also able to slow down the religation reaction. Copyright © 2017 Elsevier Inc. All rights reserved.

N-Chlorosuccinimide (NCS): A Novel Initiator for Atom Transfer Radical Polymerization of Methyl Methacrylate

Institute of Scientific and Technical Information of China (English)

WANG,Xia-Yan; CHANG,Li-Qun; ZHOU,Hong; ZHANG,Ke-Da

2006-01-01

Atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was achieved, using N-chlorosuccinimide (NCS) as an initiator together with catalytic system CuCl/PMDETA (N,N,N',N',N"-pentamethyldiethyl-enetriamine), CuCl/MA5-DETA (N,N,N',N',N"-penta(methylacrylate)diethylenetriamine), and CuCl/bipy (bipy=2,2'-bipyridyl) respectively. The results indicated that the polymerization possessed typical controlled/living radical polymerization characteristics. The analysis for terminal group of obtained polymer by 1H NMR proved that NCS is an initiator for ATRP. In comparison with NBS, the polymerization rate was slower and the resulted polymer had narrower molecular weight distribution (MWD) when NCS was employed as the initiator.

Demografia e densidade de perfilhos de capim-braquiária sob pastejo em lotação intermitente

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Jorge Nunes Portela

2011-03-01

Full Text Available O objetivo deste trabalho foi avaliar os efeitos de intensidades de pastejo e de frequências de desfolha na demografia e densidade de perfilhos de capim-braquiária (Urochloa decumbens syn. Brachiaria decumbens sob lotação intermitente. Foram avaliados duas intensidades de pastejo (5 e 10 cm de altura pós-pastejo e duas frequências de desfolha (período de descanso até que o dossel atingisse 95 e 100% de interceptação luminosa, IL, de agosto de 2007 a agosto de 2008. Utilizou-se o delineamento inteiramente casualizado, em arranjo fatorial com quatro repetições. Avaliaram-se as densidades populacionais e as taxas de aparecimento e sobrevivência de perfilhos basais (DPPb, TAPb e TSPb, respectivamente e aéreos+basais (DPPab, TAPab e TSPab. As maiores TAPb e TAPab, no outono, foram obtidas nos pastos desfolhados a 10 cm. Porém, no final da primavera e no verão, a intensidade de 5 cm resultou em maiores taxas, que promoveram maior DPPb. No verão, a TSPb foi maior para pastos manejados à intensidade de 10 cm. O manejo da pastagem que resulta em maiores DPPab, TAPab e TSPab, durante as épocas de rápido crescimento dos pastos, é o de 10 cm de intensidade de pastejo e 95% de IL de frequência de desfolha.

Exploration of spectroscopic properties of solvated tris(thenoyltrifluoroacetonate)(2,2′-bipyridine)europium(III)red hybrid organic complex for solution processed OLEDs and displays

Energy Technology Data Exchange (ETDEWEB)

Chitnis, Dipti [Department of Physics, RTM Nagpur University, Nagpur 440033 (India); Thejokalyani, N., E-mail: thejokalyani@rediffmail.com [Department of Applied Physics, Laxminarayan Institute of Technology, Nagpur 440033 (India); Dhoble, S.J. [Department of Physics, RTM Nagpur University, Nagpur 440033 (India)

2017-05-15

In order to explore the spectroscopic properties of a novel europium activated hybrid organic tris(thenoyltrifluoroacetonate)(2,2′-bipyridine)europium(III), Eu(TTA){sub 3}bipy phosphor in various solvents at different pH and molar concentrations, UV–vis optical absorption and photoluminescence spectra were carried out. With a variation in the solvent from basic (chloroform, toluene, tetrahydrofuran) to acidic (acetic acid, formic acid) media, staggering differences in optical absorptions and optical densities were noticed with hypsochromic shift in the absorption peaks. The optical density was found to be maximum for the complex with pH= 7.0 and the intensity as well as optical density gradually decreased when pH is lowered to 6.0 or raised to 8.0 (at an interval of 0.5), proving that the complex is pH sensitive. It's optical energy gap and stokes shift values in various organic solvents were also calculated on the basis of Lippert-Mataga plot. The exploration of spectroscopic properties of solvated Eu(TTA){sub 3}bipy complex demonstrates its prospective for solution processed OLEDs and display devices. - Graphical abstract: Pictorial depiction of photoluminescence in solvated Eu(TTA){sub 3}bipy complex under UV light.

Synthesis, crystal structures, and thermal and spectroscopic properties of two Cd(II) metal-organic frameworks with a versatile ligand

Energy Technology Data Exchange (ETDEWEB)

Li, Jia-Ming; He, Kun-Huan; Shi, Zhong-Feng [Qinzhou Univ. (China). Guangxi Colleges and Univs. Key Lab. of Beibu Gulf Oil and Natural Gas Resource Effective Utilization; Gao, Hui-Yuan; Jiang, Yi-Min [Guangxi Normal Univ., Guilin (China). Key Lab. for the Chemistry and Molecular Engineering of Medicinal Resources

2016-11-01

Two new metal-organic frameworks, namely, [Cd(L)(H{sub 2}O)]{sub n} (1) and {[Cd_0_._5(L)(4,4"'-bipy)_0_._5][Cd_0_._5(H_2O)(4,4"'-bipy)_0_._5].H_2O}{sub n} (2), where H{sub 2}L = N-pyrazinesulfonyl-glycine and 4,4{sup '}-bipy = 4,4{sup '}-bipyridine, have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental, thermogravimetric, and photoluminescent analysis. X-ray diffraction crystallographic analyses indicate that 1 displays a distorted octahedral metal coordination in a 3-connected (4, 8{sup 2}) topology, while the molecular structure of 2 has a 4-connected (4, 4) topology with two perfectly octahedrally coordinated Cd centers. The L{sup 2-} ligand serves as a N,N,O-tridentate, μ{sub 2}-pyrazine-bridging, and μ{sub 2}-carboxylate-bridging ligand in 1, and as a N,O-bidentate and μ{sub 2}-carboxylate-bridging ligand in 2. In the crystal, a 3D supramolecular architecture is formed by O-H..O hydrogen bond interactions in 1, but through O-H..O as well as π..π stacking in 2. The two compounds show intense fluorescence in the solid state at room temperature.

Reversible Single-Crystal-to-Single-Crystal Structural Transformation in a Mixed-Ligand 2D Layered Metal-Organic Framework: Structural Characterization and Sorption Study

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Chih-Chieh Wang

2017-12-01

Full Text Available A 3D supramolecular network, [Cd(bipy(C4O4(H2O2]·3H2O (1 (bipy = 4,4′-bipyridine and C4O42− = dianion of H2C4O4, constructed by mixed-ligand two-dimensional (2D metal-organic frameworks (MOFs has been reported and structurally determined by the single-crystal X-ray diffraction method and characterized by other physicochemical methods. In 1, the C4O42− and bipy both act as bridging ligands connecting the Cd(II ions to form a 2D layered MOF, which are then extended to a 3D supramolecular network via the mutually parallel and interpenetrating arrangements among the 2D-layered MOFs. Compound 1 shows a two-step dehydration process with weight losses of 11.0% and 7.3%, corresponding to the weight-loss of three guest and two coordinated water molecules, respectively, and exhibits an interesting reversible single-crystal-to-single-crystal (SCSC structural transformation upon de-hydration and re-hydration for guest water molecules. The SCSC structural transformation have been demonstrated and monitored by single-crystal and X-ray powder diffraction, and thermogravimetic analysis studies.

Poly[[aqua(μ2-4,4′-bipyridine-κ2N:N′[μ3-3-bromo-2-(carboxylatomethylbenzoato-κ3O1:O1′:O2]cadmium] monohydrate

Directory of Open Access Journals (Sweden)

Yangmei Liu

2012-08-01

Full Text Available In the title compound, {[Cd(C9H5BrO4(C10H8N2(H2O]·H2O}n, the CdII atom has a distorted octahedral coordination geometry. Two N atoms from two 4,4′-bipyridine (bipy ligands occupy the axial positions, while the equatorial positions are furnished by three carboxylate O atoms from three 3-bromo-2-(carboxylatomethylbenzoate (bcb ligands and one O atom from a water molecule. The bipy and bcb ligands link the CdII atoms into a three-dimensional network. O—H...O hydrogen bonds and π–π interactions between the pyridine and benzene rings [centroid–centroid distance = 3.736 (4 Å] are present in the crystal.

Potassium (2,2'-bipyridine-κN,N')bis-(carbonato-κO,O')cobaltate(III) dihydrate.

Science.gov (United States)

Wang, Jian-Fei; Lin, Jian-Li

2010-09-30

In the title compound, K[Co(CO(3))(2)(C(10)H(8)N(2))]·2H(2)O, the Co(III) atom is coordinated by two bipyridine N atoms and four O atoms from two bidentate chelating carbonate anions, and thus adopts a distorted octa-hedral N(2)O(4) environment. The [Co(bipy)(CO(3))(2)](-) (bipy is 2,2'-bipyridine) -units are stacked along [100] via π-π stacking inter-actions, with inter-planar distances between the bipyridine rings of 3.36 (4) and 3.44 (6) Å, forming chains. Classical O-H⋯O hydrogen-bonding inter-actions link the chains, forming channels along (100) in which the K(+) ions reside and leading to a three-dimensional supra-molecular architecture.

Synthesis, characterization, photoluminescent properties and antimicrobial activities of two novel polymeric silver(I) complexes with diclofenac

Science.gov (United States)

Hamamci Alisir, Sevim; Sariboga, Bahtiyar; Caglar, Sema; Buyukgungor, Orhan

2017-02-01

Two novel silver(I) complexes with diclofenac, ({2-(2,6-dicholoroanilino)phenylacetic acid} = dicl) namely [Ag(dicl)]n (1) and [Ag(dicl)(bipy)]n (2) (bipy: 4,4'-bipyridine), have been synthesized and characterized by elemental analysis, IR spectroscopy, thermal analysis and single-crystal X-ray diffraction. X-ray crystallographic data of 1 revealed that dicl anion adopts a μ3-η1,η2 coordinated mode link three Ag atoms generate 1D infinite chain structure. In 2, dicl ligand plays crucial role to form double-ladder chain structure, clamping two neighboring [Ag(μ-bipy)]∞ chains by using carboxylate oxygen atoms (O1, O2). The most interesting structural feature of 2 is the presence of strong π···π interactions between aromatic phenyl rings of dicl placed in the adjacent 1D chains, leads to forming 2D slab structure. The coordination modes of dicl in the title complexes are supported by using IR spectroscopy. Thermal stabilities of 1 and 2 have been determined by TG/DTA/DTG techniques. The luminescent properties of complex 1 and 2 have been investigated in the solid state at room temperature. Furthermore, the title complexes have been tested for their in vitro antibacterial activities and are determined to be highly effective for antibacterial activity against Gram(+) and Gram(-) pathogenic bacteria cells. 1 and 2 showed activity on Fungi, as well.

Synthesis, Structural Characterization, Antimicrobial Activity, and In Vitro Biocompatibility of New Unsaturated Carboxylate Complexes with 2,2'-Bipyridine.

Science.gov (United States)

Vasile Scăețeanu, Gina; Chifiriuc, Mariana Carmen; Bleotu, Coralia; Kamerzan, Crina; Măruţescu, Luminiţa; Daniliuc, Constantin G; Maxim, Cătălin; Calu, Larisa; Olar, Rodica; Badea, Mihaela

2018-01-12

The synthesis, structural characterization, cytotoxicity, and antimicrobial properties of four new complexes formed by employing acrylate anion and 2,2'-bipyridine are reported herein. X-ray crystallography revealed the trinuclear nature of [Mn₃(2,2'-bipy)₂(C₃H₃O₂)₆] ( 1 ), meanwhile complexes with general formula [M(2,2'-bipy)(C₃H₃O₂)₂(H₂O) x ]∙ y H₂O (( 2 ) M: Ni, x = 1, y = 0; ( 3 ) M: Cu, x = 1, y = 0; ( 4 ) M: Zn, x = 0, y = 1; 2,2'-bipy: 2,2'-bipyridine; C₃H₃O₂: acrylate anion) were shown to be mononuclear. The lowest minimum inhibitory concentration (MIC) of 128 μg mL -1 was recorded for all four tested complexes against Candida albicans , for complex ( 3 ) against Escherichia coli , and for complex ( 4 ) against Staphylocococcus aureus . Compounds ( 3 ) and ( 4 ) were also potent efflux pumps activity inhibitors (EPI), proving their potential for use in synergistic combinations with antibiotics. Complexes ( 1 )-( 4 ) revealed that they were not cytotoxic to HCT-8 cells. They also proved to interfere with the cellular cycle of tumour HCT-8 cells by increasing the number of cells found in the S and G2/M phases. Taken together, these results demonstrate the potential of zinc and copper complexes for use in the development of novel antimicrobial and anti-proliferative agents.

Electronic properties and reactivity of vanadium complexes of bipyridine and cyanometallates

International Nuclear Information System (INIS)

Lellis, F.T.P.

1988-01-01

This work deals with the chemistry of two types of vanadium compounds. The first one consists of polymeric pigments containing vanadium (III) ions and hexacyanoferrate (II) or substituted pentacyanoferrate (II) complexes. A series of 14 complexes were isolated in solid state, exhibiting the following composition V sub(4) [ Fe (CN) sub(4) ]. 16H sub(2)O or V [ Fe (CN) sub(5) L ]. 4H sub(2)O (L imidazole, pyridine and pyrazine derivatives). These complexes exhibit strong absorption bands in the visible-uv region, ascribed to intervalence transfer transitions. The infrared spectra were assigned, showing a linear correlation of the CN stretching frequencies with the sup(13)C NMR chemical shifts of the cyanide ligands in the complexes. The second system which has been investigated consists of a series of substituted species with vanadium (II) and (III) ions with 2,2 bypyridine ligands, formulated as [V (bipy) 3 - n (H sub(2)O) 6-2n ] sup(2+) and [ Cl (bipy)nVOV(bipy)nCl] sup(4)+ (n= 1-3) respectively. The electronic spectra of these complexes were assigned in parallel with magnetic and vibrational studies. Resonance Raman spectra of the vanadium (II) complexes exhibited strong enhancement of the bipyridine vibrational modes. In contrast, the vibrational modes of the V (III)-O-V(III) chromophore were preferentialy enhanced in the dimeric species. (author)

Rational assembly of Pb(II)/Cd(II)/Mn(II) coordination polymers based on flexible V-shaped dicarboxylate ligand: Syntheses, helical structures and properties

Energy Technology Data Exchange (ETDEWEB)

Yang, Gao-Shan [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Liu, Chong-Bo, E-mail: cbliu@nchu.edu.cn [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Liu, Hong [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Robbins, Julianne; Zhang, Z. John [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Yin, Hong-Shan [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Wen, Hui-Liang [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047 (China); Wang, Yu-Hua [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China)

2015-05-15

Six new coordination polymers, namely, [Pb(L)(H{sub 2}O)] (1), [Pb(L)(phen)] (2), [Pb{sub 2}(L){sub 2}(4,4′-bipy){sub 0.5}] (3), [Cd(L)(phen)] (4), [Cd(L)(4,4′-bipy)]·H{sub 2}O (5) and [Mn(L)(4,4′-bipy)]·H{sub 2}O (6) have been synthesized by the hydrothermal reaction of 2,2′-[hexafluoroisopropylidenebis(p-phenyleneoxy)]diacetic acid (H{sub 2}L) with Pb(II)/Cd(II)/Mn(II) in the presence of ancillary ligands 4,4′-bipyridine (4,4′-bipy) or 1,10-phenanthroline (phen). Complexes 1 and 4–6 exhibit 2-D structures, and complexes 2–3 display 3-D frameworks, of which L{sup 2−} ligands join metal ions to single-stranded helical chains of 1, 3–6 and double-stranded helical chains of 2. Complexes 2 and 3 also contain double-stranded Metal–O helices. Topology analysis reveals that complexes 1 and 4 both represent 4-connected sql net, 2 represents 6-connected pcu net, 3 exhibits a novel (3,12)-connected net, while 5 and 6 display (3,5)-connected gek1 net. The six complexes exhibit two kinds of inorganic–organic connectivities: I{sup 0}O{sup 2} for 1, 4–6, and I{sup 1}O{sup 2} for 2–3. The photoluminescent properties of 4–5 and the magnetic properties of 6 have been investigated. - Graphical abstract: Six new Pb(II)/Cd(II)/Mn(II) coordination polymers with helical structures based on flexible V-shaped dicarboxylate ligand have been synthesized and structurally characterized. Photoluminescent and magnetic properties have been investigated. - Highlights: • Six novel M(II) coordination polymers with 2,2′-[hexafluoroisopropylidenebis(p-phenyleneoxy)]diacetic acid and N-donor ligands. • Complexes 1–6 show diverse intriguing helical characters. • The luminescent properties of complexes 1–5 were investigated. • Complex 6 shows antiferromagnetic coupling.

Synthesis, Structural Characterization, Antimicrobial Activity, and In Vitro Biocompatibility of New Unsaturated Carboxylate Complexes with 2,2′-Bipyridine

Directory of Open Access Journals (Sweden)

Gina Vasile Scăețeanu

2018-01-01

Full Text Available The synthesis, structural characterization, cytotoxicity, and antimicrobial properties of four new complexes formed by employing acrylate anion and 2,2′-bipyridine are reported herein. X-ray crystallography revealed the trinuclear nature of [Mn3(2,2′-bipy2(C3H3O26] (1, meanwhile complexes with general formula [M(2,2′-bipy(C3H3O22(H2Ox]∙yH2O ((2 M: Ni, x = 1, y = 0; (3 M: Cu, x = 1, y = 0; (4 M: Zn, x = 0, y = 1; 2,2′-bipy: 2,2′-bipyridine; C3H3O2: acrylate anion were shown to be mononuclear. The lowest minimum inhibitory concentration (MIC of 128 μg mL−1 was recorded for all four tested complexes against Candida albicans, for complex (3 against Escherichia coli, and for complex (4 against Staphylocococcus aureus. Compounds (3 and (4 were also potent efflux pumps activity inhibitors (EPI, proving their potential for use in synergistic combinations with antibiotics. Complexes (1–(4 revealed that they were not cytotoxic to HCT-8 cells. They also proved to interfere with the cellular cycle of tumour HCT-8 cells by increasing the number of cells found in the S and G2/M phases. Taken together, these results demonstrate the potential of zinc and copper complexes for use in the development of novel antimicrobial and anti-proliferative agents.

Ternary complexes of Zn(II) and Cu(II) with 1-((2-hydroxynaphthalen-1-yl)methylene)-4-phenylthiosemicarbazide in the presence of heterocyclic bases as auxiliary ligands: Synthesis, spectroscopic and structural characterization and antibacterial activity

Science.gov (United States)

Azarkish, Mohammad; Akbari, Alireza; Sedaghat, Tahereh; Simpson, Jim

2018-03-01

The new ternary complexes, ZnLL‧ [L = 1-((2-hydroxynaphthalen-1-yl)methylene)-4-phenylthiosemicarbazide and L‧ = imidazole (1), 2, 2‧-bipyridine (2) and 2-methyimidazole (3)], Zn2L2L‧ [L‧ = 4, 4‧-bipy (4)] and CuLL‧ [L‧ = 2, 2‧-bipy (5)] have been synthesized by the reaction of a metal(II) acetate salt with the thiosemicarbazone and in presence of heterocyclic bases as auxiliary ligands. The synthesized compounds were investigated by elemental analysis and IR, 1H NMR, and 13C NMR spectroscopy and complex 5 was structurally characterized by X-ray crystallography. The results indicate the thiosemicarbazone doubly deprotonated and coordinates to metal through the thiolate sulfur, imine nitrogen and phenolic oxygen atoms. The nitrogen atom(s) of the auxiliary ligand complete the coordination sphere. Complex 4 is binuclear with 4, 4‧-bipy acting as a bridging ligand. The structure of 5 is a distorted square pyramid with one of the bipyridine nitrogen atoms in the apical position. This compound creates an inversion dimer in solid state by intermolecular hydrogen bonds of Nsbnd H⋯S type. The in vitro antibacterial activity of the synthesized compounds were evaluated against Gram-positive (B. subtilis and S. aureus) and Gram-negative (P. aeruginosa) bacteria and is compared to that of standard antibacterial drugs. All complexes exhibit good inhibitory effects and are significantly more effective than the parent ligand.

A NOVEL SAMARIUM COMPLEX WITH INTERESTING ...

African Journals Online (AJOL)

delocalized π-electrons of the pyridyl rings obtains increasing attention in ... BaSO4 plate was used as a reference (100% reflectance), on which the finely ground .... several are samarium-containing complex with bipy [41-45]. Figure 2.

Potassium (2,2′-bipyridine-κ2 N,N′)bis­(carbonato-κ2 O,O′)cobaltate(III) dihydrate

Science.gov (United States)

Wang, Jian-Fei; Lin, Jian-Li

2010-01-01

In the title compound, K[Co(CO3)2(C10H8N2)]·2H2O, the Co(III) atom is coordinated by two bipyridine N atoms and four O atoms from two bidentate chelating carbonate anions, and thus adopts a distorted octa­hedral N2O4 environment. The [Co(bipy)(CO3)2]− (bipy is 2,2′-bipyridine) ­units are stacked along [100] via π–π stacking inter­actions, with inter­planar distances between the bipyridine rings of 3.36 (4) and 3.44 (6) Å, forming chains. Classical O—H⋯O hydrogen-bonding inter­actions link the chains, forming channels along (100) in which the K+ ions reside and leading to a three-dimensional supra­molecular architecture. PMID:21587447

Poly[[diaquabis(μ2-4,4′-bipyridinemanganese(II] bis[2-(2-carboxyphenyldisulfanylbenzoate

Directory of Open Access Journals (Sweden)

Shao-Ming Fang

2009-05-01

Full Text Available The title complex, {[Mn(C10H8N22(H2O2](C14H9O4S22}n, contains an octahedrally coordinated MnII cation and 2-(2-carboxyphenyldisulfanylbenzoate anions. The MnII center is situated on a crystallographic center of inversion and is coordinated by four 4,4′-bipyridine (4,4′-bipy ligands and two water molecules. The 4,4′-bipy ligands act as bridging ligands, producing a fishing-net-like two-dimensional framework. In the crystal structure, this positively charged framework is charge balanced by 2-(2-carboxyphenyldisulfanylbenzoate anions that form a separate anionic two-dimensional framework via intermolecular O—H...O hydrogen bonds and C—H...π stacking interactions. Additional intermolecular O—H...O hydrogen bonds link the cationic and anionic frameworks to form the three-dimensional crystal structure.

New borohydride anion B6H7-

International Nuclear Information System (INIS)

Kuznetsov, I.Yu.; Vinitskij, D.M.; Solntsev, K.A.

1985-01-01

The [Ni(Bipy) 3 ] (B 6 H 7 ) 2 , (Ph 4 P)B 6 H 7 , [Ni(Phen) 3 ](B 6 H 7 ) 2 crystals (where Bipy = bipyridine, Phen = phenathroline, Ph = phenyl) are obtained via the exchange reaction with a subsequent recrystallization from aqua-acetonic and acetonic solutions. The structure is studied of a new borohydride anion B 6 H 7 - possessing a four-valence bond unique for polyhedral borohydride anions. A triangular face of boride skeleton coordinating a hydrogen atom is considerably larger than other faces, and the electron density on this hydrogen atom is evidently much higher than at the end hydride hydrogen atoms. The trend of B 6 H 7 - anion to form statistically disordered structurs testifies to a rather slight effect of the seventh hydrogen atom position on the structure pattern of the ionic crystal lattice

Synthesis, characterization and thermal decomposition kinetics of Sm(III)complex with 2,4-dichlorobenzoate and 2,2'-bipyridine

International Nuclear Information System (INIS)

Zhang Haiyan; Zhang Jianjun; Ren Ning; Xu, Su-Ling; Zhang Yonghua; Tian Liang; Song Huihua

2008-01-01

The complex of [Sm(2,4-DClBA) 3 (bipy)] 2 (2,4-DClBA, 2,4-dichlorobenzoate; bipy, 2,2'-bipyridine) was synthesized and characterized by elemental analysis, molar conductivity, IR and UV spectra. The thermal decomposition process of the complex was studied by means of TG-DTG and IR techniques. And its thermal decomposition kinetics was investigated via the analysis of the TG-DTG curves by jointly using double equal-double steps method and nonlinear integral isoconversional method. The activation energy E, the pre-exponential factor A and the most probable mechanism functions of the first decomposition stage were obtained. Meanwhile, the thermodynamic parameters (ΔH ≠ , ΔG ≠ and ΔS ≠ ) were also calculated. The lifetime equation at weight-loss of 10% was deduced as ln τ = -35.53 + 20200/T by isothermal thermogravimetric analysis

A new electrochemical sensor containing a film of chitosan-supported ruthenium: detection and quantification of sildenafil citrate and acetaminophen

International Nuclear Information System (INIS)

Delolo, Fabio Godoy; Rodrigues, Claudia; Silva, Monize Martins da; Batista, Alzir Azevedo; Dinelli, Luis Rogerio; Delling, Felix Nicolai; Zukerman-Schpector, Julio

2014-01-01

This work presents the construction of a novel electrochemical sensor for detection of organic analytes, using a glassy carbon electrode (GCE) modified with a chitosan-supported ruthenium film. The ruthenium-chitosan film was obtained starting from the mer-[RuCl 3 (dppb)(H 2 O)] complex as a [1,4-bis(diphenylphosphine)butane] (dppb) precursor, and chitosan (QT). The structure of the chitosan-supported ruthenium film on the surface of the glassy carbon electrode was characterized by UV-Vis spectroscopy, electron paramagnetic resonance (EPR), scanning electron microscopy (SEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS) techniques. The glassy carbon electrode was modified with a film formed from the evaporation of 5 μL of a solution composed of 5 mg chitosan-supported ruthenium (RuQT) in 10 mL of 0.1 mol L -1 acetic acid. The modified electrode was tested as a sensor for sildenafil citrate (Viagra® 50 mg) and acetaminophen (Tylenol®) detection. The technique utilized for these analyses was differential pulse voltammetry (DPV) in 0.1 mol L -1 H 2 SO 4 (pH 1.0) and 0.1 mol L -1 CH 3 COOK (pH 6.5) as supporting electrolyte. All analyses were carried out during a month using the same electrode. The electrode was washed only with water in between the analyses, keeping it in the refrigerator when it was not in use. This electrode was stable during the period utilized showing no degradation and presenting a linear response over the evaluated concentration interval (1.25 × 10 -5 to 4.99 × 10 -4 mol L -1 ). (author)

Zn(II) coordination polymers with flexible V-shaped dicarboxylate ligand: Syntheses, helical structures and properties

Energy Technology Data Exchange (ETDEWEB)

Li, Lin [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Liu, Chong-Bo, E-mail: cbliu@nchu.edu.cn [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Yang, Gao-Shan [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Xiong, Zhi-Qiang [Center for Analysis and Testing, Nanchang Hangkong University, Nanchang 330063 (China); Liu, Hong [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Wen, Hui-Liang [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047 (China)

2015-11-15

Hydrothermal reactions of 2,2′-[hexafluoroisopropylidenebis(p-phenyleneoxy)]diacetic acid (H{sub 2}L) and zinc ions in the presence of N-donor ancillary ligands afford four novel coordination polymers, namely, [Zn{sub 2}(μ{sub 2}-OH)(μ{sub 4}-O){sub 0.5}(L)]·0.5H{sub 2}O (1), [Zn(L)(2,2′-bipy)(H{sub 2}O)] (2), [Zn{sub 3}(L){sub 3}(phen){sub 2}]·H{sub 2}O (3) and [Zn{sub 2}(L){sub 2}(4,4′-bipy)] (4) (2,2′-bipy=2,2′-bipyridine; 4,4′-bipy=4,4′-bipyridine; phen=1,10-phenanthroline). Their structures have been determined by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. Complex 1 shows a 3-D clover framework consisting of [Zn{sub 4}(µ{sub 4}-O)(µ{sub 2}-OH){sub 2}]{sup 4+} clusters, and exhibits a novel (3,8)-connected topological net with the Schläfli symbol of {3·4·5}{sub 2}{3"4·4"4·5"2·6"6·7"1"0·8"2}, and contains double-stranded and two kinds of meso-helices. 2 displays a helical chain structure, which is further extended via hydrogen bonds into a 3-D supramolecular structure with meso-helix chains. 3 displays a 2-D {4"4·6"2} parallelogram structure, which is further extended via hydrogen bonds into a 3-D supramolecular structure with single-stranded helical chains. 4 shows a 2-D {4"4·6"2} square structure with left- and right-handed helical chains. Moreover, the luminescent properties of 1–4 have been investigated. - Graphical abstract: Four new Zn(II) coordination polymers with helical structures based on flexible V-shaped dicarboxylate ligand have been synthesized and structurally characterized. Photoluminescent properties have been investigated. - Highlights: • Four novel Zn(II) coordination polymers with V-shaped ligand were characterized. • Complexes 1–4 show diverse intriguing helical characters. • Fluorescence properties of complexes 1–4 were investigated.

Unsaturated Mn complex decorated hybrid thioarsenates: Syntheses, crystal structures and physical properties

Energy Technology Data Exchange (ETDEWEB)

Yue, Cheng-Yang [Key Laboratory of Inorganic Chemistry in Universities of Shandong, Department of Chemistry and Chemical Engineering, Jining University, Qufu, Shandong 273155 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Lei, Xiao-Wu, E-mail: xwlei_jnu@163.com [Key Laboratory of Inorganic Chemistry in Universities of Shandong, Department of Chemistry and Chemical Engineering, Jining University, Qufu, Shandong 273155 (China); Tian, Ya-Wei; Xu, Jing; Bai, Yi-Qun; Wang, Fei; Zhou, Peng-Fei; Liu, Xiao-Fan [Key Laboratory of Inorganic Chemistry in Universities of Shandong, Department of Chemistry and Chemical Engineering, Jining University, Qufu, Shandong 273155 (China); Yi, Fei-Yan, E-mail: yifeiyan@nbu.edu.cn [Faculty of Materials Science & Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211 (China)

2016-03-15

The incorporation of unsaturated [Mn(1,2-dap)]{sup 2+}, [Mn(1,2-dap){sub 2}]{sup 2+}, [Mn(2,2-bipy)]{sup 2+} (1,2-dap=1,2-diaminopropane) complex cations with thioarsenate anions of [As{sup III}S{sub 3}]{sup 3−} and [As{sup V}S{sub 4}]{sup 3−} led to three new hybrid manganese thioarsenates, namely, [Mn(1,2-dap)]{sub 2}MnAs{sub 2}S{sub 6} (1), [Mn(1,2-dap){sub 2}]{[Mn(1,2-dap)]_2As_2S_8} (2) and (NH{sub 4})[Mn(2,2-bipy){sub 2}]AsS{sub 4} (3). In compound 1, the unsaturated [Mn(1,2-dap)]{sup 2+} complexes, [MnS{sub 4}]{sup 6−} tetrahedra and [As{sup III}S{sub 3}]{sup 3−} trigonal-pyramids are condensed to form the 1D [Mn(1,2-dap)]{sub 2}MnAs{sub 2}S{sub 6} chain, whereas compound 2 features 2D layer composed of [Mn(1,2-dap)]{sup 2+} and [Mn(1,2-dap){sub 2}]{sup 2+} complexes as well as [As{sup V}S{sub 4}]{sup 3−} tetrahedral units. For compound 3, two [As{sup V}S{sub 4}]{sup 3−} anions bridge two [Mn(2,2-bipy)]{sup 2+} complex cations into a butterfly like {[Mn(2,2-bipy)]_2As_2S_8}{sup 2−} anionic unit. Magnetic measurements indicate the ferrimagnetic behavior for compound 1 and antiferromagnetic (AF) behaviors for compounds 2–3. The UV–vis diffuse-reflectance measurements and electronic structural calculations based on density functional theory (DFT) revealed the title compounds belong to semiconductors with band gaps of 2.63, 2.21, and 1.97 eV, respectively. The narrow band-gap of compound 3 led to the efficient and stable photocatalytic degradation activity over organic pollutant than N-doped P25 under visible light irradiation. - Highlights: Three new hybrid manganese thioarsenates have been prepared and structurally characterized. These hybrid phases feature interesting magnetic and visible light responding photocatalytic properties.

Testing of the BipiColombo Antenna Pointing Mechanism

Science.gov (United States)

Campo, Pablo; Barrio, Aingeru; Martin, Fernando

2015-09-01

BepiColombo is an ESA mission to Mercury, its planetary orbiter (MPO) has two antenna pointing mechanism, High gain antenna (HGA) pointing mechanism steers and points a large reflector which is integrated at system level by TAS-I Rome. Medium gain antenna (MGA) APM points a 1.5 m boom with a horn antenna. Both radiating elements are exposed to sun fluxes as high as 10 solar constants without protections.A previous paper [1] described the design and development process to solve the challenges of performing in harsh environment.. Current paper is focused on the testing process of the qualification units. Testing performance of antenna pointing mechanism in its specific environmental conditions has required special set-up and techniques. The process has provided valuable feedback on the design and the testing methods which have been included in the PFM design and tests.Some of the technologies and components were developed on dedicated items priort to EQM, but once integrated, test behaviour had relevant differences.Some of the major concerns for the APM testing are:- Create during the thermal vacuum testing the qualification temperature map with gradients along the APM. From of 200oC to 70oC.- Test in that conditions the radio frequency and pointing performances adding also high RF power to check the power handling and self-heating of the rotary joint.- Test in life up to 12000 equivalent APM revolutions, that is 14.3 million motor revolutions in different thermal conditions.- Measure low thermal distortion of the mechanical chain, being at the same time insulated from external environment and interfaces (55 arcsec pointing error)- Perform deployment of large items guaranteeing during the process low humidity, below 5% to protect dry lubrication- Verify stability with representative inertia of large boom or reflector 20 Kgm2.

Structural, spectral and magnetic studies of two Co(II)-N-heterocyclic diphosphonates based on multinuclear units

Science.gov (United States)

Zhao, Chen; Ma, Kui-Rong; Zhang, Yu; Kan, Yu-He; Li, Rong-Qing; Hu, Hua-You

2016-01-01

Two examples of Co(II)-N-heterocyclic coordination polymers based on 1-hydroxyethylidenediphosphonic acid (H5L = CH3C(OH)(PO3H2)2), namely 0.5(H3NCH2CH2NH3)·[Co6(Cl2)(H3L)2(H2L)(HL)(2,2‧-bipy)6] 1 and 2(NH4)·[Co3(HL)2(H2O)2(phen)2]·2(H2O) 2, have been solvothermally obtained by introducing the second ligands 2,2‧-bipyridine/1,10-phenanthroline (2,2‧-bipy/phen) and characterized by powder X-ray diffraction (PXRD), elemental analysis, IR, TG-DSC. The single-crystal X-ray diffractions show that compound 1 possesses a 0-D structure with hexa-nuclear cluster [Co6(O-P-O)8] built through single/double O-P-O bridges and compound 2 displays a 1-D ladder-like chain structure with magnetic topology building blocks [Co4(O-P-O)4]n. Then H-bonding and π-π stacking interactions further expand the two low-dimensional structures into three-dimensional supramolecular frameworks. Fluorescent measurements reveal that both the maximum emission peaks of 1-2 are centered at 423 nm, mainly deriving from intraligand π*-π transition state of N-heterocyclic ligand 2,2‧-bipy/phen, respectively. Magnetism data indicate that 1 exhibits antiferromagnetic behavior within hexa-nuclear Co(II) clusters, while 2 shows weak ferromagnetic interactions in 1-D topology Co(II)-chain, showing promising potential as magnetic materials.

The kinetics of substitution reaction of oxydiacetate and ...

Indian Academy of Sciences (India)

molar ratio 1:1 and the ternary complex Cu(R)B were recorded to confirm that ... tion, the values of the rate constants were determined. Figure 2. .... Table 4. The free enthalpy of activation values for the substitution reaction of CuODA with bipy.

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Chemical Sciences. DEBABRATA NANDI. Articles written in Journal of Chemical Sciences. Volume 128 Issue 8 August 2016 pp 1327-1335 Regular Article. Substitution reactions of [Pd(bipy)(malonate)] explored with a different set of ligands: Kinetic and mechanistic interpretation in aqueous ...

A new electrochemical sensor containing a film of chitosan-supported ruthenium: detection and quantification of sildenafil citrate and acetaminophen

Energy Technology Data Exchange (ETDEWEB)

Delolo, Fabio Godoy; Rodrigues, Claudia; Silva, Monize Martins da; Batista, Alzir Azevedo, E-mail: fabiodelolo@hotmail.com, E-mail: daab@power.ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica. Lab. de Estrutura e Reatividade de Compostos Inorganicos; Dinelli, Luis Rogerio [Universidade Federal de Uberlandia (UFU), Ituiutaba, MG (Brazil). Faculdade de Ciencias Integradas do Pontal; Delling, Felix Nicolai; Zukerman-Schpector, Julio [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica. Lab. de Cristalografia Estereodinamica e Modelagem Molecular

2014-03-15

This work presents the construction of a novel electrochemical sensor for detection of organic analytes, using a glassy carbon electrode (GCE) modified with a chitosan-supported ruthenium film. The ruthenium-chitosan film was obtained starting from the mer-[RuCl{sub 3}(dppb)(H{sub 2}O)] complex as a [1,4-bis(diphenylphosphine)butane] (dppb) precursor, and chitosan (QT). The structure of the chitosan-supported ruthenium film on the surface of the glassy carbon electrode was characterized by UV-Vis spectroscopy, electron paramagnetic resonance (EPR), scanning electron microscopy (SEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS) techniques. The glassy carbon electrode was modified with a film formed from the evaporation of 5 μL of a solution composed of 5 mg chitosan-supported ruthenium (RuQT) in 10 mL of 0.1 mol L{sup -1} acetic acid. The modified electrode was tested as a sensor for sildenafil citrate (Viagra® 50 mg) and acetaminophen (Tylenol®) detection. The technique utilized for these analyses was differential pulse voltammetry (DPV) in 0.1 mol L{sup -1} H{sub 2}SO{sub 4} (pH 1.0) and 0.1 mol L{sup -1} CH{sub 3}COOK (pH 6.5) as supporting electrolyte. All analyses were carried out during a month using the same electrode. The electrode was washed only with water in between the analyses, keeping it in the refrigerator when it was not in use. This electrode was stable during the period utilized showing no degradation and presenting a linear response over the evaluated concentration interval (1.25 × 10{sup -5} to 4.99 × 10{sup -4} mol L{sup -1}). (author)

Systematic Introduction of Aromatic Rings to Diphosphine Ligands for Emission Color Tuning of Dinuclear Copper(I) Iodide Complexes.

Science.gov (United States)

Okano, Yuka; Ohara, Hiroki; Kobayashi, Atsushi; Yoshida, Masaki; Kato, Masako

2016-06-06

We have newly synthesized two solution-stable luminescent dinuclear copper(I) complexes, [Cu2(μ-I)2(dpppy)2] (Cu-py) and [Cu2(μ-I)2(dpppyz)2] (Cu-pyz), where dpppy = 2,3-bis(diphenylphosphino)pyridine and dpppyz = 2,3-bis(diphenylphosphino)pyrazine, using chelating diphosphine ligands composed of N-heteroaromatic rings. X-ray analysis clearly indicates that the molecular structures of Cu-py and Cu-pyz are almost identical with that of the parent complex, [Cu2(μ-I)2(dppb)2] [Cu-bz; dppb = 2,3-bis(diphenylphosphino)benzene]. Complexes Cu-py and Cu-pyz exhibit luminescence [emission quantum yield (Φem) = 0.48 and 0.02, respectively] in the solid state at 298 K. A wide emission color tuning, from 497 to 638 nm (energy = 0.55 eV, with an emission color ranging from green to reddish-orange), was achieved in the solid state by the introduction of pyridinic N atoms into the bridging phenyl group between the two diphenylphosphine groups. Density functional theory calculations suggest that the emission could originate from the effective combination of the metal-to-ligand charge-transfer excited state with the halide-to-ligand charge-transfer excited state. Thus, the emission color change is due to stabilization of the π* levels of the central aryl group in the diphosphine ligand. Furthermore, these copper(I) complexes exhibit thermally activated delayed fluorescence at 298 K because of the small singlet-triplet energy difference (ΔE = 523 and 564 cm(-1) for Cu-py and Cu-pyz, respectively). The stability of these complexes in chloroform, due to the rigid bonds between the diphosphine ligands and the Cu(I) ions, enables the preparation of emissive poly(methyl methacrylate) films by the solution-doping technique.

Rational Organization of Lanthanide-Based SMM Dimers into Three-Dimensional Networks.

Science.gov (United States)

Yi, Xiaohui; Calvez, Guillaume; Daiguebonne, Carole; Guillou, Olivier; Bernot, Kevin

2015-06-01

Optimization of the reaction of [Ln(hfac)3]·2H2O and pyridine-N-oxide (PyNO), which is known to afford double-bridged dimers, leads to triple-bridged dimers of formula [(Ln(hfac)3)2(PyNO)3] (Ln = Gd (1), Dy (2)) from which the Dy derivative (2) behaves as a single-molecule magnet (SMM). The pseudo threefold axis symmetry of this zero-dimensional building block makes possible its extension into a tridimensional network. By changing PyNO for 4,4'-bipyridine N,N'-dioxide (4,4'BipyNO) a tridimensional compound of formula {[Ln(hfac)3]2(4,4'BipyNO)2]} (Ln = Eu (3), Gd (4), and Dy (5)) is then rationally obtained. This covalent three-dimensional (3D) network has a remarkably high cell volume (V = 24 419 A(3)) and is an arrangement of interpenetrated 3D subnetworks whose triple-bridged dimers still behave as SMMs.

Ultrasonic synthesis of two new zinc(II) bipyridine coordination polymers: New precursors for preparation of zinc(II) oxide nano-particles.

Science.gov (United States)

Fard, Mohammad Jaafar Soltanian; Hayati, Payam; Firoozadeh, Azita; Janczak, Jan

2017-03-01

Nanoparticles of two zinc(II) coordination polymers (CPs), [Zn(μ-4,4'-bipy)Cl 2 ] n (1) and [Zn(μ-4,4'-bipy)Br 2 ] n (2) L=bpy=4,4'-bipyridine ligand, have been synthesized by use of a sonochemical process and characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR) spectroscopy and elemental analyses. The single crystal X-ray data of compounds 1 and 2 imply that the Zn +2 ions are four coordinated. Topological analysis shows that 1D coordination networks of 1 and 2 can be classified as underlying nets of topological types 2C1. Nanoparticles of zinc(II) oxide have been prepared by calcination of two different zinc (II) CPs at 450°C that were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and IR spectroscopy. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis, structure and some properties of a manganese(II) benzoate containing diimine

Science.gov (United States)

Paul, Pranajit; Roy, Subhadip; Sarkar, Sanjoy; Chowdhury, Shubhamoy; Purkayastha, R. N. Dutta; Raghavaiah, Pallepogu; McArdle, Patrick; Deb, Lokesh; Devi, Sarangthem Indira

2015-12-01

A new monomeric manganese(II) benzoate complex containing nitrogen donor 2,2‧-bipyridine, [Mn(OBz)2(bipy)(H2O)] (OBz = benzoate, bipy = 2,2‧-bipyridine) has been synthesized from aqueous methanol medium and characterized by analytical, spectroscopic and single crystal X-ray diffraction studies. The compound exhibits moderate to appreciable antimicrobial activity. The complex crystallizes in space group P21/n. Mn(II) atom is ligated by two N atoms of bipyridine, three O atoms from a monodentate and a bidentate benzoate ligand and a water molecule forming distorted octahedral structure. The coordinated water molecule forms intramolecular hydrogen bonds and links the monomer molecules into hydrogen bonded dimer. The hydrogen bonded dimers are involved in intermolecular C-H···O and π-π stacking interactions. Density functional theory (DFT) computation was carried out to compute the frequencies of relevant vibrational modes and electronic properties, the results are in compliance with the experimentally obtained structural and spectral data.

Synthesis, structure, and electrochemistry and magnetic properties of a novel 1D homochiral MnIII(5-Brsalen) coordination polymer with left-handed helical character

Science.gov (United States)

Dong, Dapeng; Yu, Naisen; Zhao, Haiyan; Liu, Dedi; Liu, Jia; Li, Zhenghua; Liu, Dongping

2016-01-01

A novel homochiral manganese (III) Mn(5-Brsalen) coordination polymer with left-handed helical character by spontaneous resolution on crystallization by using Mn(5-Brsalen) and 4,4-bipyridine, [MnIII(5-Brsalen)(4,4-bipy)]·ClO4·CH3OH (1) (4,4-bipy = 4,4-bipyridine) has been synthesized and structurally characterized by X-ray single-crystal diffraction, elemental analysis and infrared spectroscopy. In compound 1, each manganese(III) anion is six-coordinate octahedral being bonded to four atoms of 5-Brsalen ligand in an equatorial plane and two nitrogen atoms from a 4,4-bipyridine ligand in axial positions. The structure of compound 1 can be described a supramolecular 2D-like structure which was formed by the intermolecular π-stacking interactions between the neighboring chains of the aromatic rings of 4,4-bipyridine and 5-Brsalen molecules. UV-vis absorption spectrum, electrochemistry and magnetic properties of the compound 1 have also been studied.

A New 1D Chained Coordination Polymer: Synthesis, Crystal Structure, Antitumor Activity and Luminescent Property

Directory of Open Access Journals (Sweden)

Xi-Shi Tai

2015-11-01

Full Text Available A new 1D chained coordination polymer of Zn(II, {[Zn(L2(4,4′-bipy]·(H2O}n(1 (HL = N-acetyl-l-phenylalanine; 4,4′-bipy = 4,4′-bipyridine has been synthesized and characterized by elemental analysis, IR and X-ray single crystal diffraction analysis. Theresults show that each asymmetric unit of Zn(II complex belongs to monoclinic, space group P21 with a = 11.421(2 Å, b = 9.2213(17 Å, c = 15.188(3 Å,β = 106.112(3°, V = 1536.7(5 Å3, Z = 2, Dc = 1.444 g·cm−3, µ = 0.857 mm−1, F(000 = 696, and final R1 = 0.0439, ωR2 = 0.1013. The molecules form one-dimensional chained structure by its the bridging 4,4′-bipyridine ligands. The antitumor activities and luminescent properties of Zn(II coordination polymer have also been investigated.

Synthesis, structures and properties of Cu(II) and Mn(II) complexes with 1,10-phenanthroline-2-carboxylic acid and 2,2'-bipyridine ligands.

Science.gov (United States)

Sun, Jingya; Xu, Huanzhi

2010-11-15

Four new 2,2'-bipyridine and 1,10-phenanthroline complexes, namely [Mn(phenca)(2)]·(H(2)O)(2) (1), [Cu(4)(phen)(4)(OH-)(4)(H(2)O)(2)](DMF)(4)(ClO(4)-)(4)(H(2)O) (2), [Cu(2)(2,2-bipy)(2)(C(2)O(4)2-)(H(2)O)(2)(NO(3))(2)] (3) and [Cu(2,2-bipy)(2)(ClO(4)-)](ClO(4)-) (4) (2,2'-bpy = 2,2'-bipyridine, Hphenca = 1,10-phenanthroline-2-carboxylic acid) have been synthesized by a hydrothermal reaction. The products were characterized by elemental analysis, infrared spectroscopy and X-ray crystal diffraction. While strong hydrogen bonds play central roles in the formation of the 3D structure, the combined influence of the weak interactions such as π···π interactions is also evident in the structures. A preliminary investigation on the ion exchange properties of the complexes is presented.

Synthesis, Structures and Properties of Cu(II and Mn(II Complexes with 1,10-Phenanthroline-2-carboxylic acid and 2,2’-Bipyridine Ligands

Directory of Open Access Journals (Sweden)

Huanzhi Xu

2010-11-01

Full Text Available Four new 2,2’-bipyridine and 1,10-phenanthroline complexes, namely [Mn(phenca2]·(H2O2 (1, [Cu4(phen4(OH-4(H2O2](DMF4(ClO4-4(H2O (2, [Cu2(2,2-bipy2(C2O42-(H2O2(NO32] (3 and [Cu(2,2-bipy2(ClO4-](ClO4- (4 (2,2’-bpy = 2,2’-bipyridine, Hphenca = 1,10-phenanthroline-2-carboxylic acid have been synthesized by a hydrothermal reaction. The products were characterized by elemental analysis, infrared spectroscopy and X-ray crystal diffraction. While strong hydrogen bonds play central roles in the formation of the 3D structure, the combined influence of the weak interactions such as π···π interactions is also evident in the structures. A preliminary investigation on the ion exchange properties of the complexes is presented.

Electrochemical synthesis and characterization of polyconjugated polyfuran

Energy Technology Data Exchange (ETDEWEB)

Zotti, G.; Schlavon, G.; Comisso, N. (Consiglio Nazionale delle Ricerche, Ist. di Polarografia ed Elettrochimica Preparativa, Padua (Italy)); Berlin, A.; Pagani, G. (Dipt. di Chimica Organica e Industriale, Milan Univ. (Italy) Centro CNR, Speciali Sistemi Organici, Milan (Italy))

1990-07-01

Polyconjugated polyfuran (PF) was produced by electroreduction of 2,5-dibromofuran in acetonitrile using Ni(bipy){sub 3}{sup 2+} as catalyst. Polymerization occurs only in the presence of excess Ni(bipy){sub 3}{sup 2+} at potentials in the range -1.7 to -2.0 V versus Ag/Ag{sup +} via binuclear organonickel complex. IR spectroscopy, elemental analysis and mass spectroscopy confirm that PF is constituted by 2.5-linked furan units and indicate a degree of polymerization >100. Red PF films ({lambda}{sub max}=420 nm, E{sub g}=2.2 eV) are reversibly oxidized at 0.45 V and reduced at -2.5 V.Doping with AsF{sub 5} gives PF a conductivity of 10{sup -3} S/cm. Polymers produced by anodic coupling of furan were also investigated for comparison. IR spectroscopy and elemental analysis indicate that they display a lower degree of conjugation due to the concomitant acidcatalyzed polymerization. (orig.).

Binding CO2 from Air by a Bulky Organometallic Cation Containing Primary Amines.

Science.gov (United States)

Luo, Yang-Hui; Chen, Chen; Hong, Dan-Li; He, Xiao-Tong; Wang, Jing-Wen; Ding, Ting; Wang, Bo-Jun; Sun, Bai-Wang

2018-03-21

The organometallic cation 1 (Fe(bipy-NH 2 ) 3 2+ , bipy-NH 2 = 4,4'-diamino-2,2'-bipyridine), which was constructed in situ in solution, can bind CO 2 from air effectively with a stoichiometric ratio of 1:4 (1/CO 2 ), through the formation of "H-bonded CO 2 " species: [CO 2 -OH-CO 2 ] - and [CO 2 -CO 2 -OH] - . These two species, along with the captured individual CO 2 molecules, connected 1 into a novel 3D (three-dimensional) architecture, that was crystal 1·2(OH - )·4(CO 2 ). The adsorption isotherms, recycling investigations, and the heat capacity of 1 have been investigated; the results revealed that the organometallic cation 1 can be recycled at least 10 times for the real-world CO 2 capture applications. The strategies presented here may provide new hints for the development of new alkanolamine-related absorbents or technologies for CO 2 capture and sequestration.

Structural diversification and photocatalytic properties of three Cd(II) coordination polymers decorated with different auxiliary ligands

Energy Technology Data Exchange (ETDEWEB)

Yin, Wen-Yu; Zhuang, Guo-Yong; Huang, Zuo-Long; Cheng, Hong-Jian; Zhou, Li; Ma, Man-Hong; Wang, Hao; Tang, Xiao-Yan, E-mail: xytang@cslg.edu.cn; Ma, Yun-Sheng; Yuan, Rong-Xin, E-mail: yuanrx@cslg.edu.cn

2016-03-15

Three cadmium coordination polymers, [Cd(bismip)]{sub n} (1), {[Cd(bismip)(phen)]·H_2O}{sub n} (2) and {[Cd_2(bismip)_2(4,4′-bipy)]·2H_2O}{sub n} (3) (H{sub 2}bismip=5-(1H-benzoimidazol-2-ylsulfanylmethyl)-isophthalic acid, phen=1,10-phenanthroline, 4,4′-bipy=4,4′-bipyridine) have been prepared under solvothermal conditions. In 1, the [Cd{sub 4}(bismip){sub 3}] units are jointed by bismip ligands to afford a three-dimensional (3D) architecture. Complex 2 exhibits a 3D supramolecular framework based on the interconnection of 1D chains through hydrogen bonding interactions and π-π packing interactions. 3 is a two-fold interpenetrating 3D architecture with a (4·8{sup 2})(4{sup 2}·8{sup 4}) Schläfli symbol in which 2D layers are interlinked by 4,4′-bipy ligands. The diverse structures of compounds 1–3 indicate that the auxiliary ligands have significant effects on the final structures. The photoluminescent properties and photocatalytic properties of these coordination polymers in the solid state were also investigated. Remarkably, 3 shows the wide gap semiconductor nature and exhibit excellent photocatalytic performance. - Graphical abstract: Three cadmium coordination polymers with different architectures based on 5-(1H-benzoimidazol-2-ylsulfanylmethyl)-isophthalic acid have been prepared. Their photoluminescent properties were also investigated. - Highlights: • Three new Cd(II) Cps were synthesized based on H{sub 2}bismip. • Compounds 1 and 3 show 3D networks and 2 exhibits a 1D chain. • Compoud 3 exhibits good catalytic activity of methylene blue photodegradation.

Substitution reactions of [Pd(bipy)(malonate)] explored with a ...

Indian Academy of Sciences (India)

−3. NaClO4. Table 1. Metal-Ligand ratios and structures of the product complexes. Metal:Ligand. Ligand. Structure ratio. Product complex. L1 Thioglycolic acid. HS ..... O. Scheme 1. Plausible mechanistic pathway. molecules substitute the bidentate malonate in a consec- utive fashion. Among the three sulphur donor ligands.

Synthesis and photoluminescence properties of silver(I) complexes based on N-benzoyl-L-glutamic acid and N-donor ligands with different flexibility

Science.gov (United States)

Yan, Ming-Jie; Feng, Qi; Song, Hui-Hua

2016-05-01

By changing the N-donor ancillary ligand, three novel silver (I) complexes {[Ag(HbzgluO) (4,4‧-bipy)]·H2O}n (1), {[Ag2(HbzgluO)2 (bpe)2]·2H2O}n (2) and {[Ag(HbzgluO)(bpp)]·2H2O}n (3) (H2bzgluO = N-benzoyl-L-glutamic acid, 4,4‧-bipy = 4,4ˊ-bipyridine, bpe = 1,2-di(4-pyridyl)ethane, bpp = 1,3-di(4-pyridyl)propane) were synthesized. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric analyses (TGA). In this study, the N-donor ligands are changed from rigidity (4,4‧-bipy), quasi-flexibility (bpe) to flexibility (bpp), the structures of complexes also change. Complex 1 features a 1D chain structure which is further linked together to construct a 2D supramolecular structure through hydrogen bonds. Complex 2 is a 1D double-chains configuration which eventually forms a 3D supramolecular network via hydrogen bonding interactions. Whereas, complex 3 exhibits a 2D pleated grid structure which is linked by hydrogen bonding interactions into a 3D supramolecular network. The present observations demonstrate that the modulation of coordination polymers with different structures can accomplish by changing the spacer length of N-donor ligands. In addition, the solid-state circular dichroism (CD) spectra indicated that compound 2 exhibited negative cotton effect which originated from the chiral ligands H2bzgluO and the solid-state fluorescence spectra of the three complexes demonstrated the auxiliary ligands have influence on the photoluminescence properties of the complexes.

High turnover catalysis of water oxidation by Mn(II) complexes of monoanionic pentadentate ligands

DEFF Research Database (Denmark)

Seidler-Egdal, Rune Kirk; Nielsen, Anne; Bond, Andrew

2011-01-01

-pyridylmethyl)ethane-1,2-diamine (bcbpen(-)), show the presence of a mixture of closely related Mn(II) species, assigned to the mono, di-, tri- and poly-cationic complexes [Mn(II)(L)(H(2)O)](n)(n+), L = mcbpen(-) or bcbpen(-) with n = 1, 2, 3, etc. In solution, these complexes are reversibly oxidized by tert......:1 reaction of TBHP with [Mn] is rate determining and the resultant species is proposed to be the mononuclear, catalytically competent, [Mn(IV)(O)(mcbpen)](+). At very close m/z values [Mn(III)(OH)(mcbpen)](+), [Mn(2)(III/IV)(O)(2)(mcbpen)(2)](+) and [Mn(IV)(2)(O)(2)(mcbpen)(2)](2+) are detected by ESI MS......-butyl hydrogen peroxide (TBHP), (NH(4))(2)[Ce(NO(3))(6)], Ce(ClO(4))(4), oxone and [Ru(bipy)(3)](3+) to form metastable (t(½) = min to h) higher valent (hydr)oxide species, showing a collective maximum absorbance at 430 nm. The same species can be produced by [Ru(bipy)(3)](2+)-mediated photooxidization...

High Turnover Catalysis of Water Oxidation by Mn(II) complexes of Monoanionic Pentadentate Ligands

DEFF Research Database (Denmark)

Seidler-Egdal, Rune Kirk; Nielsen, Anne; Bond, Andrew

2011-01-01

-pyridylmethyl)ethane-1,2-diamine (bcbpen−), show the presence of a mixture of closely related Mn(II) species, assigned to the mono, di-, tri- and poly-cationic complexes [MnII(L)(H2O)]nn+, L = mcbpen− or bcbpen− with n = 1, 2, 3, etc. In solution, these complexes are reversibly oxidized by tert-butyl hydrogen...... determining and the resultant species is proposed to be the mononuclear, catalytically competent, [MnIV(O)(mcbpen)]+. At very close m/z values [MnIII(OH)(mcbpen)]+, [Mn2III/IV(O)2(mcbpen)2]+ and [MnIV2(O)2(mcbpen)2]2+are detected by ESI MS and CE when the concentration of TBHP is comparable to or lower than...... peroxide (TBHP), (NH4)2[Ce(NO3)6], Ce(ClO4)4, oxone and [Ru(bipy)3]3+ to form metastable (t½ = min to h) higher valent (hydr)oxide species, showing a collective maximum absorbance at 430 nm. The same species can be produced by [Ru(bipy)3]2+-mediated photooxidization in the presence of an electron acceptor...

Introducing Stable Radicals into Molecular Machines.

Science.gov (United States)

Wang, Yuping; Frasconi, Marco; Stoddart, J Fraser

2017-09-27

Ever since their discovery, stable organic radicals have received considerable attention from chemists because of their unique optical, electronic, and magnetic properties. Currently, one of the most appealing challenges for the chemical community is to develop sophisticated artificial molecular machines that can do work by consuming external energy, after the manner of motor proteins. In this context, radical-pairing interactions are important in addressing the challenge: they not only provide supramolecular assistance in the synthesis of molecular machines but also open the door to developing multifunctional systems relying on the various properties of the radical species. In this Outlook, by taking the radical cationic state of 1,1'-dialkyl-4,4'-bipyridinium (BIPY •+ ) as an example, we highlight our research on the art and science of introducing radical-pairing interactions into functional systems, from prototypical molecular switches to complex molecular machines, followed by a discussion of the (i) limitations of the current systems and (ii) future research directions for designing BIPY •+ -based molecular machines with useful functions.

Chalcogenhalide cluster rhenium- and molybdenum complexes

International Nuclear Information System (INIS)

Fedin, V.P.; Gubin, S.P.; Mishchenko, A.V.; Fedorov, V.E.

1984-01-01

The interaction of rhenium- and molybdenum chalcogenhalides with n-donor ligands (L) is studied. At heating Re 3 X 2 Hal 5 complexes up to 100 deg in DMSO in the L presence obtained are the complexes of the 1-6 composition Re 3 X 2 Hal 5 -x Lx DMSO (X=Se, Hal=Cl, L=Et 3 N(1); X=Se, Hal=Cl, L=Bipy(2); X=Se, Hal=Br, L=Et 3 N(3); X=Se, Hal=Br, L=Bipy(4); X=Te, Hal=Br, L=Et 3 N(5); X=Te, Hal=Br, L=(Me 2 NCH 2 ) 2 (6). In the course of boiling of Mo 3 S 7 Hal 4 with PPh 3 in MeCN the Mo 3 S 7 Hal 4 2PPh 3 complexes (Hal=Cl(7); Br(8)) are obtained. For 1 through 8 complexes the chemical analysis data and IR spectra are given. For 4 and 8 complexes the molecular mass is measured. A possible method of obtaining molecular trinuclear clusters from polymer clusters is discussed

Synthesis, spectroscopic, DFT calculations and biological activity studies of ruthenium carbonyl complexes with 2-picolinic acid and a secondary ligand

Science.gov (United States)

Shohayeb, Shahera M.; Mohamed, Rania G.; Moustafa, H.; El-Medani, Samir M.

2016-09-01

Thermal reaction of [Ru3(CO)12] with 2-picolinic acid (Hpic) in the absence and presence of a secondary ligand (pyridine, Py, bipyridine, Bipy, or thiourea, Tu) was investigated. Four complexes with molecular formulae: [Ru(CO)3(Hpic)], 1, [Ru2(CO)5(Hpic)(Py)], 2, [Ru2(CO)5(Hpic)(Tu)], 3 and [Ru2(CO)4(Hpic)(Bipy)], 4, were isolated. All complexes were characterized based on elemental analyses, IR, 1H NMR, magnetic studies, mass spectrometry and thermal analysis. The ligand and its complexes have been screened for antibacterial activities. Density Functional Theory (DFT) calculations at the B3LYP/6-311G (d,p)_ level of theory have been carried out to investigate the equilibrium geometry of the ligands. The optimized geometry parameters of the complexes were evaluated using B3LYP method and LANL2DZ basis set. The extent of natural charge population (core, valence and rydberg), exact electronic configuration, total Lewis and total non-Lewis are estimated and discussed in terms of natural bond orbitals (NBO) analysis.

Synthesis and DNA binding/cleavage of mononuclear copper(II) phenanthroline/bipyridine proline complexes.

Science.gov (United States)

Reddy, Pulimamidi R; Raju, Nomula; Manjula, Pallerla; Reddy, Karnati V G

2007-07-01

The complexes [Cu(II)(phen)(L-Pro)(H2O)]+ ClO4(-) (1; phen = 1,10-phenanthroline) and [Cu(II)(bipy)(L-Pro)(H2O)]+ ClO4(-) (2; bipy = 2,2'-bipyridine) were synthesized and characterized by IR, magnetic susceptibility, UV/VIS, EPR, ESI-MS, elemental analysis, and theoretical calculations. The metal center was found in a square-pyramidal geometry. UV/VIS, thermal-denaturation, and fluorescence-spectroscopic studies were conducted to assess the interaction of the complexes with CT-DNA. An intercalative mode of binding was found, with intrinsic binding constants (Kb) of 3.86x10(3) and 4.6x10(3) M(-1) and Stern-Volmer quenching constants (K) of 0.15 and 0.11 for 1 and 2, respectively. Interestingly, none of the Cu(II) complexes was able to cleave pUC-19 DNA, which is attributed to the absence of a Pro amide H-atom and inhibition of the formation of an OH radical from the axially coordinated H2O molecule.

Syntheses, characterizations and crystal structures of three new organically templated or organically bonded zinc selenates

International Nuclear Information System (INIS)

Feng Meiling; Mao Jianggao; Song Junling

2004-01-01

Three new organically templated or organically bonded zinc selenates, namely, {H 2 bipy}Zn(SeO 4 ) 2 (H 2 O) 2 1 (bipy=4,4'-bipyridine), {H 2 pip}{Zn(SeO 4 ) 2 (H 2 O) 4 }·2H 2 O 2 (pip=piprazine), and Zn(SeO 4 )(phen)(H 2 O) 2 3 (phen=1,10-phenanthroline) have been synthesized by hydrothermal reactions. The structure of compound 1 features a 1D chain composed of [Zn(SeO 4 ) 2 (H 2 O) 2 ] 2- anions. Compound 2 has a 2D layer structure built from {Zn(SeO 4 ) 2 (H 2 O) 4 } 2- anions that are cross-linked by doubly protonated piperazine cations via N-H···O hydrogen bonds. The structure of compound 3 contains a 1D chain of Zn(SeO 4 )(phen)(H 2 O) 2 , such chains are further interlinked by hydrogen bonds and π···π interactions to form a layer. The different roles the templates played have also been discussed

Self-assembled polymeric nanoparticles as new, smart contrast agents for cancer early detection using magnetic resonance imaging.

Science.gov (United States)

Mouffouk, Fouzi; Simão, Teresa; Dornelles, Daniel F; Lopes, André D; Sau, Pablo; Martins, Jorge; Abu-Salah, Khalid M; Alrokayan, Salman A; Rosa da Costa, Ana M; dos Santos, Nuno R

2015-01-01

Early cancer detection is a major factor in the reduction of mortality and cancer management cost. Here we developed a smart and targeted micelle-based contrast agent for magnetic resonance imaging (MRI), able to turn on its imaging capability in the presence of acidic cancer tissues. This smart contrast agent consists of pH-sensitive polymeric micelles formed by self-assembly of a diblock copolymer (poly(ethyleneglycol-b-trimethylsilyl methacrylate)), loaded with a gadolinium hydrophobic complex ((t)BuBipyGd) and exploits the acidic pH in cancer tissues. In vitro MRI experiments showed that (t)BuBipyGd-loaded micelles were pH-sensitive, as they turned on their imaging capability only in an acidic microenvironment. The micelle-targeting ability toward cancer cells was enhanced by conjugation with an antibody against the MUC1 protein. The ability of our antibody-decorated micelles to be switched on in acidic microenvironments and to target cancer cells expressing specific antigens, together with its high Gd(III) content and its small size (35-40 nm) reveals their potential use for early cancer detection by MRI.

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

A family of entangled coordination polymers constructed from a flexible V-shaped long bicarboxylic acid and auxiliary N-donor ligands: Luminescent sensing

International Nuclear Information System (INIS)

Wang, Jun; Bai, Chao; Hu, Huai-Ming; Yuan, Fei; Xue, Gang-Lin

2017-01-01

Eight Zn(II)-based coordination polymers, namely, [Zn 2 L 2 (2,2’-bipy)] n ·nH 2 O (1), [Zn 2 L 2 (phen)] n ·nH 2 O (2), [ZnL(phen)(H 2 O)] n (3), [Zn 3 L 3 (4,4’-bipy)] n (4), [Zn 2 L 2 (4,4’-bipy) 2 ] n [Zn 2 L 2 (H 2 O) 2 ] n ·2nH 2 O (5), [Zn 4 L 4 (bpp) 2 ] n (6), [ZnL(bbi) 0.5 ] n (7), [ZnL(bpz)] n (8) (H 2 L=4,4’-([1,2-phenylenebis-(methylene)]bis(oxy))dibenzoic acid, 2,2’-bipy =2,2’-bipyridine, phen =1,10-phenanthroline, 4,4’-bpy=4,4’-bipyridine, bpp =1,3-bis(4-pyridyl)propane, bbi=1,4-bis(imidazol-1-yl)butane, bpz=3,3′,5,5′-tetramethyl-4,4′-bipyrazole), have been hydrothermally synthesized and structurally characterized. 1–8 display various coordination motifs with different entangled forms and conformations due to the effect of the assistant N-donor ligands. The photoluminescent properties of compounds 1–8 in solid state were studied. Interestingly, 3 exhibits highly efficient luminescent sensing for Cu 2+ cations and CrO 4 2- anions, as well as detection ability for the different organic solvents and nitro explosives. These results indicated that it could be utilized as a multi-responsive luminescent sensor. Furthermore, compound 3 also shows good chemical resistance to both acidity and alkalinity solutions with pH ranging from 2 to 13. Thus, multi-photofunctionality and fluorescent response to pH have been combined in the 3, which is the first example in the Zn-based hybrid materials. - Graphical abstract: Eight new Zn(II)-based coordination polymers constructed from a flexible V-shaped long bicarboxylic acid and different N-donor ligands have been hydrothermally synthesized through fixing the metal salts and the solvent systems. The photoluminescent properties of complexes 1−8 in solid state were studied. Interestingly, 3 exhibits highly efficient luminescent sensing for Cu 2+ cations and CrO 4 2- anions, as well as detection ability for the different organic solvents and nitro explosives, in which indicates it could be

Ancillary ligand-assisted assembly of C{sub 3}-symmetric 4,4′,4″-nitrilotribenzoic acid with divalent Zn{sup 2+} ions: Syntheses, topological structures, and photoluminescence properties

Energy Technology Data Exchange (ETDEWEB)

Cui, Li-Ting; Niu, Yan-Fei [Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062 (China); Han, Jie, E-mail: chan@ouhk.edu.hk [School of Science & Technology, The Open University of Hong Kong, Kowloon, Hong Kong SAR (China); Zhao, Xiao-Li, E-mail: xlzhao@chem.ecnu.edu.cn [Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062 (China)

2015-07-15

4,4′,4″-nitrilotribenzoic acid (H{sub 3}L), a C{sub 3}-symmetric ligand, was found to self-assemble into two polymorphs driven by intermolecular hydrogen-bonding interactions. Reactions of this ligand with Zn{sup 2+} under solvothermal conditions resulted in four new coordination polymers bearing interesting structural motifs: [Zn{sub 2}(L){sub 2}(py){sub 2}]·2(H{sub 2}NMe{sub 2}){sup +}·DMF·2H{sub 2}O (1), [Zn{sub 2}(L)(H{sub 2}L)(bipy)]·1.5H{sub 2}O·Guest (2), [Zn{sub 2}(L){sub 2}(bipy)]·2(H{sub 2}NMe{sub 2}){sup +}·2DMF (3), and [Zn{sub 3}(L){sub 2}(bpa)]·2H{sub 2}O·Guest (4) (H{sub 3}L=4,4′,4′′-nitrilotribenzoic acid, DMF=dimethylformamide, py=pyridine, bipy=4,4′-bipyridine, bpa=1,2-bis(4-pyridyl)diazene). Single-crystal structural analysis revealed that compound 1 exhibits a rare example of twofold interpenetrating anionic 3D (3,3)-net framework containing helical channels, whereas in 2, the 3D pillar-layer structure generated from bipy-pillared Zn{sub 2}(L)(H{sub 2}L) layer is further reinforced by intermolecular hydrogen bonding among pairs of free –COOH units. Compound 3 shows an interesting entangled architecture of 2D→3D parallel polycatenation consisting five-coordinated Zn{sup 2+} ions. Compound 4 displays a 3D pillar-layer framework with trimeric Zn{sub 3}(CO{sub 2}){sub 6} serving as secondary building unit (SBU). The syntheses, structures, thermal stabilities, powder X-ray diffractions and solid-state photoluminescence properties for these crystalline materials have been carried out. In addition, supramolecular assembly of H{sub 3}L under solvothermal conditions will also be addressed. - Graphical abstract: Supramolecular assembly of 4,4′,4′′-nitrilotribenzoic acid and its ligand behavior toward Zn{sup 2+} were investigated, which exhibit two polymorphs of the free acid and four metal coordination polymers bearing interesting structural motifs. - Highlights: • Two polymorphs of H{sub 3}L showing different hydrogen

Syntheses, structures, thermal stabilities and luminescence of two new lead sulfonates with phosphonate, carboxylate and pyridine

International Nuclear Information System (INIS)

Fu, Ruibiao; Hu, Shengmin; Wu, Xintao

2014-01-01

Hydrothermal reactions of Pb 2+ ion with disodium 4,4'-bis(2-sulfonatostyryl)biphenyl (Na 2 L1), 4-pyridyl-CH 2 N(CH 2 COOH)(CH 2 PO 3 H 2 ) (H 3 L2) and 4,4'-bipyridine (4,4'-bipy) afforded two new lead sulfonates, namely, [Pb 4 (L1) 2 (HL2) 2 (H 2 O)

Synthesis, structures and urease inhibitory activity of cobalt(III) complexes with Schiff bases.

Science.gov (United States)

Jing, Changling; Wang, Cunfang; Yan, Kai; Zhao, Kedong; Sheng, Guihua; Qu, Dan; Niu, Fang; Zhu, Hailiang; You, Zhonglu

2016-01-15

A series of new cobalt(III) complexes were prepared. They are [CoL(1)(py)3]·NO3 (1), [CoL(2)(bipy)(N3)]·CH3OH (2), [CoL(3)(HL(3))(N3)]·NO3 (3), and [CoL(4)(MeOH)(N3)] (4), where L(1), L(2), L(3) and L(4) are the deprotonated form of N'-(2-hydroxy-5-methoxybenzylidene)-3-methylbenzohydrazide, N'-(2-hydroxybenzylidene)-3-hydroxylbenzohydrazide, 2-[(2-dimethylaminoethylimino)methyl]-4-methylphenol, and N,N'-bis(5-methylsalicylidene)-o-phenylenediamine, respectively, py is pyridine, and bipy is 2,2'-bipyridine. The complexes were characterized by infrared and UV-Vis spectra, and single crystal X-ray diffraction. The Co atoms in the complexes are in octahedral coordination. Complexes 1 and 4 show effective urease inhibitory activities, with IC50 values of 4.27 and 0.35 μmol L(-1), respectively. Complex 2 has medium activity against urease, with IC50 value of 68.7 μmol L(-1). While complex 3 has no activity against urease. Molecular docking study of the complexes with Helicobacter pylori urease was performed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Redetermination of (2,2′-bipyridine-κ2N,N′dichloridopalladium(II dichloromethane solvate

Directory of Open Access Journals (Sweden)

Nam-Ho Kim

2009-06-01

Full Text Available In the title compound, [PdCl2(C10H8N2]·CH2Cl2, the Pd2+ ion is four-coordinated in a slightly distorted square-planar environment by two N atoms of the 2,2′-bipyridine (bipy ligand and two chloride ions. The compound displays intramolecular C—H...Cl hydrogen bonds and pairs of complex molecules are connected by intermolecular C—H...Cl hydrogen bonds. Intermolecular π–π interactions are present between the pyridine rings of the ligand, the shortest centroid–centroid distance being 4.096 (3 Å. As a result of the electronic nature of the chelate ring, it is possible to create π–π interactions to its symmetry-related counterpart [3.720 (2 Å] and also with a pyridine ring [3.570 (3 Å] of the bipy unit. The present structure is a redetermination of a previous structure [Vicente et al. (1997. Private communication (refcode PYCXMN02. CCDC, Cambridge, England]. In the new structure refinement all H atoms were located in a difference Fourier synthesis. Their coordinates were refined freely, together with isotropic displacement parameters.

Studies on Th(IV) and Zr(IV) complexes of oxygen donor ligands

International Nuclear Information System (INIS)

Agarwal, R.K.; Srivastava, M.; Srivastava, A.K.

1981-01-01

In recent years a large number of complexes of amine N-oxides with a wide variety of metal salts have been isolated and characterized. Less attention has been paid to the aromatic amine N-oxides complexes with Th(IV) thiocyanate. In the present communication studies are reported on Th(IV) thiocyanate complexes of pyridine N-oxide (PyO), quinoline N-oxide (QO), isoquinoline N-oxide (IsqO), 2-picoline N-oxide (2-picO), 3-picoline N-oxide (3-picO) and 4-picoline N-oxide (4-picO) and comparisons are made with the existing complexes of 2,6-lutidine N-oxide (LNO), 2, 2'bipyridine N-N'-dioxide (BipyO 2 ), mono N-oxides of 2,2'-bipyridine (BipyNO) and 1,10-phenanthroline (PhenNO) and 1, 10-phenanthroline N-N'-dioxide (PhenO 2 ). The analytical data correspond to the composition Th(NCS) 4 .4L. The molar conductance of all the complexes in nitrobenzene in the range 2.5 to 4.5 Ω -1 cm 2 mol -1 indicate them to be non-electrolytes. The results of IR spectroscopy and thermogravimetry are given and discussed. (author)

Study of the selectivity of poly-nitrogenous extracting molecules in the complexation of actinides (III) and lanthanides (III) in solution in anhydrous pyridine

International Nuclear Information System (INIS)

Riviere, Ch.

2000-01-01

The aim of this work is to better understand the factors which contribute to the separation of lanthanides(III) and actinides(III). Polydentate nitrogenous molecules present an interesting selectivity. A thermodynamic study of the complexation in pyridine of lanthanide and uranium by the bipyridine ligand (bipy) has been carried out. The formation constants and the thermodynamic values of the different complexes have been determined. It has been shown that the bipy complexes formation is controlled by the enthalpy and unfavored by the entropy. The conductometry has revealed too a significant difference in the uranium and lanthanides complexation by the bipyridine ligand. The use of the phenanthroline ligand induces a better complexation of the metallic ions but the selectivity is not improved. On the other hand, the decrease of the basicity and the increase of the ligand denticity (for instance in the case of the use of ter-pyridine) favour the selectivity without improving the complexation. The selectivity difference for the complexation of actinides(III) and lanthanides(III) by the different studied ligands (independent systems) has been confirmed by experiments of inter-metals competition. (O.M.)

A novel 3D Ag(I)-MOF: Surfactant-directed syntheses and catalytic degradation of o/m/p-Nitrophenol

Energy Technology Data Exchange (ETDEWEB)

Wu, Xue-Qian [College of Materials and Chemical Engineering, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China); Wen, Guo-Xuan [College of Science, China Three Gorges University, Yichang 443002 (China); Wu, Ya-Pan; Dong, Wen-Wen; Zhao, Jun [College of Materials and Chemical Engineering, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China); Li, Dong-Sheng, E-mail: lidongsheng1@126.com [College of Materials and Chemical Engineering, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China)

2016-10-15

For the first time, sodium caprylate has been investigated to direct the crystal growth of 3D Ag-MOF, [Ag{sub 2}(ddcba)(4,4′-bipy){sub 2}] (1), constructing from 3,5-(di(2′,5′-dicarboxylphenyl)benozoic acid and 4,4′-bipy. The single crystal diffraction analyses shows that complex 1 possess 3D neutral framework with a three-connected ThSi{sub 2} (10{sup 3}-b) topology. Compound 1 exhibits predominant catalytic activity towards the degradation of o-Nitrophenol (ONP), m-Nitrophenol (MNP) and p-Nitrophenol (PNP) in aqueous solution. The kinetics of such catalytic degradation reactions was also studied. - Graphical abstract: A novel 3D Ag(I)-MOF with ThSi{sub 2} (10{sup 3}-b) topology exhibits predominant catalytic activity towards the degradation of o-Nitrophenol (ONP), m-Nitrophenol (MNP) and p-Nitrophenol (PNP) in aqueous solution. - Highlights: • A novel 3D Ag(I)-MOF with ThSi{sub 2} (10{sup 3}-b) topology. • Surfactant as additive for directing the crystal growth. • Predominant catalytic activities for the degradation of o/m/p-nitrophenol.

Study of the selectivity of poly-nitrogenous extracting molecules in the complexation of actinides (III) and lanthanides (III) in solution in anhydrous pyridine; Etude de la selectivite de molecules extractantes polyazotees dans la complexation des actinides (III) et des lanthanides (III) en solution dans la pyridine anhydre

Energy Technology Data Exchange (ETDEWEB)

Riviere, Ch

2000-10-05

The aim of this work is to better understand the factors which contribute to the separation of lanthanides(III) and actinides(III). Polydentate nitrogenous molecules present an interesting selectivity. A thermodynamic study of the complexation in pyridine of lanthanide and uranium by the bipyridine ligand (bipy) has been carried out. The formation constants and the thermodynamic values of the different complexes have been determined. It has been shown that the bipy complexes formation is controlled by the enthalpy and unfavored by the entropy. The conductometry has revealed too a significant difference in the uranium and lanthanides complexation by the bipyridine ligand. The use of the phenanthroline ligand induces a better complexation of the metallic ions but the selectivity is not improved. On the other hand, the decrease of the basicity and the increase of the ligand denticity (for instance in the case of the use of ter-pyridine) favour the selectivity without improving the complexation. The selectivity difference for the complexation of actinides(III) and lanthanides(III) by the different studied ligands (independent systems) has been confirmed by experiments of inter-metals competition. (O.M.)

Metal-organic hybrid materials built with tetrachlorophthalate acid and different N-donor coligands: Structure diversity and photoluminescence

Science.gov (United States)

Xiao, Zhenyu; Yang, Xiao; Zhao, Siwei; Wang, Debao; Yang, Yu; Wang, Lei

2016-02-01

Eight new metal-organic hybrid materials, namely {Cd(Tcph)(4,4‧-bipy)1/2} (1), {[Cd2(Tcph)2(1,4-bimb)1/2(H2O)4]·H2O} (2), {Cd2(Tcph)2(1,4-bmimb)1/2(H2O)4} (3), {Cd(Tcph)(1,2-bmimb)} (4), {Cu(Tcph)(1,4-bimb)(H2O)} (5), {[Co(Tcph)(1,4-bimb)1/2(H2O)3]·(H2O)} (6), {Zn(Tcph)(1,2-bimb)} (7), {Cu2(Tcph)2(1,2-bimb)(H2O)4} (8), where Tcph=tetrachlorophthalate acid, 4,4‧-bipy=4,4‧-bipyridine, 1,4-bimb=1,4-bis(imidazol-1-ylmethyl)benzene, 1,4-bmimb=1,4-bis(2-methylimidazol-1-ylmethyl)benzene, 1,2-bimb=1,2-bis(imidazol-1-ylmethyl)-benzene, 1,2-bmimb=1,2-bis(2-methylimidazol-1-ylmethyl)benzene, have been synthesized and characterized. Their structures are determined by single crystal X-ray diffraction and further characterized by infrared spectra (IR) and thermogravimetric (TG) analyses. Complex 1, 4 and 7 display 2D layer structures. 1 possesses two-dimensional sheet containing an unusual [Cd(Tcph)] chains linked by 4,4‧-bipy co-ligand, while 4 and 7 hold the similar 4-connected 44-sql nets. Complex 2 and 3 feature a similar three dimensional (3D) internal compensation structure with a topology of {42·63·8}2{63}. 5 is a novel 2-fold self-penetrating 3D network with 4-coordinated 65·8-CdSO4 subnets. The ladder-like chains of 6 are further connected through O-H···O interactions to yield a 3D supramolecular structure. 8 is a discrete tetranuclear complex. The thermal stabilities of 1-8 and the luminescent properties of 1-4 and 7 in the solid state are also discussed.

A series of Zn/Cd coordination polymers constructed from 1,4-naphthalenedicarboxylate and N-donor ligands: Syntheses, structures and luminescence sensing of Cr{sup 3+} in aqueous solutions

Energy Technology Data Exchange (ETDEWEB)

Hu, Dong-Cheng [College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University, Shantou 515063 (China); Fan, Yan; Si, Chang-Dai; Wu, Ya-Jun; Dong, Xiu-Yan; Yang, Yun-Xia; Yao, Xiao-Qiang [College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Liu, Jia-Cheng, E-mail: jcliu8@nwnu.edu.cn [College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China)

2016-09-15

A novel series of Zn/Cd coordination polymers based on H{sub 3}L, namely, [Zn{sub 2}(HL){sub 2}(bipy){sub 2}(H{sub 2}O){sub 6}]{sub n} (1), [Zn(HL)(phen)]{sub n} (2), [Cd{sub 3}L{sub 2}(bbi){sub 3}]{sub n} (3), [Zn{sub 3}L{sub 2}(bbi){sub 3}]{sub n} (4) [(H{sub 3}L =4-[(1-carboxynaphthalen-2-yl)oxy]phthalic acid, bipy =4,4′-bipyridine, phen =1,10-phenanthroline, bbi =1,1′-(1,4-butanediyl)bis(imidazole] have been successfully synthesized by solvothermal reaction. Compound 1 possesses two diverse 1D chains constructed by different bipy coligands, which were further connected to form a 3D supramolecular architecture by hydrogen bonding interactions. Compound 2 possesses a complicated 1D chain based on secondary building unit (SBU) with binuclear Zn cluster. Compounds 3 and 4 exhibit similar 2D→3D framework, which can be rationalized as (3,4,4)-connected 3D net with a Schläfli symbol of (6{sup 3}.8.10{sup 2}){sub 2}(6{sup 3}){sub 2}(6{sup 4}.8.10). In particular, compound 3 exhibited a high sensitivity for Cr{sup 3+} in aqueous solutions, which suggest that compound 3 is a promising luminescent probe for selectively sensing Cr{sup 3+}. - Graphical abstract: A series of novel Zn/Cd coordination polymers have been successfully synthesized by solvothermal reaction. The unique 3D Cd{sup 2+} polymer containing bbi as second ligand demonstrates high sensitivity for detection of toxic Cr{sup 3+} in aqueous solutions. Display Omitted - Highlights: • π-conjugated semirigid tricarboxylate ligands with naphthalene rings(H{sub 3}L) were rationally designed. • Four Zn/Cd coordination polymers based on H{sub 3}L have been successfully synthesized by solvothermal reaction. • Compound 3 is a promising luminescent probe for selectively sensing Cr{sup 3+} with high sensitivity in aqueous solutions.

A family of entangled coordination polymers constructed from a flexible V-shaped long bicarboxylic acid and auxiliary N-donor ligands: Luminescent sensing

Energy Technology Data Exchange (ETDEWEB)

Wang, Jun [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710127 (China); College of Chemistry and Environmental Engineering, Sichuan University of Science & Engineering, Zigong 643000 (China); Bai, Chao [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710127 (China); Hu, Huai-Ming, E-mail: ChemHu1@NWU.EDU.CN [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710127 (China); Yuan, Fei; Xue, Gang-Lin [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710127 (China)

2017-05-15

Eight Zn(II)-based coordination polymers, namely, [Zn{sub 2}L{sub 2}(2,2’-bipy)]{sub n}·nH{sub 2}O (1), [Zn{sub 2}L{sub 2}(phen)]{sub n}·nH{sub 2}O (2), [ZnL(phen)(H{sub 2}O)]{sub n} (3), [Zn{sub 3}L{sub 3}(4,4’-bipy)]{sub n} (4), [Zn{sub 2}L{sub 2}(4,4’-bipy){sub 2}]{sub n} [Zn{sub 2}L{sub 2}(H{sub 2}O){sub 2}]{sub n}·2nH{sub 2}O (5), [Zn{sub 4}L{sub 4}(bpp){sub 2}]{sub n} (6), [ZnL(bbi){sub 0.5}]{sub n} (7), [ZnL(bpz)]{sub n} (8) (H{sub 2}L=4,4’-([1,2-phenylenebis-(methylene)]bis(oxy))dibenzoic acid, 2,2’-bipy =2,2’-bipyridine, phen =1,10-phenanthroline, 4,4’-bpy=4,4’-bipyridine, bpp =1,3-bis(4-pyridyl)propane, bbi=1,4-bis(imidazol-1-yl)butane, bpz=3,3′,5,5′-tetramethyl-4,4′-bipyrazole), have been hydrothermally synthesized and structurally characterized. 1–8 display various coordination motifs with different entangled forms and conformations due to the effect of the assistant N-donor ligands. The photoluminescent properties of compounds 1–8 in solid state were studied. Interestingly, 3 exhibits highly efficient luminescent sensing for Cu{sup 2+} cations and CrO{sub 4}{sup 2-} anions, as well as detection ability for the different organic solvents and nitro explosives. These results indicated that it could be utilized as a multi-responsive luminescent sensor. Furthermore, compound 3 also shows good chemical resistance to both acidity and alkalinity solutions with pH ranging from 2 to 13. Thus, multi-photofunctionality and fluorescent response to pH have been combined in the 3, which is the first example in the Zn-based hybrid materials. - Graphical abstract: Eight new Zn(II)-based coordination polymers constructed from a flexible V-shaped long bicarboxylic acid and different N-donor ligands have been hydrothermally synthesized through fixing the metal salts and the solvent systems. The photoluminescent properties of complexes 1−8 in solid state were studied. Interestingly, 3 exhibits highly efficient luminescent sensing for Cu{sup 2

Morphology and swelling of Os(II) polyvinyl-bypyridile films

International Nuclear Information System (INIS)

Ybarra, G.; Moina, C.; Molina, F.V.; Florit, M.I.; Posadas, D.

2005-01-01

In this work, we studied the changes in volume of an electroactive polymer as [Os(bipy) 2 (PVP) 10 Cl] 2+ . The dependence of the polymer volume on the solution pH and applied potential was measured. The morphology of [Os(bipy) 2 (PVP) 10 Cl] 2+ , deposited onto monocrystalline Si substrates, both by drop coating and by spin coating was studied by AFM. Drop-coated films show a globular structure on top of a thin and homogeneous film while spin-coated films are even and homogeneous. The volume changes with the pH of the external solution were measured following the changes in the globules size of drop-coated films. Also, the thickness dependence of spin-coated films on pH was measured by AFM. Both the size of the globules and the thickness of the films increase as the pH of the external solution decreases. The possible reasons for this increase are discussed. The volume change following the oxidation of a drop-coated polymer was estimated from the projected area obtained by optical microscopy with image capture. The images show an increase in the projected area as the film is progressively oxidized. The possible reasons for this increase in volume are discussed

Synthesis, characterization, in-vitro antimicrobial properties, molecular docking and DFT studies of 3-{(E-[(4,6-dimethylpyrimidin-2-ylimino]methyl} naphthalen-2-ol and Heteroleptic Mn(II, Co(II, Ni(II and Zn(II complexes

Directory of Open Access Journals (Sweden)

Chioma Festus

2018-03-01

Full Text Available Heteroleptic divalent metal complexes [M(L (bipy(Y]•nH2O (where M = Mn, Co, Ni, and Zn; L = Schiff base; bipy = 2,2’-bipyridine; Y = OAc and n = 0, 1 have been synthesized from pyrimidine Schiff base ligand 3-{(E-[(4,6-dimethylpyrimidin-2-ylimino]methyl} naphthalen-2-ol, 2,2’-bipyridine and metal(II acetate salts. The Schiff base and its complexes were characterized by analytical (CHN elemental analyses, solubility, melting point, conductivity measurements, spectral (IR, UV-vis, 1H and 13C-NMR and MS and magnetometry. The elemental analyses, Uv-vis spectra and room temperature magnetic moment data provide evidence of six coordinated octahedral geometry for the complexes. The metal complexes’ low molar conductivity values in dimethylsulphoxide suggested that they were non-ionic in nature. The compounds displayed moderate to good antimicrobial and antifungal activities against S. aureus, P. aeruginosa, E. coli, B. cereus, P. mirabilis, K. oxytoca, A. niger, A. flevus and R. Stolonifer. The compounds also exhibited good antioxidant potentials with ferrous ion chelation and, 1-diphenyl-2-picryl-hydrazyl (DPPH radical scavenging assays. Molecular docking studies showed a good interaction with drug targets used. The structural and electronic properties of complexes were further confirmed by density functional theory calculations.

Synthesis and Crystal Structure of a Three—dimensionla Manganese（Ⅱ）Complex COnstructed via Covalent and Hydrogen Bonds

Institute of Scientific and Technical Information of China (English)

WANGRui－Hu; ChenLi－Hua; 等

2003-01-01

The assembly of 1,4-benzenedicarboxylic acid (H2bdc),4,4′-bipyridine (4,4′-bipy),trimethyltin chloride and MnBr2.4H2O in hydrothermal conditions gave rise to a hydrogen-bonded three-dimensional complex {Mn(4,4′-bipy).4H2O](bdc}nwhich has been characterized by single-crystal X-ray diffraction.The complex crystallizes in the monoclinic system,space group,P2/n with a=7.0001(2),b=11.5540(3),c=11.4192(1)°↑A,β=101.754(2)°,V=904.21(4)°↑A3,Z=2,C18H20MnN2O8,Mr=447.30,Dc=1.643 g/cm3,F(000)=462 and μ（Mokα)=0.783mm1,The final R and wR are 0.0499 and 0.1301,respectively for 1335 observed reflctions with I≥2σ（I）.The Mn（Ⅱ）is six-coordinated in a distorted octahedral geometry,4,4′-Bipyridine in a μ-bridge mode links [Mn(H2O)4]2+ into a linear cation chain.bdc acts as a counter anion and links the linear chains into a three-dimensional structure through hydrogen bonds.

Single photon counting fluorescence lifetime detection of pericellular oxygen concentrations.

Science.gov (United States)

Hosny, Neveen A; Lee, David A; Knight, Martin M

2012-01-01

Fluorescence lifetime imaging microscopy offers a non-invasive method for quantifying local oxygen concentrations. However, existing methods are either invasive, require custom-made systems, or show limited spatial resolution. Therefore, these methods are unsuitable for investigation of pericellular oxygen concentrations. This study describes an adaptation of commercially available equipment which has been optimized for quantitative extracellular oxygen detection with high lifetime accuracy and spatial resolution while avoiding systematic photon pile-up. The oxygen sensitive fluorescent dye, tris(2,2'-bipyridyl)ruthenium(II) chloride hexahydrate [Ru(bipy)(3)](2+), was excited using a two-photon excitation laser. Lifetime was measured using a Becker & Hickl time-correlated single photon counting, which will be referred to as a TCSPC card. [Ru(bipy)(3)](2+) characterization studies quantified the influences of temperature, pH, cellular culture media and oxygen on the fluorescence lifetime measurements. This provided a precisely calibrated and accurate system for quantification of pericellular oxygen concentration based on measured lifetimes. Using this technique, quantification of oxygen concentrations around isolated viable chondrocytes, seeded in three-dimensional agarose gel, revealed a subpopulation of cells that exhibited significant spatial oxygen gradients such that oxygen concentration reduced with increasing proximity to the cell. This technique provides a powerful tool for quantifying spatial oxygen gradients within three-dimensional cellular models.

Syntheses, structures, thermal stabilities and luminescence of two new lead sulfonates with phosphonate, carboxylate and pyridine

Energy Technology Data Exchange (ETDEWEB)

Fu, Ruibiao, E-mail: furb@fjirsm.ac.cn; Hu, Shengmin; Wu, Xintao

2014-05-01

Hydrothermal reactions of Pb{sup 2+} ion with disodium 4,4'-bis(2-sulfonatostyryl)biphenyl (Na{sub 2}L1), 4-pyridyl-CH{sub 2}N(CH{sub 2}COOH)(CH{sub 2}PO{sub 3} H{sub 2}) (H{sub 3}L2) and 4,4'-bipyridine (4,4'-bipy) afforded two new lead sulfonates, namely, [Pb{sub 4}(L1){sub 2}(HL2){sub 2}(H{sub 2}O)

Pb(II) and Mn(II) Supermolecular Polymers of Bipy and (4 ...

African Journals Online (AJOL)

NICO

aCollege of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Nanning 530006, People's ... This paper reports the synthesis, structure and fluorescence ... ration of the lauter liquor at room temperature, after three.

Amine-controlled assembly of metal-sulfite architecture from 1D chains to 3D framework.

Science.gov (United States)

Austria, Cristina; Zhang, Jian; Valle, Henry; Zhang, Qichun; Chew, Emily; Nguyen, Dan-Tam; Gu, J Y; Feng, Pingyun; Bu, Xianhui

2007-08-06

Whereas open-framework materials have been made in a variety of chemical compositions, few are known in which 3-connected SO3(2)- anions serve as basic building units. Here, we report four new metal-sulfite polymeric structures, (ZnSO3)Py (1, py = pyridine), (ZnSO3)2(2,2'-bipy)H2O (2, 2,2'-bipy = 2,2'-bipyridine), (ZnSO3)2(TMDPy) (3, TMDPy = 4,4'-trimethylenedipyridine), and (MnSO3)2en (4, en = ethylenediamine) that have been synthesized hydrothermally and structurally characterized. In these compounds, low-dimensional 1D and 2D inorganic subunits are assembled into higher 2D or 3D covalent frameworks by organic ligands. In addition to the structure-directing effect of organic ligands, the flexible coordination chemistry of Zn2+ and SO3(2)- also contributes to the observed structural diversity. In compounds 1-3, Zn2+ sites alternate with trigonal pyramidal SO3(2)- anions to form three types of [ZnSO3]n chains, whereas in compound 4, a 2D-corrugated [MnSO3]n layer is present. Compound 1 features a rail-like chain with pendant pyridine rings. The pi-pi interaction between 2,2'-bipy ligands is found between adjacent chains in compound 2, resulting in 2D sheets that are further stacked through interlayer hydrogen bonds. Compound 3 exhibits a very interesting inorganic [(ZnSO3)2]n chain constructed from two chairlike subunits, and such chains are bridged by TMDPy ligands into a 2D sheet. In compound 4, side-by-side helical chains permeate through 2D-corrugated [MnSO3]n layers, which are pillared by neutral ethylenediamine molecules into a 3D framework that can be topologically represented as a (3,6)-connected net. The results presented here illustrate the rich structural chemistry of metal-sulfites and the potential of sulfite anions as a unique structural building block for the construction of novel open-framework materials, in particular, those containing polymeric inorganic subunits that may have interesting physical properties such as low-dimensional magnetism or

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.

Theoretical study on the antitumor properties of Ru(II) complexes containing 2-pyridyl, 2-pyridine-4-carboxylic acid ligands

Science.gov (United States)

Erkan kariper, Sultan; Sayin, Koray; Karakaş, Duran

2017-12-01

[Ru(bipy)2(CppH)]2+(1), [Ru(bipy)2(Cpp-NH-Hex-COOH)]2+(2), [Ru(dppz)2(CppH)]2+(3) and [Ru(dppz)2(Cpp-NH-Hex-COOH)]2+(4) were calculated by Hartree-Fock (HF), Density Functional Theory (DFT) hybrid B3LYP and Moller-Plesset Perturbation (MPn n = 2,3) theory method and CEP-4G, CEP-31G, CEP-121G, LANL2DZ, LANL2MB, SDD basic sets and a mixed basic set with the keyword GEN in gas phase and water. Structure parameters obtained from optimized structures were compared with experimental parameters. M062X/(6-31G(d))(CEP-4G) level was taken into account for the most appropriate calculation level. IR, UV-VIS and NMR spectrums were examined for structural characterization. The optimal structure was identified via structure parameters, IR, UV-VIS and NMR spectrums. For the most compatible structure, the highest molecular orbital energy (EHOMO) which one of the most effective chemical determiners on the antitumor activity of the complexes, the lowest molecular orbital energy (ELUMO), LUMO-HOMO energy gap, hardness (η), softness (σ), electronegativity (χ), chemical potential (μ), electrophilicity index (ω), molar volume (V), dipole moment (DM), total negative charge (TNC), enthalpy (H), entropy (S) and total energy (E) were calculated. The causes of anticancer activity of the complexes have been studied.

Stability and Degradation Mechanisms of Metal-Organic Frameworks Containing the Zr6O4(OH)4 Secondary Building Unit

Science.gov (United States)

2013-03-18

chemical and thermal stability.15 aScience Applications International Corporation (SAIC), Inc., PO Box 68, Gunpowder, MD 21010, USA. E-mail: jared.b.decoste2...isotherm for ZrMOF–NH2 shows micropore lling occurring at relative humidity levels less than 20%, while ZrMOF–BDC does not show micropore lling until...the –NH2 group in ZrMOF–NH2. This phenomenon can also be seen for ZrMOF–BIPY when compared to ZrMOF–BPDC, albeit these structures exhibit micropore

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

Syntheses, crystal structures, and magnetic properties of four new cyano-bridged bimetallic complexes based on the mer-[Fe(III)(qcq)(CN)3]- building block.

Science.gov (United States)

Shen, Xiaoping; Zhou, Hongbo; Yan, Jiahao; Li, Yanfeng; Zhou, Hu

2014-01-06

Four new cyano-bridged bimetallic complexes, [{Mn(III)(salen)}2{Fe(III)(qcq)(CN)3}2]n·3nCH3CN·nH2O (1) [salen = N,N'-ethylenebis(salicylideneiminato) dianion; qcq(-) = 8-(2-quinoline-2-carboxamido)quinoline anion], [{Mn(III)(salpn)}2{Fe(III)(qcq)(CN)3}2]n·4nH2O (2) [salpn = N,N'-1,2-propylenebis(salicylideneiminato)dianion], [{Mn(II)(bipy)(CH3OH)}{Fe(III)(qcq)(CN)3}2]2·2H2O·2CH3OH (3) (bipy = 2,2'-bipyridine), and [{Mn(II)(phen)2}{Fe(III)(qcq)(CN)3}2]·CH3CN·2H2O (4) (phen = 1,10-phenanthroline) have been synthesized and characterized both structurally and magnetically. The structures of 1 and 2 are both unique 1-D linear branch chains with additional structural units of {Mn(III)(salen/salpn)}{Fe(III)(qcq)(CN)3} dangling on the sides. In contrast, 3 and 4 are cyano-bridged bimetallic hexanuclear and trinuclear clusters, respectively. The intermolecular short contacts such as π-π interactions and hydrogen bonds extend 1-4 into high dimensional supermolecular networks. Magnetic investigation reveals the dominant intramolecular antiferromagnetic interactions in 1, 3, and 4, while ferromagnetic and antiferromagnetic interactions coexist in 2. Alternating current measurement at low temperature indicates the existence of slow magnetic relaxation in 1 and 2, which should be due to the single ion anisotropy of Mn(III).

Synthesis, Structural Characterization and Catalytic Activity of A Cu(II Coordination Polymer Constructed from 1,4-Phenylenediacetic Acid and 2,2’-Bipyridine

Directory of Open Access Journals (Sweden)

Wang Li-Hua

2017-04-01

Full Text Available In order to study the catalytic activity of Cu(II coordination polymer material, a novel 1D chained Cu(II coordination polymer material, [CuL(bipy(H2O5]n (A1 (H2L = 1,4-phenylenediacetic acid, bipy = 2,2’-bipyridine, has been prepared by the reaction of 1,4-phenylenediacetic acid, 2,2’-bipyridine, Cu(CH3COO2·H2O and NaOH. The composition of A1 was determined by elemental analysis, IR spectra and single crystal X-ray diffraction. The results of characterization show that each Cu(II atom adopts six-coordination and forms a distorted octahedral configuration. The catalytic activity and reusability of A1 catalyst for A3 coupling reaction of benzaldehyde, piperidine, and phenylacetylene have been investigated. And the results show that the Cu(II complex catalyst has good catalytic activity with a maximum yield of 54.3% and stability. Copyright © 2017 BCREC GROUP. All rights reserved Received: 21st October 2016; Revised: 17th November 2016; Accepted: 22nd November 2016 How to Cite: Li-Hua, W., Lei, L., Xin, W. (2017. Synthesis, Structural Characterization and Catalytic Activity of A Cu(II Coordination Polymer Constructed from 1,4-Phenylenediacetic Acid and 2,2’-Bipyridine. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (1: 113-118 (doi:10.9767/bcrec.12.1.735.113-118 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.1.735.113-118

Best combination of promoter and micellar catalyst for the rapid conversion of sorbitol to glucose

Science.gov (United States)

Mukherjee, Kakali; Ghosh, Aniruddha; Saha, Rumpa; Sar, Pintu; Malik, Susanta; Saha, Bidyut

2014-03-01

Kinetic data for oxidation of D-sorbitol to glucose by hexavalent chromium in aqueous medium and aqueous surfactant medium (SDS, TX-100) have been reported. Effect of promoter such as PA, bipy and phenanthroline on the reaction has been investigated. The reaction is performed under pseudo first order condition with an excess of substrate over the oxidant. The reaction is first order with respect to substrate and oxidant. The micelles have a catalytic effect on the reaction. Combination of phen and TX-100 produces almost twelve times increase in rate of oxidation.

Guest–Host Interactions Investigated by Time-Resolved X-ray Spectroscopies and Scattering at MHz Rates

DEFF Research Database (Denmark)

Haldrup, Martin Kristoffer; Vanko, G.; Gawelda, W.

2012-01-01

We have studied the photoinduced low spin (LS) to high spin (HS) conversion of [Fe(bipy)3]2+ in aqueous solution. In a laser pump/X-ray probe synchrotron setup permitting simultaneous, time-resolved X-ray diffuse scattering (XDS) and X-ray spectroscopic measurements at a 3.26 MHz repetition rate...... lifetime, allowing the detection of an ultrafast change in bulk solvent density. An analysis approach directly utilizing the spectroscopic data in the XDS analysis effectively reduces the number of free parameters, and both combined permit extraction of information about the ultrafast structural dynamics...

Synthesis and characterisation of thorium and uranium cyanoacetates and their coordination compounds (Preprint No. AL.14)

International Nuclear Information System (INIS)

Deshpande, S.G.; Vaidya, M.A.; Jain, S.C.

1989-01-01

Tetracyanoacetates, M(NCCH 2 COO) 4 (where M=Th or U) and UO 2 (NCCH 2 COO) 2 .H 2 O and their coordination complexes with (CH 3 ) 2 S=0 (DMSO), HCOON(CH 3 ) 2 , (DMF), 1,10-Phenenthrolene (Phen) and 2,2'Bipyridine (Bipy), have been synthesised and characterised by elemental analysis, molecular weight determination, molar conductance measurements, X-ray diffraction and infrared (IR) spectroscopic studies (4000 - 200 cm -1 ). Thermogravimetric analysis of the compounds have been carried out to study the thermal decomposition mode. (author)

2,2',-bipyridine and 1,10-phenanthroline complexes of lanthanide(III) trifluoroacetates

International Nuclear Information System (INIS)

Misra, S.N.; Singh, M.

1983-01-01

The syntheses and characterization of lanthanide(III) triflloroacetate complexes with 2,2'-bipyridine and 1,10-phenanthroline are reported. Lanthanide(III) trifluoroacetates yield compounds of the type Ln(CF 3 COO) 3 .bipy or phen with 2,2'-bipyridine and 1,10-phenanthroline. Their properties and structures have been studied using chemical analyses. electronic and infrared spectra. Thermal analysis of a few complexes have also been done. The infrared data show that the trifluoroacetate group acts as a bidentate ligand making the coordination number of lanthanide eight. (author)

Soft X-ray excited optical luminescence from functional organic materials

Energy Technology Data Exchange (ETDEWEB)

Sham, T.K., E-mail: tsham@uwo.ca

2015-10-01

Highlights: • Many functional organic materials convert X-ray energy into visible light. • The X-ray induced luminescence (XEOL) across an absorption edge can be site and excitation channel specific. • XEOL is composition, morphology, size and crystallinity dependent. • XEOL using the time structure of a synchrotron can reveal the decay and energy transfer dynamics of the sample. • The combined use of XEOL and XAS in the analysis of functional organic materials is illustrated. - Abstract: This brief report reviews some of the recent findings in the study of synchrotron based X-ray excited optical luminescence (XEOL) from representative organic light emitting device (OLED) and related functional organic materials. The systems of interest include Alq{sub 3}, aluminium tris(8-hydroxylquinoline); Ru(bipy){sub 3}{sup 2+}, tris-(2,2-bipyridine) ruthenium(II); Ir(bpy){sub 3}, tris(2-phenyl-bipyridine)iridium; PVK (poly(N-vinylcarbazole)) and [Au{sub 2}(dppe)(bipy)]{sup 2+}, a Au(I) polymer containing 1,2-bis(diphenylphosphino)ethane and the 4,40-bipyridyl ligands, as well as TBPe (2,5,8,11-tetra-tert-butylperylene) polyhedral crystals and fluorescein isothiocyanate (FITC) and FITC-labelled proteins. It is shown that tunable and pulsed X-rays from synchrotron light sources enable the detailed tracking of the optical properties of organic functional materials by monitoring the luminescence in both the energy and time domain as the excitation energy is scanned across an element-specific absorption edge. The use of XEOL and X-ray absorption spectroscopy (XAS) in materials analysis is illustrated.

Synthesis, structural characterization and photoluminescent properties of 2D multilayer Cu+ coordination polymers via Csbnd H⋯π and π⋯π interactions

Science.gov (United States)

Huang, Ting-Hong; Zhu, Sheng-Lan; Xiong, Xian-Lian; Li, Jia-Dong; Yang, Hu; Huang, Xin; Huang, Xue-Ren; Zhang, Kunming

2017-09-01

Two Cu(I) coordination polymers, {[Cu(pmbb)0.5(4,4'-bipy)0.5(PPh3)](BF4) (H2O)2}n (1) and {[Cu(pmbb)0.5(bpe)0.5(PPh3)](BF4)(DMF)}n (2) (pmbb = N, N'-bis(pyridin-2-ylmethylene)biphenyl -4,4'-diamine, 4,4'-bipy = 4,4'-bipyridine, bpe = 1,2-bis(4-pyridyl)ethylene), PPh3 = triphenyl phosphine), have been synthesized and characterized by IR, 1H NMR, 13C NMR, 31P NMR, 19F NMR, 11B-NMR, TG and X-ray crystal structure analysis. The structural analysis shows that complexes 1 and 2 contain diverse and interesting 2D supramolecular networks based on inter-chain interactions. Complex 1 displays a 1D zig-zag chain and a 1D+1D→2D supramolecular network formed by intermolecular Csbnd H···π interaction. For 2, each 1D zig-zag chain interacts with neighboring ones via intermolecular Csbnd H···π and π···π stacking interactions, leading to the formation of a 2D-stacking network. Furthermore, solid-state UV-Vis absorption spectra of complexes 1 and 2 indicate the existence of MLCT absorption. Complexes 1 and 2 show efficient luminescent emission peaks at 435 and 452 nm assigned to MLCT excited states, and the emission decay lifetimes are 20.82 μs for 1 and 20.72 μs for 2, displaying strong room-temperature solid-state photoluminescence. Moreover, thermogravimetric analysis shows that the heat stability of polymers is 1>2.

The titanium tris-anilide cation [Ti(N[(t)Bu]Ar)3](+) stabilized as its perfluoro-tetra-phenylborate salt: structural characterization and synthesis in connection with redox activity of 4,4'-bipyridine dititanium complexes.

Science.gov (United States)

Spinney, Heather A; Clough, Christopher R; Cummins, Christopher C

2015-04-21

This work explores the reduction of 4,4'-bipyridine using two equivalents of the titanium(iii) complex Ti(N[(t)Bu]Ar)3 resulting in formation of a black, crystalline complex, (4,4'-bipy){Ti(N[(t)Bu]Ar)3}2, for which an X-ray structure determination is reported. The neutral, black, 4,4'-bipyridine-bridged bimetallic was found to be redox active, with mono- and di-anions being accessible electrochemically, and with the mono- and di-cations also being accessible chemically, and isolable, at least when using the weakly coordinating anion [B(C6F5)4](-) as the counter-ion. It proved possible to crystallize the salt [(4,4'-bipy){Ti(N[(t)Bu]Ar)3}2][B(C6F5)4]2 for a single-crystal X-ray structure investigation; in this instance it was revealed that the aromaticity of the 4,4'-bipyridine ligand, that had been disrupted upon reduction, had been regained. A rare cationic d(0) metal tris-amide complex, shown by X-ray crystallography to contain an intriguing pyramidal TiN3 core geometry, namely {Ti(N[(t)Bu]Ar)3}(+), could also be isolated when using [B(C6F5)4] as the essentially non-interacting counter-ion. This highly reactive cation should be considered as a potential intermediate in the plethora of reactions wherein Ti(N[(t)Bu]Ar)3 has been shown to effect the reduction of substrates including halogenated organic molecules, carbonyl compounds, organic nitriles, and metal complexes.

BIPI: desarrollo de un Buscador Inteligente para Internet basado en agentes móviles

OpenAIRE

Confeggi, Claudio; Felix, Sebastián

2000-01-01

A fines del año 1997, habiendo concluido la cursada de la carrera de Licenciatura en Informática, debimos orientar nuestros esfuerzos hacia la definición de un tema que se concretara en una tesis. Pero no fue, hasta fines de 1999, que realmente dedicamos nuestro tiempo a esta investigación. Comenzamos reconociendo problemáticas que podían ser satisfechas en el ámbito informático, que nos movilizaran a la adquisición de conocimientos teóricos y técnicos y que, al mismo tiempo, puedan ser profu...

Topological evolution and photoluminescent properties of a series of divalent zinc-based metal–organic frameworks tuned via ancillary ligating spacers

Energy Technology Data Exchange (ETDEWEB)

Lian, Xiao-Min; Zhao, Wen [Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062 (China); Zhao, Xiao-Li, E-mail: xlzhao@chem.ecnu.edu.cn [Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062 (China)

2013-04-15

The combination of divalent zinc ions, 4-(4-carboxybenzamido)benzoic acid and exo-bidendate bipyridine ligands gave rise to a series of new MOFs: [ZnL(bipy)]·DMF·H{sub 2}O (1), [ZnL(bpe)]·1.5H{sub 2}O (2), [ZnL(bpa)]·4H{sub 2}O (3) and [ZnL(bpp)]·1.75H{sub 2}O (4) (MOF=metal-organic framework, bipy=4,4′-bipyridine, bpe=trans-1,2-bis(4-pyridyl)ethylene, bpa=1,2-bis(4-pyridinyl)ethane, bpp=1,3-bis(4-pyridinyl)propane, H{sub 2}L=4,4′-(carbonylimino)dibenzoic acid). Fine tune over the topology of the MOFs was achieved via systematically varying the geometric length of the second ligating bipyridine ligands. Single-crystal X-ray analysis reveals that complex 1 has a triply interpenetrated three-dimensional (3D) framework with elongated primitive cubic topology, whereas isostructural complexes 2 and 3 each possesses a 6-fold interpenetrated diamondiod 3D framework. Further expansion of the length of the bipyridine ligand to bpp leads to the formation of 4, which features an interesting entangled architecture of 2D→3D parallel polycatenation. In addition, the thermogravimetric analyses and solid-state photoluminescent properties of the selected complexes are investigated. - Graphical abstract: The incorporation of exo-bidendate bipyridine spacers into the Zn–H{sub 2}L system has yielded a series of new MOFs exhibiting topological evolution from 3-fold interpenetration to 6-fold interpenetration and 2D→3D parallel polycatenation. Highlights: ► The effect of the pyridyl-based spacers on the formation of MOFs was explored. ► Fine tune over the topology of the MOFs was achieved. ► An interesting structure of 2D→3D parallel polycatenation is reported.

Heteroleptic complexes of Zn(II) based on 1-(5-bromo-2-hydroxybenzylidene)-4-phenylthiosemicarbazide: Synthesis, structural characterization, theoretical studies and antibacterial activity

Science.gov (United States)

Azarkish, Mohammad; Akbari, Alireza; Sedaghat, Tahereh; Simpson, Jim

2017-04-01

Four new ternary complexes, [ZnL (2,2‧-bipy)] (1), Zn2L2(4,4‧-bipy)] (2), [ZnL(Imd)]·H2O (3) and [ZnL3(MeImd)] (4), have been synthesized from the reaction of Zn(II) acetate with 1-(5-bromo-2-hydroxybenzylidene)-4-phenylthiosemicarbazide (H2L) in the presence of a heterocyclic base, 2,2‧-bipyridine, 4,4‧-bipyridine, imidazole or 2-methylimidazole, as an auxiliary ligand. The complexes have been investigated by elemental analysis and FT-IR, UV-Vis and 1HNMR spectroscopy. These data show that the thiosemicarbazone acts as a tridentate dianionic ligand and coordinates via the thiol group, imine nitrogen, and phenolic oxygen. The coordination sphere was completed by the nitrogen atom(s) of the secondary ligand. The structure of 1 was also confirmed by X-ray crystallography and shown to be a five coordinate complex with coordination geometry between the square-pyramidal and trigonal-bipyramidal. Density functional theory (DFT) calculations including geometry optimization, vibrational frequencies and electronic absorptions have been performed for 1 with the B3LYP functional at the TZP(6-311G*) basis set using the Gaussian 03 or ADF 2009 packages. The optimization calculation showed that the crystallographically determined geometry parameters can be reproduced with that basis set. Experimental IR frequencies and calculated vibration frequencies also support each other. The in vitro antibacterial activities of the ligand and complexes have been evaluated against Gram-positive (B. subtilis and S. aureus) and Gram-negative (P. aeruginosa) bacteria and compared with the standard antibacterial drugs. The results reveal that all of the complexes show much better activity in comparison to the individual thiosemoicarbazone ligand (H2L), against all bacterial strains used, with complex 3 showing the most promising results.

A new continuous two-step molecular precursor route to rare-earth oxysulfides Ln2O2S

International Nuclear Information System (INIS)

De Crom, N.; Devillers, M.

2012-01-01

A continuous two-step molecular precursor pathway is designed for the preparation of rare-earth oxysulfides Ln 2 O 2 S (Ln=Y, La, Pr, Nd, Sm–Lu). This new route involves a first oxidation step leading to the rare-earth oxysulfate Ln 2 O 2 SO 4 which is subsequently reduced to the rare-earth oxysulfide Ln 2 O 2 S by switching to a H 2 –Ar atmosphere. The whole process occurs at a temperature significantly lower than usual solid state synthesis (T≤650 °C) and avoids the use of dangerous sulfur-based gases, providing a convenient route to the synthesis of the entire series of Ln 2 O 2 S. The molecular precursors consist in heteroleptic dithiocarbamate complexes [Ln(Et 2 dtc) 3 (phen)] and [Ln(Et 2 dtc) 3 (bipy)] (Et 2 dtc=N,N-diethyldithiocarbamate; phen=1,10-phenanthroline; bipy=2,2′-bipyridine) and were synthesized by a new high yield and high purity synthesis route. The nature of the molecular precursor determines the minimum synthesis temperature and influences therefore the purity of the final Ln 2 O 2 S crystalline phase. - Graphical abstract: A continuous two-step molecular precursor pathway was designed for the preparation of rare-earth oxysulfides Ln 2 O 2 S (Ln=Y, La, Pr, Nd, Sm–Lu), starting from heteroleptic dithiocarbamate complexes. The influence of the nature of the molecular precursor on the minimum synthesis temperature and on the purity of the final Ln 2 O 2 S crystalline phase is discussed. Highlights: ► A new high yield and high purity synthesis route of rare earth dithiocarbamates is described. ► These compounds are used as precursors in a continuous process leading to rare-earth oxysulfides. ► The oxysulfides are obtained under much more moderate conditions than previously described.

Synthesis and spectroscopic behavior of highly luminescent trinuclear europium complexes with tris-β-diketone ligand

Energy Technology Data Exchange (ETDEWEB)

Wang, Dunjia, E-mail: dunjiawang@163.com; Pi, Yan; Liu, Hua; Wei, Xianhong; Hu, Yanjun; Zheng, Jing

2014-11-15

Highlights: • Synthesis of the tris-β-diketone ligand and its trinuclear europium complexes. • Photoluminescence behavior of trinuclear europium complexes. • Analysis of the Judd–Ofelt intensity parameters (Ω{sub t}), lifetime (τ) and quantum yield (η). - Abstract: A new tris-β-diketone ligand, 2-[4,6-bis-(1-benzoyl-2-oxo-2-phenyl-ethyl)-[1,3,5]triazin-2-yl] -1,3-diphenyl-propane-1,3-dione (H{sub 3}L), and its trinuclear europium complexes, Eu{sub 3}(DBM){sub 6}L (C1), Eu{sub 3}(DBM){sub 6}(Bipy){sub 3}L (C2) and Eu{sub 3}(DBM){sub 6}(Phen){sub 3}L (C3) were synthesized and their spectroscopic behaviors were studied by FT-IR, {sup 1}H NMR, UV–vis and photoluminescence spectroscopic techniques. These europium complexes exhibited the characteristic emission bands that arise from the {sup 5}D{sub 0} → {sup 7}F{sub J} (J = 0–4) transitions of the europium ion in solid state. The Ω{sub 2} and Ω{sub 4} intensity parameters, lifetime (τ) and luminescence quantum yield (η) were calculated according to the emission spectra and luminescence decay curves in solid state. The results indicated that these trinuclear europium complexes displayed a longer lifetime (τ) and higher luminescence quantum efficiency (η), especially complexes C2 (τ = 0.820 ms, η = 46.5%) and C3 (τ = 0.804 ms, η = 47.4%), which due to the effect of two additional europium ion lumophors and the introduction of the third ligands, Bipy or Phen in trinuclear complexes. Their Ω{sub 2} values demonstrated that the europium ion in these complexes is in a highly polarizable chemical environment.

Topological evolution and photoluminescent properties of a series of divalent zinc-based metal–organic frameworks tuned via ancillary ligating spacers

International Nuclear Information System (INIS)

Lian, Xiao-Min; Zhao, Wen; Zhao, Xiao-Li

2013-01-01

The combination of divalent zinc ions, 4-(4-carboxybenzamido)benzoic acid and exo-bidendate bipyridine ligands gave rise to a series of new MOFs: [ZnL(bipy)]·DMF·H 2 O (1), [ZnL(bpe)]·1.5H 2 O (2), [ZnL(bpa)]·4H 2 O (3) and [ZnL(bpp)]·1.75H 2 O (4) (MOF=metal-organic framework, bipy=4,4′-bipyridine, bpe=trans-1,2-bis(4-pyridyl)ethylene, bpa=1,2-bis(4-pyridinyl)ethane, bpp=1,3-bis(4-pyridinyl)propane, H 2 L=4,4′-(carbonylimino)dibenzoic acid). Fine tune over the topology of the MOFs was achieved via systematically varying the geometric length of the second ligating bipyridine ligands. Single-crystal X-ray analysis reveals that complex 1 has a triply interpenetrated three-dimensional (3D) framework with elongated primitive cubic topology, whereas isostructural complexes 2 and 3 each possesses a 6-fold interpenetrated diamondiod 3D framework. Further expansion of the length of the bipyridine ligand to bpp leads to the formation of 4, which features an interesting entangled architecture of 2D→3D parallel polycatenation. In addition, the thermogravimetric analyses and solid-state photoluminescent properties of the selected complexes are investigated. - Graphical abstract: The incorporation of exo-bidendate bipyridine spacers into the Zn–H 2 L system has yielded a series of new MOFs exhibiting topological evolution from 3-fold interpenetration to 6-fold interpenetration and 2D→3D parallel polycatenation. Highlights: ► The effect of the pyridyl-based spacers on the formation of MOFs was explored. ► Fine tune over the topology of the MOFs was achieved. ► An interesting structure of 2D→3D parallel polycatenation is reported

Studies on the rare earth complexes with pyridine derivatives and their N-oxide(II) - Synthesis and properties of fluorescent solid complexes of samarium, europium, gadolium and terbium chlorides with 2,2'-bipyridine-N,N'-dioxide

International Nuclear Information System (INIS)

Minyu, T.; Ning, T.; Yingli, Z.; Jiyuan, B.

1985-01-01

The solid complexes of rare earth nitrates perchlorates and thiocyanates with 2,2'-bipyridine-N,N'-dioxide (bipyO/sub 2/) have been reported. However, the corresponding complexes of other rear earth chlorides have not been investigated except lanthanum, cerium and yttrium. As an extension of our previous work on the synthesis of complexes of praseodymium and neodymium chlorides wiht bipoyO/sub 2/, the authors have now prepared fluorescent solid complexes of samarium, europium, gadolium and terbium chlorides with biphyO/sub 2/, using methanol as a reaction medium. The new synthesized compounds have been identified by means of elemental analysis, infrared spectrometry, conductometry, differential thermal analysis (DTA), thermogravimetry (TG) and X-ray powder diffraction

Mixed ligand complexes of uranyl lactate with some simple and heterocyclic amines

International Nuclear Information System (INIS)

Jaiswal, S.R.; Rupainwar, D.C.

1984-01-01

Mixed ligand complexes of uranyl lactate with simple and heterocyclic amines having a general formula UO 2 (C 3 H 5 O 3 ).nL.xH 2 O, were prepared, where n=1 and x=1 for L=ethylenediamine (En), dimethyl aniline (DMAn), diethyl amine (DEA), orthophenylenediamine (OPDA), pyridine (Py), 2-picoline(2-Pic), 3-picoline(3-Pic), 4-Picoline(4-Pic), piperidine (Pipy), 2,4-lutidine (2,4 Lut), 2-Aminopyridine (2 APy), quinoline (Quin), isoquinoline (Isoquin) but x=0 for the ligands 2,2'-bipyrldyl (Bipy) and 1,10-phenenthroline (Phen). All the compounds are bright yellow coloured with high decomposition temp. (>200deg) and were characterized by electronic and infrared spectral data. (author)

Complexes of Th(IV) perchlorates, nitrates and thiocyanates with some heterocyclic bases

International Nuclear Information System (INIS)

Agarwal, R.K.; Srivastava, A.K.; Srivastava, M.; Bhakru, N.; Srivastava, T.N.

1980-01-01

Some Th(IV) perchlorate complexes of heterocyclic bases have been reported previously. Adducts of Th(IV) nitrates and thiocyanates with some heterocyclic N-oxides have been prepared and physico-chemical properties investigated. Comparatively little is known about the complexes of Th(IV) ion with the ligands containing nitrogen atom acting as electron donating centres. In view of this, the adducts of Th(IV) ion with certain nitrogen heterocyclic bases such as pyridine (Py), α-picoline (Pic), 2-amino pyridine (NH 2 Py), 2:4-lutidine (2,4LN), 2:6-lutidine, (2,6LN), quinoline (Q), isoquinoline (Isoq), 2,2'-bipyridine (Bipy) and 1,10-phenanthroline (Phen) were synthesised and characterised by analysis and IR absorption spectra. The results are presented and discussed. (author)

The solvent extraction of ytterbium from a molten eutectic

International Nuclear Information System (INIS)

Lengyel, T.

1977-01-01

The paper summarizes the results which were obtained in measurements performed with different binary mixtures of solvents being capable of effectively extracting ytterbium from the molten eutectic lithium nitrate--ammonium nitrate. In the course of elaborating the possible ways of extractive separation of rare earths systematic investigations regarding the individual members of the group are required. The binary solvent mixtures consisted of thenoyl-trifluoracetone (TTA), β-isopropil-tropolone (IPT), tributyl phosphate (TBP), di-2-ethylhexyl phosphoric acid (HDEHP), 2,2'-bipyridyl (bipy), dibutyl phtalate (DBP) and Amberlite LA-2 (LA-2). The concentration of the central ion was kept at 5x10 -6 M by using Yb-169 of high specific activity as a tracer for the radiometric assay. (T.I.)

Os(VI)bipy-based electrochemical assay for detection of specific microRNAs as potential cancer biomarkers

Czech Academy of Sciences Publication Activity Database

Bartošík, Martin; Trefulka, Mojmír; Hrstka, R. (ed.); Vojtěšek, B.; Paleček, Emil

2013-01-01

Roč. 33, AUG2013 (2013), s. 55-58 ISSN 1388-2481 R&D Projects: GA ČR(CZ) GBP206/12/G151; GA ČR(CZ) GAP301/11/2055 Institutional research plan: CEZ:AV0Z50040702 Institutional support: RVO:68081707 Keywords : OS(VI)-MODIFIED POLYSACCHARIDES * VOLTAMMETRY * COMPLEXES Subject RIV: BO - Biophysics Impact factor: 4.287, year: 2013

Trinuclear ruthenium dioxolene complexes based on the bridging ligand hexahydroxytriphenylene: electrochemistry, spectroscopy, and near-infrared electrochromic behaviour associated with a reversible seven-membered redox chain.

Science.gov (United States)

Grange, Christopher S; Meijer, Anthony J H M; Ward, Michael D

2010-01-07

The trinuclear complexes [{(R2bipy)2Ru}3(mu3-HHTP)](PF6)3 [1(PF6)3, R = H; 2(PF6)3, R = 4-tBu] contain three {Ru(R2bipy)2}2+ fragments connected to the triangular tris-chelating ligand hexahydroxytriphenylene (H6HHTP). This bridging ligand contains three dioxolene-type binding sites, each of which can reversibly convert between dianionic catecholate (cat), monoanionic semiquinone (sq) or neutral quinone (q) redox states. The bridging ligand as a whole can therefore exist in seven different redox states from fully reduced [cat,cat,cat]6- through to fully oxidised, neutral [q,q,q]. Cyclic voltammetry of 1(PF6)3 in MeCN reveals six redox processes of which the three at more positive potentials (the sq/q couples) are reversible but the three at more negative potentials (the sq/cat couples) are irreversible with distorted wave shapes due to the insolubility of the reduced forms of the complex. In contrast, the more soluble complex 2(PF6)3 displays six reversible one-electron redox processes making all components of a seven-membered redox chain accessible. UV/Vis/NIR spectro-electrochemical studies reveal rich spectroscopic behaviour, with--in particular--very intense transitions in the near-IR region in many of the oxidation states associated with Ru(II)-->(dioxolene) MLCT and bridging ligand centred pi-pi* transitions. TDDFT calculations were used to analyse the electronic spectra in all seven oxidation states; the calculated spectra generally show very good agreement with experiment, which has allowed a fairly complete assignment of the low-energy transitions. The strong electrochromism of the complexes in the near-IR region has formed the basis of an optical window in which a thin film of 1(PF6)3 or 2(PF6)3 on a conductive glass surface can be reversibly and rapidly switched between redox states that alternate between strongly absorbing or near-transparent at 1100 nm, with--for 2(PF6)3--the switching being stable and reversible in water over thousands of cycles.

Synthesis, characterization, electrochemical studies and X-ray structures of mixed-ligand polypyridyl copper(II complexes with the acetate

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Adekunle Oluwafunmilayo F.

2016-01-01

Full Text Available [Cu(phen2(CH3COO](ClO4.2H2O (1 and [Cu(bipy2(CH3COO]-(ClO4.H2O (2 {phen = 1,10-phenanthroline, bipy = 2,2’-bipyridine}were synthesized and characterized. The complexes were characterized by employying elemental analyses, infrared and UV-Visible spectroscopy, room temperature magnetic measurements and the crystal structures elucidated using X-ray diffraction experiment. The redox properties of the complexes were also investigated. Both structures have a square pyramidal CuN4O chromophore which exhibit significant distortions due to long Cu-O [2.217(3 Å for (1 and 2.179 (1 for (2] and Cu-N [2.631(2 Å for (1 and 2.714(1 Å for (2] bonds. This distortion if further shown by the O-Cu-N bond angles [147.71(8 o for (1 and 153.40(5 o for (2]. The elemental analyses further support the structural details unveiled by the single crystal X-ray diffraction analysis. The infrared spectra shows the acetate vibrational frequencies at 1587 cm-1,1428 cm-1, 1314 cm-1 for (1 and 1571 cm-1, 1441 cm-1, 1319c m-1 for (2 and the perchlo-rate bands at 1059 cm-1, 720 cm-1 (1 and 1080 cm-1,768 cm-1 (2. The broad d-d bands for the copper ion at 14,514 cm-1(1 and 14,535 cm-1(2 support the adoption of square pyramid geometries. The magnetic moments for the two complexes are 1.83 B.M for (1 and 1.72 B.M for (2. The peak to peak values of the two complexes show that the electrode reactions are quasi-reversibile with ΔEp = 0.023V (1 and 0.025V for (2. In both structures, there are π-π intermolecular interactions in addition to hydrogen bonding between the units.

Metal-organic frameworks in mixed-matrix membranes for gas separation.

Science.gov (United States)

Tanh Jeazet, Harold B; Staudt, Claudia; Janiak, Christoph

2012-12-14

Mixed-matrix membranes (MMMs) with metal-organic frameworks (MOFs) as additives (fillers) exhibit enhanced gas permeabilities and possibly also selectivities when compared to the pure polymer. Polyimides (Matrimid®) and polysulfones are popular polymer matrices for MOF fillers. Presently investigated MOFs for MMMs include [Cu(SiF(6))(4,4'-BIPY)(2)], [Cu(3)(BTC)(2)(H(2)O)(3)] (HKUST-1, Cu-BTC), [Cu(BDC)(DMF)], [Zn(4)O(BDC)(3)] (MOF-5), [Zn(2-methylimidazolate)(2)] (ZIF-8), [Zn(purinate)(2)] (ZIF-20), [Zn(2-carboxyaldehyde imidazolate)(2)] (ZIF-90), Mn(HCOO)(2), [Al(BDC)(μ-OH)] (MIL-53(Al)), [Al(NH(2)-BDC)(μ-OH)] (NH(2)-MIL-53(Al)) and [Cr(3)O(BDC)(3)(F,OH)(H(2)O)(2)] (MIL-101) (4,4'-BIPY = 4,4'-bipyridine, BTC = benzene-1,3,5-tricarboxylate, BDC = benzene-1,4-dicarboxylate, terephthalate). MOF particle adhesion to polyimide and polysulfone organic polymers does not represent a problem. MOF-polymer MMMs are investigated for the permeability of the single gases H(2), N(2), O(2), CH(4), CO(2) and of the gas mixtures O(2)/N(2), H(2)/CH(4), CO(2)/CH(4), H(2)/CO(2), CH(4)/N(2) and CO(2)/N(2) (preferentially permeating gas named first). Permeability increases can be traced to the MOF porosity. Since the porosity of MOFs can be tuned very precisely, which is not possible with polymeric material, MMMs offer the opportunity of significantly increasing the selectivity compared to the pure polymeric matrix. Additionally in most of the cases the permeability is increased for MMM membranes compared to the pure polymer. Addition of MOFs to polymers in MMMs easily yields performances similar to the best polymer membranes and gives higher selectivities than those reported to date for any pure MOF membrane for the same gas separation. MOF-polymer MMMs allow for easier synthesis and handability compared to pure MOF membranes.

Capped Mesoporous Silica Nanoparticles for the Selective and Sensitive Detection of Cyanide.

Science.gov (United States)

Sayed, Sameh El; Licchelli, Maurizio; Martínez-Máñez, Ramón; Sancenón, Félix

2017-10-18

The development of easy and affordable methods for the detection of cyanide is of great significance due to the high toxicity of this anion and the potential risks associated with its pollution. Herein, optical detection of cyanide in water has been achieved by using a hybrid organic-inorganic nanomaterial. Mesoporous silica nanoparticles were loaded with [Ru(bipy) 3 ] 2+ , functionalized with macrocyclic nickel(II) complex subunits, and capped with a sterically hindering anion (hexametaphosphate). Cyanide selectively induces demetallation of nickel(II) complexes and the removal of capping anions from the silica surface, allowing the release of the dye and the consequent increase in fluorescence intensity. The response of the capped nanoparticles in aqueous solution is highly selective and sensitive towards cyanide with a limit of detection of 2 μm. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Interaction of dinuclear cadmium(II) 5-Cl-salicylaldehyde complexes with calf-thymus DNA

Energy Technology Data Exchange (ETDEWEB)

Ristovic, Maja Sumar [Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece); Faculty of Chemistry, University of Belgrade, Studenski Trg 12-16, Belgrade (Serbia); Zianna, Ariadni; Psomas, George; Hatzidimitriou, Antonios G. [Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece); Coutouli-Argyropoulou, Evdoxia [Department of Organic Chemistry and Biochemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece); Lalia-Kantouri, Maria, E-mail: lalia@chem.auth.gr [Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece)

2016-04-01

Five dinuclear Cd(II) complexes with the anion of 5-Cl-salicylaldehyde (5-Cl-saloH) were synthesized in the absence or presence of the α-diimines: 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen), 2,9-dimethyl-1,10-phenanthroline (neoc) or 2,2′-dipyridylamine (dpamH) and characterized as [Cd(5-Cl-salo){sub 2}(CH{sub 3}OH)]{sub 2} (1), [Cd(5-Cl-salo){sub 2}(bipy)]{sub 2} (2), [Cd(5-Cl-salo){sub 2}(phen)]{sub 2} (3), [Cd(5-Cl-salo)(neoc)(ONO{sub 2})]{sub 2} (4) and [Cd(5-Cl-salo)(dpamΗ)(ONO{sub 2})]{sub 2} (5). The complexes were characterized by spectroscopic techniques (IR, UV‐vis, {sup 1}H-NMR and {sup 13}C–NMR), elemental analysis and molar conductivity measurements. The structures of four complexes (1–3 and 5) were determined by X-ray crystallography, providing all three possible coordination modes of the ligand 5-Cl-salicylaldehyde, i.e. bidentate or tridentate chelating and/or bridging mode. The complexes bind to calf-thymus (CT) DNA mainly by intercalation, as concluded by the viscosity measurements and present relatively high DNA-binding constants. The complexes exhibit significant ability to displace ethidium bromide (EB) from the EB-DNA complex, thus indirectly proving the intercalation as the most possible binding mode to CT DNA. - Graphical abstract: Cadmium complexes of the formulae [Cd(5-Cl-salo){sub 2}(CH{sub 3}OH)]{sub 2} and [Cd(5-Cl-salo){sub 2}(α-diimine)]{sub 2} or [Cd(5-Cl-salo)(α-diimine)(ONO{sub 2})]{sub 2} have been synthesized and characterized. The complexes bind tightly to CT DNA probably by intercalation competing with ethidium bromide for the intercalation site of DNA. - Highlights: • Synthesis of a series of dinuclear Cd complexes • The complexes characterized by diverse techniques. • The crystal structures of four complexes have been determined. • Intercalation is the most possible binding mode of the complexes to DNA. • The complexes compete with ethidium bromide for the DNA-intercalating sites.

Design of co-crystals/salts of some Nitrogenous bases and some derivatives of thiophene carboxylic acids through a combination of hydrogen and halogen bonds.

Science.gov (United States)

Jennifer, Samson Jegan; Muthiah, Packianathan Thomas

2014-01-01

The utility of N-heterocyclic bases to obtain molecular complexes with carboxylic acids is well studied. Depending on the solid state interaction between the N-heterocyclic base and a carboxylic acid a variety of neutral or ionic synthons are observed. Meanwhile, pyridines and pyrimidines have been frequently chosen in the area of crystal engineering for their multipurpose functionality. HT (hetero trimers) and LHT (linear heterotetramers) are the well known synthons that are formed in the presence of pyrimidines and carboxylic acids. Fourteen crystals involving various substituted thiophene carboxylic acid derivatives and nitrogenous bases were prepared and characterized by using single crystal X-ray diffraction. The 14 crystals can further be divided into two groups [1a-7a], [8b-14b] based on the nature of the nitrogenous base. Carboxylic acid to pyridine proton transfer has occurred in 3 compounds of each group. In addition to the commonly occurring hydrogen bond based pyridine/carboxylic acid and pyrimidine/carboxylic acid synthons which is the reason for assembly of primary motifs, various other interactions like Cl…Cl, Cl…O, C-H…Cl, C-H…S add additional support in organizing these supermolecules into extended architectures. It is also interesting to note that in all the compounds π-π stacking occurs between the pyrimidine-pyrimidine or pyridine-pyridine or acid-acid moieties rather than acid-pyrimidine/pyridine. In all the compounds (1a-14b) either neutral O-H…Npyridyl/pyrimidine or charge-assisted Npyridinium-H…Ocarboxylate hydrogen bonds are present. The HT (hetero trimers) and LHT (linear heterotetramers) are dominant in the crystal structures of the adducts containing N-heterocyclic bases with two proton acceptors (1a-7a). Similar type supramolecular ladders are observed in 5TPC44BIPY (8b), TPC44BIPY (9b), TPC44TMBP (11b). Among the seven compounds [8b-14b] the extended ligands are linear in all except for the TMBP (10b, 11b, 12b). The

Self-assembled polymeric nanoparticles as new, smart contrast agents for cancer early detection using magnetic resonance imaging

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Mouffouk F

2014-12-01

Full Text Available Fouzi Mouffouk,1,* Teresa Simão,2,* Daniel F Dornelles,2 André D Lopes,3 Pablo Sau,4 Jorge Martins,2,5 Khalid M Abu-Salah,6 Salman A Alrokayan,6 Ana M Rosa da Costa,3 Nuno R dos Santos2 1Chemistry Department, Faculty of Science, Kuwait University, Safat, Kuwait; 2IBB – Institute for Biotechnology and Bioengineering, CBME – Centre for Molecular and Structural Biomedicine, 3CIQA-Algarve Chemistry Research Center, Department of Chemistry and Pharmacy, Faculty of Sciences and Technology, University of Algarve, Campus de Gambelas, Faro, Portugal; 4Centro Radiológico Computarizado SA (CERCO, Seville, Spain; 5Department of Biological Sciences and Bioengineering, Faculty of Sciences and Technology, University of Algarve, Campus de Gambelas, Faro, Portugal; 6King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, Saudi Arabia *These authors contributed equally to this work Abstract: Early cancer detection is a major factor in the reduction of mortality and cancer management cost. Here we developed a smart and targeted micelle-based contrast agent for magnetic resonance imaging (MRI, able to turn on its imaging capability in the presence of acidic cancer tissues. This smart contrast agent consists of pH-sensitive polymeric micelles formed by self-assembly of a diblock copolymer (poly(ethyleneglycol-b-trimethylsilyl methacrylate, loaded with a gadolinium hydrophobic complex (tBuBipyGd and exploits the acidic pH in cancer tissues. In vitro MRI experiments showed that tBuBipyGd-loaded micelles were pH-sensitive, as they turned on their imaging capability only in an acidic microenvironment. The micelle-targeting ability toward cancer cells was enhanced by conjugation with an antibody against the MUC1 protein. The ability of our antibody-decorated micelles to be switched on in acidic microenvironments and to target cancer cells expressing specific antigens, together with its high Gd(III content and its small size (35–40 nm reveals

Thermo-Kinetic Investigation of Comparative Ligand Effect on Cysteine Iron Redox Reaction

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Masood Ahmad Rizvi

2015-03-01

Full Text Available Transition metal ions in their free state bring unwanted biological oxidations generating oxidative stress. The ligand modulated redox potential can be indispensable in prevention of such oxidative stress by blocking the redundant bio-redox reactions. In this study we investigated the comparative ligand effect on the thermo-kinetic aspects of biologically important cysteine iron (III redox reaction using spectrophotometric and potentiometric methods. The results were corroborated with the complexation effect on redox potential of iron(III-iron(II redox couple. The selected ligands were found to increase the rate of cysteine iron (III redox reaction in proportion to their stability of iron (II complex (EDTA < terpy < bipy < phen. A kinetic profile and the catalytic role of copper (II ions by means of redox shuttle mechanism for the cysteine iron (III redox reaction in presence of 1,10-phenanthroline (phen ligand is also reported.

Novel cleavage and oligomerization reactions of nickel (o) complexes. Application to homogeneous deoxygenation and desulfurization

International Nuclear Information System (INIS)

Eisch, J.J.; Im, K.R.

1979-01-01

The ease of interaction of Ni(0) complexes with organic substrates has been shown to depend upon both the ligands on nickel and the solvent. The presence of α,α'-bipyridyl with the Ni(0) complex and the alkyne led to the isolation of a nickelacyclopropene, an observation in accord with the recently proposed metallocyclic pathway for the Ni(0)-catalyzed trimerization of alkynes. Allylic and benzylic ethers and epoxides have been observed to undergo oxidative insertion of Ni(0) into their C-O bonds with solvent (TMEDA > THF (tetrahydrofuran) > Et 2 O > C 6 H 6 ) and ligand (Et 3 P (tripthyl phosphine) > Ph 3 P (triphenyl phosphine); α,α'-bipy > COD) effects consistent with an electron-transfer attack by Ni(0). With such sulfur heterocycles as dibenzothiophene, phenoxathiin, phenothiazine, and thianthrene, a 1:1 admixture of (COD) 2 Ni with α,α'-bipyridyl gave as the principal product the desulfurized, ring-contracted cyclic product

Two Chemically Stable Cd(II Polymers as Fluorescent Sensor and Photocatalyst for Aromatic Dyes

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Jun Wang

2018-03-01

Full Text Available Two new 2D Cd(II-based coordination polymers (CPs, viz. [Cd2(H2L2(2,2’-bipy2] (1 and [Cd(L0.5(phen·0.5H2O] (2, have been constructed using ethylene glycol ether bridging tetracarboxylate ligand 5,5′(4,4′-phenylenebis(methyleneoxy diisophthalic acid (H4L. Both CPs behaved as profound fluorescent sensor for Fe3+ ion and nitro-aromatics (NACs, specifically 2,4,6-trinitrophenol (TNP. The stability at elevated temperature and photocatalytic behaviors of both 1 and 2 for photo-decomposition of aromatic dyes have also been explored. An attempt has been made to explore the plausible mechanism related with the decrease in fluorescence intensity of 1 and 2 in presence of NACs using theoretical calculations. Additionally, the probable mechanism of photo catalysis by 1 and 2 to photo-degrade aromatic dyes has been explained using density of states (DOS calculations.

Heptanuclear Fe5Cu2-Phenylgermsesquioxane containing 2,2'-Bipyridine: Synthesis, Structure, and Catalytic Activity in Oxidation of C-H Compounds.

Science.gov (United States)

Bilyachenko, Alexey N; Khrustalev, Victor N; Zubavichus, Yan V; Shul'pina, Lidia S; Kulakova, Alena N; Bantreil, Xavier; Lamaty, Frédéric; Levitsky, Mikhail M; Gutsul, Evgeniy I; Shubina, Elena S; Shul'pin, Georgiy B

2018-01-02

A new representative of an unusual family of metallagermaniumsesquioxanes, namely the heterometallic cagelike phenylgermsesquioxane (PhGeO 2 ) 12 Cu 2 Fe 5 (O)OH(PhGe) 2 O 5 (bipy) 2 (2), was synthesized and structurally characterized. Fe(III) ions of the complex are coordinated by oxa ligands: (i) cyclic (PhGeO 2 ) 12 and acyclic (Ph 2 Ge 2 O 5 ) germoxanolates and (ii) O 2- and (iii) HO - moieties. In turn, Cu(II) ions are coordinated by both oxa (germoxanolates) and aza ligands (2,2'-bipyridines). This "hetero-type" of ligation gives in sum an attractive pagoda-like molecular architecture of the complex 2. Product 2 showed a high catalytic activity in the oxidation of alkanes to the corresponding alkyl hydroperoxides (in yields up to 30%) and alcohols (in yields up to 100%) and in the oxidative formation of benzamides from alcohols (catalyst loading down to 0.4 mol % in Cu/Fe).

μ-Oxalato-bis[(2,2′-bipyridylcopper(II] bis(perchlorate dimethylformamide disolvate monohydrate

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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.

Two Water Stable Copper Metal-Organic Frameworks with Performance in the Electrocatalytic Activity for Water Oxidation

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Liu Xiuping

2018-01-01

Full Text Available Two novel water stable metal-organic frameworks, [Cu(L·(4,4′-bipy·(ClO4]n (1, [Cu(L·(phen·(ClO4·(H2O]2 (2, have been constructed by HL=[5-Mercapto-1-methyl] tetrazole acetic acid and Cu (II salt in the presence of assistant N-containing ligands. MOF 1 and MOF 2 with open CuII sites, resulting the framework 1 and 2 show electrocatalytic activity for water oxidation in alkaline solution. The electrochemical properties of complex for oxygen evolution reaction (OER were evaluated by linear sweep voltammetry (LSV and the Tafel slopes. Complex 1 has a higher LSV activity with a lower over potential of 1.54 V and a much higher increase in current density. Meanwhile, the Tafel slope of complex 1 (122.0 mV dec-1 is much lower than complex 2 (243.5 mV dec-1. This phenomenon makes complex 1 a promising porous material for electrocatalytic activity.

Voltammetric Detection of Damage to DNA by Arsenic Compounds at a DNA Biosensor

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R. Wennrich

2005-11-01

Full Text Available DNA biosensor can serve as a powerfull tool for simple in vitro tests of chemicaltoxicity. In this paper, damage to DNA attached to the surface of screen-printed carbonelectrode by arsenic compounds in solution is described. Using the Co(III complex with1,10-phenanthroline, [Co(phen3]3+ , as an electrochemical DNA marker and the Ru(IIcomplex with bipyridyne, [Ru(bipy3]2+ , as a DNA oxidation catalyst, the portion of originaldsDNA which survives an incubation of the biosensor in the cleavage medium was evaluated.The model cleavage mixture was composed of an arsenic compound at 10-3 mol/Lconcentration corresponding to real contaminated water, 2x10-4 mol/L Fe(II or Cu(II ions asthe redox catalyst, and 1.5x10-2 mol/L hydrogen peroxide. DNA damage by arsenite,dimethylarsinic acid as the metabolic product of inorganic arsenic and widely used herbicide,as well as phenylarsonic acid and p-arsanilic acid as the representatives of feed additives wasfound in difference to arsenate.

Calcium manganese oxides as oxygen evolution catalysts: O2 formation pathways indicated by 18O-labelling studies.

Science.gov (United States)

Shevela, Dmitriy; Koroidov, Sergey; Najafpour, M Mahdi; Messinger, Johannes; Kurz, Philipp

2011-05-02

Oxygen evolution catalysed by calcium manganese and manganese-only oxides was studied in (18)O-enriched water. Using membrane-inlet mass spectrometry, we monitored the formation of the different O(2) isotopologues (16)O(2), (16)O(18)O and (18)O(2) in such reactions simultaneously with good time resolution. From the analysis of the data, we conclude that entirely different pathways of dioxygen formation catalysis exist for reactions involving hydrogen peroxide (H(2)O(2)), hydrogen persulfate (HSO(5)(-)) or single-electron oxidants such as Ce(IV) and [Ru(III) (bipy)(3)](3+) . Like the studied oxide catalysts, the active sites of manganese catalase and the oxygen-evolving complex (OEC) of photosystem II (PSII) consist of μ-oxido manganese or μ-oxido calcium manganese sites. The studied processes show very similar (18)O-labelling behaviour to the natural enzymes and are therefore interesting model systems for in vivo oxygen formation by manganese metalloenzymes such as PSII. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multifunctional uranyl hybrid materials: structural diversities as a function of pH, luminescence with potential nitrobenzene sensing, and photoelectric behavior as p-type semiconductors.

Science.gov (United States)

Song, Jian; Gao, Xue; Wang, Zhi-Nan; Li, Cheng-Ren; Xu, Qi; Bai, Feng-Ying; Shi, Zhong-Feng; Xing, Yong-Heng

2015-09-21

A series of uranyl-organic frameworks (UOFs), {[(UO2)2(H2TTHA)(H2O)]·4,4'-bipy·2H2O}n (1), {[(UO2)3(TTHA)(H2O)3]}n (2), and {[(UO2)5(TTHA) (HTTHA)(H2O)3]·H3O}n (3), have been obtained by the hydrothermal reaction of uranyl acetate with a flexible hexapodal ligand (1,3,5-triazine-2,4,6-triamine hexaacetic acid, H6TTHA). These compounds exhibited three distinct 3D self-assembly architectures as a function of pH by single-crystal structural analysis, although the used ligand was the same in each reaction. Surprisingly, all of the coordination modes of the H6TTHA ligand in this work are first discovered. Furthermore, the photoluminescent results showed that these compounds displayed high-sensitivity luminescent sensing functions for nitrobenzene. Additionally, the surface photovoltage spectroscopy and electric-field-induced surface photovoltage spectroscopy showed that compounds 1-3 could behave as p-type semiconductors.

Spectrochemical investigation of neodymium fluorinated #betta#-diketonates

International Nuclear Information System (INIS)

Khomenko, V.S.; Rasshinina, T.A.; Lozinskij, M.O.; Fialkov, Yu.A.

1982-01-01

A spectrochemical study is carried out on neodymium complexes with #betta#-diketonates of the following contents: Nd(tdh) 4 xHP, Nd(tdh) 3 xbipy, Nd(tdh) 3 xC 10 D 8 N 2 , Nd(tdh) 3 xphen, Nd(fod) 4 xHP, Nd(fod) 3 xbipy, Nd(fod) 3 xphen, where tdh - 1, 1, 1,-trifluoro-5, 5 dimethylhexanedione-2, 4; fod - 1, 1, 1, 2, 2, 3, 3-heptafluoro-7, 7-dimethyloctanedione-4, 6; bipy - 2, 2'-dipyridyl- phen - 1, 10-phenanthroline; p - piperidine; C 10 D 8 N 2 - deuterated 2, 2'-dipyridyl. A change in the metal-ligand bond character was determined by means of the nepheloxetic effect (band shift in absorption spectra at the expense of an interelectron repulsion decrease in the 4f-electron shell due to its expansion during the formation of partially covalent metal-ligand bonds). Mutual ligand effect on the complex properties was also studied using the mass spectrometric method. It is established that an extra addition of a bisheterocycle to a triligand rare-earth complex makes an average bond in a complex more covalent

Synthesis, characterization, DFT and Td-dfT study of the [Fe(mnt(L(t-BuNC 2] octahedral complex (L = phen, bipy

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Milton K. MorigakiI

2009-01-01

Full Text Available FeBr2 has reacted with an equivalent of mnt2- (mnt = cis-1,2-dicyanoethylene-1,2-dithiolate and the α-diimine L (L = 1,10'-phenantroline, 2,2'-bipyridine in THF solution, and followed by adding of t-butyl-isocyanide to give [Fe(mnt(L(t-BuNC2] neutral compound. The products were characterized by infrared, UV-visible and Mössbauer spectroscopy, besides thermogravimetric and conductivity data. The geometry in the equilibrium was calculated by the density functional theory and the electronic spectrum by the time-dependent. The experimental and theoretical results in good agreement have defined an octahedral geometry with two isocyanide neighbours. The π→π* intraligand electronic transition was not observed for cis-isomers in the near-IR spectral region.

Solvothermal Synthesis, Crystal Structure, and Magnetic Properties of [Co3(SDA)3(DMF)2]: 2-D Layered Metal-organic Framework Derived from 4,4'-Stilbenedicarboxylic Acid (H2SDA)

International Nuclear Information System (INIS)

Park, Gyung Se; Kim, Hyun Uk; Kim, Ki Moon; Lee, Gang Ho; Park, Sang Kyu

2006-01-01

A new 2-D coordination polymer has been synthesized and characterized by using a novel 4,4'-stilbene dicarboxylic acid and Co(ClO 4 ) 2 ·6H 2 O. The title complex has an unique Co 3 pin-wheel cluster in which central Co has octahedral geometry and two surrounding Co have tetrahedral geometry. The Co 3 pin-wheel clusters, the building unit, are linked through carboxylate oxygens to generate a 2-D layered coordination polymer in ABCABC packing mode. Variable-temperature magnetic susceptibility data of the title compound confirms the high spin splitting of Co with S=3/2. Syntheses of MOF by using SDA and other transition metal ions, Zn, Cd, and Mn, are on progress in this lab. Metal-organic frameworks (MOF) have attracted much more attention in the past decade owing to their various intriguing framework topologies and potential applications as functional materials in gas storage, separation, and catalysis. Because high framework stability is fundamental and essential property for many practical applications, multi-dentate linkers such as carboxylates have been extensively investigated for the formation of more rigid frameworks due to their ability to aggregate metal ions into M-O-C clusters called secondary building units (SBUs) rather than N-bound organic linkers such as 4,4-bipyridine (bipy)

Modeling of Platinum-Aryl Interaction with Amyloid-β Peptide.

Science.gov (United States)

Turner, Matthew; Platts, James A; Deeth, Robert J

2016-03-08

Ligand field molecular mechanics (LFMM), density functional theory (DFT), and semiempirical PM7 methods are used to study the binding of two Pt(II)-L systems to an N-terminal fragment of the amyloid-β peptide, where L = 2,2-bipyridyl or 1,10-phenanthroline. Molecular dynamics simulations are used to explore the conformational freedom of the peptide using LFMM combined with AMBER molecular mechanics parameters. We establish a modeling protocol, allowing for identification and analysis of favorable platinum-binding modes and peptide conformations. Preferred binding modes are identified for each ligand investigated; metal coordination occurs via Nε in His residues for both ligands--His6ε-His13ε and His6ε-His14ε for the bipyridyl and phenanthroline ligands, respectively. The observed change in binding mode for the different ligands suggests that the binding mode of these platinum-based structures can be controlled by the choice of ligand. In the bipy systems, Boltzmann population at 310 K is dominated by a single conformer, while in the phenanthroline case, three conformations make significant contributions to the ensemble. The relative stability of these conformations is due to the inherent stability of binding platinum via Nε in addition to subtle H-bonding effects.

Spectrochemical investigation of neodymium fluorinated. beta. -diketonates

Energy Technology Data Exchange (ETDEWEB)

Khomenko, V.S.; Rasshinina, T.A.; Lozinskij, M.O.; Fialkov, Yu.A.

1982-10-01

A spectrochemical study is carried out on neodymium complexes with ..beta..-diketonates of the following contents: Nd(tdh)/sub 4/xHP, Nd(tdh)/sub 3/xbipy, Nd(tdh)/sub 3/xC/sub 10/D/sub 8/N/sub 2/, Nd(tdh)/sub 3/xphen, Nd(fod)/sub 4/xHP, Nd(fod)/sub 3/xbipy, Nd(fod)/sub 3/xphen, where tdh - 1, 1, 1,-trifluoro-5, 5 dimethylhexanedione-2, 4; fod - 1, 1, 1, 2, 2, 3, 3-heptafluoro-7, 7-dimethyloctanedione-4, 6; bipy - 2, 2'-dipyridyl- phen - 1, 10-phenanthroline; p - piperidine; C/sub 10/D/sub 8/N/sub 2/ - deuterated 2, 2'-dipyridyl. A change in the metal-ligand bond character was determined by means of the nepheloxetic effect (band shift in absorption spectra at the expense of an interelectron repulsion decrease in the 4f-electron shell due to its expansion during the formation of partially covalent metal-ligand bonds). Mutual ligand effect on the complex properties was also studied using the mass spectrometric method. It is established that an extra addition of a bisheterocycle to a triligand rare-earth complex makes an average bond in a complex more covalent.

Synthesis and crystal structures of new complexes of Np(V) glycolate with 2,2'-bipyridine, [NpO2(C10H8N2)(OOC2H2OH)].1.5H2O and [NpO2(C10H8N2)(OOC2H2OH)].2.5H2O

International Nuclear Information System (INIS)

Charushnikova, I.A.; Krot, N.N.; Starikova, Z.A.

2009-01-01

Single crystals were prepared, and the structures of two complexes of Np(V) glycolate with 2,2'-bipyridine of the compositions [NpO 2 (C 10 H 8 N 2 )(OOC 2 H 2 OH)].1.5H 2 O (I) and [NpO 2 (C 10 H 8 N 2 )(OOC 2 H 2 OH)]2.5H 2 O (II) were studied. The structures of the compounds are based on neptunyl-glycolate chains in which the glycolate anion manifests its complexation ability in different manner. In structure I, the bidentate-bridging anion links the adjacent NpO 2 - cations through the oxygen atoms of the carboxylate group. The neptunyl-glycolate chains of I exhibits the mutual coordination of the NpO 2 - cations acting toward each other simultaneously as ligands and coordinating centers. In compound II, the glycolate anion is bidentately coordinated to one neptunium atom to form a planar five-membered metallocycle [NpOCCO]. The O atom external with respect to the metallocycle is in the coordination environment of the adjacent neptunyl. The nitrogen-containing molecular ligand Bipy is included into the coordination environment of Np. The coordination polyhedron of the Np atoms in both structures is a pentagonal bipyramid in which the average Np-N bond length is 2.666 Aa (I) and 2.596 Aa (II). (orig.)

Sub-Picosecond Injection of Electrons from Excited {Ru (2,2'-bipy-4,4'-dicarboxy)2(SCN)2} into TiO2 Using Transient Mid-Infrared Spectroscopy

International Nuclear Information System (INIS)

Nozik, A.J.; Ghosh, H.N.; Asbury, J.B.; Sprague, J.R.; Ellingson, R.J.; Ferrere, S.; Lian, T.

1999-01-01

We have used femtosecond pump-probe spectroscopy to time resolve the injection of electrons into nanocrystalline TiO2 film electrodes under ambient conditions following photoexcitation of the adsorbed dye, [Ru(4,4'-dicarboxy-2,2'-bipyridine)2(NCS)2] (N3). Pumping at one of the metal-to-ligand charge transfer adsorption peaks and probing the absorption of electrons injected into the TiO2 conduction band at 1.52 m and in the range of 4.1 to 7.0 m, we have directly observed the arrival of the injected electrons. Our measurements indicate an instrument-limited 50-fs upper limit on the electron injection time under ambient conditions in air. We have compared the infrared transient absorption for non-injecting (blank) systems consisting of N3 in ethanol and N3 adsorbed to films of nanocrystalline Al2O3 and ZrO2, and found no indication of electron injection at probe wavelengths in the mid-IR (4.1 to 7.0 m). At 1.52 m interferences exist in the observed transient adsorption signal for the blanks

Probing the influence of N-donor capping ligands on supramolecular assembly in molecular uranyl materials

Energy Technology Data Exchange (ETDEWEB)

Carter, Korey P.; Kalaj, Mark; Cahill, Christopher L. [Department of Chemistry, The George Washington University, Washington, DC (United States)

2016-01-15

The syntheses and crystal structures of six new compounds containing the UO{sub 2}{sup 2+} cation, 3,5-dichlorobenzoic acid, and a chelating N-donor [2,2'-bipyridine (bipy), 1,10-phenanthroline (phen), 4,7-dimethyl-1,10-phenanthroline (dimethylphen), 2,2{sup '}:6{sup '},2''-terpyridine (terpy), 4{sup '}-chloro-2,2{sup '}:6{sup '},2''-terpyridine (Cl-terpy), or 2,4,6-tris(2-pyridyl)-s-triazine (TPTZ)] are reported. Single-crystal X-ray diffraction analysis of these materials enabled the exploration of the structural relationship between the benzoic acids and the chelating N-donor as well as providing a platform to evaluate the effects of ligand choice on uranyl hydrolysis and subsequent oligomerization. At an unadjusted pH (ca. 3), a mix of uranyl monomers and dimers are observed, dimer formation resulting from both bridging carboxylate linkers and hydroxo bridges. Assembly by halogen- and hydrogen-bonding interactions as well as π-π interactions was observed depending on the experimental conditions utilized. Further, spectroscopic characterization (both vibrational and luminescence) of complexes 1, 4, and 5 to explore the effects of the electron-donating ability of the capping ligand on the corresponding uranyl luminescence and vibrational spectra suggests that there is a relationship between the observed bathochromic shifts and the electron-donating ability of the capping ligands. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Engaging the Terminal: Promoting Halogen Bonding Interactions with Uranyl Oxo Atoms.

Science.gov (United States)

Carter, Korey P; Kalaj, Mark; Surbella, Robert G; Ducati, Lucas C; Autschbach, Jochen; Cahill, Christopher L

2017-11-02

Engaging the nominally terminal oxo atoms of the linear uranyl (UO 2 2+ ) cation in non-covalent interactions represents both a significant challenge and opportunity within the field of actinide hybrid materials. An approach has been developed for promoting oxo atom participation in a range of non-covalent interactions, through judicious choice of electron donating equatorial ligands and appropriately polarizable halogen-donor atoms. As such, a family of uranyl hybrid materials was generated based on a combination of 2,5-dihalobenzoic acid and aromatic, chelating N-donor ligands. Delineation of criteria for oxo participation in halogen bonding interactions has been achieved by preparing materials containing 2,5-dichloro- (25diClBA) and 2,5-dibromobenzoic acid (25diBrBA) coupled with 2,2'-bipyridine (bipy) (1 and 2), 1,10-phenanthroline (phen) (3-5), 2,2':6',2''-terpyridine (terpy) (6-8), or 4'-chloro-2,2':6',2''-terpyridine (Cl-terpy) (9-10), which have been characterized through single crystal X-ray diffraction, Raman, Infrared (IR), and luminescence spectroscopy, as well as through density functional calculations of electrostatic potentials. Looking comprehensively, these results are compared with recently published analogues featuring 2,5-diiodobenzoic acid which indicate that although inclusion of a capping ligand in the uranyl first coordination sphere is important, it is the polarizability of the selected halogen atom that ultimately drives halogen bonding interactions with the uranyl oxo atoms. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Probing the influence of N-donor capping ligands on supramolecular assembly in molecular uranyl materials

International Nuclear Information System (INIS)

Carter, Korey P.; Kalaj, Mark; Cahill, Christopher L.

2016-01-01

The syntheses and crystal structures of six new compounds containing the UO 2 2+ cation, 3,5-dichlorobenzoic acid, and a chelating N-donor [2,2'-bipyridine (bipy), 1,10-phenanthroline (phen), 4,7-dimethyl-1,10-phenanthroline (dimethylphen), 2,2 ' :6 ' ,2''-terpyridine (terpy), 4 ' -chloro-2,2 ' :6 ' ,2''-terpyridine (Cl-terpy), or 2,4,6-tris(2-pyridyl)-s-triazine (TPTZ)] are reported. Single-crystal X-ray diffraction analysis of these materials enabled the exploration of the structural relationship between the benzoic acids and the chelating N-donor as well as providing a platform to evaluate the effects of ligand choice on uranyl hydrolysis and subsequent oligomerization. At an unadjusted pH (ca. 3), a mix of uranyl monomers and dimers are observed, dimer formation resulting from both bridging carboxylate linkers and hydroxo bridges. Assembly by halogen- and hydrogen-bonding interactions as well as π-π interactions was observed depending on the experimental conditions utilized. Further, spectroscopic characterization (both vibrational and luminescence) of complexes 1, 4, and 5 to explore the effects of the electron-donating ability of the capping ligand on the corresponding uranyl luminescence and vibrational spectra suggests that there is a relationship between the observed bathochromic shifts and the electron-donating ability of the capping ligands. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Coupling of the 4f Electrons in Lanthanide Molecules

Energy Technology Data Exchange (ETDEWEB)

Kazhdan, Daniel [Univ. of California, Berkeley, CA (United States)

2008-09-01

;-dimethyl-2,2'-bipyridine) and (C₅Me₅)₂Yb(6-methyl-2,2'-bipyridine), the valence, as measured by XANES, changes as a function of temperature. In general, the magnetism in complexes of the type (C₅Me₅)₂Yb(bipy.-), where bipyo represents 2,2'-bipyridine and substituted 2,2'-bipyridine ligands, is described by a multiconfiguration model, in which the ground state is an open-shell singlet composed of two configurations: Yb(III, f¹³)(bipy.-) and Yb(II, f¹⁴)(bipyo). The relative contributions of the two configurations depends on the substituents on the bipyridine ligand.[(C₅Me₅)₃Ln]₂(L) (Ln = Ce, Tb; L = 4,4'-bipyridine, 1,4-benzoquinone) are synthesized in order to study the effect of these ligands on the oxidation states of the metal as well as to study intramolecular coupling between two lanthanides fragments.

Spectroscopy, crystal structure, valance molecular orbital energy level diagram and DFT study of cis-[Cr(2,2'-bipy) 2Cl 2](Cl) 0.38(PF 6) 0.62

Science.gov (United States)

Kar, Tapas; Liao, Meng-Sheng; Biswas, Susobhan; Sarkar, Saikat; Dey, Kamalendu; Yap, Glenn P. A.; Kreisel, Kevin

2006-11-01

A new octahedral chromium(III) complex having 2,2'-bipyridine as ligand system was synthesized in methanol. Single crystal X-ray diffraction analysis shows that it possesses non-stoichiometry in its anionic primary covalency. It has also been studied by elemental analyses, optical spectroscopy (UV-vis, IR) and magnetic susceptibility data. DFT calculations (with B3LYP functional and double-ξ quality LANLDZ(D95V) basis set) were carried out to interpret the electronic and infrared spectra of the complex. The DFT optimized geometric structure for the complex is compared with the X-ray crystallographic data; the theory-experiment agreement is satisfactory.

Preparation, characterization, and kinetics of thermolysis of nickel and copper nitrate complexes with 2,2 Prime -bipyridine ligand

Energy Technology Data Exchange (ETDEWEB)

Kumar, Dinesh; Kapoor, I.P.S. [Department of Chemistry, DDU Gorakhpur University, Gorakhpur 273 009 (India); Singh, Gurdip, E-mail: gsingh4us@yahoo.com [Department of Chemistry, DDU Gorakhpur University, Gorakhpur 273 009 (India); Froehlich, Roland [Institut fuer Organische Chemie, Universitaet Muenster, D-48149 Muenster (Germany)

2012-10-10

Graphical abstract: Nickel and copper nitrate complexes with 2,2 Prime -bipyridine, nitrate and water ligands have been prepared and characterized by single crystal X-ray diffraction, FT-IR and CHN analyses. Thermolysis was performed by using TG, DTA and ignition delay measurements. The kinetics of thermolysis were also evaluated. Highlights: Black-Right-Pointing-Pointer Preparation and characterization of Ni and Cu nitrate complexes have been reported. Black-Right-Pointing-Pointer Thermolysis has been carried out using TG-DTA and ignition delay measurements. Black-Right-Pointing-Pointer Their thermal decomposition pathways have been proposed. Black-Right-Pointing-Pointer Oxides residues as end product of thermolysis were revealed by XRD patterns. Black-Right-Pointing-Pointer Kinetics of their isothermal decomposition was evaluated. - Abstract: Nickel and copper nitrate complexes with 2,2 Prime -bipyridine (bipy) as a N donor and nitrate and water as oxygen donor ligands of the general formula [M(NO{sub 3})(C{sub 10}H{sub 8}N{sub 2})(H{sub 2}O){sub 3}](NO{sub 3}), where M = Ni and Cu, have been obtained from the corresponding metal nitrate salts. These complexes were characterized by X-ray crystallography, FT-IR, and CHN analysis. Both the complexes have been found to be six coordinated. Their thermal decomposition behaviour was investigated by TG, DTA, and ignition delay measurements. TG-DTA examinations of these complexes revealed multistep thermal decomposition. The corresponding metal oxide residues obtained after thermolysis were identified from their X-ray diffraction patterns (XRD). Kinetics of isothermal decomposition of the complexes was established from both the model-fitting as well as isoconversional methods.

Uptake of some lanthanides on γ-zirconium phosphate-phosphite and its 1,10-phenanthroline and 2,2-bipyridyl intercalated products

International Nuclear Information System (INIS)

Shakshooki, S.K.; El Hanash, H.B.; El-Mehdawi, R.M.; El-Mellah, M.A.; Arafa, E.A.; Bejey, A.M.

1999-01-01

γ-zirconium phosphate-phosphite, γ-Zr x PO 4 x H 2 PO 3 x 2H 2 O, (γ-ZrPP), was prepared and characterized. Direct treatment of γ-zirconium phosphate-phosphite with an ethanol solution of 0.1M 1,10-phenanthrolin and 2,2'-bipyridyl gave the well defined composites, γ-Zr x PO 4 x H 2 PO 3 (phen) 0.15 x H 2 O and γ-Zr x PO 4 x H 2 PO 3 (bipy) 0.18 x 0.6H 2 O respectively. K d values of a mixture of lanthanide ions: La 3+ , Sm 3+ , Eu 3+ and Yb 3+ for the intercalated products and for γ-ZrPP in HNO 3 solution at room temperature and at pH 2 and 4 were determined by a radiotracer technique. 140 La, 152m Eu, 153 Sm and 175 Yb radioisotopes were used for the equilibration experiment using 500 μl (4.0 x 10 -5 mmole) each of the solutions of the tracers as a mixture in 7.5 M HNO 3 solution at the desired pH with 0.1 g of γ-ZrPP and of the intercalated products. The selectivity order was found to be dependent on the nature of the ligand and on the pH. The 2,2'-bipyridyl product possesses, at pH 2 in general, a high K d value, specially for Sm 3+ (9815.9) compared to that of the 1,10-phenanthrolin product (3375.5) and to γ-ZrPP (419.8). This could be attributed to partial deintercalation of the 2,2' -bipyridyl at pH 2 and increasing of ionogenic groups. (author)

Synthesis and magnetic properties of layered MnPSxSe3-x (0 < x < 3) and corresponding intercalation compounds of 2,2'-bipyridine

International Nuclear Information System (INIS)

Yan, Xiaobing; Chen, Xingguo; Qin, Jingui

2011-01-01

Graphical abstract: A series of new layered MnPS x Se 3-x (0 x Se 3-x exhibited antiferromagnetism similar to MnPS 3 or MnPSe 3 , but the intercalation of 2,2'-bipyridine can dramatically change the properties of MnPS x Se 3-x slab. Research highlights: → A series of new MnPS x Se 3-x are designed and synthesized for the first time and their layered structure has been determined. → The intercalation chemistry has been initially studied via the intercalation of 2,2'-bipyridine with MnPS x Se 3-x . → The magnetic properties of the series MnPS x Se 3-x and the corresponding intercalation compounds of 2,2'-bipydine have been studied. And the relationship between the structure and the magnetic propertied has been primarily explored. -- Abstract: In this work, we synthesize a series of new MnPS x Se 3-x (0 1-y PS x Se 3-x (bipy) 4y , x = 1.2, 1.8 and 2.4) via the intercalation of 2,2'-bipyridine with MnPS x Se 3-x . XRD results confirm that MnPS x Se 3-x compounds show the layered structure and can be regarded as the solid solution of MnPS 3 and MnPSe 3 . Magnetic measurements indicate that MnPS x Se 3-x compounds exhibit paramagnetism with negative Weiss constant in the paramagnetic temperature region, and an antiferromagnetic phase transition occurs at the Neel temperature. It is found that the magnetic properties of MnPS x Se 3-x slab are dramatically changed after the intercalation of 2,2'-bipyridine, which is close related to the relative ratio of S and Se atom as well as the intralayered Mn 2+ vacancies of MnPS x Se 3-x slab.

Reversible Sigma C-C Bond Formation Between Phenanthroline Ligands Activated by (C5Me5)2Yb

Energy Technology Data Exchange (ETDEWEB)

Nocton, Gr& #233; gory; Lukens, Wayne W.; Booth, Corwin H.; Rozenel, Sergio S.; Medling, Scott A.; Maron, Laurent; Andersen, Richard A.

2014-06-26

The electronic structure and associated magnetic properties of the 1,10-phenanthroline adducts of Cp*2Yb are dramatically different from those of the 2,2?-bipyridine adducts. The monomeric phenanthroline adducts are ground state triplets that are based upon trivalent Yb(III), f13, and (phen ) that are only weakly exchange coupled, which is in contrast to the bipyridine adducts whose ground states are multiconfigurational, open-shell singlets in which ytterbium is intermediate valent ( J. Am. Chem. Soc 2009, 131, 6480; J. Am. Chem. Soc 2010, 132, 17537). The origin of these different physical properties is traced to the number and symmetry of the LUMO and LUMO+1 of the heterocyclic diimine ligands. The bipy has only one 1 orbital of b1 symmetry of accessible energy, but phen has two orbitals of b1 and a2 symmetry that are energetically accessible. The carbon p-orbitals have different nodal properties and coefficients and their energies, and therefore their populations change depending on the position and number of methyl substitutions on the ring. A chemical ramification of the change in electronic structure is that Cp 2Yb(phen) is a dimer when crystallized from toluene solution, but a monomer when sublimed at 180190 C. When 3,8-Me2phenanthroline is used, the adduct Cp*2Yb(3,8-Me2phen) exists in the solution in a dimer monomer equilibrium in which G is near zero. The adducts with 3-Me, 4-Me, 5-Me, 3,8-Me2, and 5,6-Me2-phenanthroline are isolated and characterized by solid state X-ray crystallography, magnetic susceptibility and LIII-edge XANES spectroscopy as a function of temperature and variable-temperature 1H NMR spectroscopy.

Structure and luminescent property of complexes of aryl carboxylic acid-functionalized polystyrene with Eu(III) and Tb(III) ions.

Science.gov (United States)

Gao, Baojiao; Shi, Nan; Qiao, Zongwen

2015-11-05

Via polymer reactions, naphthoic acid (NA) and benzoic acid (BA) were bonded onto the side chains of polystyrene (PS), respectively, and two aryl carboxylic acid-functionalized polystyrenes, PSNA and PSBA, were obtained. Using PSNA and PSBA as macromolecule ligands and Eu(3+) and Tb(3+) ions as central ions, various luminescent binary polymer-rare earth complexes were prepared. At the same time, with 1,10-phenanthroline (Phen) and 4,4'-bipyridine (Bipy) as small-molecule co-ligands, various ternary polymer-rare earth complexes were also prepared. On the basis of characterizing PSNA, PSBA and complexes, the relationship between structure and luminescent property for these prepared complexes were mainly investigated. The study results show that the macromolecule ligands PSNA and PSBA, or the bonded NA and BA ligands, can strongly sensitize the fluorescence emissions of Eu(3+) ion or Tb(3+) ion, but the sensitization effect is strongly dependent on the structure of the ligands and the property of the central ions, namely it is strongly dependent on the matching degree of energy levels. The fluorescence emission of the binary complex PS-(NA)3-Eu(III) is stronger than that PS-(BA)3-Eu(III), indicating ligand NA has stronger sensitization action for Eu(3+) ion than ligand BA; the binary complex PS-(BA)3-Tb(III) emit strong characteristic fluorescence of Tb(3+) ion, displaying that ligand BA can strongly sensitize Tb(3+) ion, whereas the binary complex PS-(NA)3-Tb(III) nearly does not emit the characteristic fluorescence of Tb(3+) ion, showing that ligand NA does not sensitize Tb(3+) ion. The fluorescence intensity of the ternary complexes is much stronger than that of the binary complexes in the same series. Copyright © 2015 Elsevier B.V. All rights reserved.

An experimental study on the preparation of tochilinite-originated intercalation compounds comprised of Fe 1-xS host layers and various kinds of guest layers

Science.gov (United States)

Peng, Yiya; Xi, Guangcheng; Zhong, Chang; Wang, Linping; Lu, Jun; Sun, Ximeng; Zhu, Lu; Han, Qikun; Chen, Lin; Shi, Lei; Sun, Mei; Li, Qianrong; Yu, Min; Yin, Mingwen

2009-08-01

Tochilinite represents a mineral group of ordered mixed-layer structures containing alternating Fe 1-xS layers with mackinawite-like structure and metal hydroxide layers with Mg(OH) 2-like structure. In this article, we report the preparation of a series of tochilinite-originated (or Fe 1-xS-based) intercalation compounds (ICs). According to their preparation procedures, these ICs can be divided into four kinds. The first kind of IC was sodium tochilinite (Na-tochilinite), which was prepared by the hydrothermal reaction of metallic Fe particles with concentrated Na 2S·9H 2O aqueous solutions. The hydroxide layer of the Na-tochilinite was a mixed hydroxide of Na + ions along with a certain amount of Fe 2+ ions. When the hydroxide layer of the Na-tochilinite completely dissolved in aqueous solutions, a Fe-deficient mackinawite-like phase Fe 1-xS was obtained, which was probably an electron-deficient p-type conductor. The second kind of ICs was prepared by 'low-temperature direct intercalation in aqueous solutions, using Na-tochilinite as a parental precursor. When the Na-tochilinite was ultrasonicated in aqueous solutions containing Lewis basic complexing agents (like NH 3, N 2H 4, 2,2'-bipyridine (bipy), and 1,10-phenanthroline (phen)), the Na + ions of the Na-tochilinite were removed and the Lewis basic complexing agents entered the hydroxide layer of the Na-tochilinite and became coordinated with the Fe 2+ ions, and the second kind of ICs was thus produced. The second kind of ICs includes NH 3 IC, N 2H 4 IC, N 2H 4-NH 3 IC, [Fe(bipy) 3] 2+-containing IC and [Fe(phen) 3] 2+-containing IC. The third kind of ICs, which includes NH 3 IC, N 2H 4-NH 3 IC and N 2H 4-LiOH (NaOH) IC, was prepared by the hydrothermal reaction of metallic Fe particles with (NH 4) 2S aqueous solution, S (elemental) + N 2H 4·H 2O aqueous solution, and S + N 2H 4·H 2O + LiOH (NaOH) aqueous solution, respectively. The third kind of ICs has a close relationship with the second kind of ICs both

Structure and photoluminescence property of complexes of aromatic carboxylic acid-functionalized polysulfone with Eu(Ⅲ) and Tb(Ⅲ)

International Nuclear Information System (INIS)

Gao, Baojiao; Qiao, Zongwen; Chen, Tao

2014-01-01

With chloromethylated polysulfone as starting substance, naphthoic acid (NA) and benzoic acid (BA) were bonded onto the side chains of polysulfone (PSF) via polymer reactions, obtaining two kinds of aromatic carboxyl acid-functionalized polysulfone, PSFNA and PSFBA. Subsequently, the luminescent binary and ternary polymer-rare earth complexes of Eu(Ⅲ) and Tb(Ⅲ) were prepared through coordination reactions, respectively, with PSFNA and PSFBA as macromolecule ligands and with 1,10-phenanthroline (Phen) and 4,4′-bipyridine (Bipy) as small-molecule co-ligands. This work focuses on investigating the relationship between structure and photoluminescence property of these complexes. The experimental results indicate that the macromolecule ligands PSFNA and PSFBA can strongly sensitize the fluorescence emissions of Eu 3+ ion or Tb 3+ ion, and the sensitization effect is strongly dependent on the structure of the ligands and the property of the central ions. The fluorescence emission of the binary complex PSF–(NA) 3 –Eu(Ⅲ) is stronger than that PSF–(BA) 3 –Eu(Ⅲ), suggesting the bonded ligand NA has stronger sensitization action for Eu 3+ ion than ligand BA; The binary complex PSF–(BA) 3 –Tb(Ⅲ) emit very strong characteristic fluorescence of Tb 3+ ion, displaying that ligand BA can strongly sensitize Tb 3+ ion, whereas PSF–(NA) 3 –Tb(Ⅲ) does not emit the characteristic fluorescence of Tb 3+ ion, showing that the bonded ligand NA does not sensitize Tb 3+ ion. The fluorescence intensity of the ternary complexes is stronger than that of the binary complexes in the same series. The solid films of these complexes also emit the strong characteristic fluorescence of Eu 3+ ion or Tb 3+ ion. - Highlights: • We prepared two kinds of aromatic carboxyl acid-functionalized polysulfone, PSFNA and PSFBA via polymer reaction. • Various binary and ternary luminescent polymer-rare earth complexes of Eu(Ⅲ) and Tb (Ⅲ) were obtained. • The relationship

Synthesis and structure of bivalent ytterbocenes and their coordination chemistry with pi-acceptor ligands

Energy Technology Data Exchange (ETDEWEB)

Schultz, Madeleine [Univ. of California, Berkeley, CA (United States)

2000-05-01

The bivalent lanthanide metallocenes [1,3-(Me₃C)₂C₅H₃]₂Yb and (Me₄C₅H)₂Yb have been synthesized and their structures have been determined by X-ray crystallography. Comparison with the known structures of (Me₅C₅)₂Yb and [1,3 -(Me₃Si)₂C₅H₃]₂Yb leads to an understanding of the role of intermolecular contacts in stabilizing these coordinatively unsaturated molecules. The optical spectra of the base-free ytterbocenes and their Lewis-base adducts have been measured; the position of the HOMO - LUMO transition can be correlated with the degree of bending of the complexes in solution according to a molecular orbital model. Electron - electron repulsion, resulting from additional σ-donor ligands, also affects the HOMO - LUMO transition by increasing the energy of the filled f-orbitals. The base-free metallocene (Me₅C₅)₂Yb coordinates carbon monoxide, resulting in a decrease in V_co relative to that of fi-ee carbon monoxide. This behavior is reminiscent of d-transition metallocene chemistry. Other base-free ytterbocenes also coordinate carbon monoxide and the degree of back-donation is related to the substituents on the cyclopentadienide rings. Isocyanides are coordinated in a 1:2 ratio by the ytterbocenes, giving complexes having v_cN higher than those of the free isocyanides. An electrostatic bonding model has been used to explain the changes in CN stretching frequencies. The optical spectra of the carbonyl and isocyanide complexes are consistent with the molecular orbital model of the variation in the HOMO - LUMO gap upon bending, and the increase in electron - electron repulsion due to the additional ligands. The complex (Me₅C₅)₂Yb(bipy) exhibits optical, infrared and NMIZ spectroscopy and an X-ray crystal

[KDy(Hptc3(H3ptc]n·2n(Hbipy·5n(H2O, a Layered Coordination Polymer Containing DyO6N3 Tri-Capped Trigonal Prisms (H3ptc = Pyridine 2,4,6-Tricarboxylic Acid, C8H5NO6; Bipy = 2,2'-Bipyridine, C10H8N2

Directory of Open Access Journals (Sweden)

Shoaib Anwar

2012-08-01

Full Text Available The synthesis, structure and properties of the bimetallic layered coordination polymer, [KDy(C8H3NO63(C8H5NO6]n·2n(C10H9N2·5n(H2O = [KDy(Hptc3(H3ptc]n·2n(Hbipy·5n(H2O, are described. The Dy3+ ion is coordinated by three O,N,O-tridentate doubly-deprotonated pyridine tri-carboxylate (Hptc ligands to generate a fairly regular DyO6N3 tri-capped trigonal prism, with the N atoms acting as the caps. The potassium ion is coordinated by an O,N,O-tridentate H3ptc molecule as well as monodentate and bidentate Hptc ligands to result in an irregular KNO9 coordination geometry. The ligands bridge the metal-atom nodes into a bimetallic, layered, coordination polymer, which extends as corrugated layers in the (010 plane, with the mono-protonated bipyridine cations and water molecules occupying the inter-layer regions: Unlike related structures, there are no dysprosium–water bonds. Many O–HLO and N–HLO hydrogen bonds consolidate the structure. Characterization and bioactivity data are described. Crystal data: C52H42DyKN8O29, Mr = 1444.54, triclinic,  (No. 2, Z = 2, a = 9.188(2 Å, b = 15.7332(17 Å, c = 19.1664(19 Å, α = 92.797(6°, β = 92.319(7°, γ = 91.273(9°, V = 2764.3(7 Å3, R(F = 0.029, wR(F2 = 0.084.