C-N bond cleavage of anilines by a (salen)ruthenium(VI) nitrido complex.

Science.gov (United States)

Man, Wai-Lun; Xie, Jianhui; Pan, Yi; Lam, William W Y; Kwong, Hoi-Ki; Ip, Kwok-Wa; Yiu, Shek-Man; Lau, Kai-Chung; Lau, Tai-Chu

2013-04-17

We report experimental and computational studies of the facile oxidative C-N bond cleavage of anilines by a (salen)ruthenium(VI) nitrido complex. We provide evidence that the initial step involves nucleophilic attack of aniline at the nitrido ligand of the ruthenium complex, which is followed by proton and electron transfer to afford a (salen)ruthenium(II) diazonium intermediate. This intermediate then undergoes unimolecular decomposition to generate benzene and N2.

Elution behavior of N-heterocyclic derivatives of mixed ruthenium(II)-sulfoxide complexes in reversed-phase high-performance liquid chromatography

International Nuclear Information System (INIS)

Toma, H.E.; Silva, D.O.

1991-01-01

The elution behaviour of a series of dichlorobis-(dimethylsulfoxide)bis(N-heterocyclic) ruthenium(II) complexes has been investigated using reversed-phase HPLC. Similar trends as those displayed by the free N-heterocyclic bases have been observed for the complexes, essentially reflecting the hydrophobic properties of the aromatic ligands. (orig.)

Study of the emission oxidative reactions of ruthenium (II) complex by cationic compounds in anionic micelles

International Nuclear Information System (INIS)

Bonilha, J.B.S.

1985-01-01

The oxidative quenching of the emission of the tetraanionic complex tris (4,4' dicarboxylate - 2,2' - bipyridine ruthenium (II) in aqueous solution, by both organic and inorganic compounds in presence of anionic detergents, above and below the critical micelle concentration is studied. The organic cations, the inorganic ion and detergents used are shown. (M.J.C.) [pt

Quantum chemical studies on electronic structure and photodynamics of ruthenium complexes

International Nuclear Information System (INIS)

Freitag, L.

2015-01-01

Ruthenium complexes have found their way into many applications in the last decades. Among those, ruthenium polypyridyl compounds have been employed as light harvesting devices and photosensitisers in artificial photosynthesis and molecular photocatalysis. Ruthenium nitrosyl complexes are rapidly emerging as NO delivery agents to biological tissues with promising applications in anticancer photodynamic therapy, thanks to their ability to photorelease nitric oxide (NO). This thesis encompasses computational studies on reactivity, electronic structure, excited states and photodynamics of several ruthenium nitrosyl and polypyridyl complexes. The first part of the thesis deals with ruthenium nitrosyls. The cis-trans isomerisation mechanism of RuHIndNO, a ruthenium nitrosyl derivate of the prominent anti-cancer drug candidate KP1019, is investigated with density functional theory calculations. Next, the electronic structure of the ground and the first excited triplet state of RuHIndNO is studied with multiconfigurational methods including the density-matrix renormalisation group (DMRG). The obtained multiconfigurational wavefunctions and DMRG-based orbital entanglement analysis provides theoretical insight into the non-innocence of the NO ligand in nitrosyl complexes by describing the electron correlation in the Ru--NO bond and assigning oxidation states to the metal and the NO ligand. Another study is performed on excited states of ruthenium nitrosyl complexes with quantum chemical calculations and surface-hopping dynamics to obtain insights into the photodissociation mechanism of NO. The second part of this thesis is devoted to the excited states and photophysics of ruthenium polypyridyl complexes. Accurate excitation energies of tris(2,2-bipyridine)ruthenium (II), the prototype ruthenium polypyridyl are obtained with multiconfigurational calculations assisted by an orbital entanglement analysis. Subsequently, the effect of the ligand substitution on the photophysics

Ruthenium (II) complexes of thiosemicarbazone: Synthesis, biosensor applications and evaluation as antimicrobial agents

International Nuclear Information System (INIS)

Yildirim, Hatice; Guler, Emine; Yavuz, Murat; Ozturk, Nurdan; Kose Yaman, Pelin; Subasi, Elif; Sahin, Elif; Timur, Suna

2014-01-01

A conformationally rigid half-sandwich organoruthenium (II) complex [(η 6 -p-cymene)RuClTSC N–S ]Cl, (1) and carbonyl complex [Ru(CO)Cl(PPh 3 ) 2 TSC N–S ] (2) have been synthesized from the reaction of [{(η 6 -p-cymene)RuCl} 2 (μ-Cl) 2 ] and [Ru(H)(Cl)(CO)(PPh 3 ) 3 ] with thiophene-2-carboxaldehyde thiosemicarbazon (TSC) respectively and both novel ruthenium (II) complexes have been characterized by elemental analysis, FT-IR and NMR spectroscopy. The peripheral TSC in the complexes acts as an electrochemical coupling unit providing the ability to carry out electrochemical deposition (ED) and to form an electro-deposited film on a graphite electrode surface. The biosensing applicability of complexes 1 and 2 was investigated by using glucose oxidase (GOx) as a model enzyme. Electrochemical measurements at − 0.9 V versus Ag/AgCl electrode by following the ED Ru(II) reduction/oxidation due to from the enzyme activity, in the presence of glucose substrate. The designed biosensor showed a very good linearity for 0.01–0.5 mM glucose. The in vitro antimicrobial activities of complexes 1 and 2 were also investigated against nine bacterial strains and one fungus by the disc diffusion test method. No activity was observed against the Gram-negative strains and fungus, whereas complex 1 showed moderate antibacterial activities against Gram-positive bacterial strains. - Highlights: • Novel Ru (II) thiosemicarbazone complexes were synthesized and characterized. • Electrochemical depositions were performed. • Rigid half-sandwich Ru (II) complex showed enhanced antibacterial activity

Mitochondria are the primary target in the induction of apoptosis by chiral ruthenium(II) polypyridyl complexes in cancer cells.

Science.gov (United States)

Wang, Jin-Quan; Zhang, Ping-Yu; Qian, Chen; Hou, Xiao-Juan; Ji, Liang-Nian; Chao, Hui

2014-03-01

A series of novel chiral ruthenium(II) polypyridyl complexes (Δ-Ru1, Λ-Ru1, Δ-Ru2, Λ-Ru2, Δ-Ru3, Λ-Ru3) were synthesized and evaluated to determine their antiproliferative activities. Colocalization, inductively coupled plasma mass spectrometry, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay studies showed that these ruthenium(II) complexes accumulated preferentially in the mitochondria and exhibited cytotoxicity against various cancer cells in vitro. The complex Δ-Ru1 is of particular interest because it was found to have half-maximal inhibitory concentrations comparable to those of cisplatin and better activity than cisplatin against a cisplatin-resistant cell line, A549-CP/R. Δ-Ru1 induced alterations in the mitochondrial membrane potential and triggered intrinsic mitochondria-mediated apoptosis in HeLa cells, which involved the regulation of Bcl-2 family members and the activation of caspases. Taken together, these data suggest that Δ-Ru1 may be a novel mitochondria-targeting anticancer agent.

Ruthenium (II) complexes of thiosemicarbazone: Synthesis, biosensor applications and evaluation as antimicrobial agents

Energy Technology Data Exchange (ETDEWEB)

Yildirim, Hatice [Dokuz Eylul University, The Graduate School of Natural and Applied Sciences, Department of Chemistry, 35160 Buca, Izmir (Turkey); Guler, Emine [Ege University, Faculty of Science, Department of Biochemistry, 35100 Bornova, Izmir (Turkey); Yavuz, Murat, E-mail: myavuz@dicle.edu.tr [Ege University, Faculty of Science, Department of Biochemistry, 35100 Bornova, Izmir (Turkey); Dicle University, Faculty of Science, Department of Chemistry, 21280 Diyarbakir (Turkey); Ozturk, Nurdan; Kose Yaman, Pelin [Dokuz Eylul University, The Graduate School of Natural and Applied Sciences, Department of Chemistry, 35160 Buca, Izmir (Turkey); Subasi, Elif; Sahin, Elif [Dokuz Eylul University, Faculty of Science, Department of Chemistry, 35160 Buca, Izmir (Turkey); Timur, Suna [Ege University, Faculty of Science, Department of Biochemistry, 35100 Bornova, Izmir (Turkey); Ege University, Institute on Drug Abuse, Toxicology and Pharmaceutical Science (BATI), 35100 Bornova, Izmir (Turkey)

2014-11-01

A conformationally rigid half-sandwich organoruthenium (II) complex [(η{sup 6}-p-cymene)RuClTSC{sup N–S}]Cl, (1) and carbonyl complex [Ru(CO)Cl(PPh{sub 3}){sub 2}TSC{sup N–S}] (2) have been synthesized from the reaction of [{(η"6-p-cymene)RuCl}{sub 2}(μ-Cl){sub 2}] and [Ru(H)(Cl)(CO)(PPh{sub 3}){sub 3}] with thiophene-2-carboxaldehyde thiosemicarbazon (TSC) respectively and both novel ruthenium (II) complexes have been characterized by elemental analysis, FT-IR and NMR spectroscopy. The peripheral TSC in the complexes acts as an electrochemical coupling unit providing the ability to carry out electrochemical deposition (ED) and to form an electro-deposited film on a graphite electrode surface. The biosensing applicability of complexes 1 and 2 was investigated by using glucose oxidase (GOx) as a model enzyme. Electrochemical measurements at − 0.9 V versus Ag/AgCl electrode by following the ED Ru(II) reduction/oxidation due to from the enzyme activity, in the presence of glucose substrate. The designed biosensor showed a very good linearity for 0.01–0.5 mM glucose. The in vitro antimicrobial activities of complexes 1 and 2 were also investigated against nine bacterial strains and one fungus by the disc diffusion test method. No activity was observed against the Gram-negative strains and fungus, whereas complex 1 showed moderate antibacterial activities against Gram-positive bacterial strains. - Highlights: • Novel Ru (II) thiosemicarbazone complexes were synthesized and characterized. • Electrochemical depositions were performed. • Rigid half-sandwich Ru (II) complex showed enhanced antibacterial activity.

Synthesis, structure, DNA binding and anticancer activity of mixed ligand ruthenium(II) complex

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Gilewska, Agnieszka; Masternak, Joanna; Kazimierczuk, Katarzyna; Trynda, Justyna; Wietrzyk, Joanna; Barszcz, Barbara

2018-03-01

In order to obtain a potential chemotherapeutic which is not affected on the normal BALB/3T3 cell line, a new arene ruthenium(II) complex {[RuCl(L1)(η6-p-cymene)]PF6}2 · H2O has been synthesized by a direct reaction of precursor, [{(η6-p-cymene)Ru(μ-Cl)}2Cl2], with N,N-chelating ligand (L1 - 2,2‧-bis(4,5-dimethylimidazole). The compound has been fully characterized by elemental analysis, X-ray diffraction, IR, UV-Vis and 1H, 13C NMR spectroscopies. X-ray analysis have confirmed that the compound crystallized in the monoclinic group Cc as an inversion twin. The asymmetric unit contains two symmetrically independent cationic complexes [RuCl(L1)(η6-p-cymene)]+ whose charge is balanced by two PF6- counterions. The shape of each cationic coordination polyhedral can be described as a distorted dodecahedron and shows a typical piano-stool geometry. In addition, an analysis of the crystal structure and the Hirshfeld surface analysis were used to detect and visualize important hydrogen bonds and intermolecular interaction. Moreover, the antiproliferative behavior of the obtained complex was assayed against three human cells: MV-4-11, LoVo, MCF-7 and BALB/3T3 - normal mice fibroblast cells. To predict a binding mode, a potential interaction of ruthenium complex with calf thymus DNA (CT-DNA) has been explored using UV absorption and circular dichroism (CD).

Ruthenium(II)- bipyridyl with extended π-system: Improved thermo ...

Indian Academy of Sciences (India)

aInorganic and Physical Chemistry Division, Indian Institute of Chemical Technology, Uppal Road, Tarnaka, ... A new extended thermo-stable high molar extinction coefficient bipyridyl ruthenium(II) complex ... cyanines and metal free organic sensitizers have been ..... Iodide-based ionic liquids are more viscous than.

Synthesis and characterization of new mixed ligand complexes of ruthenium(II) containing triphenylphosphine and 2'-hydroxychalcones

International Nuclear Information System (INIS)

Dharmaraj, N.; Natarajan, K.

1994-01-01

A few hexacoordinated ruthenium(II) complexes of the type [RuCl(CO) (HLL')(PPh 3 ) 2 ] and [RuCl(CO)(HLL')(B) (PPh 3 )] (where HLL' 2'-hydroxychalcone, 2'-hydroxy-4-methoxychalcone, 2'-hydroxy-3,4-dimethoxychalcone and B=pyridine(Py), piperidine(Pip), morpholine (Morph)) have been synthesised and characterized on the basis of their analytical and spectral data (IR, electronic and 1 H NMR). In all these complexes, the 2'-hydroxychalcones behave as a uninegative bidentate (OO - ) chelating ligand. (author). 17 refs., 1 tab

3-Methylindole-Based Tripodal Tetraphosphine Ruthenium Complexes in N2 Coordination and Reduction and Formic Acid Dehydrogenation

Directory of Open Access Journals (Sweden)

Fenna F. van de Watering

2017-10-01

Full Text Available The ruthenium(II complexes RuCl2L1H, RuCl2L1CF3, RuCl2L1OMe and RuCl2L2H were synthesized from [Ru(η6-benzeneCl(μ-Cl]2 and the corresponding tripodal tris-3-methylindolephosphine-based ligands L1H, L1CF3, L1OMe, and L2H. Stoichiometric reduction of these complexes with KC8 yielded the corresponding ruthenium(0 dinitrogen complexes. The latter complexes were studied in the N2 reduction with chlorosilanes and KC8, yielding stoichiometric amounts of the silylamines. The synthesized ruthenium(II complexes are also active catalysts for the formic acid dehydrogenation reaction.

Studies on the interaction of benzotriazole (a corrosion inibitor) with the ruthenium (II) (III) ammincomplexes and pentacyanoferrate (II)

International Nuclear Information System (INIS)

Espinoza R, R.L.

1985-01-01

Some studies on the interaction of benzotriazole with the aquapentacyanoferrate (II), aquapentaamminruthenium (II) and cis-and trans-(NH 3 ) 4 Ru(H 2 O) 2 2+ complexes are described. The reactions, substituted products and complexes production are demonstrated. The absorption bands for the ammine (benzotriazole) and ruthenium (II) complexes as well as the activation parameters and kinetics of reactions are discussed. (M.J.C.) [pt

Impact of aromaticity on anticancer activity of polypyridyl ruthenium(II) complexes: synthesis, structure, DNA/protein binding, lipophilicity and anticancer activity.

Science.gov (United States)

Čanović, Petar; Simović, Ana Rilak; Radisavljević, Snežana; Bratsos, Ioannis; Demitri, Nicola; Mitrović, Marina; Zelen, Ivanka; Bugarčić, Živadin D

2017-10-01

With the aim of assessing how the aromaticity of the inert chelating ligand can influence the activity of ruthenium(II) polypyridyl complexes, two new monofunctional ruthenium(II) complexes, [Ru(Cl-Ph-tpy)(phen)Cl]Cl (1) and [Ru(Cl-Ph-tpy)(o-bqdi)Cl]Cl (2) (where Cl-Ph-tpy = 4'-(4-chlorophenyl)-2,2':6',2″-terpyridine, phen = 1,10-phenanthroline, o-bqdi = o-benzoquinonediimine), were synthesized. All complexes were fully characterized by elemental analysis and spectroscopic techniques (IR, UV-Vis, 1D and 2D NMR, XRD). Their chemical behavior in aqueous solution was studied by UV-Vis and NMR spectroscopy showing that both compounds are relatively labile leading to the formation of the corresponding aqua species 1a and 2a. 1 H NMR spectroscopy studies performed on complexes 1 and 2 demonstrated that after the hydrolysis of the Cl ligand, they are capable to interact with guanine derivatives (i.e., 9-methylguanine (9MeG) and 5'-GMP) through the N7, forming monofunctional adduct. The kinetics and the mechanism of the reaction of complexes 1 and 2 with the biologically more relevant 5'-GMP ligand were studied by UV-Vis spectroscopy. DNA/protein interactions of the complexes have been examined by photophysical studies, which demonstrated a bifunctional binding mode of the complexes with DNA and the complexes strongly quench the fluorescence intensity of bovine serum albumin (BSA) through the mechanism of both static and dynamic quenching. Complexes 1 and 2 strongly induced apoptosis of treated cancer cells with high percentages of apoptotic cells and negligible percentage of necrotic cells. In addition, both ruthenium complexes decreased Bcl-2/Bax ratio causing cytochrome c mitochondrial release, the activation of caspase-3 and induction of apoptosis.

Ruthenium(II) bipyridine complexes bearing quinoline-azoimine (NN'N″) tridentate ligands: synthesis, spectral characterization, electrochemical properties and single-crystal X-ray structure analysis.

Science.gov (United States)

Al-Noaimi, Mousa; Abdel-Rahman, Obadah S; Fasfous, Ismail I; El-khateeb, Mohammad; Awwadi, Firas F; Warad, Ismail

2014-05-05

Four octahedral ruthenium(II) azoimine-quinoline complexes having the general molecular formula [Ru(II)(L-Y)(bpy)Cl](PF6) {L-Y=YC6H4N=NC(COCH3)=NC9H6N, Y=H (1), CH3 (2), Br (3), NO2 (4) and bpy=2,2'-bipyrdine} were synthesized. The azoimine-quinoline based ligands behave as NN'N″ tridentate donors and coordinated to ruthenium via azo-N', imine-N' and quinolone-N″ nitrogen atoms. The composition of the complexes has been established by elemental analysis, spectral methods (FT-IR, electronic, (1)H NMR, UV/Vis and electrochemical (cyclic voltammetry) techniques. The crystal structure of complex 1 is reported. The Ru(II) oxidation state is greatly stabilized by the novel tridentate ligands, showing Ru(III/II) couples ranging from 0.93-1.27 V vs. Cp2Fe/Cp2Fe(+). The absorption spectrum of 1 in dichloromethane was modeled by time-dependent density functional theory (TD-DFT). Copyright © 2014 Elsevier B.V. All rights reserved.

Preparation of Different Substitued Polypyridine Ligands, Ruthenium(II)-Bridged Complexes and Spectoscopıc Studies.

Science.gov (United States)

Obali, Aslihan Yilmaz; Ucan, Halil Ismet

2016-09-01

Novel different substitued polypyridine ligands 4-((4-(1H-imidazo[4,5-f][1,10]phenanthroline-2-yl)phenoxy)methyl)benzaldehyde (BA-PPY), (E)-N-(4-((4-(1H-imidazo[4,5-f][1,10]phenanthroline-2-yl)phenoxy)methyl)benzylidene)-pyrene-4-amine (PR-PPY), (E)-N-(4-((4-(1H-imidazo[4,5-f][1,10] phenanthroline-2-yl)phenoxy)methyl)benzylidene)-1,10-phenanthroline-5amine (FN-PPY), 2-(4-(bromomethyl)phenyl)-1H-imidazo[4,5-f][1,10] phenanthroline (BR-PPY), 2-(4-(azidomethyl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (N3-PPY) and triazole containing polypyridine ligand 3,4-bis[(4-(metoxy)-1,2,3-triazole)1-methylphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline)] benzaldehyde (BA-DIPPY) and Ruthenium(II) complexes were synthesized and characterized. Their photopysical properties were investigated. The complexes RuP(PR-PPY), RuB(PR-PPY, RuP(FN-PPY) and RuB(FN-PPY) exhibited a broad absorption bands at 485, 475, 476, and 453 nm, respectively, assignable to the spin-allowed MLCT (dπ-π*) transition. The emission maxima of the pyrene-appended polypyridine ligand PR-PPY was observed at λems = 616 nm and the phenanthroline-appended polypyridine ligand FN-PPY was observed at λems = 668 nm. And the emission maxima of the complexes RuP(PR-PPY), RuB(PR-PPY), RuP(FN-PPY) and RuB(FN-PPY) were observed at λems = 646, 646, 685 and 685 nm, respectively. As seen in fluorescence spectra, the fluorescence intensities of the ligands are higher than their metal complexes. This is because of quenching effect of Ruthenium(II) metal on chromophore groups.

Ruthenium(II) carbonyl compounds with the 4'-chloro-2,2':6',2''-terpyridine ligand.

Science.gov (United States)

Tatikonda, Rajendhraprasad; Haukka, Matti

2017-04-01

Two ruthenium carbonyl complexes with the 4'-chloro-2,2':6',2''-terpyridine ligand (tpy-Cl, C 15 H 10 ClN 3 ), i.e. [RuCl(tpy-Cl)(CO) 2 ][RuCl 3 (CO) 3 ] (I) [systematic name: cis -di-carbonyl-chlorido(4'-chloro-2,2':6',2''-terpyridine-κ 3 N )ruthenium(II) fac -tricarbonyltri-chlorido-ruthenate(II)], and [RuCl 2 (tpy-Cl)(CO) 2 ] (II) [ cis -dicarbonyl- trans -di-chlorido(4'-chloro-2,2':6',2''-terpyridine-κ 2 N 1 , N 1' )ruthenium(II)], were synthesized and characterized by single-crystal X-ray diffraction. The Ru II atoms in both centrosymmetric structures (I) and (II) display similar, slightly distorted octa-hedral coordination spheres. The coordination sphere in the complex cation in compound (I) is defined by three N atoms of the tridentate tpy-Cl ligand, two carbonyl carbon atoms and one chlorido ligand; the charge is balanced by an octa-hedral [Ru(CO) 3 Cl 3 ] - counter-anion. In the neutral compound (II), the tpy-Cl ligand coordinates to the metal only through two of its N atoms. The coordination sphere of the Ru II atom is completed by two carbonyl and two chlorido ligands. In the crystal structures of both (I) and (II), weak C-H⋯Cl inter-actions are observed.

Amidines for versatile ruthenium(II)-catalyzed oxidative C-H activations with internal alkynes and acrylates.

Science.gov (United States)

Li, Jie; John, Michael; Ackermann, Lutz

2014-04-25

Cationic ruthenium complexes derived from KPF6 or AgOAc enabled efficient oxidative CH functionalizations on aryl and heteroaryl amidines. Thus, oxidative annulations of diversely decorated internal alkynes provided expedient access to 1-aminoisoquinolines, while catalyzed C-H activations with substituted acrylates gave rise to structurally novel 1-iminoisoindolines. The powerful ruthenium(II) catalysts displayed a remarkably high site-, regio- and, chemoselectivity. Therefore, the catalytic system proved tolerant of a variety of important electrophilic functional groups. Detailed mechanistic studies provided strong support for the cationic ruthenium(II) catalysts to operate by a facile, reversible C-H activation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DNA interaction, antioxidant activity, and bioactivity studies of two ruthenium(II) complexes

Science.gov (United States)

Han, Bing-Jie; Jiang, Guang-Bin; Yao, Jun-Hua; Li, Wei; Wang, Ji; Huang, Hong-Liang; Liu, Yun-Jun

2015-01-01

Two new ruthenium(II) polypyridyl complexes [Ru(dmb)2(dcdppz)](ClO4)2 (1) and [Ru(bpy)2(dcdppz)](ClO4)2 (2) were prepared and characterized. The crystal structure of the complex 2 was solved by single crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group P21/n with a = 12.9622(14) Å, b = 17.1619(19) Å, c = 22.7210(3) Å, β = 100.930(2)°, R = 0.0536, Rω = 0.1111. The DNA-binding constants for complexes 1 and 2 were determined to be 1.92 × 105 (s = 1.72) and 2.24 × 105 (s = 1.86) M-1, respectively. The DNA-binding behaviors showed that complexes 1 and 2 interact with DNA by intercalative mode. The antioxidant activities of the ligand and the complexes were performed. Ligand, dcdppz, has no cytotoxicity against the selected cell lines. Complex 1 shows higher cytotoxicity than complex 2, but lower than cisplatin toward selected cell lines. The apoptosis and cell cycle arrest were investigated, and the apoptotic mechanism of BEL-7402 cells was studied by reactive oxygen species (ROS), mitochondrial membrane potential and western blot analysis. Complex 1 induces apoptosis in BEL-7402 cells through ROS-mediated mitochondrial dysfunction pathway and by regulating the expression of Bcl-2 family proteins.

Study of some properties of the ruthenium (II) trans-tetra-ammines with nitrogened aromatic heterocyclic ligands

International Nuclear Information System (INIS)

Bento, M.L.

1985-01-01

The ruthenium (II) complexes trans [Ru(NH 3 ) 4 LL'] (BF 4 ) 2 , where L and L' are 4-picoline, pyridine, isonicatinamide, pyrazine or 4-acetylpyridine are studied. The U.V-visible range spectra, bands in the U.V. and in the visible range is analysed. The spectra and the bands by comparison with other ruthenium (II) ammines are discussed, and a qualitative molecular orbital model is used. (M.J.C.) [pt

New ruthenium(II) carbonyl complexes bearing disulfide Schiff base ligands and their applications as catalyst for some organic transformations

Science.gov (United States)

Prakash, Govindan; Viswanathamurthi, Periasamy

2014-08-01

Schiff base disulfide ligands (H2L1-6) were synthesized from the condensation of cystamine with salicylaldehyde(H2L1), 5-chlorosalicylaldehyde(H2L2), o-vanillin(H2L3), 2-hydroxyacetophenone(H2L4), 3-methyl-2-hydroxyacetophenone(H2L5), and 2-hydroxy-1-naphthaldehyde(H2L6). H2L1-6 reacts with the ruthenium precursor complex [RuHCl(CO)(PPh3)3] in benzene giving rise to six new ruthenium(II) complexes of general formula [Ru(CO)L1-6]. Characterization of the new complexes was carried out by using elemental and spectral (IR, UV-Vis, NMR (1H and 13C) and Mass) techniques. An octahedral geometry was assigned for all the complexes based on the spectral data obtained. The catalytic efficiency of the new complexes in aldehyde to amide conversion in the presence of NaHCO3, N-alkylation of aniline in the presence of t-BuOK, and transfer hydrogenation of ketones in the presence of iPrOH/KOH reactions were studied. Furthermore, the effect of solvents and catalyst/substrate ratio on the catalytic aldehyde to amide conversion were also discussed.

Dehydrogenative Coupling of Primary Alcohols To Form Esters Catalyzed by a Ruthenium N-Heterocyclic Carbene Complex

DEFF Research Database (Denmark)

Sølvhøj, Amanda Birgitte; Madsen, Robert

2011-01-01

The ruthenium complex [RuCl2(IiPr)(p-cymene)] catalyzes the direct condensation of primary alcohols into esters and lactones with the release of hydrogen gas. The reaction is most effective with linear aliphatic alcohols and 1,4-diols and is believed to proceed with a ruthenium dihydride...

Pharmacophore Modelling and 4D-QSAR Study of Ruthenium(II) Arene Complexes as Anticancer Agents (Inhibitors) by Electron Conformational- Genetic Algorithm Method.

Science.gov (United States)

Yavuz, Sevtap Caglar; Sabanci, Nazmiye; Saripinar, Emin

2018-01-01

The EC-GA method was employed in this study as a 4D-QSAR method, for the identification of the pharmacophore (Pha) of ruthenium(II) arene complex derivatives and quantitative prediction of activity. The arrangement of the computed geometric and electronic parameters for atoms and bonds of each compound occurring in a matrix is known as the electron-conformational matrix of congruity (ECMC). It contains the data from HF/3-21G level calculations. Compounds were represented by a group of conformers for each compound rather than a single conformation, known as fourth dimension to generate the model. ECMCs were compared within a certain range of tolerance values by using the EMRE program and the responsible pharmacophore group for ruthenium(II) arene complex derivatives was found. For selecting the sub-parameter which had the most effect on activity in the series and the calculation of theoretical activity values, the non-linear least square method and genetic algorithm which are included in the EMRE program were used. In addition, compounds were classified as the training and test set and the accuracy of the models was tested by cross-validation statistically. The model for training and test sets attained by the optimum 10 parameters gave highly satisfactory results with R2 training= 0.817, q 2=0.718 and SEtraining=0.066, q2 ext1 = 0.867, q2 ext2 = 0.849, q2 ext3 =0.895, ccctr = 0.895, ccctest = 0.930 and cccall = 0.905. Since there is no 4D-QSAR research on metal based organic complexes in the literature, this study is original and gives a powerful tool to the design of novel and selective ruthenium(II) arene complexes. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Photo-degradation of CT-DNA with a series of carbothioamide ruthenium (II) complexes - Synthesis and structural analysis

Science.gov (United States)

Muthuraj, V.; Umadevi, M.

2018-04-01

The present research article is related with the method of preparation, structure and spectroscopic properties of a series of carbothioamide ruthenium (II) complexes with N and S donor ligands namely, 2-((6-chloro-4-oxo-4H-chromen-3-yl)methylene) hydrazine carbothioamide (ClChrTs)/2-((6-methoxy-4-oxo-4H-chromen-3-yl)methylene)hydrazine carbothioamide (MeOChrTS). The synthesized complexes were characterized by several techniques using analytical methods as well as by spectral techniques such as FT-IR, 1HNMR, 13CNMR, ESI mass and thermogravimetry/differential thermal analysis (TG-DTA). The IR spectra shows that the ligand acts as a neutral bidentate with N and S donor atoms. The biological activity of the prepared compounds and metal complexes were tested against cell line of calf-thymus DNA via an intercalation mechanism (MCF-7). In addition, the interaction of Ru(II) complexes and its free ligands with CT-DNA were also investigated by titration with UV-Vis spectra, fluorescence spectra, and Circular dichroism studies. Results suggest that both of the two Ru(II) complexes can bind with calf-thymus DNA via an intercalation mechanism.

Reduced Graphene Oxide-Immobilized Tris(bipyridine)ruthenium(II) Complex for Efficient Visible-Light-Driven Reductive Dehalogenation Reaction.

Science.gov (United States)

Li, Xiaoyan; Hao, Zhongkai; Zhang, Fang; Li, Hexing

2016-05-18

A sodium benzenesulfonate (PhSO3Na)-functionalized reduced graphene oxide was synthesized via a two-step aryl diazonium coupling and subsequent NaCl ion-exchange procedure, which was used as a support to immobilize tris(bipyridine)ruthenium(II) complex (Ru(bpy)3Cl2) by coordination reaction. This elaborated Ru(bpy)3-rGO catalyst exhibited excellent catalytic efficiency in visible-light-driven reductive dehalogenation reactions under mild conditions, even for ary chloride. Meanwhile, it showed the comparable reactivity with the corresponding homogeneous Ru(bpy)3Cl2 catalyst. This high catalytic performance could be attributed to the unique two-dimensional sheet-like structure of Ru(bpy)3-rGO, which efficiently diminished diffusion resistance of the reactants. Meanwhile, the nonconjugated PhSO3Na-linkage between Ru(II) complex and the support and the very low electrical conductivity of the catalyst inhibited energy/electron transfer from Ru(II) complex to rGO support, resulting in the decreased support-induced quenching effect. Furthermore, it could be easily recycled at least five times without significant loss of catalytic reactivity.

Cellular responses of BRCA1-defective and triple-negative breast cancer cells and in vitro BRCA1 interactions induced by metallo-intercalator ruthenium(II) complexes containing chloro-substituted phenylazopyridine

International Nuclear Information System (INIS)

Nhukeaw, Tidarat; Temboot, Pornvichai; Hansongnern, Kanidtha; Ratanaphan, Adisorn

2014-01-01

Triple-negative breast cancer (TNBC) is defined by the absence of expression of estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2. Breast cancers with a BRCA1 mutation are also frequently triple-negative. Currently, there is a lack of effective therapies and known specific molecular targets for this aggressive breast cancer subtype. To address this concern, we have explored the cellular responses of BRCA1-defective and triple-negative breast cancer cells, and in vitro BRCA1 interactions induced by the ruthenium(II) complexes containing the bidentate ligand, 5-chloro-2-(phenylazo)pyridine. Triple-negative MDA-MB-231, BRCA1-defective HCC1937 and BRCA1-competent MCF-7 breast cancer cell lines were treated with ruthenium(II) complexes. The cytoxoxicity of ruthenium-induced breast cancer cells was evaluated by a real time cellular analyzer (RTCA). Cellular uptake of ruthenium complexes was determined by ICP-MS. Cell cycle progression and apoptosis were assessed using propidium iodide and Annexin V flow cytometry. The N-terminal BRCA1 RING protein was used for conformational and functional studies using circular dichroism and in vitro ubiquitination. HCC1937 cells were significantly more sensitive to the ruthenium complexes than the MDA-MB-231 and MCF-7 cells. Treatment demonstrated a higher degree of cytotoxicity than cisplatin against all three cell lines. Most ruthenium atoms were retained in the nuclear compartment, particularly in HCC1937 cells, after 24 h of incubation, and produced a significant block at the G2/M phase. An increased induction of apoptotic cells as well as an upregulation of p53 mRNA was observed in all tested breast cancer cells. It was of interest that BRCA1 mRNA and replication of BRCA1-defective cells were downregulated. Changes in the conformation and binding constants of ruthenium-BRCA1 adducts were observed, causing inactivation of the RING heterodimer BRCA1/BARD1-mediated E3 ubiquitin ligase activity

Ruthenium(II) pincer complexes with oxazoline arms for efficient transfer hydrogenation reactions

KAUST Repository

Chen, Tao

2012-08-01

Well-defined P NN CN pincer ruthenium complexes bearing both strong phosphine and weak oxazoline donors were developed. These easily accessible complexes exhibit significantly better catalytic activity in transfer hydrogenation of ketones compared to their PN 3P analogs. These reactions proceed under mild and base-free conditions via protonation- deprotonation of the \\'NH\\' group in the aromatization-dearomatization process. © 2012 Elsevier Ltd. All rights reserved.

Cyclometalated Ruthenium(II) Anthraquinone Complexes Exhibit Strong Anticancer Activity in Hypoxic Tumor Cells.

Science.gov (United States)

Zeng, Leli; Chen, Yu; Huang, Huaiyi; Wang, Jinquan; Zhao, Donglei; Ji, Liangnian; Chao, Hui

2015-10-19

Hypoxia is the critical feature of the tumor microenvironment that is known to lead to resistance to many chemotherapeutic drugs. Six novel ruthenium(II) anthraquinone complexes were designed and synthesized; they exhibit similar or superior cytotoxicity compared to cisplatin in hypoxic HeLa, A549, and multidrug-resistant (A549R) tumor cell lines. Their anticancer activities are related to their lipophilicity and cellular uptake; therefore, these physicochemical properties of the complexes can be changed by modifying the ligands to obtain better anticancer candidates. Complex 1, the most potent member of the series, is highly active against hypoxic HeLa cancer cells (IC50 =0.53 μM). This complex likely has 46-fold better activity than cisplatin (IC50 =24.62 μM) in HeLa cells. This complex tends to accumulate in the mitochondria and the nucleus of hypoxic HeLa cells. Further mechanistic studies show that complex 1 induced cell apoptosis during hypoxia through multiple pathways, including those of DNA damage, mitochondrial dysfunction, and the inhibition of DNA replication and HIF-1α expression, making it an outstanding candidate for further in vivo studies. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrochemical behavior of ruthenium (III), rhodium (III) and palladium (II) in 1-butyl-3-methylimidazolium chloride ionic liquid

Energy Technology Data Exchange (ETDEWEB)

Jayakumar, M.; Venkatesan, K.A. [Fuel Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Srinivasan, T.G. [Fuel Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)], E-mail: tgs@igcar.gov.in; Vasudeva Rao, P.R. [Fuel Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

2009-11-01

Electrochemical behavior of ruthenium (III), rhodium (III) and palladium (II) in 1-butyl-3-methylimidazolium chloride (bmimCl) and their ternary and binary solutions in bmimCl was studied at various working electrodes at 373 K by cyclic voltammetry and chronoamperometry. Ruthenium (III) chloride forms a stable solution with bmimCl and the cyclic voltammogram of ruthenium (III) in bmimCl recorded at glassy carbon electrode consisted of several redox waves due to the complex nature of ruthenium to exist in several oxidation states. Electrolysis of ruthenium (III) chloride in bmimCl at the cathodic limit of bmimCl (-1.8 V (vs. Pd)) did not result in ruthenium metal deposition. However, it was deposited from bmimPF{sub 6} and bmimNTf{sub 2} room temperature ionic liquids at -0.8 V (vs. Pd). The electrochemical behavior of ruthenium (III) in bmimCl in the presence of palladium (II) and rhodium (III) was studied by cyclic voltammetry. The presence of palladium (II) in bmimCl favors underpotential deposition of ruthenium metal. The nuclear loop at -0.5 V (vs. Pd) was observed in all solutions when palladium (II) co-existed with other two metal ions. Nucleation and growth of the metal on glassy carbon working electrode was investigated by chronoamperometry. The growth and decay of chronocurrents has been found to follow the instantaneous nucleation model with three-dimensional growth of nuclei.

A ruthenium(II) complex as turn-on Cu(II) luminescent sensor based on oxidative cyclization mechanism and its application in vivo

Science.gov (United States)

Zhang, Yunfei; Liu, Zonglun; Yang, Kui; Zhang, Yi; Xu, Yongqian; Li, Hongjuan; Wang, Chaoxia; Lu, Aiping; Sun, Shiguo

2015-02-01

Copper ions play a vital role in a variety of fundamental physiological processes not only in human beings and plants, but also for extensive insects and microorganisms. In this paper, a novel water-soluble ruthenium(II) complex as a turn-on copper(II) ions luminescent sensor based on o-(phenylazo)aniline was designed and synthesized. The azo group would undergo a specific oxidative cyclization reaction with copper(II) ions and turn into high luminescent benzotriazole, triggering significant luminescent increasements which were linear to the concentrations of copper(II) ions. The sensor distinguished by its high sensitivity (over 80-fold luminescent switch-on response), good selectivity (the changes of the emission intensity in the presence of other metal ions or amino acids were negligible) and low detection limit (4.42 nM) in water. Moreover, the copper(II) luminescent sensor exhibited good photostability under light irradiation. Furthermore, the applicability of the proposed sensor in biological samples assay was also studied and imaged copper(II) ions in living pea aphids successfully.

Selective extraction of lithium with a macrocyclic trinuclear complex of (1,3,5-trimethylbenzene)ruthenium(II) bridged by 2,3-dioxopyridine.

Science.gov (United States)

Katsuta, Shoichi; Imoto, Takahiro; Kudo, Yoshihiro; Takeda, Yasuyuki

2008-10-01

A macrocyclic trinuclear complex of (1,3,5-trimethylbenzene)ruthenium(II) bridged by 2,3-dioxopyridine was synthesized, and the extraction properties for lithium and sodium picrates were investigated in a dichloromethane/water system at 25 degrees C. The complex was found to have extremely high extractability and selectivity for lithium picrate; the logarithmic values of the extraction constants are 5.86 and 2.63 for Li(+) and Na(+), respectively. By using this complex as an extractant, nearly quantitative extraction and separation of Li(+) from Na(+) could be achieved by a single extraction.

A water-soluble and retrievable ruthenium-based probe for colorimetric recognition of Hg(II) and Cys.

Science.gov (United States)

Cui, Yali; Hao, Yuanqiang; Zhang, Yintang; Liu, Baoxia; Zhu, Xu; Qu, Peng; Li, Deliang; Xu, Maotian

2016-08-05

A new ruthenium-based complex 1 [(bis(4,4'-dimethylphosphonic-2,2'-bipyridine) dithiocyanato ruthenium (II))] was developed as a colorimetric probe for the detection of Hg(II) and Cys (Cysteine). The obtained compound 1 can give interconversional color changes upon the alternating addition of Hg(II) and Cys in 100% aqueous solution. The specific coordination between NCS groups with Hg(II) can lead to the formation of 1-Hg(2+) complex, which can induce a remarkable spectral changes of probe 1. Afterwards the formed 1-Hg(2+) complex can act as effective colorimetric sensor for Cys. Owing to the stronger binding affinity of sulfhydryl group to Hg(2+), Cys can extract Hg(2+) from 1-Hg(2+) complex resulting in the release of 1 and the revival of absorption profile of the probe 1. By introducing the hydrophilic phosphonic acid groups, the proposed probe exhibited excellent water solubility. The limits of detection (LODs) of the assay for Hg(2+) and Cys are calculated to be 15nM and 200nM, respectively. Copyright © 2016. Published by Elsevier B.V.

Synthesis, spectroscopic studies and reactivity of triphenylphosphine ruthenium (II) complexes with N-heterocyclic ligands

International Nuclear Information System (INIS)

Rivera, A.B.

1989-01-01

Reported is the chemistry of triphenylphosphine ruthenium (II) complexes of general formula RuCl 2 (PPh 3 ) 2 L 2 and RuCl 2 (PPh 3 ) 2 A, obtained from the reaction of RuCl 2 (PPh 3 ) 3 with N-heterocyclic ligands L, or A (of ambidentate nature). The electronic spectra exhibit two strong metal-to-ligand charge-transfer bands, ascribed to the b 1 (dxz)->b 1 (pi) and a 2 (dxy)->a 2 (pi) transitions, and a third, weak band ascribed to the b 2 (dyz)->a 2 (pi) transition. The electronic states and the vibrational modes of the complexes were characterized by means of their resonance Raman and infrared absorption spectra. Thermogravimetric and thermodifferential analysis indicated that the melting process is succeeded by an exothermic reaction, and that the weigh loss starts to occur only after this step. The complexes dissociated in CHCl 3 solution, showing preferential labilization of the phosphine ligands, as in the case of the hydrogenation catalyst Ru(PPh 3 ) 3 Cl 2 . In the presence of CO, RuCl 2 (CO) 2 L 2 complexes were gennerated. Several derivatives were isolated and characterized. (author) [pt

Photo-induced DNA cleavage and cytotoxicity of a ruthenium(II) arene anticancer complex

Czech Academy of Sciences Publication Activity Database

Brabec, Viktor; Prachařová, J.; Štěpánková, Jana; Sadler, P. J.; Kašpárková, Jana

2016-01-01

Roč. 160, JUL2016 (2016), s. 149-155 ISSN 0162-0134 R&D Projects: GA ČR(CZ) GA14-21053S; GA MŠk(CZ) LD14019 Institutional support: RVO:68081707 Keywords : Ruthenium anticancer complex * DNA cleavage * Phototoxicity Subject RIV: BO - Biophysics Impact factor: 3.348, year: 2016

Properties and reactivities of pentadentate ethylenediaminetetraacetate complexes of ruthenium(III) and -(II)

International Nuclear Information System (INIS)

Matsubara, T.; Creutz, C.

1979-01-01

The reaction of the pentadentate edta complex of ruthenium(III) with various entering ligands L has been studied as a function of pH, temperature, and L at 0.2 M ionic strength in aqueous solution. Over the pH range 0.8 to 8.5, the species Ru/sup III/(edta)H 2 O - is the sole form reactive in the substitution processes. Both forward (k 1 ) and reverse (k/sub -1/) rate constants Ru(edta)H 2 O - + L in equilibrium (k 1 ,k/sub -1/) Ru(edta)L - + H 2 O have been determined, as well as activation parameters for the complexation (k 1 ) process (L, k 1 in M -1 s -1 (25 0 C), k/sub -1/ in s -1 (25 0 C), ΔH 1 + in kcal mol -1 , ΔS 1 + in cal deg -1 mol -1 ): acetonitrile, 30 +- 7, 3.2 +- 0.2, 8.3 +- 0.5, -24 +- 4; thiocyanate, 270 +- 20, 0.5 +- 0.1, 8.9 +- 0.5, -18 +- 3; pyridine, 6300 +- 500, 0.061 +- 0.002; isonicotinamide, 8300 +- 600, 0.7 +- 0.2, 6.6 +- 0.5, -19 +- 3; pyrazine, 20,000 +- 1000, 2.0 +- 0.5, 5.7 +- 0.5, -20 +- 3. Forward rate constants for the analogous substitution reaction for Ru/sup II/(edta) H 2 O 2- (25 0 C, 0.2 M ionic strength) are as follows: thiocyanate, 2.7 +- 0.2 M -1 s -1 ; acetonitrile, 13 +- 1 M -1 s -1 ; isonicotinamide, 30 +- 15 M -1 s -1 . The substitution reactions of Ru/sup III/(edta)H 2 O - proceed by an associative mechanism, while those of Ru/sup II/(edta)H 2 O 2 - appear to be dissociative in nature. Spectra and reduction potentials for the Ru(edta)L/sup -/2-/ complexes are reported. 4 figures, 11 tables

Evaluation of DNA binding, DNA cleavage, protein binding, radical scavenging and in vitro cytotoxic activities of ruthenium(II) complexes containing 2,4-dihydroxy benzylidene ligands

Energy Technology Data Exchange (ETDEWEB)

Mohanraj, Maruthachalam; Ayyannan, Ganesan; Raja, Gunasekaran; Jayabalakrishnan, Chinnasamy, E-mail: drcjbstar@gmail.com

2016-12-01

The new ruthenium(II) complexes with hydrazone ligands, 4-Methyl-benzoic acid (2,4-dihydroxy-benzylidene)-hydrazide (HL{sup 1}), 4-Methoxy-benzoic acid (2,4-dihydroxy-benzylidene)-hydrazide (HL{sup 2}), 4-Bromo-benzoic acid (2,4-dihydroxy-benzylidene)-hydrazide (HL{sup 3}), were synthesized and characterized by various spectro analytical techniques. The molecular structures of the ligands were confirmed by single crystal X-ray diffraction technique. The DNA binding studies of the ligands and complexes were examined by absorption, fluorescence, viscosity and cyclic voltammetry methods. The results indicated that the ligands and complexes could interact with calf thymus DNA (CT-DNA) through intercalation. The DNA cleavage activity of the complexes was evaluated by gel electrophoresis assay, which revealed that the complexes are good DNA cleaving agents. The binding interaction of the ligands and complexes with bovine serum albumin (BSA) was investigated using fluorescence spectroscopic method. Antioxidant studies showed that the complexes have a strong radical scavenging properties. Further, the cytotoxic effect of the complexes examined on cancerous cell lines showed that the complexes exhibit significant anticancer activity. - Highlights: • Synthesis of ruthenium(II) hydrazone complexes • Molecular structure of the ligands was elucidated by single crystal X-ray diffraction method. • The ligands and complexes interact with CT-DNA via intercalation. • The complexes possess significant antioxidant activity against DPPH, OH and NO radicals. • The complex 6 shows higher IC{sub 50} value than the other complexes against cancer cells.

New soluble functional polymers by free-radical copolymerization of methacrylates and bipyridine ruthenium complexes

NARCIS (Netherlands)

Holder, E.; Meier, M.A.R.; Marin, V.N.; Schubert, U.S.

2003-01-01

The luminescent complex [4-(3-hydroxypropyl)-4-methyl-2,2-bipyridine]-bis(2,2-bipyridine)-ruthenium(II)-bis(hexafluoroantimonate) and its methacrylate derivative were successfully synthesized and fully characterized by two-dimensional 1H and 13C{1H} NMR techniques [correlation spectroscopy (COSY)

Aquation Is a Crucial Activation Step for Anticancer Action of Ruthenium(II) Polypyridyl Complexes to Trigger Cancer Cell Apoptosis.

Science.gov (United States)

Li, Meng; Lai, Lanhai; Zhao, Zhennan; Chen, Tianfeng

2016-01-01

Aquation has been proposed as crucial chemical action step for ruthenium (Ru) complexes, but its effects on the action mechanisms remain elusive. Herein, we have demonstrated the aquation process of a potent Ru polypyridyl complex (RuBmp=[Ru(II) (bmbp)(phen)Cl]ClO4 , bmbp=2,6-bis(6-methylbenzimidazol-2-yl) pyridine, phen=phenanthroline) with a chloride ligand, and revealed that aquation of RuBmp effectively enhanced its hydrophilicity and cellular uptake, thus significantly increasing its anticancer efficacy. The aquation products (H-RuBmp=[Ru(II) (bmbp)(phen)Cl]ClO4 , [Ru(II) (bmbp)(phen)(H2 O)]ClO4 , bmbp) exhibited a much higher apoptosis-inducing ability than the intact complex, with involvement of caspase activation, mitochondria dysfunction, and interaction with cell membrane death receptors. H-RuBmp demonstrated a higher interaction potency with the cell membrane and induced higher levels of ROS overproduction in cancer cells to regulate the AKT, MAPK, and p53 signaling pathways. Taken together, this study could provide useful information for fine-tuning the rational design of next-generation metal medicines. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of ozone on ruthenium species in alkaline medium. Pt. II. Oxidation of pentahydroxo nitrosyl ruthenate(II) ion RuNO(OH)52-

International Nuclear Information System (INIS)

Floquet, S.; Eysseric, C.

2006-01-01

Oxidation of the nitrosyl ruthenium complex RuNO(OH) 5 2- has been carried out in sodium hydroxide solutions in contact with a gas flow containing ozone. The RuNO(OH) 5 2- complex is converted successively into ruthenate and perruthenate ions. An empirical kinetic rate law for the first step has been determined and was shown to depend on concentrations of (i) the ruthenium complex, (ii) the hydroxide ions and (iii) ozone concentration in the gas flow. The second step of the reaction, corresponding to the perruthenate ion formation, shows a complex mechanism and four competing reactions have been proposed to represent it. The influences on the second step kinetics of several parameters such as ozone or hydroxide concentrations or the conditions of the gas-liquid exchange area are also qualitatively discussed. (orig.)

Synthesis, structure and photoluminescence of (PLAGH)2[ZnCl4] and comparative analysis of photoluminescence properties with tris(2,2′-bipyridine)ruthenium(II)

International Nuclear Information System (INIS)

Radanović, Mirjana M.; Jelić, Miodrag G.; Romčević, Nebojša Ž.; Boukos, Nikos; Vojinović-Ješić, Ljiljana S.; Leovac, Vukadin M.; Hadžić, Branka B.; Bajac, Branimir M.; Nađ, Laslo F.; Chandrinou, Chrysoula; Baloš, Sebastian S.

2015-01-01

Highlights: • New zinc(II) complex with pyridoxalaminoguanidine was synthesized. • The enhancement of the photoluminescence due to the compound formation was achieved. • Very high photoluminescence of Zn(II) compound was noticed. • Comparative analysis of photoluminescence with tris(2,2′-bipyridine) ruthenium(II) was provided. - Abstract: The first compound of zinc(II) containing pyridoxalaminoguanidine has been synthesized and characterized by elemental analysis, infrared spectra, conductometric measurements and X-ray crystallography. Single crystals of the compound were obtained in the reaction of methanolic solution of zinc(II) chloride and pyridoxalaminoguanidine hydrochloride. In this compound the coordination of chelate ligand is absent and tetrachlorido complex of zinc(II) with pyridoxalaminuguanidinium cation as contraion is obtained. Photoluminescence spectra were measured. Lorentzian multipeak technique was used to determine peak wavelengths and their intensities. Photoluminescence spectroscopy upon 325, 488 and 514 nm laser excitation light was used to obtain results. This novel compound of zinc(II) was compared to the well-known organic light emitting diode material—ruthenium(II) complex with bypiridine i.e., tris(2,2′-bipyridine)ruthenium(II), under the same circumstances and the identical experimental setup. A scheme of energy levels and transitions is proposed to explain the obtained experimental results

Ruthenium nitrosyl complexes in radioactive waste solutions in reprocessing plants. Pt. 3

International Nuclear Information System (INIS)

Blasius, E.; Mueller, K.

1984-01-01

With capillary isotachophoresis and free-flow isotachophoresis it is possible to separate and isolate preparatively the mononuclear cationic ruthenium nitrosyl nitrato complexes. The behaviour of these complexes during storage, concentration and calcination is studied: The conversion of six ruthenium nitrosyl nitrato complexes as a function of time is studied at -36 0 C, 0 0 C, +3 0 C and 100 0 C. The percentage of ruthenium nitrosyl complexes with NO 3 - as ligand increased markedly during concentration experiments. Above 250 0 C NOsub(x) is liberated and the colour of the residue changes from brown to brownish-grey. At 400 0 C ruthenium complexes are no longer detected and the inner walls of the apparatus are covered with RuO 2 . (orig.)

A new probe of solvent accessibility of bound photosensitizers. 1. Ruthenium(II) and osmium(II) photosensitizers in sodium lauryl sulfate micelles

International Nuclear Information System (INIS)

Hauenstein, B.L. Jr.; Dressick, W.J.; Buell, S.L.; Demas, J.N.; DeGraff, B.A.

1983-01-01

A new method of measuring solvent accessibility of photosensitizers bound to organized media is presented. In particular, the solvent accessibility of a series of ruthenium(II) and osmium(II) photosensitizers bound to sodium lauryl sulfate micelles has been determined. The method takes advantage of the large solvent deuterium effect on the excited-state lifetimes of these complexes. The solvent accessibility of the bound complexes correlates with the hydrophobicity of the ligands. The potential application of this method to a variety of other systems is mentioned

Ruthenium(II) 2,2'-bibenzimidazole complex as a second-sphere receptor for anions interaction and colorimeter.

Science.gov (United States)

Cui, Ying; Niu, Yan-Li; Cao, Man-Li; Wang, Ke; Mo, Hao-Jun; Zhong, Yong-Rui; Ye, Bao-Hui

2008-07-07

A ruthenium(II) complex [Ru(bpy) 2(H 2bbim)](PF 6) 2 ( 1) as anions receptor has been exploited, where Ru(II)-bpy moiety acts as a chromophore and the H 2bbim ligand as an anion binding site. A systematic study suggests that 1 interacts with the Cl (-), Br (-), I (-), NO 3 (-), HSO 4 (-), and H 2PO 4 (-) anions via the formation of hydrogen bonds. Whereas 1 undergoes a stepwise process with the addition of F (-) and OAc (-) anions: formation of the monodeprotonated complex [Ru(bpy) 2(Hbbim)] with a low anion concentration, followed by the double-deprotonated complex [Ru(bpy) 2(bbim)], in the presence of a high anion concentration. These stepwise processes concomitant with the changes of vivid colors from yellow to orange brown and then to violet can be used for probing the F (-) and OAc (-) anions by naked eye. The deprotonation processes are not only determined by the basicity of the anion but also related to the strength of hydrogen bonding, as well as the stability of the formed compounds. Moreover, a double-deprotonated complex [Ru(bpy) 2(bbim)].CH 3OH.H 2O ( 3) has been synthesized, and the structural changes induced by the deprotonation has also been investigated. In addition, complexes [Ru(bpy) 2(Hbbim)] 2(HOAc) 3Cl 2.12H 2O ( 2), [Ru(bpy) 2(Hbbim)](HCCl 3CO 2)(CCl 3CO 2).2H 2O ( 4), and [Ru(bpy) 2(H 2bbim)](CF 3CO 2) 2.4H 2O ( 5) have been synthesized to observe the second sphere coordination between the Ru(II)-H 2bbim moiety and carboxylate groups via hydrogen bonds in the solid state.

Synthesis, structure and photoluminescence of (PLAGH){sub 2}[ZnCl{sub 4}] and comparative analysis of photoluminescence properties with tris(2,2′-bipyridine)ruthenium(II)

Energy Technology Data Exchange (ETDEWEB)

Radanović, Mirjana M. [University of Novi Sad, Faculty of Sciences, Novi Sad (Serbia); Jelić, Miodrag G., E-mail: jelicmgm@uns.ac.rs [University of Novi Sad, Faculty of Technical Sciences, Novi Sad (Serbia); Romčević, Nebojša Ž. [University of Belgrade, Institute of Physics, Belgrade (Serbia); Boukos, Nikos [National Centre for Scientific Research “Demokritos”, Institute of Materials Science, Athens (Greece); Vojinović-Ješić, Ljiljana S.; Leovac, Vukadin M. [University of Novi Sad, Faculty of Sciences, Novi Sad (Serbia); Hadžić, Branka B. [University of Belgrade, Institute of Physics, Belgrade (Serbia); Bajac, Branimir M. [University of Novi Sad, Faculty of Technology, Novi Sad (Serbia); Nađ, Laslo F. [University of Novi Sad, Faculty of Technical Sciences, Novi Sad (Serbia); Chandrinou, Chrysoula [National Centre for Scientific Research “Demokritos”, Institute of Materials Science, Athens (Greece); Baloš, Sebastian S. [University of Novi Sad, Faculty of Technical Sciences, Novi Sad (Serbia)

2015-10-15

Highlights: • New zinc(II) complex with pyridoxalaminoguanidine was synthesized. • The enhancement of the photoluminescence due to the compound formation was achieved. • Very high photoluminescence of Zn(II) compound was noticed. • Comparative analysis of photoluminescence with tris(2,2′-bipyridine) ruthenium(II) was provided. - Abstract: The first compound of zinc(II) containing pyridoxalaminoguanidine has been synthesized and characterized by elemental analysis, infrared spectra, conductometric measurements and X-ray crystallography. Single crystals of the compound were obtained in the reaction of methanolic solution of zinc(II) chloride and pyridoxalaminoguanidine hydrochloride. In this compound the coordination of chelate ligand is absent and tetrachlorido complex of zinc(II) with pyridoxalaminuguanidinium cation as contraion is obtained. Photoluminescence spectra were measured. Lorentzian multipeak technique was used to determine peak wavelengths and their intensities. Photoluminescence spectroscopy upon 325, 488 and 514 nm laser excitation light was used to obtain results. This novel compound of zinc(II) was compared to the well-known organic light emitting diode material—ruthenium(II) complex with bypiridine i.e., tris(2,2′-bipyridine)ruthenium(II), under the same circumstances and the identical experimental setup. A scheme of energy levels and transitions is proposed to explain the obtained experimental results.

Reactivity studies of eta sup (6)-p-cymene ruthenium(II) carboxylato complexes towards azide some neutral ligands

Digital Repository Service at National Institute of Oceanography (India)

Singh, K.S.; Kollipara, M.R.

sub (2)O sub (4)(7) or C sub (2)CH sub (2)O sub (4)(10)] have been prepared by the reaction of [(p-cymene)RuCl sub (2)]sub (2) with the corresponding sodium salts of the carboxylic acids. Treatment of (eta sup (6)-p-cymene) ruthenium(II) carboxylato...

Unsaturated carbone and allenylidene ruthenium complexes from alkynes

International Nuclear Information System (INIS)

Bozek, Yu.L.; Diznev, P.A.

1995-01-01

The author's studies aimed at activation of terminal alkynes by metal complexes, reactivity patterns and selective preparations of unsaturated carbene, allenylidene and cumulenylidene derivatives of (arene)ruthenium complexes are reviewed. 48 refs

In vitro evaluation of the cyto-genotoxic potential of Ruthenium(II) SCAR complexes: a promising class of antituberculosis agents.

Science.gov (United States)

De Grandis, Rone Aparecido; Resende, Flávia Aparecida; da Silva, Monize Martins; Pavan, Fernando Rogério; Batista, Alzir Azevedo; Varanda, Eliana Aparecida

2016-03-01

Tuberculosis is a top infectious disease killer worldwide, caused by the bacteria Mycobacterium tuberculosis. Increasing incidences of multiple drug-resistance (MDR) strains are emerging as one of the major public health threats. However, the drugs in use are still incapable of controlling the appalling upsurge of MDR. In recent years a marked number of research groups have devoted their attention toward the development of specific and cost-effective antimicrobial agents against targeted MDR-Tuberculosis. In previous studies, ruthenium(II) complexes (SCAR) have shown a promising activity against MDR-Tuberculosis although few studies have indeed considered ruthenium toxicity. Therefore, within the preclinical requirements, we have sought to determine the cyto-genotoxicity of three SCAR complexes in this present study. The treatment with the SCARs induced a concentration-dependent decrease in cell viability in CHO-K1 and HepG2 cells. Based on the clonogenic survival, SCAR 5 was found to be more cytotoxic while SCAR 6 exhibited selectivity action on tumor cells. Although SCAR 4 and 5 did not indicate any mutagenic activity as evidenced by the Ames and Cytokinesis block micronucleus cytome assays, the complex SCAR 6 was found to engender a frameshift mutation detected by Salmonella typhimurium in the presence of S9. Similarly, we observed a chromosomal damage in HepG2 cells with significant increases of micronuclei and nucleoplasmic bridges. These data indicate that SCAR 4 and 5 complexes did not show genotoxicity in our models while SCAR 6 was considered mutagenic. This study presented a comprehensive genotoxic evaluation of SCAR complexes were shown to be genotoxic in vitro. All in all, further studies are required to fully elucidate how the properties can affect human health. Copyright © 2016 Elsevier B.V. All rights reserved.

Dehydrogenative Synthesis of Imines from Alcohols and Amines Catalyzed by a Ruthenium N-Heterocyclic Carbene Complex

DEFF Research Database (Denmark)

Maggi, Agnese; Madsen, Robert

2012-01-01

A new method for the direct synthesis of imines from alcohols and amines is described where hydrogen gas is liberated. The reaction is catalyzed by the ruthenium N-heterocyclic carbene complex [RuCl2(IiPr)(p-cymene)] in the presence of the ligand DABCO and molecular sieves. The imination can...... be applied to a variety of primary alcohols and amines and can be combined with a subsequent addition reaction. A deuterium labeling experiment indicates that the catalytically active species is a ruthenium dihydride. The reaction is believed to proceed by initial dehydrogenation of the alcohol...

Photoreactions of ruthenium(II) and osmium(II) complexes with deoxyribonucleic acid (DNA).

Science.gov (United States)

Moucheron, C; Kirsch-De Mesmaeker, A; Kelly, J M

1997-09-01

The design of Ru(II) and Os(II) complexes which are photoreactive with deoxyribonucleic acid (DNA) represents one of the main targets for the development of novel molecular tools for the study of DNA and, in the future, for the production of new, metal-based, anti-tumor drugs. In this review, we explain how it is possible to make a complex photoreactive with nucleobases and nucleic acids. According to the photophysical behaviour of the Ru(II) compounds, two types of photochemistry are expected: (1) photosubstitution of a ligand by a nucleobase and another monodentate ligand, which takes place from the triplet, metal-centred (3MC) state; this state is populated thermally from the lowest lying triplet metal to ligand charge transfer (3MLCT) state; (2) photoreaction from the 3MLCT state, corresponding to photoredox processes with DNA bases. The two photoreactivities are in competition. By modulating appropriately the redox properties of the 3MLCT state, an electron transfer process from the base to the excited complex takes place, and is directly correlated with DNA cleavage or the formation of an adduct of the complex to DNA. In this adduct, guanine is linked by N2 to the alpha-position of a non-chelating nitrogen of the polyazaaromatic ligand without destruction of the complex. Different strategies are explained which increase the affinity of the complexes for DNA and direct the complex photoreactivity to sites of special DNA topology or targeted sequences of bases. Moreover, the replacement of the Ru(II) ion by the Os(II) ion in the photoreactive complexes leads to an increased specificity of photoreaction. Indeed, only one type of photoreactivity (from the 3MLCT state) is present for the Os(II) complexes because the 3MC state is too high in energy to be populated at room temperature.

Ruthenium(II) bipyridine complexes bearing new keto-enol azoimine ligands: synthesis, structure, electrochemistry and DFT calculations.

Science.gov (United States)

Al-Noaimi, Mousa; Awwadi, Firas F; Mansi, Ahmad; Abdel-Rahman, Obadah S; Hammoudeh, Ayman; Warad, Ismail

2015-01-25

The novel azoimine ligand, Ph-NH-N=C(COCH3)-NHPh(C≡CH) (H2L), was synthesized and its molecular structure was determined by X-ray crystallography. Catalytic hydration of the terminal acetylene of H2L in the presence of RuCl3·3H2O in ethanol at reflux temperature yielded a ketone (L1=Ph-N=N-C(COCH3)=N-Ph(COCH3) and an enol (L2=Ph-N=N-C(COCH3)=N-PhC(OH)=CH2) by Markovnikov addition of water. Two mixed-ligand ruthenium complexes having general formula, trans-[Ru(bpy)(Y)Cl2] (1-2) (where Y=L1 (1) and Y=L2 (2), bpy is 2.2'-bipyrdine) were achieved by the stepwise addition of equimolar amounts of (H2L) and bpy ligands to RuCl3·3H2O in absolute ethanol. Theses complexes were characterized by elemental analyses and spectroscopic (IR, UV-Vis, and NMR (1D (1)H NMR, (13)C NMR, (DEPT-135), (DEPT-90), 2D (1)H-(1)H and (13)C-(1)H correlation (HMQC) spectroscopy)). The two complexes exhibit a quasi-reversible one electron Ru(II)/Ru(III) oxidation couple at 604 mV vs. ferrocene/ferrocenium (Cp2Fe(0/+)) couple along with one electron ligand reduction at -1010 mV. The crystal structure of complex 1 showed that the bidentate ligand L1 coordinates to Ru(II) by the azo- and imine-nitrogen donor atoms. The complex adopts a distorted trans octahedral coordination geometry of chloride ligands. The electronic spectra of 1 and 1+ in dichloromethane have been modeled by time-dependent density functional theory (TD-DFT). Copyright © 2014 Elsevier B.V. All rights reserved.

RutheniumII Complexes bearing Fused Polycyclic Ligands: From Fundamental Aspects to Potential Applications

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Ludovic Troian-Gautier

2014-04-01

Full Text Available In this review, we first discuss the photophysics reported in the literature for mononuclear ruthenium complexes bearing ligands with extended aromaticity such as dipyrido[3,2-a:2',3'-c]phenazine (DPPZ, tetrapyrido[3,2-a:2',3'-c:3'',2''-h:2''',3'''-j]-phenazine (TPPHZ,  tetrapyrido[3,2-a:2',3'-c:3'',2''-h:2''',3'''-j]acridine (TPAC, 1,10-phenanthrolino[5,6-b]1,4,5,8,9,12-hexaazatriphenylene (PHEHAT 9,11,20,22-tetraaza- tetrapyrido[3,2-a:2',3'-c:3'',2''-l:2''',3'''-n]pentacene (TATPP, etc. Photophysical properties of binuclear and polynuclear complexes based on these extended ligands are then reported. We finally develop the use of binuclear complexes with extended π-systems for applications such as photocatalysis.

Effect of ozone on ruthenium species in alkaline medium. Pt. II. Oxidation of pentahydroxo nitrosyl ruthenate(II) ion RuNO(OH){sub 5}{sup 2-}

Energy Technology Data Exchange (ETDEWEB)

Floquet, S. [Commissariat a l' Energie Atomique (CEA/Valrho), Bagnols-sur-Ceze (France); Inst. Lavoisier, IREM UMR 8637, Univ. de Versailles Saint-Quentin, Versailles (France); Eysseric, C. [Commissariat a l' Energie Atomique (CEA/Valrho), Bagnols-sur-Ceze (France)

2006-07-01

Oxidation of the nitrosyl ruthenium complex RuNO(OH){sub 5}{sup 2-} has been carried out in sodium hydroxide solutions in contact with a gas flow containing ozone. The RuNO(OH){sub 5}{sup 2-} complex is converted successively into ruthenate and perruthenate ions. An empirical kinetic rate law for the first step has been determined and was shown to depend on concentrations of (i) the ruthenium complex, (ii) the hydroxide ions and (iii) ozone concentration in the gas flow. The second step of the reaction, corresponding to the perruthenate ion formation, shows a complex mechanism and four competing reactions have been proposed to represent it. The influences on the second step kinetics of several parameters such as ozone or hydroxide concentrations or the conditions of the gas-liquid exchange area are also qualitatively discussed. (orig.)

Cobalt(III), nickel(II) and ruthenium(II) complexes of 1,10 ...

Indian Academy of Sciences (India)

Co(II) and Ru(II) complexes investigated in this study effect photocleavage of the supercoiled ... DNA is related to their utility in the design and development of synthetic restriction ..... ∗Quasi-reversible/irreversible (electrochemical behaviour of ...

A ruthenium(II) complex inhibits tumor growth in vivo with fewer side-effects compared with cisplatin.

Science.gov (United States)

Wang, Jin-Quan; Zhang, Ping-Yu; Ji, Liang-Nian; Chao, Hui

2015-05-01

The antitumor activity of a ruthenium(II) polypyridyl complex, Δ-[Ru(bpy)2(HPIP)](ClO4)2 (Δ-Ru1, where bpy=2,2'-bipyridine, HPIP=2-(2-hydroxyphenyl)imidazo[4,5-f][1,10]phenanthroline), was evaluated. The in vivo experiments showed that Δ-Ru1 inhibited the growth of a human cervical carcinoma cell line (HeLa) xenotransplanted into nude mice with efficiency similar to that of cisplatin. Histopathology examination of the tumors from treated xenograft models was consistent with apoptosis in tumor cells. Importantly, in striking contrast with cisplatin, Δ-Ru1 did not cause any detectable side effects on the kidney, liver, peripheral neuronal system, or the hematological system at the pharmacologically effective dose. The preclinical studies reported here provide support for the clinical use of Δ-Ru1 as an exciting new drug candidate with lower toxicity than cisplatin, endowed with proapoptotic properties. Copyright © 2015 Elsevier Inc. All rights reserved.

Synthesis of cationic diphosphine ruthenium complexes with nido-dicarbaundecaborate anions. Molecular structure of [RuCl(dppe)2]+[7,8-nido-C2B9H12]-

International Nuclear Information System (INIS)

Cheredilin, D.N.; Dolgushin, F.M.; Balagurova, E.V.; Godovikov, I.A.; Chizhevskij, I.T.

2004-01-01

Five new diphosphine ruthenium(II) complexes with nido-dicarbaundecaborate anions were synthesized. The composition and structure of the complexes were confirmed by data of 1 H, 31 P{ 1 H} NMR and elementary analysis. The crystal and molecular structure of solvated complex [RuCl(dppe) 2 + [7,8-nido-C 2 B 9 H 12 ] - ·CH 2 Cl 2 was ascertained by the method of X-ray diffraction analysis. It is shown that coordination sphere of ruthenium atom in the complex cation is a distorted trigonal bipyramid. The distances from ruthenium atom to phosphorus atoms are 2.398(1) and 2.391(1) A, while the angle P-Ru-P equals 175.85(5) Deg [ru

Ruthenium(II carbonyl compounds with the 4′-chloro-2,2′:6′,2′′-terpyridine ligand

Directory of Open Access Journals (Sweden)

Rajendhraprasad Tatikonda

2017-04-01

Full Text Available Two ruthenium carbonyl complexes with the 4′-chloro-2,2′:6′,2′′-terpyridine ligand (tpy-Cl, C15H10ClN3, i.e. [RuCl(tpy-Cl(CO2][RuCl3(CO3] (I [systematic name: cis-dicarbonylchlorido(4′-chloro-2,2′:6′,2′′-terpyridine-κ3Nruthenium(II fac-tricarbonyltrichloridoruthenate(II], and [RuCl2(tpy-Cl(CO2] (II [cis-dicarbonyl-trans-dichlorido(4′-chloro-2,2′:6′,2′′-terpyridine-κ2N1,N1′ruthenium(II], were synthesized and characterized by single-crystal X-ray diffraction. The RuII atoms in both centrosymmetric structures (I and (II display similar, slightly distorted octahedral coordination spheres. The coordination sphere in the complex cation in compound (I is defined by three N atoms of the tridentate tpy-Cl ligand, two carbonyl carbon atoms and one chlorido ligand; the charge is balanced by an octahedral [Ru(CO3Cl3]− counter-anion. In the neutral compound (II, the tpy-Cl ligand coordinates to the metal only through two of its N atoms. The coordination sphere of the RuII atom is completed by two carbonyl and two chlorido ligands. In the crystal structures of both (I and (II, weak C—H...Cl interactions are observed.

Disposable biosensor based on cathodic electrochemiluminescence of tris(2,2-bipyridine)ruthenium(II) for uric acid determination

International Nuclear Information System (INIS)

Ballesta-Claver, J.; Rodríguez-Gómez, R.; Capitán-Vallvey, L.F.

2013-01-01

Highlights: ► Cathodic ECL offers conventional and non-aggressive analysis conditions. ► The ECL hydrogen peroxide/ruthenium complex system for uric acid determination is novel. ► The ruthenium complex is electrochemically immobilized on graphite screen-printed electrodes. ► The quantification of the uric acid is based on a Stern–Volmer type equation. ► The use of the cathodic ECL working methodology reduces interferences during analysis. -- Abstract: A new method for uric acid (UA) determination based on the quenching of the cathodic ECL of the tris(2,2-bipyridine)ruthenium(II)–uricase system is described. The biosensor is based on a double-layer design containing first tris(2,2-bipyridine)ruthenium(II) (Ru(bpy) 3 2+ ) electrochemically immobilized on graphite screen-printed cells and uricase in chitosan as a second layer. The uric acid biosensing is based on the ECL quenching produced by uric acid over the cathodic ECL caused by immobilized Ru(bpy) 3 2+ in the presence of uricase. The use of a −1.1 V pulse for 1 s with a dwelling time of 10 s makes it possible to estimate the initial enzymatic rate, which is used as the analytical signal. The Stern–Volmer type calibration function shows a dynamic range from 1.0 × 10 −5 to 1.0 × 10 −3 M with a limit of detection of 3.1 × 10 −6 M and an accuracy of 13.6% (1.0 × 10 −4 M, n = 5) as relative standard deviation. Satisfactory results were obtained for urine samples, creating an affordable alternative for uric acid determination

Ruthenium Complexes as NO Donors for Vascular Relaxation Induction

Directory of Open Access Journals (Sweden)

Renata Galvão de Lima

2014-07-01

Full Text Available Nitric oxide (NO donors are substances that can release NO. Vascular relaxation induction is among the several functions of NO, and the administration of NO donors is a pharmacological alternative to treat hypertension. This review will focus on the physicochemical description of ruthenium-derived NO donor complexes that release NO via reduction and light stimulation. In particular, we will discuss the complexes synthesized by our research group over the last ten years, and we will focus on the vasodilation and arterial pressure control elicited by these complexes. Soluble guanylyl cyclase (sGC and potassium channels are the main targets of the NO species released from the inorganic compounds. We will consider the importance of the chemical structure of the ruthenium complexes and their vascular effects.

Facile synthesis of RuII Schiff base complexes: spectral characterization and antimicrobial applications

International Nuclear Information System (INIS)

Arunachalam, S.; Padma Priya, N.; Shahul Meeran, H.

2014-01-01

Diamagnetic ruthenium (II) complexes of the type (RuCl (CO) (pyridine) (L)) (where L = monobasic tridentate Schiff base ligands) were synthesized by the reactions of Schiff bases derived from the reactions of o-aminobenzoic acid and Knovenegal condensate of β - ketoesters and appropriate ruthenium metal precursor (RuHCl (CO) (PPh 3 ) 2 (py)). Elemental analyses and spectral (FT-IR, UV-Vi s and 1 H, 31 P NMR) studies of all the new synthesized complexes suggest the presence of an octahedral environment around the Ru II ion. Cyclic voltammograms of all the complexes display oxidation and reduction potentials. Superoxide dismutase activity (SOD) of these complexes has also been examined. These complexes were also subjected to study their biocidal activity against Staphylococcus epidermidis, Escherichia coli, Botrytis cinerea and Aspergillus niger. (author)

Synthesis of ruthenium (III) complexes with benzimidazole derivatives

International Nuclear Information System (INIS)

Vyas, P.C.; Chahar, Yogesh K.; Garg, Yajula; Seth, Gita

2003-01-01

Complexes of ruthenium with biologically important benzimidazole derivatives, viz. 2-(2'-hydroxyphenyl) benzimidazole (HOPBI), 2-2'- mercaptophenyl) benzimidazole (HSPBI), 2- (2'-hydroxynaphthyl) benzimidazole (HONBI) have been synthesized and characterized. (author)

Synthesis and Characterization of a Heteroleptic Ru(II Complex of Phenanthroline Containing Oligo-Anthracenyl Carboxylic Acid Moieties

Directory of Open Access Journals (Sweden)

Peter A. Ajibade

2010-09-01

Full Text Available In an effort to develop new ruthenium(II complexes, this work describes the design, synthesis and characterization of a ruthenium(II functionalized phenanthroline complex with extended π-conjugation. The ligand were L1 (4,7-bis(2,3-dimethylacrylic acid-1,10-phenanthroline, synthesized by a direct aromatic substitution reaction, and L2 (4,7-bis(trianthracenyl-2,3-dimethylacrylic acid-1,10-phenanthroline, which was synthesized by the dehalogenation of halogenated aromatic compounds using a zero-valent palladium cross-catalyzed reaction in the absence of magnesium-diene complexes and/or cyclooctadienyl nickel (0 catalysts to generate a new carbon-carbon bond (C-C bond polymerized hydrocarbon units. The ruthenium complex [RuL1L2(NCS2] showed improved photophysical properties (red-shifted metal-to-ligand charge-transfer transition absorptions and enhanced molar extinction coefficients, luminescence and interesting electrochemical properties. Cyclic and square wave voltammetry revealed five major redox processes. The number of electron(s transferred by the ruthenium complex was determined by chronocoulometry in each case. The results show that processes I, II and III are multi-electron transfer reactions while processes IV and V involved one-electron transfer reaction. The photophysical property of the complex makes it a promising candidate in the design of chemosensors and photosensitizers, while its redox-active nature makes the complex a potential mediator of electron transfer in photochemical processes.

(II) complexes containing isocyanide and labile nitrile ligands

African Journals Online (AJOL)

A new ruthenium(II) complex containing both acetonitrile and propionitrile moieties as coordinating ligands has been prepared. The treatment of the polymer [{RuCl2(COD)}x], (COD = cycloocta-1,5-diene) (1) with a mixture of acetonitrile and propionitrile under reflux produced a new precursor ...

Extraction and atomic absorption spectrophotometric determination of iron and ruthenium by using potassium xanthates

Energy Technology Data Exchange (ETDEWEB)

Aihara, M; Kiboku, M [Kinki Univ., Higashi-Osaka, Osaka (Japan)

1981-06-01

Potassium xanthates (potassium o-alkyl dithiocarbonate; KRX) react with many metal ions, and so the complex formation with iron (II, III) ion and the extraction of their complexes has been studied to some extent, but those of ruthenium (III) have not been. Iron-xanthate and ruthenium-xanthate complexes can be extracted into methyl isobutyl ketone (MIBK) from weakly acidic solution to weakly alkaline solution. For quantitative extraction of iron (20 ..mu..g/40 ml), KRX concentration should be above 2.0 x 10/sup -2/ mol dm/sup -3/ of KEtX, 1.0 x 10/sup -2/ mol dm/sup -3/ of KPrX, and 5.0 x 10/sup -3/ mol dm/sup -3/ of KBtX and KPeX, and for that of ruthenium (202 ..mu..g/40 ml), it should be above 2.0 x 10/sup -1/ mol dm/sup -3/ of KEtX and KPrX. Formation constant of ruthenium-xanthate complexes is presumed to be small. A 100-fold excess of Ni(II), Co(II), Cu(II), WO/sub 4//sup 2 -/, PO/sub 4//sup 3 -/, CrO/sub 4//sup 2 -/, and Cr/sub 2/O/sub 7//sup 2 -/ interfered with the determination of iron, however, the interferences are eliminated by adding 5 ml of 0.1 mol dm/sup -3/ ascorbic acid solution. For the determination of ruthenium, a 50-fold excess of Ag(I), Hg(II), Pb(II), Zn(II), Mn(II), Cr(III), and Pt(II), or a 100-fold excess of NO/sub 2//sup -/, S/sub 2/O/sub 3//sup 2 -/, CrO/sub 4//sup 2 -/ and Cr/sub 2/O/sub 7//sup 2 -/, respectively, interfered. The coefficient of variation after each ten runs, ranges from 0.9% to 3.2% in the determination of 10 ..mu..g, 20 ..mu..g, and 30 ..mu..g of iron, and from 1.4% to 4.3% in the determination of 100 ..mu..g, 200 ..mu..g, and 300 ..mu..g of ruthenium. The determination limit in aqueous samples is 0.02 ppm for iron and 0.2 ppm for ruthenium, when the volume ratio of aqueous phase to organic phase (MIBK) is 10:1.

Ru-OSO coordination photogenerated at 100 K in tetraammineaqua(sulfur dioxide)ruthenium(II) (±)-camphorsulfonate.

Science.gov (United States)

Phillips, Anthony E; Cole, Jacqueline M; d'Almeida, Thierry; Low, Kian Sing

2012-02-06

The photoinduced O-bound coordination mode in RuSO(2) complexes, previously observed only at 13 K, has been generated at 100 K in tetraammineaqua(sulfur dioxide)ruthenium(II) (±)-camphorsulfonate. This coordination state, often denoted MS1, decays to the η(2)-bound MS2 state, with an estimated half-life of 3.4(8) h and a long-lived population of 2.9(4)% at 120 K.

Nonlinear optical properties of systems based on ruthenium(II) tetra-15-crown-5-phthalocyaninate

International Nuclear Information System (INIS)

Grishina, A.D.; Gorbunova, Yu.G.; Enakieva, Yu.Yu.; Krivenko, T.V.; Savel'ev, V.V.; Vannikov, A.V.; Tsivadze, A.Yu.

2008-01-01

The third-order nonlinear optical properties of the ruthenium (II) complex with tetra-15-crown-5-phthalocyanine and axially coordinated triethylenediamine molecules (R 4 Pc)Ru(TED) 2 were analyzed by means of the z-scanning technique. A solution of (R 4 Pc)Ru(TED) 2 in tetrachloroethane was exposed to nanosecond laser pulses at a wavelength of 1064 nm. It was found that the third-order molecular polarizability of the Ru(II) complex is 4.5 x 10 -32 cm 4 /C (esu). The polarizability per molecule increases by a factor of 3.6 when the single molecule occurs in a supramolecular assembly of (R 4 Pc)Ru(TED) 2 complexes. The photoelectric and photorefractive properties at 1064 nm of polymer composites, determined by the supramolecular assemblies that exhibits optical absorption and photoelectric sensitivity in the near IR region, are reported [ru

Biological properties of novel ruthenium- and osmium-nitrosyl complexes with azole heterocycles

KAUST Repository

Novak, Maria S.; Bü chel, Gabriel E.; Keppler, Bernhard K.; Jakupec, Michael A.

2016-01-01

Since the discovery that nitric oxide (NO) is a physiologically relevant molecule, there has been great interest in the use of metal nitrosyl compounds as antitumor pharmaceuticals. Particularly interesting are those complexes which can deliver NO to biological targets. Ruthenium- and osmium-based compounds offer lower toxicity compared to other metals and show different mechanisms of action as well as different spectra of activity compared to platinum-based drugs. Novel ruthenium- and osmium-nitrosyl complexes with azole heterocycles were studied to elucidate their cytotoxicity and possible interactions with DNA. Apoptosis induction, changes of mitochondrial transmembrane potential and possible formation of reactive oxygen species were investigated as indicators of NO-mediated damage by flow cytometry. Results suggest that ruthenium- and osmium-nitrosyl complexes with the general formula (indazolium)[cis/trans-MCl4(NO)(1H-indazole)] have pronounced cytotoxic potency in cancer cell lines. Especially the more potent ruthenium complexes strongly induce apoptosis associated with depolarization of mitochondrial membranes, and elevated reactive oxygen species levels. Furthermore, a slight yet not unequivocal trend to accumulation of intracellular cyclic guanosine monophosphate attributable to NO-mediated effects was observed.

Biological properties of novel ruthenium- and osmium-nitrosyl complexes with azole heterocycles

KAUST Repository

Novak, Maria S.

2016-03-09

Since the discovery that nitric oxide (NO) is a physiologically relevant molecule, there has been great interest in the use of metal nitrosyl compounds as antitumor pharmaceuticals. Particularly interesting are those complexes which can deliver NO to biological targets. Ruthenium- and osmium-based compounds offer lower toxicity compared to other metals and show different mechanisms of action as well as different spectra of activity compared to platinum-based drugs. Novel ruthenium- and osmium-nitrosyl complexes with azole heterocycles were studied to elucidate their cytotoxicity and possible interactions with DNA. Apoptosis induction, changes of mitochondrial transmembrane potential and possible formation of reactive oxygen species were investigated as indicators of NO-mediated damage by flow cytometry. Results suggest that ruthenium- and osmium-nitrosyl complexes with the general formula (indazolium)[cis/trans-MCl4(NO)(1H-indazole)] have pronounced cytotoxic potency in cancer cell lines. Especially the more potent ruthenium complexes strongly induce apoptosis associated with depolarization of mitochondrial membranes, and elevated reactive oxygen species levels. Furthermore, a slight yet not unequivocal trend to accumulation of intracellular cyclic guanosine monophosphate attributable to NO-mediated effects was observed.

Enyne Metathesis Catalyzed by Ruthenium Carbene Complexes

DEFF Research Database (Denmark)

Poulsen, Carina Storm; Madsen, Robert

2003-01-01

Enyne metathesis combines an alkene and an alkyne into a 1,3-diene. The first enyne metathesis reaction catalyzed by a ruthenium carbene complex was reported in 1994. This review covers the advances in this transformation during the last eight years with particular emphasis on methodology...

Disposable biosensor based on cathodic electrochemiluminescence of tris(2,2-bipyridine)ruthenium(II) for uric acid determination

Energy Technology Data Exchange (ETDEWEB)

Ballesta-Claver, J.; Rodríguez-Gómez, R. [ECsens, Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, University of Granada, E-18071 Granada (Spain); Capitán-Vallvey, L.F., E-mail: lcapitan@ugr.es [ECsens, Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, University of Granada, E-18071 Granada (Spain)

2013-04-03

Highlights: ► Cathodic ECL offers conventional and non-aggressive analysis conditions. ► The ECL hydrogen peroxide/ruthenium complex system for uric acid determination is novel. ► The ruthenium complex is electrochemically immobilized on graphite screen-printed electrodes. ► The quantification of the uric acid is based on a Stern–Volmer type equation. ► The use of the cathodic ECL working methodology reduces interferences during analysis. -- Abstract: A new method for uric acid (UA) determination based on the quenching of the cathodic ECL of the tris(2,2-bipyridine)ruthenium(II)–uricase system is described. The biosensor is based on a double-layer design containing first tris(2,2-bipyridine)ruthenium(II) (Ru(bpy){sub 3}{sup 2+}) electrochemically immobilized on graphite screen-printed cells and uricase in chitosan as a second layer. The uric acid biosensing is based on the ECL quenching produced by uric acid over the cathodic ECL caused by immobilized Ru(bpy){sub 3}{sup 2+} in the presence of uricase. The use of a −1.1 V pulse for 1 s with a dwelling time of 10 s makes it possible to estimate the initial enzymatic rate, which is used as the analytical signal. The Stern–Volmer type calibration function shows a dynamic range from 1.0 × 10{sup −5} to 1.0 × 10{sup −3} M with a limit of detection of 3.1 × 10{sup −6} M and an accuracy of 13.6% (1.0 × 10{sup −4} M, n = 5) as relative standard deviation. Satisfactory results were obtained for urine samples, creating an affordable alternative for uric acid determination.

Removal of fission product ruthenium from purex process solutions: thiourea as complexing agent

International Nuclear Information System (INIS)

Floh, B.; Abrao, A.

1980-01-01

A new method for the treatment of spent uranium fuel is presented. It is based on the Purex Process using thiourea to increase the ruthenium decontamination factor. Thiourea exhibits a strong tendency for the formation of coordination compounds in acidic media. This tendency serves as a basis to transform nitrosyl-ruthenium species into Ru /SC(NH)(NH 2 )/ 2+ and Ru /SC(NH)(NH 2 )/ 3 complexes which are unextractable by TBP-varsol. The best conditions for the ruthenium-thiourea complex formation were found to be: thiourea-ruthenium ratio (mass/mass) close to 42, at 75 0 C, 30 minutes reaction time and aging period of 60 minutes. The ruthenium decontamination factor for a single uranium extraction are ca. 80-100, not interfering with extraction of actinides. These values are rather high in comparison to those obtained using the conventional Purex Process (e.g. F.D. sub(Ru)=10). By this reason the method developed here is suitable for the treatment of spent uranium fuels. Thiourea (100g/l) scrubbing experiments of ruthenium, partially co-extracted with actinides, confirmed the possibility of its removal from the extract. A decontamination greater than 83,5% for ruthenium as fission product is obtained in two stages with this procedure. (Author) [pt

Ruthenium(II) arene complexes with chelating chloroquine analogue ligands: Synthesis, characterization and in vitro antimalarial activity†

Science.gov (United States)

Glans, Lotta; Ehnbom, Andreas; de Kock, Carmen; Martínez, Alberto; Estrada, Jesús; Smith, Peter J.; Haukka, Matti; Sánchez-Delgado, Roberto A.; Nordlander, Ebbe

2012-01-01

Three new ruthenium complexes with bidentate chloroquine analogue ligands, [Ru(η6-cym)(L1)Cl]Cl (1, cym = p-cymene, L1 = N-(2-((pyridin-2-yl)methylamino)ethyl)-7-chloroquinolin-4-amine), [Ru(η6-cym)(L2)Cl]Cl (2, L2 = N-(2-((1-methyl-1H-imidazol-2-yl)methylamino)ethyl)-7-chloroquinolin-4-amine) and [Ru(η6-cym)(L3)Cl] (3, L3 = N-(2-((2-hydroxyphenyl)methylimino)ethyl)-7-chloroquinolin-4-amine) have been synthesized and characterized. In addition, the X-ray crystal structure of 2 is reported. The antimalarial activity of complexes 1–3 and ligands L1, L2 and L3, as well as the compound N-(2-(bis((pyridin-2-yl)methyl)amino)ethyl)-7-chloroquinolin-4-amine (L4), against chloroquine sensitive and chloroquine resistant Plasmodium falciparum malaria strains was evaluated. While 1 and 2 are less active than the corresponding ligands, 3 exhibits high antimalarial activity. The chloroquine analogue L2 also shows good activity against both the choloroquine sensitive and the chloroquine resistant strains. Heme aggregation inhibition activity (HAIA) at an aqueous buffer/n-octanol interface (HAIR50) and lipophilicity (D, as measured by water/n-octanol distribution coefficients) have been measured for all ligands and metal complexes. A direct correlation between the D and HAIR50 properties cannot be made because of the relative structural diversity of the complexes, but it may be noted that these properties are enhanced upon complexation of the inactive ligand L3 to ruthenium, to give a metal complex (3) with promising antimalarial activity. PMID:22249579

The thermodynamic effects of ligand structure on the molecular recognition of mononuclear ruthenium polypyridyl complexes with B-DNA

Science.gov (United States)

The ruthenium(II) polypyridyl complexes (RPCs), [(phen)2Ru(tatpp)]Cl2 (3Cl2) and [(phen)2Ru (tatpp)Ru(phen)2]Cl4 (4Cl4), containing the large planar and redox-active tetraazatetrapyrido- pentacene (tatpp) ligand, cleave DNA in the presence of reducing agents in cell-free assays and show significant...

Design and synthesis of ruthenium(II) OCO pincer type NHC ...

Indian Academy of Sciences (India)

The tridentate nature of the tBu(OCO)2− ligand as well as some level of steric protection ... our previous results of ruthenium(II) o-hydroxyaryl sub- stituted bidentate NHC ...... (a) Ribelin T, Katz C E, English D G, Smith S,. Manukyan A K, Day ...

Spectrophotometric determination of ruthenium(III) and rhodium(III) after extraction of their cyclohexylthioglycolate complexes into chloroform

International Nuclear Information System (INIS)

Rao, A.L.J.; Gupta, Usha; Puri, B.K.

1986-01-01

Cyclohexylthioglycolate has been used as a reagent for the spectrophotometric determination of ruthenium(III) and rhodium(III) after the extraction of their complexes into chloroform. Various parameters involved in the extraction have been studied and the composition of the extracted complex has been established in each instance. Ruthenium and rhodium complexes are extracted into chloroform in the pH ranges 5.0-9.0 and 9.0-12.5, respectively. The ruthenium complex absorbs strongly at 365 nm, whereas the rhodium complex shows a maximum absorption at 345 nm. Beer's law is obeyed over the concentration range 6-96 μg for ruthenium and 2-41 μg for rhodium in 10 ml of the chloroform solution. The molar absorptivities are 5.02 x 10 3 l mol -1 cm -1 for ruthenium and 1.60 x 10 4 l mol -1 cm -1 for rhodium. Ten replicate determinations on a sample solution containing 60.3 μg of ruthenium or 20.6 μg of rhodium gave mean absorbances of 0.300 and 0.320 with standard deviations of 0.0021 and 0.0025 and relative standard deviations of 0.70% and 0.78%, respectively. The interference of various ions has been studied and the method has been applied to the determination of the metals in various synthetic samples. Conditions have also been developed for the simultaneous determination of ruthenium and rhodium. (author)

Several novel Ru(II) and Ru(III) complexes formed by reduction of (RuO4bipy) and (RuO3phen)2O with hydroquinone and methanol

International Nuclear Information System (INIS)

Ishiyama, Toshio

1975-01-01

The geometrical isomers, cis-dichloro-trans-(methanol)(hydroquinone)(2,2'-bipyridine)ruthenium(II) and cis-dichloro-cis-(methanol)(hydroquinone)(2,2'-bipyridine)ruthenium(II), [RuCl 2 (MeOH)(QH 2 )bipy] (complex I and II), were synthesized by reduction and substitution reactions of [RuO 4 bipy] and [RuO 2 (OH) 2 bipy] with hydroquinone in hydrochloric acid solution, and methanol. cis-Chloro(hydroquinonato)bis(2,2'-bipyridine)ruthenium(II), cis-[RuCl(QH)(bipy) 2 ], was obtained from the substitution reaction of complex I or II with 2,2'-bipyridine in methanol, and cis-chloro(hydroquinone)bis(2,2'-bipyridine)ruthenium(II) chloride, cis-[RuCl(QH 2 )(bipy) 2 ]Cl, was also obtained from the substitution of cis-trans-[RuCl 2 (MeOH)(QH 2 )bipy] in methanol containing hydrochloric acid. cis-Dihydroxobis(2,2'-bipyridine)ruthenium(II), cis-[Ru(OH) 2 (bipy) 2 ], was obtained by heating an aqueous solution of cis-[RuCl(QH)(bipy) 2 ]. Trihydroxoaquo(1,10-phenanthroline)ruthenium(III), [Ru(OH) 3 (H 2 O)phen] was also synthesized from [RuO 3 phen] 2 O and [Ru(OH) 3 phen] 2 O by reduction reactions similar to those used for [RuCl 2 (MeOH)(QH 2 )bipy]. These complexes were characterized by the infrared, visible and ultraviolet absorption spectra, and also by polarographic and magnetic measurements. The structures are discussed. (auth.)

Kinetics and Photochemistry of Ruthenium Bisbipyridine Diacetonitrile Complexes: An Interdisciplinary Inorganic and Physical Chemistry Laboratory Exercise

Science.gov (United States)

Rapp, Teresa L.; Phillips, Susan R.; Dmochowski, Ivan J.

2016-01-01

The study of ruthenium polypyridyl complexes can be widely applied across disciplines in the undergraduate curriculum. Ruthenium photochemistry has advanced many fields including dye-sensitized solar cells, photoredox catalysis, lightdriven water oxidation, and biological electron transfer. Equally promising are ruthenium polypyridyl complexes…

Synthesis and spectroscopic properties of Tris(2,2'-bipyridine)ruthenium(II) in zeolite Y

International Nuclear Information System (INIS)

DeWilde, W.; Peeters, G.; Lunsford, J.H.

1980-01-01

Tris(2,2'-bipyridine)ruthenium(II) complexes have been synthesized within the large cavities of dehydrated Y-type zeolites by allowing bipyridine to react with a Ru(NH 3 ) 6 -Y form of the zeolite. The resulting Ru(bpy) 3 2+ complexes are characterized by absorption and emission bands similar to those found in aqueous solutions. The relatively high concentration of the Ru(bpy) 3 2+ complexes resulted in concentration quenching. As the addition of water to the samples approached saturation, the luminescence was quenched; however, small amounts of water increased the luminescence in a sample which contained 2.8 complexes per unit cell. Emission was also quenched upon addition of O 2 to the zeolite, with the effect being more pronounced in samples having a smaller concentration of complexes. 30 references, 6 figures, 1 table

Ruthenium phosphine complexes as catalysts for alternating co-polymerization of ethylene and CO

International Nuclear Information System (INIS)

Gusev, O.V.; Kal'sin, A.M.; Peganov, T.A.; Petrovskij, P.V.; Belov, G.P.; Novikova, E.V.

2000-01-01

Ruthenium (2) complexes, [Ru(dppe) 2 (OTs) 2 ] and [Ru(PhP(CH 2 CH 2 CH 2 PPh 2 ) 2 )(OTs) 2 ], where dppe (diphenylphosphino)ethane; OTs = tosylate, were synthesized with the yield of 67 and 76%, respectively, and characterized by 31 P NMR. The properties of the above complexes as catalysts of alternating co-polymerization of ethylene and carbon monoxide were studied. A considerable increase in catalytic activity of the complexes was established in the presence of trifluoroacetic acid and 1,4-benzoquinone. These compounds are the first example of ruthenium complexes that catalyse co-polymerization of ethylene and CO [ru

Tris(2,2'-bipyridyl) ruthenium(II)-bisoprolol-based electrochemiluminescence coupled with capillary zone electrophoresis

Energy Technology Data Exchange (ETDEWEB)

Wang Jingwu [Department of Chemistry, Nanchang University, Nanchang 330031 (China)], E-mail: wangjingwu@ncu.edu.cn; Zhang Xiaojun; Pi Fangfang [Department of Chemistry, Nanchang University, Nanchang 330031 (China); Wang Xiaoxia [Graduate School of Engineering, University of Fukui, Fukui 910-8507 (Japan); Yang Nianjun [Diamond Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Central 2-13, 1-1-1 Umezono, Tsukuba 305-8568 (Japan)], E-mail: nianjun.yang@iaf.fraunhofer.de

2009-03-01

Capillary zone electrophoresis (CZE) coupled with tris(2,2'-bipyridyl) ruthenium(II)-based end-column electrogenerated chemiluminescence (ECL) has been utilized to detect bisoprolol in drugs and tablets after its separation from metoprolol. Tetrahydrofuran was used as an additive in the running buffer to obtain the absolute ECL peak of bisoprolol. Bisoprolol reacts as a co-reactant in tris(2,2'-bipyridyl) ruthenium(II) ECL system. Under the optimized experimental conditions, bisoprolol was separated successfully and efficiently from metoprolol and other co-existed materials in tablets and urine samples. The ECL intensity of tris(2,2'-bipyridyl) ruthenium(II)-bisoprolol-based system is linear with the concentration of bisoprolol from 1.5 {mu}M to 0.3 mM with a detection limit of 0.3 {mu}M. Relative standard derivations of the ECL intensity are 2.58% for the detection of 15 {mu}M bisoprolol. This method is a simple, rapid, selective, and sensitive. It was applied successfully for the monitoring of bisoprolol in market available tablets and human urine samples.

Highly efficient and stable cyclometalated ruthenium(II) complexes as sensitizers for dye-sensitized solar cells

International Nuclear Information System (INIS)

Huang, Jian-Feng; Liu, Jun-Min; Su, Pei-Yang; Chen, Yi-Fan; Shen, Yong; Xiao, Li-Min; Kuang, Dai-Bin; Su, Cheng-Yong

2015-01-01

Highlights: • Four novel thiocyanate-free cyclometalated ruthenium sensitizer were conveniently synthesized. • The D-CF 3 -sensitized DSSCs show higher efficiency compared to N719 based cells. • The DSSCs based on D-CF 3 and D-bisCF 3 sensitizers exhibit excellent long-term stability. • The diverse cyclometalated Ru complexes can be developed as high-performance sensitizers for use in DSSC. - Abstract: Four novel thiocyanate-free cyclometallted Ru(II) complexes, D-bisCF 3 , D-CF 3 , D-OMe, and D-DPA, with two 4,4′-dicarboxylic acid-2,2′-bipyridine together with a functionalized phenylpyridine ancillary ligand, have been designed and synthesized. The effect of different substituents (R = bisCF 3 , CF 3 , OMe, and DPA) on the ancillary C^N ligand on the photophysical properties and photovoltaic performance is investigated. Under standard global AM 1.5 solar conditions, the device based on D-CF 3 sensitizer gives a higher conversion efficiency of 8.74% than those based on D-bisCF 3 , D-OMe, and D-DPA, which can be ascribed to its broad range of visible light absorption, appropriate localization of the frontier orbitals, weak hydrogen bonds between -CF 3 and -OH groups at the TiO 2 surface, moderate dye loading on TiO 2 , and high charge collection efficiency. Moreover, the D-bisCF 3 and D-CF 3 based DSSCs exhibit good stability under 100 mW cm −2 light soaking at 60 °C for 400 h

Post-synthetic modification of mesoporous zinc-adeninate framework with tris(2,2′-biprydine) ruthenium(II) complex and its electrochemiluminescence

Energy Technology Data Exchange (ETDEWEB)

Park, Ji Eun; Shin, Ik Soo [Dept. of Chemistry, Soongsil University, Seoul (Korea, Republic of); Oh, Hye Jae; An, Ji Hyun [Dept. of Chemistry Education, Seoul National University, Seoul (Korea, Republic of)

2017-04-15

Herein we report a redox-active metal-organic framework (MOF) via post-synthetic cation exchange with tris(2,2′-biprydine) ruthenium(II) complex (Ru(bpy){sub 3}{sup 2+}). A porous anionic zinc-adeninate framework (bMOF-100) is spacious enough to easily entrap 2.43 of Ru(bpy){sub 3}{sup 2+} cations within the mesopore. The encapsulation supported the framework structure preventing any distortion from a rapid solvent evaporation under SEM observation. Ru(bpy){sub 3}{sup 2+}@bMOF-100 was then immobilized on the surface of glassy carbon electrode, and its electrocatalytic and electrochemiluminescent (ECL) properties were investigated in aqueous and organic solution. Especially, Ru(bpy){sub 3}{sup 2+}@bMOF-100 showed the excellent electrochemical properties of Ru(bpy){sub 3}{sup 2+}, but gradual decomposition of the MOF structure was observed under electrochemical measurements because of the sluggish oxidation of adeninate ligand.

Preparation and characterization of nickel-caffeine and ruthenium-arborine complexes

International Nuclear Information System (INIS)

Rusmidah Ali

1998-01-01

In this study, two types of complexes were synthesised, namely, nickel-cafeine and ruthenium-arborine by using NiCl 2 6H 2 O and RuCl 3 3H 2 O as starting materials. The complexes were characterised using far- and near infrared and CHN analysis. The proposed complexes were (Ni(kaf)Cl 2 ) 4 and (RuCl 3 Ab)EtOH

Reinvestigating 2,5-di(pyridin-2-yl)pyrazine ruthenium complexes : Selective deuteration and Raman spectroscopy as tools to probe ground and excited-state electronic structure in homo- and heterobimetallic complexes

NARCIS (Netherlands)

Schulz, M.; Hirschmann, J.; Draksharapu, A.; Singh Bindra, G.; Soman, S.; Paul, A.; Groarke, R.; T. Pryce, M.; Rau, S.; R. Browne, W.; Vos, J.

2011-01-01

The mono- (1) and dinuclear (2) ruthenium(II) bis(2,2'-bipyridine) complexes of 2,5-di(pyridin-2-yl)pyrazine (2,5-dpp), for which the UV/Vis absorption and emission as well as electrochemical properties have been described earlier, are reinvestigated here by resonance, surface enhanced and transient

A Smart Europium-Ruthenium Complex as Anticancer Prodrug: Controllable Drug Release and Real-Time Monitoring under Different Light Excitations.

Science.gov (United States)

Li, Hongguang; Xie, Chen; Lan, Rongfeng; Zha, Shuai; Chan, Chi-Fai; Wong, Wing-Yan; Ho, Ka-Lok; Chan, Brandon Dow; Luo, Yuxia; Zhang, Jing-Xiang; Law, Ga-Lai; Tai, William C S; Bünzli, Jean-Claude G; Wong, Ka-Leung

2017-11-09

A unique, dual-function, photoactivatable anticancer prodrug, RuEuL, has been tailored that features a ruthenium(II) complex linked to a cyclen-europium chelate via a π-conjugated bridge. Under irradiation at 488 nm, the dark-inactive prodrug undergoes photodissociation, releasing the DNA-damaging ruthenium species. Under evaluation-window irradiation (λ irr = one-photon 350 nm or two-photon 700 nm), the drug delivery process can be quantitatively monitored in real-time because of the long-lived red europium emission. Linear relationships between released drug concentration and ESI-MS or luminescence responses are established. Finally, the efficiency of the new prodrug is demonstrated both in vitro RuEuL anticancer prodrug over some existing ones and open the way for decisive improvements in multipurpose prodrugs.

A mixed ruthenium polypyridyl complex containing a PEG-bipyridine macroligand

Energy Technology Data Exchange (ETDEWEB)

Marin, Veronica; Holder, Elisabeth; Meier, Michael A.R.; Hoogenboom, Richard; Schubert, Ulrich S. [Laboratory of Macromolecular Chemistry and Nanoscience, Eindhoven University of Technology and Dutch Polymer Institute (DPI), P. O. Box 513, 5600 MB Eindhoven (Netherlands)

2004-04-06

An amino-functionalized bipyridine ligand was prepared in order to serve as a bridging unit to an activated low-molecular-weight monomethyl ether of poly(ethylene glycol) (PEG). Coordination of a ruthenium(II) phenantroline precursor onto the formed PEG-containing bipyridine ligand yielded a metal-containing polymer which shows interesting properties for solar cell applications. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

Cytogenotoxic effects of two potential anticancer Ruthenium(III Schiff Bases complexes

Directory of Open Access Journals (Sweden)

Izet Eminovic

2016-10-01

Full Text Available Introduction: Treatment of cancer has been subject of great interest. Researchers are continuously searching for new medicines. In this sense, ruthenium complexes have big potential. Some evidences suggest that ruthenium compounds possess anticancer activities. We synthesized two recently published ruthenium(III complexes with bidentate O,N and tridentate O,O,N Schiff bases derived from 5-substituted salicylaldehyde and aminophenol or anilineare. These compounds showed affinity for binding to the DNA molecule, however, insufficient data are available regarding their possible toxic effects on biological systems.Methods: In the present study we evaluated genotoxic, cytotoxic, and cytostatic effects of Na[RuCl2(L12] and Na[Ru(L22], using the Allium cepa assay.Results: Different toxic effects were observed depending on the substance, tested concentration, and endpoint measured. In general, the tested compounds significantly lowered the root growth and mitotic index values as compared to the control group. Additionally, a wide range of abnormal mitotic stages, both clastogenic and non-clastogenic were observed in the treated cells. Na[RuCl2(L12] significantly increased the frequency of sticky metaphases, chromosome bridges, micronuclei, impaired chromosome segregation, as well as number of apoptotic and necrotic cells over the controls. In contrast, Na[Ru(L22] did not show significant evidence of genotoxicity with regard to chromosome aberrations and micronuclei, however, significant differences were detected in the number of apoptotic and necrotic cells when the highest concentration was applied.Conclusions: In this study we demonstrated antiproliferative effects of Na[RuCl2(L12] and Na[Ru(L22]. At clinical level, these results could be interesting for further studies on anticancer potential of the ruthenium(III complexes using animal models.

Oxidation of Bromide to Bromine by Ruthenium(II) Bipyridine-Type Complexes Using the Flash-Quench Technique.

Science.gov (United States)

Tsai, Kelvin Yun-Da; Chang, I-Jy

2017-07-17

Six ruthenium complexes, [Ru(bpy) 3 ] 2+ (1), [Ru(bpy) 2 (deeb)] 2+ (2), [Ru(deeb) 2 (dmbpy)] 2+ (3), [Ru(deeb) 2 (bpy)] 2+ (4), [Ru(deeb) 3 ] 2+ (5), and [Ru(deeb) 2 (bpz)] 2+ (6) (bpy: 2,2'-bipyridine; deeb: 4,4'-diethylester-2,2'-bipyridine; dmbpy: 4,4'-dimethyl-2,2'-bipyridine, bpz: 2,2'-bipyrazine), have been employed to sensitize photochemical oxidation of bromide to bromine. The oxidation potential for complexes 1-6 are 1.26, 1.36, 1.42, 1.46, 1.56, and 1.66 V vs SCE, respectively. The bimolecular rate constants for the quenching of complexes 1-6 by ArN 2 + (bromobenzenediazonium) are determined as 1.1 × 10 9 , 1.6 × 10 8 , 1.4 × 10 8 , 1.2 × 10 8 , 6.4 × 10 7 , and 8.9 × 10 6 M -1 s -1 , respectively. Transient kinetics indicated that Br - reacted with photogenerated Ru(III) species at different rates. Bimolecular rate constants for the oxidation of Br - by the Ru(III) species derived from complexes 1-5 are observed as 1.2 × 10 8 , 1.3 × 10 9 , 4.0 × 10 9 , 4.8 × 10 9 , and 1.1 × 10 10 , M -1 s -1 , respectively. The last reaction kinetics observed in the three-component system consisting of a Ru sensitizer, quencher, and bromide is shown to be independent of the Ru sensitizer. The final product was identified as bromine by its reaction with hexene. The last reaction kinetics is assigned to the disproportionation reaction of Br 2 -• ions, for which the rate constant is determined as 5 × 10 9 M -1 s -1 . Though complex 6 has the highest oxidation potential in the Ru(II)/Ru(III) couple, its excited state fails to react with ArN 2 + sufficiently for subsequent reactions. The Ru(III) species derived from complex 1 reacts with Br - at the slowest rate. Complexes 2-5 are excellent photosensitizers to drive photooxidation of bromide to bromine.

Electrochemical analysis of coordination sphere of ruthenium(II) as an electron transport mediator in glucose oxidase catalysis in aqueous solutions

International Nuclear Information System (INIS)

Kurova, V.S.; Ryabov, A.D.; Ershov, A.Yu.

2001-01-01

The redox-potentials of the cis-[Ru(LL) 2 XY] n+ complexes (LL=2,2' bipyridil, 1,10 phenanthrolin and 4,4'-dimethyl-2,2-bipyridil; X, Y = Cl - , Br - , CO 3 2- , No 2 - , SCN - , H 2 O and methylsulfoxide) in water solutions are measured through the cyclic voltamperometry method. The linear dependence of the ruthenium complexes(II) measured redox-potentials on the ligand sphere is established. It is shown, that these complexes manifest the properties of the reversible or quasi-reversible redox-systems, the formal redox-potential values whereof are within the 0.2-0.5 V interval [ru

Electrochemical properties of the hexacyanoferrate(II)–ruthenium(III) complex immobilized on silica gel surface chemically modified with zirconium(IV) oxide

International Nuclear Information System (INIS)

Panice, Lucimara B.; Oliveira, Elisangela A. de; Filho, Ricardo A.D. Molin; Oliveira, Daniela P. de; Lazarin, Angélica M.; Andreotti, Elza I.S.; Sernaglia, Rosana L.; Gushikem, Yoshitaka

2014-01-01

Highlights: • The cyano-bridged mixed valence ruthenium composite material was synthesized. • This newly synthesized compound was incorporated into a carbon paste electrode. • The electrode did not show significant changes in response after six months of use. • The modified electrode is very stable and reproducible. • The electrode sensor was successfully applied for ascorbic acid determination. - Abstract: The chemically modified silica gel with zirconium(IV) oxide was used to immobilize the [Fe(CN) 6 ] 4− complex ion initially. The reaction of this material with [Ru(edta)H 2 O] − complex ion formed the immobilized cyano-bridged mixed valence ruthenium complex, (≡Zr) 5 [(edta)RuNCFe(CN) 5 ]. This material was incorporated into a carbon paste electrode and, its electrochemical properties were investigated. However, for an ascorbic acid solution, an enhancement of the anodic peak current was detected due to electrocatalytic oxidation. The electrode presented the same response for at least 150 successive measurements, with a good repeatability. The modified electrode is very stable and reproducible. The sensor was applied for ascorbic acid determination in pharmaceutical preparation with success

Synthesis, photo-, and electrochemistry of ruthenium bis(bipyridine) complexes comprising a N-heterocyclic carbene ligand.

Science.gov (United States)

Leigh, Vivienne; Ghattas, Wadih; Lalrempuia, Ralte; Müller-Bunz, Helge; Pryce, Mary T; Albrecht, Martin

2013-05-06

Analogues of [Ru(bpy)3](2+) were prepared in which one pyridine ligand site is substituted by a N-heterocyclic carbene (NHC) ligand, that is, either by an imidazolylidene with a variable wingtip group R (R = Me, 3a; R = Et, 3b; R = iPr, 3c), or by a benzimidazolylidene (Me wingtip group, 3d), or by a 1,2,3-triazolylidene (Me wingtip group, 3e). All complexes were characterized spectroscopically, photophysically, and electrochemically. An increase of the size of the wingtip groups from Me to Et or iPr groups distorts the octahedral geometry (NMR spectroscopy) and curtails the reversibility of the ruthenium oxidation. NHC ligands with methyl wingtip groups display reversible ruthenium oxidation at a potential that reflects the donor properties of the NHC ligand (triazolylidene > imidazolylidene > benzimidazolylidene). The most attractive properties were measured for the triazolylidene ruthenium complex 3e, featuring the smallest gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) in the series (2.41 eV), a slightly red-shifted absorption profile, and reasonable excited-state lifetime (188 ns) when compared to [Ru(bpy)3](2+). These features demonstrate the potential utility of triazolylidene ruthenium complexes as photosensitizers for solar energy conversion.

Excitation energy transfer in ruthenium (II)-porphyrin conjugates led to enhanced emission quantum yield and 1O2 generation

International Nuclear Information System (INIS)

Pan, Jie; Jiang, Lijun; Chan, Chi-Fai; Tsoi, Tik-Hung; Shiu, Kwok-Keung; Kwong, Daniel W.J.; Wong, Wing-Tak; Wong, Wai-Kwok; Wong, Ka-Leung

2017-01-01

Porphyrins are good photodynamic therapy (PDT) agents due to its flexibility for modifications to achieve tumor localization and photo-cytotoxicity against cancer. Yet they are not perfect. In a Ru(polypyridyl)-porphyrin system, the Ru(polypyridyl) moiety improves the water solubility and cell permeability. Consider the similar excited state energies between Ru(polypyridyl) and porphyrin moieties; a small perturbation (e.g. Zn(II) metalation) would lead to a marked change in the energy migration process. In this work, we have synthesized a series of porphyrins conjugated with Ru(polypyridyl) complexes using different linkers and investigated their photophysical properties, which included singlet oxygen quantum yield and their in vitro biological properties, resulting from linker variation and porphyrin modification by Zn(II) metalation. - Graphical abstract: Four amphiphilic ruthenium(II)-porphyrin complexes were prepared that display energy transfer conversion with zinc coordination, lysosome specific target, low dark toxicity and efficient photodynamic therapy.

Electrochemiluminescent determination of nicotine based on tri(2,2'-bipyridyl) ruthenium (II) complex through flow injection analysis

International Nuclear Information System (INIS)

Lin Mengshan; Wang Junsheng; Lai Chienhung

2008-01-01

This paper describes the electrogenerated chemiluminescence (ECL) processes of Ru(bpy) 3 2+ /nicotine system at ITO working electrode. An ECL-based method for rapid and sensitive detection of nicotine in phosphate buffer solution at pH 8.0 is established. Strong ECL emission was observed at a positive potential of 1.4 V vs. Ag/AgCl. A possible ECL mechanism is proposed for the Ru(bpy) 3 2+ /nicotine system, the oxidation product of nicotine at the electrode surface reacts with the 3+ state of ruthenium bipyridyl (2+) complex and form ruthenium complex exited state ions and thus releases photons. Effect of pH (medium/electrolyte), working potential, buffer composition, buffer concentration, reactant and co-reactant (nicotine) concentration, flow rate and loop size on the ECL spectrum of the Ru(bpy) 3 2+ /nicotine were studied. At the optimized experimental conditions, lower detection limit for nicotine was observed as 1.2 nmol L -1 (S/N = 3). Linear relationship between ECL current and concentration of nicotine was observed (up to 100 μmol L -1 ) with R-value of 0.997. The relative standard deviation with 5 μmol L -1 concentration of nicotine for 20 analyses was only 1.4%. A 94% recovery rate was observed in a real sample analysis without any complications/disturbance in measurement. Interferences of humid acid, camphor and SDS were not observed in their presence in the sample solution. The established procedure for nicotine quantification manifests fascinating results and can be suggested for further applications

Ground vs. excited state interaction in ruthenium-thienyl dyads : implications for through bond interactions in multicomponent systems

NARCIS (Netherlands)

Henry, William; Browne, Wesley R.; Ronayne, Kate L.; O’Boyle, Noel M.; Vos, Johannes G.; McGarvey, John J.

2005-01-01

The vibrational and photophysical properties of mononuclear ruthenium(II) and ruthenium(III) polypyridyl complexes based on the, ligands 2-(5-(pyridin-2"-yl)-1'H-1',2',4'-triaz-3'-yl)-thiophene, 2-(5-(pyrazin-2"-yl)-1'H-1',2,4-triaz-3'-yl)-thiophene, are reported. The effect of the introduction of

Synthesis and characterisation of ruthenium(III) complexes with benzimidazole derivatives

International Nuclear Information System (INIS)

Vyas, P.C.; Kaur, N.; Goel, A.K.; Vyas, S.

1995-01-01

Complexes of ruthenium trichloride with biologically important benzimidazole derivatives, viz., 2-(hydroxy methyl) benzimidazole, 2-(l-hydroxy ethyl) benzimidazole, 2-(mercapto methyl) benzimidazole, 2-(l-mercapto ethyl) benzimidazole, and 2,2'-bis-benzimidazole have been synthesized by reacting the above metal chloride and ligands respectively in 1:3 molar ratio. These complexes are characterised on the basis of elemental analysis, molar conductance data, room temperature, magnetic moment values, electronic spectral and IR spectral studies. (author). 17 refs., 2 tabs

Long-Range Intramolecular Electronic Communication in a Trinuclear Ruthenium Tropolonate Complex.

Science.gov (United States)

Yoshida, Jun; Kuwahara, Kyohei; Suzuki, Kota; Yuge, Hidetaka

2017-02-20

Dinuclear and trinuclear ruthenium complexes, [Ru(trop) 2 (C 2 trop)Ru(dppe)Cp] [2b; trop = tropolonato, C 2 trop = ethynyltropolonato, dppe = 1,2-bis(diphenylphosphino)ethane] and [Ru(trop){(C 2 trop)Ru(dppe)Cp} 2 ] (3), were synthesized, and their electronic and electrochemical properties were investigated in comparison with our previously reported complex [Ru(acac) 2 (C 2 trop)Ru(dppe)Cp] (2a). The electron-donating Ru II (dppe)Cp unit and electron-accepting Ru III O 6 unit are connected by C 2 trop in these complexes. 2a incorporates acetylacetonate as an ancillary ligand, while 2b and 3 incorporate tropolonate as an ancillary ligand. Every complex, 2a, 2b, and 3, exhibits similar UV-vis-near-IR (NIR) absorption spectra, demonstrating the lack of explicit intramolecular electronic communication between the units at least in the neutral state. The weak NIR absorption in 2a further diminished upon electrochemical oxidation, indicating almost no electronic communication between the units. In contrast, 2b and 3 exhibit broad NIR absorptions upon oxidation. Additionally, 3 exhibits four stepwise redox couples in the electrochemical study, which are formally attributed to [Ru II (trop) 3 ] - /[Ru III (trop) 3 ], two [Ru II (dppe)Cp]/[Ru III (dppe)Cp] + , and [Ru III (trop) 3 ]/[Ru IV (trop) 3 ] + couples. Clear separation of the redox couples attributed to the two terminal [Ru(dppe)Cp] units demonstrates the thermodynamic stability of the intermediate oxidation states with respect to disproportionation. Further electrochemical studies using an electrolyte including perfluorinated weakly coordinating anions and density functional theory/time-dependent density functional theory calculations confirmed the effect of ancillary ligands, acetylacetonate and tropolonate. In the case of 2a, electronic delocalization over the whole complex, especially over the [Ru(acac) 2 (trop)] unit, appears to be small. In contrast, the electronic communication between [Ru(dppe)Cp] and [Ru

A study of ruthenium complexes of some biologically relevant a-N ...

Indian Academy of Sciences (India)

Home; Journals; Journal of Chemical Sciences; Volume 112; Issue 3. A study of ruthenium complexes of some biologically relevant ∙ -N-heterocyclic ... Author Affiliations. P Sengupta1 S Ghosh1. Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta 700 032, India ...

Bifunctional amine-tethered ruthenium(II) arene complexes form monofunctional adducts on DNA

Czech Academy of Sciences Publication Activity Database

Melchart, M.; Habtemariam, A.; Nováková, Olga; Moggach, S.A.; Fabbiani, F.P.A.; Parsons, S.; Brabec, Viktor; Sadler, P.J.

2007-01-01

Roč. 46, č. 21 (2007), s. 8950-8962 ISSN 0020-1669 R&D Projects: GA ČR(CZ) GA305/05/2030; GA ČR(CZ) GA203/06/1239; GA AV ČR(CZ) 1QS500040581; GA AV ČR(CZ) KAN200200651 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : DNA * ruthenium * cancer Subject RIV: BO - Biophysics Impact factor: 4.123, year: 2007

Allenylidene Complexes of Ruthenium: Synthesis, Spectroscopy and Electron Transfer Properties

Czech Academy of Sciences Publication Activity Database

Winter, R. F.; Záliš, Stanislav

2004-01-01

Roč. 248, 15/16 (2004), s. 1565-1583 ISSN 0010-8545 R&D Projects: GA ČR GA203/03/0821; GA MŠk OC D14.20 Institutional research plan: CEZ:AV0Z4040901 Keywords : spectroscopy * allenylidine complexes of ruthenium * electron transfer Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.446, year: 2004

Estimation of very low concentrations of Ruthenium by spectrophotometric method using barbituric acid as complexing agent

International Nuclear Information System (INIS)

Ramakrishna Reddy, S.; Srinivasan, R.; Mallika, C.; Kamachi Mudali, U.; Natarajan, R.

2012-01-01

Spectrophotometric method employing numerous chromogenic reagents like thiourea, 1,10-phenanthroline, thiocyanate and tropolone is reported in the literature for the estimation of very low concentrations of Ru. A sensitive spectrophotometric method has been developed for the determination of ruthenium in the concentration range 1.5 to 6.5 ppm in the present work. This method is based on the reaction of ruthenium with barbituric acid to produce ruthenium(ll)tris-violurate, (Ru(H 2 Va) 3 ) -1 complex which gives a stable deep-red coloured solution. The maximum absorption of the complex is at 491 nm due to the inverted t 2g → Π(L-L ligand) electron - transfer transition. The molar absorptivity of the coloured species is 9,851 dm 3 mol -1 cm -1

Tracking the Oxygen Status in the Cell Nucleus with a Hoechst-Tagged Phosphorescent Ruthenium Complex.

Science.gov (United States)

Hara, Daiki; Umehara, Yui; Son, Aoi; Asahi, Wataru; Misu, Sotaro; Kurihara, Ryohsuke; Kondo, Teruyuki; Tanabe, Kazuhito

2018-05-04

Molecular oxygen in living cells is distributed and consumed inhomogeneously, depending on the activity of each organelle. Therefore, tractable methods that can be used to monitor the oxygen status in each organelle are needed to understand cellular function. Here we report the design of a new oxygen-sensing probe for use in the cell nucleus. We prepared "Ru-Hoechsts", each consisting of a phosphorescent ruthenium complex linked to a Hoechst 33258 moiety, and characterized their properties as oxygen sensors. The Hoechst unit shows strong DNA-binding properties in the nucleus, and the ruthenium complex shows oxygen-dependent phosphorescence. Thus, Ru-Hoechsts accumulated in the cell nucleus and showed oxygen-dependent signals that could be monitored. Of the Ru-Hoechsts prepared in this study, Ru-Hoechst b, in which the ruthenium complex and the Hoechst unit were linked through a hexyl chain, showed the most suitable properties for monitoring the oxygen status. Ru-Hoechsts are probes with high potential for visualizing oxygen fluctuations in the nucleus. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ruthenium and iron complexes with benzotriazole and benzimidazole derivatives as simple models for proton-coupled electron transfer systems

Directory of Open Access Journals (Sweden)

Rocha Reginaldo C.

2001-01-01

Full Text Available Iron and ruthenium complexes of the type [M-LH]n (where M = RuII,III(NH35(2+,3+, RuII,III(edta2-,- [edta = ethylenedinitrilotetraacetate], or FeII,III(CN5(3-,2- and LH = benzotriazole or benzimidazole were prepared and characterized in aqueous solutions by means of electrochemical and spectroelectrochemical methods. Special emphasis was given to the pH-dependent redox processes, exhibited by all the investigated complexes. From their related Pourbaix diagrams, which displayed a typically Nernstian behavior, the pKa and formal reduction potential values were extracted. In addition, these E1/2 versus pH curves were also used to illustrate the partitioning relationship concerning the redox and acid-base species, and their interconversion equilibria. The active area in which the dependence of the M III/M II couple on the pH takes place, as delimited by pKaIII and pKaII, was taken into account in order to evaluate the usefulness of such simple complexes as models for proton-coupled electron transfer (PCET. The results were interpreted in terms of the acceptor/donor electronic character of the ligands and sigma,pi-metal-ligand interactions in both redox states of the metal ion.

Ruthenium (4) and ruthenium (3) state in hydrochloric acid solutions under microwave irradiation

International Nuclear Information System (INIS)

Bashilov, A.V.; Kuz'min, N.M.; Nesterov, A.A.; Runov, V.K.

2000-01-01

Reactions of hydration, poly- and depolymerization, oxidation-reduction processes with ruthenium (4) and ruthenium (3) participation are investigated in hydrochloric acid solutions under microwave irradiation by the methods of molecular absorption spectroscopy in UV visible region taking K 4 [Ru 2 OCl 10 ] as an example. Content of state forms of ruthenium (4) and ruthenium (3), absorption characteristics of forming complexes are calculated. Variation of microwave irradiation parameters and HCl concentration permits to prepare solutions containing [RuCl 6 ] 2+ (95 %) and [(RuOH) 2 (H 2 O) 6 (OH) 2 ] 4+ (98 %) preeminently predominant forms. The role of microwave effect directly is established taking as an example the process of ruthenium (4) hydration [ru

Ruthenium(ii)-catalyzed olefination via carbonyl reductive cross-coupling.

Science.gov (United States)

Wei, Wei; Dai, Xi-Jie; Wang, Haining; Li, Chenchen; Yang, Xiaobo; Li, Chao-Jun

2017-12-01

Natural availability of carbonyl groups offers reductive carbonyl coupling tremendous synthetic potential for efficient olefin synthesis, yet the catalytic carbonyl cross-coupling remains largely elusive. We report herein such a reaction, mediated by hydrazine under ruthenium(ii) catalysis. This method enables facile and selective cross-couplings of two unsymmetrical carbonyl compounds in either an intermolecular or intramolecular fashion. Moreover, this chemistry accommodates a variety of substrates, proceeds under mild reaction conditions with good functional group tolerance, and generates stoichiometric benign byproducts. Importantly, the coexistence of KO t Bu and bidentate phosphine dmpe is vital to this transformation.

Topoisomerase II poisoning by indazole and imidazole complexes ...

Indian Academy of Sciences (India)

Unknown

These molecules constitute two of the few most effective anticancer ruthenium compounds. ... however was hindered due to toxic side effects on the human body. Our ... cells. The catalytic cycle of topoisomerase II (topo II) typically involves ...

Electrochemiluminescent determination of nicotine based on tri(2,2'-bipyridyl) ruthenium (II) complex through flow injection analysis

Energy Technology Data Exchange (ETDEWEB)

Lin Mengshan [Department of Chemistry, Tamkang University, Tamsui 25137, Taiwan (China)], E-mail: mslin@mail.tku.edu.tw; Wang Junsheng; Lai Chienhung [Department of Chemistry, Tamkang University, Tamsui 25137, Taiwan (China)

2008-11-01

This paper describes the electrogenerated chemiluminescence (ECL) processes of Ru(bpy){sub 3}{sup 2+}/nicotine system at ITO working electrode. An ECL-based method for rapid and sensitive detection of nicotine in phosphate buffer solution at pH 8.0 is established. Strong ECL emission was observed at a positive potential of 1.4 V vs. Ag/AgCl. A possible ECL mechanism is proposed for the Ru(bpy){sub 3}{sup 2+}/nicotine system, the oxidation product of nicotine at the electrode surface reacts with the 3+ state of ruthenium bipyridyl (2+) complex and form ruthenium complex exited state ions and thus releases photons. Effect of pH (medium/electrolyte), working potential, buffer composition, buffer concentration, reactant and co-reactant (nicotine) concentration, flow rate and loop size on the ECL spectrum of the Ru(bpy){sub 3}{sup 2+}/nicotine were studied. At the optimized experimental conditions, lower detection limit for nicotine was observed as 1.2 nmol L{sup -1} (S/N = 3). Linear relationship between ECL current and concentration of nicotine was observed (up to 100 {mu}mol L{sup -1}) with R-value of 0.997. The relative standard deviation with 5 {mu}mol L{sup -1} concentration of nicotine for 20 analyses was only 1.4%. A 94% recovery rate was observed in a real sample analysis without any complications/disturbance in measurement. Interferences of humid acid, camphor and SDS were not observed in their presence in the sample solution. The established procedure for nicotine quantification manifests fascinating results and can be suggested for further applications.

Electrochemiluminescent determination of nicotine based on tri(2,2'-bipyridyl) ruthenium (II) complex through flow injection analysis

Energy Technology Data Exchange (ETDEWEB)

Lin, Meng Shan; Wang, Jun Sheng; Lai, Chien Hung [Department of Chemistry, Tamkang University, Tamsui 25137 (China)

2008-11-01

This paper describes the electrogenerated chemiluminescence (ECL) processes of Ru(bpy){sub 3}{sup 2+}/nicotine system at ITO working electrode. An ECL-based method for rapid and sensitive detection of nicotine in phosphate buffer solution at pH 8.0 is established. Strong ECL emission was observed at a positive potential of 1.4 V vs. Ag/AgCl. A possible ECL mechanism is proposed for the Ru(bpy){sub 3}{sup 2+}/nicotine system, the oxidation product of nicotine at the electrode surface reacts with the 3+ state of ruthenium bipyridyl (2+) complex and form ruthenium complex exited state ions and thus releases photons. Effect of pH (medium/electrolyte), working potential, buffer composition, buffer concentration, reactant and co-reactant (nicotine) concentration, flow rate and loop size on the ECL spectrum of the Ru(bpy){sub 3}{sup 2+}/nicotine were studied. At the optimized experimental conditions, lower detection limit for nicotine was observed as 1.2 nmol L{sup -1} (S/N = 3). Linear relationship between ECL current and concentration of nicotine was observed (up to 100 {mu}mol L{sup -1}) with R-value of 0.997. The relative standard deviation with 5 {mu}mol L{sup -1} concentration of nicotine for 20 analyses was only 1.4%. A 94% recovery rate was observed in a real sample analysis without any complications/disturbance in measurement. Interferences of humid acid, camphor and SDS were not observed in their presence in the sample solution. The established procedure for nicotine quantification manifests fascinating results and can be suggested for further applications. (author)

Excitation energy transfer in ruthenium (II)-porphyrin conjugates led to enhanced emission quantum yield and {sup 1}O{sub 2} generation

Energy Technology Data Exchange (ETDEWEB)

Pan, Jie; Jiang, Lijun; Chan, Chi-Fai [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region (Hong Kong); Tsoi, Tik-Hung [Department of Applied Biology and Chemical Technology, Hung Hom, Hong Kong Special Administrative Region (Hong Kong); Shiu, Kwok-Keung; Kwong, Daniel W.J. [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region (Hong Kong); Wong, Wing-Tak [Department of Applied Biology and Chemical Technology, Hung Hom, Hong Kong Special Administrative Region (Hong Kong); Wong, Wai-Kwok, E-mail: wkwong@hkbu.edu.hk [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region (Hong Kong); Wong, Ka-Leung, E-mail: klwong@hkbu.edu.hk [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region (Hong Kong)

2017-04-15

Porphyrins are good photodynamic therapy (PDT) agents due to its flexibility for modifications to achieve tumor localization and photo-cytotoxicity against cancer. Yet they are not perfect. In a Ru(polypyridyl)-porphyrin system, the Ru(polypyridyl) moiety improves the water solubility and cell permeability. Consider the similar excited state energies between Ru(polypyridyl) and porphyrin moieties; a small perturbation (e.g. Zn(II) metalation) would lead to a marked change in the energy migration process. In this work, we have synthesized a series of porphyrins conjugated with Ru(polypyridyl) complexes using different linkers and investigated their photophysical properties, which included singlet oxygen quantum yield and their in vitro biological properties, resulting from linker variation and porphyrin modification by Zn(II) metalation. - Graphical abstract: Four amphiphilic ruthenium(II)-porphyrin complexes were prepared that display energy transfer conversion with zinc coordination, lysosome specific target, low dark toxicity and efficient photodynamic therapy.

Influence of different ruthenium(II) bipyridyl complex on the photocatalytic H{sub 2} evolution over TiO{sub 2} nanoparticles with mesostructures

Energy Technology Data Exchange (ETDEWEB)

Peng, Tianyou [College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072 (China); Hubei Key Laboratory for Catalysis and Material Science, College of Chemistry and Material Science, South-Central University for Nationalities, Wuhan 430074 (China); Ke, Dingning; Cai, Ping; Dai, Ke; Ma, Liang; Zan, Ling [College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072 (China)

2008-05-15

H{sub 2} production over dye-sensitized Pt/TiO{sub 2} nanoparticles with mesostructures (m-TiO{sub 2}) under visible light ({lambda} > 420 nm) was investigated by using methanol as electron donors. Experimental results indicate that three types of ruthenium(II) bipyridyl complex dyes (one binuclear Ru, two mononuclear Ru), which can be attached to Pt/m-TiO{sub 2} with different linkage modes, show different photosensitization effects due to their different coordination circumstances and physicochemical properties. The dye tightly linked with m-TiO{sub 2} has better durability but the lowest H{sub 2} evolution efficiency, whereas the loosely attached dyes possess higher H{sub 2} evolution efficiency and preferable durability. It seems that the dynamic equilibrium between the linkage of the ground state dye with TiO{sub 2} and the divorce of the oxidization state dye from the surfaces plays a crucial role in the photochemical behavior during the photocatalyst sensitization process. It is helpful to improve the H{sub 2} evolution efficiency by enhancing the electron injection and hindering the backward transfer. The binuclear Ru(II) dye shows a better photosensitization in comparison with mononuclear Ru(II) dyes due to its large molecular area, conjugation system, and ''antenna effect'', which, in turn, improve the visible light harvesting and electron transfer between the dye molecules and TiO{sub 2}. (author)

The synthesis and luminescence quenching of the water-soluble polymer-supported tris(2,2'-bipyridine)ruthenium(II) analogue

International Nuclear Information System (INIS)

Kurimura, Yoshimi; Shinozaki, Norio; Ito, Fumio; Uratani, Yasuyo; Shigehara, Kiyotaka; Tsuchida, Eishun; Kaneko, Masao; Yamada, Akira.

1982-01-01

The p-aminostyrene-N-vinylpyrrolidone copolymer-supported tris(2,2'-bipyridine)ruthenium (II) analogue, [Ru(bpy) 2 (pbyCOOH)] 2 + (bpy = 2,2'-bipyridine and pbyCOOH = polymeric bipyridine ligand), has been prepared, and the luminescence behavior of the polymer complex has been investigated in an aqueous solution. The efficiency of the quenching of the excited state of the polymer complex with [Fe(CN) 6 ] 4 - , [Co(phen) 3 ] 2 + , and Cu 2 + is compared with that of [Ru(bpy) 3 ] 2 + . The quenching of the excited state of the polymer complex by Cu 2 + is strongly enhanced by the effect of the polymer chains. In the polymer complex/Cu 2 + system, the quenching by Cu 2 + in the presence of poly(p-styrenesulfonate) is much more effective than in the absence of the polyion. The characteristics of the polymer complex in terms of the luminescence behavior are discussed. (author)

Photorefractive IR-spectrum composites prepared from polyimide and ruthenium(II) tetra-15-crown-5-phthalocyaninate with axially coordinated triethylenediamine molecules

International Nuclear Information System (INIS)

Vannikov, A.V.; Grishina, A.D.; Gorbunova, Yu.G.; Enakieva, Yu.Yu.; Krivenko, T.V.; Savel'ev, V.V.; Tsivadze, A.Yu.

2006-01-01

Photoelectric, non-linear optical, and photorefractive properties of aromatic polyimine doped with ruthenium(II) complex with tetra-15-crown-5-phthalocyanine and axially coordinated triethylenediamine molecules, (R 4 Pc)Ru(TED) 2 , where R 4 Pc 2- and TED denote 4,5,4',5',4'',5'',4''',5'''-tetrakis-(1,4,7,10,13- pentaoxatridecamethylene)phthalocyaninate ion and triethylenediamine molecule, respectively, were studied. It is established that supramolecular ensembles on the basis of the complex make an aromatic polyimide layer photoelectrically sensitive to 1064-nm Nd : YAG laser radiation, exhibit third-order susceptibility, and, consequently, impart photorefractive properties to the polymer layer at this wavelength [ru

Asymmetric Ruthenium(II and Osmium(II Complexes with New Bidentate Polyquinoline Ligands. Synthesis and NMR Characterization

Directory of Open Access Journals (Sweden)

Antonino Mamo

2010-03-01

Full Text Available A series of Ru(II and Os(II tris-chelate complexes with new bidentate 2-pyridylquinoline ligands have been synthesized and fully characterized by EA,1H-NMR and FAB-MS techniques. The new ligands are: L1 = 4-p-methoxyphenyl-6-bromo-2-(2′- pyridylquinoline (mphbr-pq and L2 = 4-p-hydroxyphenyl-6-bromo-2-(2′-pyridyl-quinoline (hphbr-pq. The complexes studied are: [Ru(bpy2L1](PF62 (C1, [Ru(bpy2L2](PF62 (C2, [Os(bpy2L1](PF62 (C3, [Os(bpy2L2](PF62 (C4 (bpy = 2,2′-bipyridine, [Ru(dmbpy2L1](PF62 (C5, [Ru(dmbpy2L2](PF62 (C6, [Os(dmbpy2L1](PF62 (C7, and [Os(dmbpy2L2](PF62 (C8 (dmbpy = 4,4′-dimethyl-2,2′-bipyridine. Moreover, new functionalized complexes C9-C12 were obtained by the basecatalyzed direct alkylation of C2, C4, C6, and C8 with 6-bromo-1-hexene. The complete assignment of the 1H-NMR spectra for the two new ligands (L1 and L2, and their Ru(II or Os(II complexes has been accomplished using a combination of one- and two-dimensional NMR techniques. The JH,H values have been determined for the majority of the resonances.

Ruthenium complexes containing 2-(2-nitrosoaryl)pyridine: structural, spectroscopic, and theoretical studies.

Science.gov (United States)

Chan, Siu-Chung; Cheung, Ho-Yuen; Wong, Chun-Yuen

2011-11-21

Ruthenium complexes containing 2-(2-nitrosoaryl)pyridine (ON(^)N) and tetradentate thioether 1,4,8,11-tetrathiacyclotetradecane ([14]aneS4), [Ru(ON(^)N)([14]aneS4)](2+) [ON(^)N = 2-(2-nitrosophenyl)pyridine (2a), 10-nitrosobenzo[h]quinoline (2b), 2-(2-nitroso-4-methylphenyl)pyridine, (2c), 2-(2-nitrosophenyl)-5-(trifluoromethyl)pyridine (2d)] and analogues with the 1,4,7-trithiacyclononane ([9]aneS3)/tert-butylisocyanide ligand set, [Ru(ON(^)N)([9]aneS3)(C≡N(t)Bu)](2+) (4a and 4b), have been prepared by insertion of a nitrosonium ion (NO(+)) into the Ru-aryl bond of cyclometalated ruthenium(II) complexes. The molecular structures of the ON(^)N-ligated complexes 2a and 2b reveal that (i) the ON(^)N ligands behave as bidentate chelates via the two N atoms and the bite angles are 86.84(18)-87.83(16)° and (ii) the Ru-N(NO) and N-O distances are 1.942(5)-1.948(4) and 1.235(6)-1.244(5) Å, respectively. The Ru-N(NO) and N-O distances, together with ν(N═O), suggest that the coordinated ON(^)N ligands in this work are neutral moiety (ArNO)(0) rather than monoanionic radical (ArNO)(•-) or dianion (ArNO)(2-) species. The nitrosated complexes 2a-2d show moderately intense absorptions centered at 463-484 nm [ε(max) = (5-6) × 10(3) dm(3) mol(-1) cm(-1)] and a clearly discriminable absorption shoulder around 620 nm (ε(max) = (6-9) × 10(2) dm(3) mol(-1) cm(-1)), which tails up to 800 nm. These visible absorptions are assigned as a mixing of d(Ru) → ON(^)N metal-to-ligand charge-transfer and ON(^)N intraligand transitions on the basis of time-dependent density functional theory (TD-DFT) calculations. The first reduction couples of the nitrosated complexes range from -0.53 to -0.62 V vs Cp(2)Fe(+/0), which are 1.1-1.2 V less negative than that for [Ru(bpy)([14]aneS4)](2+) (bpy = 2,2'-bipyridine). Both electrochemical data and DFT calculations suggest that the lowest unoccupied molecular orbitals of the nitrosated complexes are ON(^)N-centered. Natural population

Electrochemical oxidation of chlorpheniramine at polytyramine film doped with ruthenium (II) complex: Measurement, kinetic and thermodynamic studies

International Nuclear Information System (INIS)

Khudaish, Emad A.; Al-Hinaai, Mohammed; Al-Harthy, Salim; Laxman, Karthik

2014-01-01

Highlights: • XPS data confirm doping of ruthenium onto the polytyramine moiety. • Doping of Ru decreases the Pty resistivity and increases the electron transfer kinetics. • The resulting sensor is stable for a large range of CPM concentration. • Estimated values of thermodynamic and kinetic parameters were comparable. • Application to commercial dosage forms was excellent and satisfactory. - Abstract: A solid-state sensor based on polytyramine film deposited at glassy carbon electrode doped with tris(2,2′-bipyridyl)Ru(II) complex (Ru/Pty/GCE) was constructed electrochemically. A redox property represented by [Ru(bpy) 3 ] 3+/2+ couple immobilized at the Pty moiety was characterized using typical voltammetric techniques. The XPS data and AFM images confirm the grafting of Ru species on the top of Pty while the electrochemical impedance spectroscopy (EIS) data supports the immobilization of both surface modifiers onto the GCE. The constructed sensor exhibits a substantial reactivity, stability and high sensitivity to chlorpheniramine maleate (CPM) oxidation. The detection limit (S/N = 3) was brought down to 338 nM using differential pulse voltammetry method. Thermodynamic and kinetic parameters were evaluated using hydrodynamic method. The apparent diffusion coefficient and the heterogeneous electron transfer rate constant for the CPM oxidation were 2.67 × 10 −5 cm 2 s −1 and 3.21 × 10 −3 cm s −1 , respectively. Interference studies and real sample analysis were conducted with excellent performance and satisfactory results

Robust binding between carbon nitride nanosheets and a binuclear ruthenium(II) complex enabling durable, selective CO{sub 2} reduction under visible light in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Kuriki, Ryo; Ishitani, Osamu; Maeda, Kazuhiko [Department of Chemistry, School of Science, Tokyo Institute of Technology (Japan); Yamamoto, Muneaki; Yoshida, Tomoko [Advanced Research Institute for Natural Science and Technology, Osaka City University (Japan); Higuchi, Kimitaka; Yamamoto, Yuta; Akatsuka, Masato; Yagi, Shinya [Institute of Materials and Systems for Sustainability, Nagoya University (Japan); Lu, Daling [Suzukakedai Materials Analysis Division, Technical Department, Tokyo Institute of Technology, Yokohama (Japan)

2017-04-18

Carbon nitride nanosheets (NS-C{sub 3}N{sub 4}) were found to undergo robust binding with a binuclear ruthenium(II) complex (RuRu') even in basic aqueous solution. A hybrid material consisting of NS-C{sub 3}N{sub 4} (further modified with nanoparticulate Ag) and RuRu' promoted the photocatalytic reduction of CO{sub 2} to formate in aqueous media, in conjunction with high selectivity (approximately 98 %) and a good turnover number (>2000 with respect to the loaded Ru complex). These represent the highest values yet reported for a powder-based photocatalytic system during CO{sub 2} reduction under visible light in an aqueous environment. We also assessed the desorption of RuRu' from the Ag/C{sub 3}N{sub 4} surface, a factor that can contribute to a loss of activity. It was determined that desorption is not induced by salt additives, pH changes, or photoirradiation, which partly explains the high photocatalytic performance of this material. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

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

Directory of Open Access Journals (Sweden)

Adewale O. Adeloye

2014-01-01

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

THE SYNTHESIS AND THE REACTIVITY OF ARENE RUTHENIUM ...

African Journals Online (AJOL)

a

[RuCl(η6-p-cymene)(η2-dppm)][PF6] ruthenium complexes with C2O4(Me4N)2 in the ... the Service de Microanalyse du CNRS (Vernaison/France). .... Once bonded to the Ru(II), the characterization of the oxalato ligand by infrared .... The 1H NMR spectrum shows signals of the aromatic proton resonances at 5.45 and 5.15,.

Amide Synthesis from Alcohols and Amines Catalyzed by Ruthenium N-Heterocyclic Carbene Complexes

DEFF Research Database (Denmark)

Dam, Johan Hygum; Osztrovszky, Gyorgyi; Nordstrøm, Lars Ulrik Rubæk

2010-01-01

The direct synthesis of amides from alcohols and amines is described with the simultaneous liberation of dihydrogen. The reaction does not require any stoichiometric additives or hydrogen acceptors and is catalyzed by ruthenium N-heterocyclic carbene complexes. Three different catalyst systems...... are presented that all employ 1,3-diisopropylimidazol-2-ylidene (IiPr) as the carbene ligand. In addition, potassium tert-butoxide and a tricycloalkylphosphine are required for the amidation to proceed. In the first system, the active catalyst is generated in situ from [RuCl2(cod)] (cod = 1,5-cyclooctadiene), 1...... chloride and base. A range of different primary alcohols and amines have been coupled in the presence of the three catalyst systems to afford the corresponding amides in moderate to excellent yields. The best results are obtained with sterically unhindered alcohols and amines. The three catalyst systems do...

Synthesis, DNA Cleavage Activity, Cytotoxicity, Acetylcholinesterase Inhibition, and Acute Murine Toxicity of Redox-Active Ruthenium(II) Polypyridyl Complexes.

Science.gov (United States)

Alatrash, Nagham; Narh, Eugenia S; Yadav, Abhishek; Kim, Mahn-Jong; Janaratne, Thamara; Gabriel, James; MacDonnell, Frederick M

2017-07-06

Four mononuclear [(L-L) 2 Ru(tatpp)] 2+ and two dinuclear [(L-L) 2 Ru(tatpp)Ru(L-L) 2 ] 4+ ruthenium(II) polypyridyl complexes (RPCs) containing the 9,11,20,22-tetraazatetrapyrido[3,2-a:2',3'-c:3'',2''-l:2''',3'''-n]pentacene (tatpp) ligand were synthesized, in which L-L is a chelating diamine ligand such as 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen), 3,4,7,8-tetramethyl-1,10-phenanthroline (Me 4 phen) or 4,7-diphenyl-1,10-phenanthroline (Ph 2 phen). These Ru-tatpp analogues all undergo reduction reactions with modest reducing agents, such as glutathione (GSH), at pH 7. These, plus several structurally related but non-redox-active RPCs, were screened for DNA cleavage activity, cytotoxicity, acetylcholinesterase (AChE) inhibition, and acute mouse toxicity, and their activities were examined with respect to redox activity and lipophilicity. All of the redox-active RPCs show single-strand DNA cleavage in the presence of GSH, whereas none of the non-redox-active RPCs do. Low-micromolar cytotoxicity (IC 50 ) against malignant H358, CCL228, and MCF7 cultured cell lines was mainly restricted to the redox-active RPCs; however, they were substantially less toxic toward nonmalignant MCF10 cells. The IC 50 values for AChE inhibition in cell-free assays and the acute toxicity of RPCs in mice revealed that whereas most RPCs show potent inhibitory action against AChE (IC 50 values <15 μm), Ru-tatpp complexes as a class are surprisingly well tolerated in animals relative to other RPCs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

New carboxy-functionalized terpyridines as precursors for zwitterionic ruthenium complexes for polymer-based solar cells

DEFF Research Database (Denmark)

Duprez, V.; Krebs, Frederik C

2006-01-01

New carboxy-terpyridines selectively functionalized at the 4-, 4'- and 4"-positions were prepared in a three-step procedure with good yields using, the Krohnke reaction followed by saponification. Their complexation with ruthenium led to symmetric and unsymmetric terpyridinyl zwitterionic complexes...

Synthesis and catalytic activity of ruthenium complexes modified with chiral racemic per- and polyfluorooxaalkanoates

Czech Academy of Sciences Publication Activity Database

Lipovská, P.; Rathouská, L.; Šimůnek, O.; Hošek, J.; Kolaříková, V.; Rybáčková, M.; Cvačka, Josef; Svoboda, Martin; Kvíčala, J.

2016-01-01

Roč. 191, Nov (2016), s. 14-22 ISSN 0022-1139 Institutional support: RVO:61388963 Keywords : racemic * chiral * ruthenium complex * perfluorooxaalkanoate * polyfluorooxaalkanoate Subject RIV: CC - Organic Chemistry Impact factor: 2.101, year: 2016

Synthesis, structural characterization and cytotoxic activity of two new organoruthenium(II complexes

Directory of Open Access Journals (Sweden)

SANJA GRGURIC-SIPKA

2008-06-01

Full Text Available Two new p-cymene ruthenium(II complexes containing as additional ligands N-methylpiperazine ([(η6-p-cymeneRuCl2(CH3NH(CH24NH]PF6, complex 1 or vitamin K3-thiosemicarbazone ([(η6-p-cymeneRuCl2(K3tsc], complex 2 were synthesized starting from [(η6-p-cymene2RuCl2]2 and the corresponding ligand. The complexes were characterized by elemental analysis, IR, electronic absorption and NMR spectroscopy. The X-ray crystal structure determination of complex 1 revealed “piano-stool” geometry. The differences in the cytotoxic activity of the two complexes are discussed in terms of the ligand present.

Detection of pyrrolizidine alkaloids using flow analysis with both acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence

International Nuclear Information System (INIS)

Gorman, Bree A.; Barnett, Neil W.; Bos, Richard

2005-01-01

For the first time, analytically useful chemiluminescence was elicited from the reactions of the pyrrolizidine alkaloids. Heliotrine, retronecine, supinine, monocrotaline and echinatine N-oxide yielded chemiluminescence upon reaction with tris(2,2'-bipyridyl)ruthenium(II) whilst lasiocarpine, its N-oxide and supinine elicited light upon reaction with acidic potassium permanganate. Detection limits for heliotrine were 1.25 x 10 -7 M and 9 x 10 -9 M for tris(2,2'-bipyridyl)ruthenium(III) perchlorate with flow injection analysis (FIA) and the silica-immobilised reagent (4-[4-(dichloromethylsilanyl)-butyl]-4'-methyl-2,2'-bipyridine)bis (2,2'-bipyridyl)ruthenium(II) with sequential injection analysis (SIA), respectively. Lasiocarpine was detectable at 1.4 x 10 -7 M using acidic potassium permanganate with FIA. Additionally, the silica-immobilised reagent was optimised with respect to the oxidant (ammonium ceric nitrate) concentration and the aspiration times which afforded a detection limit for codeine of 5 x 10 -10 M using SIA

Dinuclear ruthenium sawhorse-type complexes containing carboxylato bridges and ferrocenyl substituents: Synthesis and electrochemistry

Czech Academy of Sciences Publication Activity Database

Auzias, M.; Süss-Fink, G.; Štěpnička, P.; Ludvík, Jiří

2007-01-01

Roč. 360, č. 6 (2007), s. 2023-2028 ISSN 0020-1693 Institutional research plan: CEZ:AV0Z40400503 Keywords : carboxylato bridges * dinuclear complexes * ruthenium * electrochemistry Subject RIV: CG - Electrochemistry Impact factor: 1.713, year: 2007

Electrochemiluminescence and chemiluminescence of a carboxylic acid derivative of ruthenium(II) tris-(2,2'-bipyridine) chelate synthesized for labeling purposes

International Nuclear Information System (INIS)

Jiang Qinghong; Sun Shiguo; Hakansson, Markus; Langel, Kaarina; Ylinen, Tiina; Suomi, Johanna; Kulmala, Sakari

2006-01-01

Synthesis, purification and characterization of [4-ethoxycarbonyl-4'-carboxy-2,2'-bipyridine]bis(2,2'-bipyridine) ruthenium(II) hexafluorophosphate is described. This complex is shown to be electrochemiluminescent in aqueous solution during cathodic pulse polarization of thin insulating film-coated electrodes. Electrochemiluminescence (ECL) lifetime of the complex was observed to be ca. 40 μs at oxide-coated n-silicon electrodes; thus time-resolved detection is also possible. The ECL emission maximum of this carboxylate derivative is somewhat red-shifted when compared with an unmodified Ru(bpy) 3 2+ . Because the present complex can be easily covalently coupled with antibodies and oligonucleotides it is usable as an electrochemiluminescent label in various bioaffinity assays. The present chelates also produce strong chemiluminescence during dissolution of metallic magnesium in aqueous solution

Organoruthenium (II) complexes produced by insertion reactions of substituted olefins into a hydrido-ruthenium bond

Energy Technology Data Exchange (ETDEWEB)

Hiraki, Katsuma; Sasada, Yoko; Kitamura, Tsuneyuki [Nagasaki Univ. (Japan)

1980-04-01

Dimethyl fumarate, 2-vinylpyridine, and acrylonitrile insert into a H-Ru bond of (RuClH(CO)(PPh/sub 3/)/sub 3/) (1) to yield new substituted alkylruthenium(II) complexes. Methyl sorbate also reacted with 1 to give a new substituted eta/sup 3/-allylruthenium(II) complex.

Detection of pyrrolizidine alkaloids using flow analysis with both acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence

Energy Technology Data Exchange (ETDEWEB)

Gorman, Bree A. [School of Biological and Chemical Sciences, Deakin University, Geelong, Vic. 3217 (Australia); Barnett, Neil W. [School of Biological and Chemical Sciences, Deakin University, Geelong, Vic. 3217 (Australia)]. E-mail: barnie@deakin.edu.au; Bos, Richard [School of Biological and Chemical Sciences, Deakin University, Geelong, Vic. 3217 (Australia)

2005-06-13

For the first time, analytically useful chemiluminescence was elicited from the reactions of the pyrrolizidine alkaloids. Heliotrine, retronecine, supinine, monocrotaline and echinatine N-oxide yielded chemiluminescence upon reaction with tris(2,2'-bipyridyl)ruthenium(II) whilst lasiocarpine, its N-oxide and supinine elicited light upon reaction with acidic potassium permanganate. Detection limits for heliotrine were 1.25 x 10{sup -7} M and 9 x 10{sup -9} M for tris(2,2'-bipyridyl)ruthenium(III) perchlorate with flow injection analysis (FIA) and the silica-immobilised reagent (4-[4-(dichloromethylsilanyl)-butyl]-4'-methyl-2,2'-bipyridine)bis (2,2'-bipyridyl)ruthenium(II) with sequential injection analysis (SIA), respectively. Lasiocarpine was detectable at 1.4 x 10{sup -7} M using acidic potassium permanganate with FIA. Additionally, the silica-immobilised reagent was optimised with respect to the oxidant (ammonium ceric nitrate) concentration and the aspiration times which afforded a detection limit for codeine of 5 x 10{sup -10} M using SIA.

Flow-injection chemiluminescent determination of estrogen benzoate using the tris(1,10-phenanthroline) ruthenium(II)-permanganate system.

Science.gov (United States)

Ma, Yan; Cao, Wei; Qiao, Shuang; Liu, Wenwen; Yang, Jinghe

2011-01-01

Chemiluminescence (CL) detection for the determination of estrogen benzoate, using the reaction of tris(1,10-phenanthroline)ruthenium(II)-Na(2)SO(3)-permanganate, is described. This method is based on the CL reaction of estrogen benzoate (EB) with acidic potassium permanganate and tris(1,10-phenanthroline)ruthenium(II). The CL intensity is greatly enhanced when Na(2)SO(3) is added. After optimization of the different experimental parameters, a calibration graph for estrogen benzoate is linear in the range 0.05-10 µg/mL. The 3 s limit of detection is 0.024 µg/mL and the relative standard deviation was 1.3% for 1.0 µg/mL estrogen benzoate (n = 11). This proposed method was successfully applied to commercial injection samples and emulsion cosmetics. The mechanism of CL reaction was also studied. Copyright © 2011 John Wiley & Sons, Ltd.

1.3.3. Synthesis, characterization and crystal structure of a new ruthenium polypyridyl complex [Ru(phen2(4,4'-dicarboxy-2,2'- bipyridine]PF6

Directory of Open Access Journals (Sweden)

Jiaxi Chen, Jing Sun*, Jufang Kong, Wenxiu Chen and Hongqing Hao*

2015-03-01

Full Text Available Abstract: A new Ru(II polypyridyl complex, [Ru(phen2(4,4'-dicarboxy-2,2'-bipyridine]PF6·1.5H2O, was synthesized andcharacterized by single crystal X-ray diffraction, elementalanalyses, electrospray ionization mass spectrometry, infraredspectra, ultraviolet (UV spectra, and emission spectra. Thestructure of the cation [Ru(phen2(4,4'-(COO-,(COOH-2,2'-bpy]+ consists of a six-coordinated ruthenium atom chelated bytwo phen ligands and one 4,4'-dicarboxy-2,2'-bipyridine ligand.The absorption spectrum of the Ru(II complex is characterizedby two intense ligand-centered transitions in the UV region andone metal to ligand charge transfer in the visible region. Moreover,the complex can display luminescence in water at roomtemperature, with maximum emission at 623 nm.Supporting information: Cif file

Bioorthogonal Diversification of Peptides through Selective Ruthenium(II)-Catalyzed C-H Activation.

Science.gov (United States)

Schischko, Alexandra; Ren, Hongjun; Kaplaneris, Nikolaos; Ackermann, Lutz

2017-02-01

Methods for the chemoselective modification of amino acids and peptides are powerful techniques in biomolecular chemistry. Among other applications, they enable the total synthesis of artificial peptides. In recent years, significant momentum has been gained by exploiting palladium-catalyzed cross-coupling for peptide modification. Despite major advances, the prefunctionalization elements on the coupling partners translate into undesired byproduct formation and lengthy synthetic operations. In sharp contrast, we herein illustrate the unprecedented use of versatile ruthenium(II)carboxylate catalysis for the step-economical late-stage diversification of α- and β-amino acids, as well as peptides, through chemo-selective C-H arylation under racemization-free reaction conditions. The ligand-accelerated C-H activation strategy proved water-tolerant and set the stage for direct fluorescence labelling as well as various modes of peptide ligation with excellent levels of positional selectivity in a bioorthogonal fashion. The synthetic utility of our approach is further demonstrated by twofold C-H arylations for the complexity-increasing assembly of artificial peptides within a multicatalytic C-H activation manifold. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ruthenium(II)-catalysed remote C-H alkylations as a versatile platform to meta-decorated arenes

Science.gov (United States)

Li, Jie; Korvorapun, Korkit; de Sarkar, Suman; Rogge, Torben; Burns, David J.; Warratz, Svenja; Ackermann, Lutz

2017-06-01

The full control of positional selectivity is of prime importance in C-H activation technology. Chelation assistance served as the stimulus for the development of a plethora of ortho-selective arene functionalizations. In sharp contrast, meta-selective C-H functionalizations continue to be scarce, with all ruthenium-catalysed transformations currently requiring difficult to remove or modify nitrogen-containing heterocycles. Herein, we describe a unifying concept to access a wealth of meta-decorated arenes by a unique arene ligand effect in proximity-induced ruthenium(II) C-H activation catalysis. The transformative nature of our strategy is mirrored by providing a step-economical entry to a range of meta-substituted arenes, including ketones, acids, amines and phenols--key structural motifs in crop protection, material sciences, medicinal chemistry and pharmaceutical industries.

Characterisation and application of new carboxylic acid-functionalised ruthenium complexes as dye-sensitisers for solar cells

DEFF Research Database (Denmark)

Duprez, Virginie; Biancardo, Matteo; Krebs, Frederik C

2007-01-01

A series of ruthenium complexes with and without TiO2, anchoring carboxylic acid groups have been synthesised and characterised using nuclear magnetic resonance (NMR), UV-vis and luminescence. These complexes were adsorbed on thin films of the wide band-gap semiconductor anatase and were tested a...

DNA effects upon the reaction between acetonitrile pentacyanoferrate (II) and ruthenium pentammine pyrazine: Kinetic and thermodynamic evidence of the interaction of DNA with anionic species

International Nuclear Information System (INIS)

Grueso, E.; Prado-Gotor, R.; Lopez, M.; Gomez-Herrera, C.; Sanchez, F.

2005-01-01

The kinetics of the reaction between ruthenium pentaammine pyrazine and acetonitrile pentacyanoferrate (II) to obtain the binuclear anionic complex [Fe(CN) 5 pzRu(NH 3 ) 5 ] - , and the reverse (dissociation) process, have been studied in solutions containing DNA. The results corresponding to this reaction and those corresponding to the reverse (dissociation) process show a clear influence of DNA on their kinetics. The results can be interpreted using a modified Pseudophase Model. From the results obtained for the dissociation reaction one can conclude that the binuclear anionic complex [Fe(CN) 5 pzRu(NH 3 ) 5 ] - interacts with DNA

Ruthenium complexing in sorption by granulated sorbents with ethylene diamine and diethyl amine groups

International Nuclear Information System (INIS)

Simanova, S.A.; Kolmakova, A.I.; Konovalov, L.V.; Kukushkin, Yu.N.; Kalalova, E.

1986-01-01

The sorption process of ruthenium (4) chlorocomplexes - K 2 (RuCl 6 ) macroporous granulated copolymers of glycidylmethacrylate ethylene dimethacrylate with ethylene diamine and diethyl amine has been studied. Sorption has been carried out under the static conditions (at 20 and 98 deg C) from 0.1-2.0 MxHCl and 1.0 M NaCl solutions. It is established that the sorption from acidic solutions proceeds according to anion exchange mechanism with formation of onium chlorocomplexes in the sorbent phase, subjecting to Anderson regrouping during the heating. During the sorption from neutral solutions the second-sphere coordination of polymer amino groups accirs near ruthenium atom and amino-chloride complexes are formed in the sorbent phase

Ruthenium-complex catalyzed N-(cyclo)alkylation of aromatic amines with diols. Selective synthesis of N-(n-hydroixyalkyl)anilines of type PhNH(CH2)nOH and of some bioactive arylpiperazines,

NARCIS (Netherlands)

Koten, G. van; Abbenhuis, R.A.T.M.; Boersma, J.

1998-01-01

A new class of well-defined neutral mono-, and dicationic ruthenium(II) complexes containing a neutral terdentate donor system [C5H3N(CH2E)(2)-2,6] (E = PPh2 (PNP) or NMe2 (NN'N)) has been found effective as catalyst precursor in N-(cyclo)alkylation reactions of aromatic amines with diols

Through-Space Paramagnetic NMR Effects in Host-Guest Complexes: Potential Ruthenium(III) Metallodrugs with Macrocyclic Carriers.

Science.gov (United States)

Chyba, Jan; Novák, Martin; Munzarová, Petra; Novotný, Jan; Marek, Radek

2018-04-05

The potential of paramagnetic ruthenium(III) compounds for use as anticancer metallodrugs has been investigated extensively during the past several decades. However, the means by which these ruthenium compounds are transported and distributed in living bodies remain relatively unexplored. In this work, we prepared several novel ruthenium(III) compounds with the general structure Na + [ trans-Ru III Cl 4 (DMSO)(L)] - (DMSO = dimethyl sulfoxide), where L stands for pyridine or imidazole linked with adamantane, a hydrophobic chemophore. The supramolecular interactions of these compounds with macrocyclic carriers of the cyclodextrin (CD) and cucurbit[ n]uril (CB) families were investigated by NMR spectroscopy, X-ray diffraction analysis, isothermal titration calorimetry, and relativistic DFT methods. The long-range hyperfine NMR effects of the paramagnetic guest on the host macrocycle are related to the distance between them and their relative orientation in the host-guest complex. The CD and CB macrocyclic carriers being studied in this account can be attached to a vector that attracts the drug-carrier system to a specific biological target and our investigation thus introduces a new possibility in the field of targeted delivery of anticancer metallodrugs based on ruthenium(III) compounds.

Half -sand wish ruthenium complexes of heterocyclic-dithio carboxylato ligands

International Nuclear Information System (INIS)

El-khateeb, M.; Al-Noaimi, M.; Harb, M.; Gorls, H.; Weigand, W.

2008-01-01

The heterocyclic-dithio carboxylato complexes Cp Ru(PPh 3 )(κ 2 S,S-S 2 C-h et) [h et= 2-C 4 H 3 O (1), 2-C 4 H 3 S (2), 1-C 4 H 8 N (3)] are obtained by the reaction of the ruthenium chloride, Cp Ru(PPh 3 ) 2 CI, with the anions, h et-CS 2 . The X-ray structure of Cp Ru(PPh 3 )(κ 2 S, S-S 2 C-1- C 4 H 8 N) (3) is determined by single crystal X-ray diffraction.

Kinetic effects of sulfur oxidation on catalytic nitrile hydration: nitrile hydratase insights from bioinspired ruthenium(II) complexes.

Science.gov (United States)

Kumar, Davinder; Nguyen, Tho N; Grapperhaus, Craig A

2014-12-01

Kinetic investigations inspired by the metalloenzyme nitrile hydratase were performed on a series of ruthenium(II) complexes to determine the effect of sulfur oxidation on catalytic nitrile hydration. The rate of benzonitrile hydration was quantified as a function of catalyst, nitrile, and water concentrations. Precatalysts L(n)RuPPh3 (n = 1-3; L(1) = 4,7-bis(2'-methyl-2'-mercapto-propyl)-1-thia-4,7-diazacyclononane; L(2) = 4-(2'-methyl-2'-sulfinatopropyl)-7-(2'-methyl-2'-mercapto-propyl)-1-thia-4,7-diazacyclononane; L(3) = 4-(2'-methyl-2'-sulfinatopropyl)-7-(2'-methyl-2'-sulfenato-propyl)-1-thia-4,7-diazacyclononane) were activated by substitution of triphenylphosphine with substrate in hot dimethylformamide solution. Rate measurements are consistent with a dynamic equilibrium between inactive aqua (L(n)Ru-OH2) and active nitrile (L(n)Ru-NCR) derivatives with K = 21 ± 1, 9 ± 0.9, and 23 ± 3 for L(1) to L(3), respectively. Subsequent hydration of the L(n)Ru-NCR intermediate yields the amide product with measured hydration rate constants (k's) of 0.37 ± 0.01, 0.82 ± 0.07, and 1.59 ± 0.12 M(-1) h(-1) for L(1) to L(3), respectively. Temperature dependent studies reveal that sulfur oxidation lowers the enthalpic barrier by 27 kJ/mol, but increases the entropic barrier by 65 J/(mol K). Density functional theory (DFT) calculations (B3LYP/LanL2DZ (Ru); 6-31G(d) (all other atoms)) support a nitrile bound catalytic cycle with lowering of the reaction barrier as a consequence of sulfur oxidation through enhanced nitrile binding and attack of the water nucleophile through a highly organized transition state.

(II) complexes as sensitizers for dye sensitized solar cells

Indian Academy of Sciences (India)

dimethyl-3-propyl-1 H-imidazol-3-ium iodide (DMPII),. 4-tert-butyl-pyridine (TBP) and ... cymene) ruthenium(II) dimer was synthesized according to the reported ... saturated ammonium chloride (200 ml) solution was added to decompose the ...

Distinction of tris(diimine)ruthenium(II) enantiomers chiral by virtue of helical chirality: temperature-dependent deuterium NMR spectroscopy in partially oriented phases.

Science.gov (United States)

Szalontai, Gábor; Kovács, Margit

2006-11-01

2H NMR spectra of perdeuterated tris(diimine)ruthenium(II) complexes have been recorded in lyotropic liquid crystalline phase formed by the chiral polypeptide, poly-gamma-benzyl-L-glutamate (PBLG) and co-solvents. It is demonstrated that the left- and right-rotation isomers of these octahedral metal complexes with D3 symmetry can be distinguished. The effects of temperature and ligand size on spectral resolution were also studied. Although in the case of free bipyridine ligands excellent optical resolution could be obtained at room temperature in the complexes studied, the increase in ligand size has a detrimental effect on the resolution. This can be compensated to some extent by elevating the sample temperature and decreasing the deuterium relaxation rates, but the available temperature range and therefore the applicability of the technique are limited. Copyright 2006 John Wiley & Sons, Ltd.

Cyclometallated ruthenium(II) carbonyl complexes with 1 ...

Indian Academy of Sciences (India)

The characterization of the complexes having the ... Electronic spectra of the complexes display multiple strong absorptions in the ... Microanalyses (CHN) were performed by using a ..... proton.47,49 Absence of this signal in the spectra of.

Ruthenium Sensitizers and Their Applications in Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Yuancheng Qin

2012-01-01

Full Text Available Dye-sensitized solar cells (DSSCs have attracted considerable attention in recent years due to the possibility of low-cost conversion of photovoltaic energy. The DSSCs-based ruthenium complexes as sensitizers show high efficiency and excellent stability, implying potential practical applications. This review focuses on recent advances in design and preparation of efficient ruthenium sensitizers and their applications in DSSCs, including thiocyanate ruthenium sensitizers and thiocyanate-free ruthenium sensitizers.

Chemical vapor deposition of amorphous ruthenium-phosphorus alloy films

International Nuclear Information System (INIS)

Shin Jinhong; Waheed, Abdul; Winkenwerder, Wyatt A.; Kim, Hyun-Woo; Agapiou, Kyriacos; Jones, Richard A.; Hwang, Gyeong S.; Ekerdt, John G.

2007-01-01

Chemical vapor deposition growth of amorphous ruthenium-phosphorus films on SiO 2 containing ∼ 15% phosphorus is reported. cis-Ruthenium(II)dihydridotetrakis-(trimethylphosphine), cis-RuH 2 (PMe 3 ) 4 (Me = CH 3 ) was used at growth temperatures ranging from 525 to 575 K. Both Ru and P are zero-valent. The films are metastable, becoming increasingly more polycrystalline upon annealing to 775 and 975 K. Surface studies illustrate that demethylation is quite efficient near 560 K. Precursor adsorption at 135 K or 210 K and heating reveal the precursor undergoes a complex decomposition process in which the hydride and trimethylphosphine ligands are lost at temperatures as low at 280 K. Phosphorus and its manner of incorporation appear responsible for the amorphous-like character. Molecular dynamics simulations are presented to suggest the local structure in the films and the causes for phosphorus stabilizing the amorphous phase

Covalent attachment of pyridine-type molecules to glassy carbon surfaces by electrochemical reduction of in situ generated diazonium salts. Formation of ruthenium complexes on ligand-modified surfaces

International Nuclear Information System (INIS)

Yesildag, Ali; Ekinci, Duygu

2010-01-01

In this study, pyridine, quinoline and phenanthroline molecules were covalently bonded to glassy carbon (GC) electrode surfaces for the first time using the diazonium modification method. Then, the complexation ability of the modified films with ruthenium metal cations was investigated. The derivatization of GC surfaces with heteroaromatic molecules was achieved by electrochemical reduction of the corresponding in situ generated diazonium salts. X-ray photoelectron spectroscopy (XPS) was used to confirm the attachment of heteroaromatic molecules to the GC surfaces and to determine the surface concentration of the films. The barrier properties of the modified GC electrodes were studied in the presence of redox probes such as Fe(CN) 6 3- and Ru(NH 3 ) 6 3+ by cyclic voltammetry. Additionally, the presence of the resulting organometallic films on the surfaces was verified by XPS after the chemical transformation of the characterized ligand films to the ruthenium complex films. The electrochemical behavior of these films in acetonitrile solution was investigated using voltammetric methods, and the surface coverage of the organometallic films was determined from the reversible metal-based Ru(II)/Ru(III) oxidation waves.

The effect of annealing temperature on the optical properties of a ruthenium complex thin film

Energy Technology Data Exchange (ETDEWEB)

Ocakoglu, Kasim, E-mail: kasim.ocakoglu@mersin.edu.tr [Advanced Technology Research & Application Center, Mersin University, TR-33343, Yenisehir, Mersin (Turkey); Department of Energy Systems Engineering, Faculty of Technology, Mersin University, TR-33480 Mersin (Turkey); Okur, Salih, E-mail: salih.okur@ikc.edu.tr [Department of Materials Science and Engineering, Faculty of Engineering and Architecture, Izmir Katip Celebi University, Izmir (Turkey); Aydin, Hasan [Izmir Institute of Technology, Department of Material Science and Engineering, Gulbahce Campus, 35430, Urla, Izmir (Turkey); Emen, Fatih Mehmet [Faculty of Arts and Sciences, Department of Chemistry, Mehmet Akif Ersoy University, TR-15030 Burdur (Turkey)

2016-08-01

The stability of the optical parameters of a ruthenium polypyridyl complex (Ru-PC K314) film under varying annealing temperatures between 278 K and 673 K was investigated. The ruthenium polypyridyl complex thin film was prepared on a quartz substrate by drop casting technique. The transmission of the film was recorded by using Ultraviolet/Visible/Near Infrared spectrophotometer and the optical band gap energy of the as-deposited film was determined around 2.20 eV. The optical parameters such as refractive index, extinction coefficient, and dielectric constant of the film were determined and the annealing effect on these parameters was investigated. The results show that Ru PC K314 film is quite stable up to 595 K, and the rate of the optical band gap energy change was found to be 5.23 × 10{sup −5} eV/K. Furthermore, the thermal analysis studies were carried out in the range 298–673 K. The Differential Thermal Analysis/Thermal Gravimmetry/Differantial Thermal Gravimmetry curves show that the decomposition is incomplete in the temperature range 298–673 K. Ru-PC K314 is thermally stable up to 387 K. The decomposition starts at 387 K with elimination of functional groups such as CO{sub 2}, CO molecules and SO{sub 3}H group was eliminated between 614 K and 666 K. - Highlights: • Optical parameters of a ruthenium polypyridyl complex film under varying annealing temperatures • The film is quite stable up to 573 K. • The rate of change of optical energy gap was obtained as 5.23 × 10{sup −5} eV/K.

Thiolato-bridged RuIIAgIRuII trinuclear complex composed of bis(bipyridine)ruthenium(II) units with chelating 2-aminoethanethiolate: conversion to a disulfide-bridged RuIIRuII dinuclear complex.

Science.gov (United States)

Tamura, Motoshi; Matsuura, Noriyuki; Kawamoto, Tatsuya; Konno, Takumi

2007-08-20

The reaction of [Ru(solvent)2(bpy)2]2+ (bpy = 2,2'-bipyridine) with Haet (2-aminoethanethiol) in ethanol/water in the presence of Ag+ gave a thiolato-bridged RuIIAgIRuII trinuclear complex, [Ag{Ru(aet)(bpy)2}2]3+, in which two [RuII(aet)(bpy)2]+ units are linked by an AgI atom. When this complex was treated with HCl in acetonitrile/water, a disulfide-bridged RuIIRuII dinuclear complex, [Ru2(cysta)(bpy)4]4+ (cysta = cystamine), was produced as a result of the removal of an AgI atom and the autoxidation of thiolato groups. It was found that the dinuclear structure in [Ru2(cysta)(bpy)4]4+ is reverted back to [Ag{Ru(aet)(bpy)2}2]3+ by treatment with Ag+ assisted by Zn reduction.

Photolabile ruthenium complexes to cage and release a highly cytotoxic anticancer agent.

Science.gov (United States)

Wei, Jianhua; Renfrew, Anna K

2018-02-01

CHS-828 (N-(6-(4-chlorophenoxy)hexyl)-N'-cyano-N″-4-pyridyl guanidine) is an anticancer agent with low bioavailability and high systemic toxicity. Here we present an approach to improve the therapeutic profile of the drug using photolabile ruthenium complexes to generate light-activated prodrugs of CHS-828. Both prodrug complexes are stable in the dark but release CHS-828 when irradiated with visible light. The complexes are water-soluble and accumulate in tumour cells in very high concentrations, predominantly in the mitochondria. Both prodrug complexes are significantly less cyototoxic than free CHS-828 in the dark but their toxicity increases up to 10-fold in combination with visible light. The cellular responses to light treatment are consistent with release of the cytotoxic CHS-828 ligand. Copyright © 2017 Elsevier Inc. All rights reserved.

Cell cycle, apoptosis, cellular uptake and whole-transcriptome microarray gene expression analysis of HeLa cells treated with a ruthenium(II)-arene complex with an isoquinoline-3-carboxylic acid ligand.

Science.gov (United States)

Jovanović, Katarina K; Tanić, Miljana; Ivanović, Ivanka; Gligorijević, Nevenka; Dojčinović, Biljana P; Radulović, Siniša

2016-10-01

Ruthenium(II)-arene complexes are promising drug candidates for the therapy of solid tumors. In previous work, seven new compounds of the general formula [Ru(η 6 -p-cymene)(L 1-7 )Cl] were synthesized and characterized, of which the complex with L=isoquinoline-3-carboxylic acid (RuT 7 ) was two times as active on HeLa cells compared to normal cell line MRC-5, as indicated by IC 50 values determined after 48h of incubation (45.4±3.0 vs. 84.2±5.7μM, respectively). In the present study, cell cycle analysis of HeLa cells treated with RuT 7 showed S phase arrest and an increase in sub-G1 population. The apoptotic potential of the title compound was confirmed with the Annexin V-FITC/PI assay together with a morphological evaluation of cells using fluorescent microscopy. Analysis of the intracellular accumulation of ruthenium showed 8.9ng Ru/10 6 cells after 6h of incubation. To gain further insight in the molecular mechanism of action of RuT 7 on HeLa cells, a whole-transcriptome microarray gene expression analysis was performed. Analysis of functional categories and signaling and biochemical pathways associated with the response of HeLa cells to treatment with RuT 7 showed that it leads the cells through the intrinsic (mitochondrial) apoptotic pathway, via indirect DNA damage due to the action of reactive oxygen species, and through direct DNA binding of RuT 7 . Statistical analysis for enrichment of gene sets associated with known drug-induced toxicities identified fewer associated toxicity profiles in RuT 7 -treated cells compared to cisplatin treatment. Altogether these results provide the basis for further development of RuT 7 in animal and pre-clinical studies as a potential drug candidate. Copyright © 2016 Elsevier Inc. All rights reserved.

Coordinatively unsaturated ruthenium complexes as efficient alkyneazide cycloaddition catalysts

KAUST Repository

Lamberti, Marina

2012-01-23

The performance of 16-electron ruthenium complexes with the general formula Cp*Ru(L)X (in which L = phosphine or N-heterocyclic carbene ligand; X = Cl or OCH2CF3) was explored in azidealkyne cycloaddition reactions that afford the 1,2,3- triazole products. The scope of the Cp*Ru(PiPr 3)Cl precatalyst was investigated for terminal alkynes leading to new 1,5-disubstituted 1,2,3-triazoles in high yields. Mechanistic studies were conducted and revealed a number of proposed intermediates. Cp*Ru- (PiPr3)(2-HCCPh)Cl was observed and characterized by 1H, 13C, and 31P NMR at temperatures between 273 and 213 K. A rare example of N,N-κ2-phosphazide complex, Cp*Ru(κ2- iPr3PN3Bn)Cl, was fully characterized, and a single-crystal X-ray diffraction structure was obtained. DFT calculations describe a complete map of the catalytic reactivity with phenylacetylene and/or benzylazide. © 2012 American Chemical Society.

Coordinatively unsaturated ruthenium complexes as efficient alkyneazide cycloaddition catalysts

KAUST Repository

Lamberti, Marina; Fortman, George C.; Poater, Albert; Broggi, Julie; Slawin, Alexandra M. Z.; Cavallo, Luigi; Nolan, Steven P.

2012-01-01

The performance of 16-electron ruthenium complexes with the general formula Cp*Ru(L)X (in which L = phosphine or N-heterocyclic carbene ligand; X = Cl or OCH2CF3) was explored in azidealkyne cycloaddition reactions that afford the 1,2,3- triazole products. The scope of the Cp*Ru(PiPr 3)Cl precatalyst was investigated for terminal alkynes leading to new 1,5-disubstituted 1,2,3-triazoles in high yields. Mechanistic studies were conducted and revealed a number of proposed intermediates. Cp*Ru- (PiPr3)(2-HCCPh)Cl was observed and characterized by 1H, 13C, and 31P NMR at temperatures between 273 and 213 K. A rare example of N,N-κ2-phosphazide complex, Cp*Ru(κ2- iPr3PN3Bn)Cl, was fully characterized, and a single-crystal X-ray diffraction structure was obtained. DFT calculations describe a complete map of the catalytic reactivity with phenylacetylene and/or benzylazide. © 2012 American Chemical Society.

Separation of the noble metals ruthenium and palladium from nitric acid solution of the nuclear fuel reprocessing containing complexing agents

International Nuclear Information System (INIS)

Ghafourian, H.

1989-06-01

Two extraction chromatographic techniques have been developed. N'N diethylthiourea (DETU), which forms complexes with ruthenium that can be retained on an AG50W-X2 ion exchanger, has proved to be a suitable reagent. The structures of these complexes were elucidated by electrophoresis, ion exchange and IR spectroscopy. Under the same conditions Pd forms an insoluble DETU-complex of the formula [Pd(DETU) 4 ] 2+ , which allows the separation of this metal quantitatively. With regard to the application of the developed technique for recovery of the mentioned noble metals from dissolver residues of the nuclear fuel reprocessing, comparative studies were carried out for accompanying fission product nuclides and actinides such as Mo, Tc, Zr, Ce, U and Pu. It was found out that no complex between diethylthiourea and the fission products zirconium, molybdenum and cerium and the actinides uranium, plutonium and americium were formed. Technetium, which was originally present as pertechnetate, is reduced to Tc(IV) and retained on the cation exchanger together with ruthenium. Ruthenium was eluted with 6 M HNO 3 . The efficiency of the developed process has been demonstrated with simulated solutions. The achieved decontamination factors ranged from 10 2 to 10 6 depending on the nuclide. (orig./RB) [de

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

Science.gov (United States)

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

2014-04-01

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

Hydrogenation of esters catalyzed by ruthenium PN3-Pincer complexes containing an aminophosphine arm

KAUST Repository

Chen, Tao

2014-08-11

Hydrogenation of esters under mild conditions was achieved using air-stable ruthenium PN3-pincer complexes containing an aminophosphine arm. High efficiency was achieved even in the presence of water. DFT studies suggest a bimolecular proton shuttle mechanism which allows H2 to be activated by the relatively stable catalyst with a reasonably low transition state barrier. © 2014 American Chemical Society.

Caprolactone-based bipyridine macroligands for novel ruthenium polypyridyl complexes for applications in dye-sensitized solar cells

NARCIS (Netherlands)

Marin, V.N.; Holder, E.; Hoogenboom, R.; Schubert, U.S.

2004-01-01

In an attempt to reduce electrolyte loss in solar cells, the use of sold or quasi-solid state electrolytes is advantageous. The authors synthesized a metal contg. polymer via two synthetic pathways. In the first, a bipyridine-bisphenanthroline ruthenium metal complex with a hydroxy functionality was

The contrasting chemistry and cancer cell cytotoxicity of bipyridine and bipyridinediol ruthenium(II) arene complexes

Czech Academy of Sciences Publication Activity Database

Bugarcic, T.; Habtemariam, A.; Štěpánková, Jana; Heringová, Pavla; Kašpárková, Jana; Deeth, R.J.; Johnstone, R.D.L.; Prescimone, A.; Parkin, A.; Parsons, S.; Brabec, Viktor; Sadler, P.J.

2008-01-01

Roč. 47, č. 24 (2008), s. 11470-11486 ISSN 0020-1669 R&D Projects: GA MŠk(CZ) LC06030; GA MŠk(CZ) ME08017; GA MŠk(CZ) OC08003; GA AV ČR(CZ) 1QS500040581; GA AV ČR(CZ) KAN200200651; GA AV ČR(CZ) IAA400040803; GA MZd(CZ) NR8562 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : DNA * ruthenium * cancer Subject RIV: BO - Biophysics Impact factor: 4.147, year: 2008

Highly efficient quenching of tris(2,2'-bipyridyl)ruthenium(II) electrochemiluminescence by ozone using formaldehyde, methylglyoxal, and glyoxalate as co-reactants and its application to ozone sensing.

Science.gov (United States)

Gao, Ying; Liu, Xiaoyun; Qi, Wenjing; Gao, Wenyue; Li, Yunhui; Xu, Guobao

2015-06-21

Most electrochemiluminescence (ECL) systems require high concentrations of quencher to totally quench ECL. In this study, we found that ozone can quench tris(2,2'-bipyridyl)ruthenium(II) ECL using formaldehyde, methylglyoxal, or glyoxalate as co-reactants at a glassy carbon electrode with remarkable efficiencies even when the concentration of ozone is merely 0.25% of that of the co-reactant. The strongest quenching is observed with the tris(2,2'-bipyridyl)ruthenium(II)/formaldehyde ECL system. The tris(2,2'-bipyridyl)ruthenium(II)/formaldehyde ECL intensities decrease linearly with the ozone concentration over the range of 0.025-25 μM (r = 0.9947) with a limit of detection of 8 nM. The method is more sensitive and faster than most methods. It shows high selectivity in the presence of other ROS or oxidants and some metal ions, such as H2O2, ClO(-), Mg(2+), Ni(2+), etc. The method exhibits high recoveries for the detection of ozone in a ventilated photocopy room.

Dual triggering of DNA binding and fluorescence via photoactivation of a dinuclear ruthenium(II) arene complex

Czech Academy of Sciences Publication Activity Database

Magennis, S.W.; Habtemariam, A.; Nováková, Olga; Henry, J.B.; Meier, S.; Parsons, S.; Oswald, D.H.; Brabec, Viktor; Sadler, P.J.

2007-01-01

Roč. 46, č. 12 (2007), s. 5059-5068 ISSN 0020-1669 R&D Projects: GA ČR(CZ) GA203/06/1239; GA ČR(CZ) GA305/05/2030; GA AV ČR(CZ) 1QS500040581; GA AV ČR(CZ) KAN200200651 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : DNA * ruthenium * fluorescence Subject RIV: BO - Biophysics Impact factor: 4.123, year: 2007

Covalent attachment of pyridine-type molecules to glassy carbon surfaces by electrochemical reduction of in situ generated diazonium salts. Formation of ruthenium complexes on ligand-modified surfaces

Energy Technology Data Exchange (ETDEWEB)

Yesildag, Ali [Department of Chemistry, Faculty of Sciences, Atatuerk University, 25240 Erzurum (Turkey); Ekinci, Duygu, E-mail: dekin@atauni.edu.t [Department of Chemistry, Faculty of Sciences, Atatuerk University, 25240 Erzurum (Turkey)

2010-09-30

In this study, pyridine, quinoline and phenanthroline molecules were covalently bonded to glassy carbon (GC) electrode surfaces for the first time using the diazonium modification method. Then, the complexation ability of the modified films with ruthenium metal cations was investigated. The derivatization of GC surfaces with heteroaromatic molecules was achieved by electrochemical reduction of the corresponding in situ generated diazonium salts. X-ray photoelectron spectroscopy (XPS) was used to confirm the attachment of heteroaromatic molecules to the GC surfaces and to determine the surface concentration of the films. The barrier properties of the modified GC electrodes were studied in the presence of redox probes such as Fe(CN){sub 6}{sup 3-} and Ru(NH{sub 3}){sub 6}{sup 3+} by cyclic voltammetry. Additionally, the presence of the resulting organometallic films on the surfaces was verified by XPS after the chemical transformation of the characterized ligand films to the ruthenium complex films. The electrochemical behavior of these films in acetonitrile solution was investigated using voltammetric methods, and the surface coverage of the organometallic films was determined from the reversible metal-based Ru(II)/Ru(III) oxidation waves.

Mathematical modelling of brittle phase precipitation in complex ruthenium containing nickel-based superalloys

International Nuclear Information System (INIS)

Rettig, Ralf

2010-01-01

A new model has been developed in this work which is capable of simulating the precipitation kinetics of brittle phases, especially TCP-phases (topologically close packed phases) in ruthenium containing superalloys. The model simultaneously simulates the nucleation and the growth stage of precipitation for any number of precipitating phases. The CALPHAD method (Calculation of Phase Diagrams) is employed to calculate thermodynamic properties, such as the driving force or phase compositions in equilibrium. For calculation of diffusion coefficients, kinetic mobility databases which are also based on the CALPHAD-method are used. The model is fully capable of handling multicomponent effects, which are common in complex superalloys. Metastable phases can be treated and will automatically be dissolved if they get unstable. As the model is based on the general CALPHAD method, it can be applied to a broad range of precipitation processes in different alloys as long as the relevant thermodynamic and kinetic databases are available. The developed model proves that the TCP-phases precipitate in a sequence of phases. The first phase that is often formed is the metastable σ-phase because it has the lowest interface energy due to low-energy planes at the interface between matrix and precipitate. After several hundred hours the stable μ- and P-phases start to precipitate by nucleating at the σ-phase which is energetically favourable. During the growth of these stable phases the sigma-phase is continuously dissolved. It can be shown by thermodynamic CALPHAD calculations that the sigma-phase has a lower Gibbs free enthalpy than the μ- and P-phase. All required parameters of the model, such as interface energy and nucleate densities, have been estimated. The mechanisms of suppression of TCP-phase precipitation in the presence of ruthenium in superalloys were investigated with the newly developed model. It is shown by the simulations that ruthenium mostly affects the nucleation

Electrochemical Sensing of Casein Based on the Interaction between Its Phosphate Groups and a Ruthenium(III) Complex.

Science.gov (United States)

Inaba, Iku; Kuramitz, Hideki; Sugawara, Kazuharu

2016-01-01

A reaction to casein, along with β-lactoglobulin, is a main cause of milk allergies, and also is a useful indicator of protein in allergic analyses. In the present study, a simple casein sensor was developed based on the interaction between a phosphate group of casein and electroactive [Ru(NH3)6](3+). We evaluated the voltammetric behavior of a casein-[Ru(NH3)6](3+) complex using a glassy carbon electrode. When the ruthenium(III) complex was combined with the phosphate groups of casein, the structure of the casein was changed. Since the hydrophobicity of casein was increased due to the binding, the casein was adsorbed onto the electrode. Furthermore, we modified an electrode with a ruthenium(III) ions/collagen film. When the sensor was applied to the detection of the casein contained in milk, the values coincided with those indicated by the manufacturer. Accordingly, this electrode could be a powerful sensor for the determination of casein in several foods.

Iodide Ion Pairing with Highly Charged Ruthenium Polypyridyl Cations in CH3CN.

Science.gov (United States)

Swords, Wesley B; Li, Guocan; Meyer, Gerald J

2015-05-04

A series of three highly charged cationic ruthenium(II) polypyridyl complexes of the general formula [Ru(deeb)3-x(tmam)x](PF6)2x+2, where deeb is 4,4'-diethyl ester-2,2'-bipyridine and tmam is 4,4'-bis[(trimethylamino)methyl]-2,2'-bipyridine, were synthesized and characterized and are referred to as 1, 2, or 3 based on the number of tmam ligands. Crystals suitable for X-ray crystallography were obtained for the homoleptic complex 3, which was found to possess D3 symmetry over the entire ruthenium complex. The complexes displayed visible absorption spectra typical of metal-to-ligand charge-transfer (MLCT) transitions. In acetonitrile, quasi-reversible waves were assigned to Ru(III/II) electron transfer, with formal reduction potentials that shifted negative as the number of tmam ligands was increased. Room temperature photoluminescence was observed in acetonitrile with quantum yields of ϕ ∼ 0.1 and lifetimes of τ ∼ 2 μs. The spectroscopic and electrochemical data were most consistent with excited-state localization on the deeb ligand for 1 and 2 and on the tmam ligand for 3. The addition of tetrabutylammonium iodide to the complexes dissolved in a CH3CN solution led to changes in the UV-vis absorption spectra consistent with ion pairing. A Benesi-Hildebrand-type analysis of these data revealed equilibrium constants that increased with the cationic charge 1 10(8) s(-1). The possible relevance of this work to solar energy conversion and dye-sensitized solar cells is discussed.

Determination of microgramme amounts of osmium and ruthenium based on inhibition of the iodine-azide reaction by their complexes with 6-mercaptopurine

International Nuclear Information System (INIS)

Matusiewicz, H.; Kurzawa, Z.

1976-01-01

A new kinetic method of the determination of microamounts of osmium and ruthenium has been developed. The reaction between sodum azide and iodine induced by 6-mercaptopurine (6-MP) was used for this purpose. Under suitable experimental conditions the induction coefficient of 6-MP amounts to 1750+-40. The formed complexes of the metals are stable in the medium containing an excess of azide ions and do not induce the iodine-azide reaction. The method consists in the determination of the 6-MP not bound to the metal. The amount of osmium or ruthenium is then determined from linear relations. Before the determination osmium and ruthenium must be separated from other cations and from each other by distillation as volatile tetroxides. The iodine-azide method is simple, sensitive and does not require any apparatus. The range of the determination is 0.1-5.0 μg in 5 cm 3 of the solution of Os(8) and 0.5-5.0 μg for Ru(8). The error of the determination is +-6.4% and +- 6.1% for osmium and ruthenium, respectively. The time of the determination is 30 minutes not taking into account 2-hour waiting time necessary for the formation of the complexes. (author)

Ruthenium sulfoxides structure and reactivity with nitrogen heterocyclic bases

International Nuclear Information System (INIS)

Oliveira, Denise de.

1990-01-01

Ruthenium (II) sulfoxides are compounds of great interest in oxidative catalysis and in chemotherapy. In order to contribute for the understanding of the chemistry and electronic structure of this class of compounds, it has been studied a series of [Ru Cl 2 (S-DMSO) 2 L x ] complexes, where x = 1 (polymeric compounds) or 2 (monomers) and L N-heterocyclic ligands (pyridine, pyrazine and imidazole derivatives). The nature of N-heterocyclic ligand and their coordination are of great relevance to the stability, spectroscopic and electrochemical characteristics of the complexes. The trans-interactions are extremely important in this series, influencing the strength of the Ru(II)-> S-DMSO and Ru(II)-> L π-back donation. The DMSO and L ligands are π-acceptors. The metal-> ligand π-back donation is strengthened when the ligand is trans to chloride, which is π-donor, due to trans-cooperative interactions of the type: π-donor -> Ru(II) π-acceptor. Another interesting aspect in the series of [Ru Cl 2 (S-DMSO) 2 L 2 ] complexes is the occurrence of dissociative equilibria in the solution, due to the existence of three types of ligands. It was observed that the trans-N isomer of 2,6-dimethyl pyrazine derivative undergoes thermal substitution, with preferential liabilization of the N-heterocyclic ligand. Chloride ion is the most inert ligand in this complex. (author). 145 refs., 76 figs., 21 tabs

A New Homogeneous Catalyst for the Dehydrogenation of Dimethylamine Borane Starting with Ruthenium(III Acetylacetonate

Directory of Open Access Journals (Sweden)

Ebru Ünel Barın

2015-06-01

Full Text Available The catalytic activity of ruthenium(III acetylacetonate was investigated for the first time in the dehydrogenation of dimethylamine borane. During catalytic reaction, a new ruthenium(II species is formed in situ from the reduction of ruthenium(III and characterized using UV-Visible, Fourier transform infrared (FTIR, 1H NMR, and mass spectroscopy. The most likely structure suggested for the ruthenium(II species is mer-[Ru(N2Me43(acacH]. Mercury poisoning experiment indicates that the catalytic dehydrogenation of dimethylamine-borane is homogeneous catalysis. The kinetics of the catalytic dehydrogenation of dimethylamine borane starting with Ru(acac3 were studied depending on the catalyst concentration, substrate concentration and temperature. The hydrogen generation was found to be first-order with respect to catalyst concentration and zero-order regarding the substrate concentration. Evaluation of the kinetic data provides the activation parameters for the dehydrogenation reaction: the activation energy Ea = 85 ± 2 kJ·mol−1, the enthalpy of activation ∆H# = 82 ± 2 kJ·mol−1 and the entropy of activation; ∆S# = −85 ± 5 J·mol−1·K−1. The ruthenium(II catalyst formed from the reduction of ruthenium(III acetylacetonate provides 1700 turnovers over 100 hours in hydrogen generation from the dehydrogenation of dimethylamine borane before deactivation at 60 °C.

Radiochemistry of ruthenium

Energy Technology Data Exchange (ETDEWEB)

Schulz, W W; Metcalf, S G; Barney, G S

1984-06-01

Information on ruthenium is presented. Topics include the following; isotopes and nuclear properties of ruthenium; review of the chemistry of ruthenium including metal and alloys, compounds of ruthenium, and solution chemistry; separation methods including volatilization of RuO{sub 4}, precipitation and coprecipitation, solvent extraction, chromatographic techniques, and analysis for radioruthenium. 445 refs., 7 figs., 23 tabs.

Radiochemistry of ruthenium

International Nuclear Information System (INIS)

Schulz, W.W.; Metcalf, S.G.; Barney, G.S.

1984-01-01

Information on ruthenium is presented. Topics include the following; isotopes and nuclear properties of ruthenium; review of the chemistry of ruthenium including metal and alloys, compounds of ruthenium, and solution chemistry; separation methods including volatilization of RuO 4 , precipitation and coprecipitation, solvent extraction, chromatographic techniques, and analysis for radioruthenium. 445 refs., 7 figs., 23 tabs

Some mixed ligand hydridocarbonyl and hydridophosphine complexes of ruthenium(II) and iridium(III)

International Nuclear Information System (INIS)

Pandey, R.N.; Kumar, Sunil; Kumar, Arun; Kumar, S.K.

1993-01-01

Mixed-ligand hydridocarbonyl and hydridophosphine complexes of Ru II and Ir III have been isolated from the displacement reaction of [RuH(CO)(Pφ 3 ) 3 Cl] with ligand isonicotinic acid hydrazide (INAH) in benzene medium. Most probable structures are assigned on the basis of elemental analysis, electronic, infrared and far-infrared spectral studies. In all cases bonding of INAH occurs through amino nitrogen of hydrazine residue. (author). 15 refs., 1 tab

Ruthenium(II)-tris-bipyridine and titaniumdioxide - photocatalysts for solar induced water remediation; Ruthenium(II)-tris-bipyridin und Titandioxid - Photokatalysatoren zum solarinduzierten Abbau von Schadstoffen

Energy Technology Data Exchange (ETDEWEB)

Bossmann, S [Lehrstuhl fuer Umweltmesstechnik, Engler-Bunte-Inst., Karlsruhe Univ. (Germany)

1997-01-01

The photophysical and photochemical properties of photocatalysts capable of working under solar-light-irradiation are of great interest. An especially promising application is the development of low-cost `Advanced Oxidation Procedures` (AOP). The aim of this endeavor is the detoxification of hazardous chemicals in wastewaters, which cannot be treated by conventional techniques. The mineralization of the most (highly) toxic chemicals to CO{sub 2}, H{sub 2}O and simple inorganic compounds is favored by thermodynamics, however various difficulties such as kinetic barriers and hindered diffusion exist in systems for heterogeneous photocatalysis. In that respect, Ruthenium(II)-tris-bipyridine ([Ru(bpy){sub 3}]{sup 2+}) and TiO{sub 2} - codoped photocatalysts offer several advantages. The photoreactive centers consist of supramolecular units of [Ru(bpy){sub 3}]{sup 2+} and TiO{sub 2} - nanocrystals. Pollutants, such as our model compound 2,4-Dimethylaniline, diffuse through the framework of zeolite Y and undergo oxidative degradation at the reactive centers of the photocatalysts in the presence of H{sub 2}O{sub 2}. Under the aspect of application, the size of the zeolite Y-particles (diameter: 1x10{sup -6} m in average) permits their easy handling in filtration and recyling operations. (orig.) [Deutsch] Die photophysikalischen und -chemischen Eigenschaften von Katalysatoren, die das Licht der Sonne als kostenguenstige Energiequelle ausnutzen, treten immer staerker in den Vordergrund des Interesses. Dies gilt vor allem fuer ihren Einsatz in `Advanced Oxidation Technologies` (AOT`s) zur Entgiftung toxischer Substanzen im Abwasser. Die Mineralisation der meisten (hoch)giftigen Chemikalien zu CO{sub 2}, H{sub 2}O und einfachen anorganischen Verbindungen ist zwar thermodynamisch beguenstigt, es treten jedoch sowohl kinetische Hemmschwellen als auch Diffusionshindernisse in der heterogenen Photokatalyse auf. Ruthenium(II)-tris-bipyridin ([Ru(bpy){sub 3}]{sup 2+}) und TiO{sub 2

环戊二烯基钌配合物催化的高选择性苯乙炔二聚反应%HIGHLY SELECTIVE CATALYTIC DIMERIZATION OF PHENYLACETYLENE BY CYCLOPENTADIENYL RUTHENIUM COMPLEXES

Institute of Scientific and Technical Information of China (English)

金军挺; 黄吉玲; 陶晓春; 钱延龙

1999-01-01

@@ Transition metal vinylidene complexes (M=C=CHR) have attracted a great deal of attention in recent years as a new type of organometallic intermediates that may have unusual reactivity[1]. Their reactivity has been explored and their application to organic synthesis is developed[2]. Recent reports on the ruthenium-vinylidene complexes[3]suggest that the reaction of ruthenium-vinylidene complexes with a base generates the coordinatively unsaturated ruthenium acetylide species, which are involved in a number of catalytic and stoichiometric reactions of alkynes. For example,the coordinatively unsaturated ruthenium acetylide species C5Me5Ru(PPh3)-C≡CPh,formed from the reaction of the vinylidene complex C5Me5Ru(PPh3) (Cl)=C=CHPh with a base was reactive toward a variety of small molecules and active in catalytic dimerization of terminal alkynes[4]. The dimerization of terminal alkyne is an effective method of forming enynes, but its synthetic application in organic synthesis has been limited dueto low selectivity for dimeric products[5]. In this communication, we report that three ruthenium complexes were used as catalysts for the highly selective dimerization of phenylacetylene.

X-Ray structure and cytotoxic activity of a picolinate ruthenium(II–arene complex

Directory of Open Access Journals (Sweden)

IVANKA IVANOVIĆ

2011-01-01

Full Text Available A ruthenium(II–arene complex with picolinic acid, [(η6-p-cymeneRuCl(pico]∙H2O, was prepared by the reaction of [(η6-p-cymeneRuCl2]2 with picolinic acid in a 1:2 molar ratio in 2-propanol. The compound was characterized by elemental analysis, and IR and NMR spectroscopy. X-ray diffraction analysis showed that the molecule adopts a “three-leg piano-stool” geometry, which is common for this type of complexes. The cytotoxic activity of the complex was tested in two human cancer cell lines HeLa (cervix and FemX (melanoma by MTT assay. The IC50 values were at 82.0 and 36.2 µmol dm-3 for HeLa and FemX cells, respectively.

A ruthenium anticancer compound interacts with histones and impacts differently on epigenetic and death pathways compared to cisplatin.

Science.gov (United States)

Licona, Cynthia; Spaety, Marie-Elodie; Capuozzo, Antonelle; Ali, Moussa; Santamaria, Rita; Armant, Olivier; Delalande, Francois; Van Dorsselaer, Alain; Cianferani, Sarah; Spencer, John; Pfeffer, Michel; Mellitzer, Georg; Gaiddon, Christian

2017-01-10

Ruthenium complexes are considered as potential replacements for platinum compounds in oncotherapy. Their clinical development is handicapped by a lack of consensus on their mode of action. In this study, we identify three histones (H3.1, H2A, H2B) as possible targets for an anticancer redox organoruthenium compound (RDC11). Using purified histones, we confirmed an interaction between the ruthenium complex and histones that impacted on histone complex formation. A comparative study of the ruthenium complex versus cisplatin showed differential epigenetic modifications on histone H3 that correlated with differential expression of histone deacetylase (HDAC) genes. We then characterized the impact of these epigenetic modifications on signaling pathways employing a transcriptomic approach. Clustering analyses showed gene expression signatures specific for cisplatin (42%) and for the ruthenium complex (30%). Signaling pathway analyses pointed to specificities distinguishing the ruthenium complex from cisplatin. For instance, cisplatin triggered preferentially p53 and folate biosynthesis while the ruthenium complex induced endoplasmic reticulum stress and trans-sulfuration pathways. To further understand the role of HDACs in these regulations, we used suberanilohydroxamic acid (SAHA) and showed that it synergized with cisplatin cytotoxicity while antagonizing the ruthenium complex activity. This study provides critical information for the characterization of signaling pathways differentiating both compounds, in particular, by the identification of a non-DNA direct target for an organoruthenium complex.

Macromolecules containing bipyridine and terpyridine metal complexes: towards metallo-supramolecular polymers

NARCIS (Netherlands)

Schubert, U.S.; Eschbaumer, C.

2002-01-01

The ability of a broad range of N-heterocycles to act as very effective and stable complexation agents for several transition metal ions, such as cobalt(II), copper(II), nickel(II), and ruthenium(II), has long been known in analytical chemistry. This behavior was later utilized in supramolecular

Rolling cycle amplification based single-color quantum dots–ruthenium complex assembling dyads for homogeneous and highly selective detection of DNA

Energy Technology Data Exchange (ETDEWEB)

Su, Chen; Liu, Yufei; Ye, Tai; Xiang, Xia; Ji, Xinghu; He, Zhike, E-mail: zhkhe@whu.edu.cn

2015-01-01

Graphical abstract: A universal, label-free, homogeneous, highly sensitive, and selective fluorescent biosensor for DNA detection is developed by using rolling-circle amplification (RCA) based single-color quantum dots–ruthenium complex (QDs–Ru) assembling dyads. - Highlights: • The single-color QDs–Ru assembling dyads were applied in homogeneous DNA assay. • This biosensor exhibited high selectivity against base mismatched sequences. • This biosensor could be severed as universal platform for the detection of ssDNA. • This sensor could be used to detect the target in human serum samples. • This DNA sensor had a good selectivity under the interference of other dsDNA. - Abstract: In this work, a new, label-free, homogeneous, highly sensitive, and selective fluorescent biosensor for DNA detection is developed by using rolling-circle amplification (RCA) based single-color quantum dots–ruthenium complex (QDs–Ru) assembling dyads. This strategy includes three steps: (1) the target DNA initiates RCA reaction and generates linear RCA products; (2) the complementary DNA hybridizes with the RCA products to form long double-strand DNA (dsDNA); (3) [Ru(phen){sub 2}(dppx)]{sup 2+} (dppx = 7,8-dimethyldipyrido [3,2-a:2′,3′-c] phenanthroline) intercalates into the long dsDNA with strong fluorescence emission. Due to its strong binding propensity with the long dsDNA, [Ru(phen){sub 2}(dppx)]{sup 2+} is removed from the surface of the QDs, resulting in restoring the fluorescence of the QDs, which has been quenched by [Ru(phen){sub 2}(dppx)]{sup 2+} through a photoinduced electron transfer process and is overlaid with the fluorescence of dsDNA bonded Ru(II) polypyridyl complex (Ru-dsDNA). Thus, high fluorescence intensity is observed, and is related to the concentration of target. This sensor exhibits not only high sensitivity for hepatitis B virus (HBV) ssDNA with a low detection limit (0.5 pM), but also excellent selectivity in the complex matrix. Moreover

Hydrogenation of imines catalysed by ruthenium(II) complexes based on lutidine-derived CNC pincer ligands.

Science.gov (United States)

Hernández-Juárez, Martín; Vaquero, Mónica; Álvarez, Eleuterio; Salazar, Verónica; Suárez, Andrés

2013-01-14

The preparation of new Ru(II) complexes incorporating fac-coordinated lutidine-derived CNC ligands is reported. These derivatives are selectively deprotonated by (t)BuOK at one of the methylene arms of the pincer, leading to catalytically active species in the hydrogenation of imines.

Two half-sandwiched ruthenium (II compounds containing 5-fluorouracil derivatives: synthesis and study of DNA intercalation.

Directory of Open Access Journals (Sweden)

Zhao-Jun Li

Full Text Available Two novel coordination compounds of half-sandwiched ruthenium(II containing 2-(5-fluorouracil-yl-N-(pyridyl-acetamide were synthesized, and their intercalation binding modes with calf thymus DNA were revealed by hyperchromism of ultraviolet-visible spectroscopy; the binding constants were determined according to a Langmuir adsorption equation that was deduced on the base of careful cyclic voltammetry measurements. The two compounds exhibited DNA intercalation binding activities with the binding constants of 1.13×106 M-1 and 5.35 ×105 M-1, respectively.

(II) complexes

African Journals Online (AJOL)

activities of Schiff base tin (II) complexes. Neelofar1 ... Conclusion: All synthesized Schiff bases and their Tin (II) complexes showed high antimicrobial and ...... Singh HL. Synthesis and characterization of tin (II) complexes of fluorinated Schiff bases derived from amino acids. Spectrochim Acta Part A: Molec Biomolec.

Sweetening ruthenium and osmium: organometallic arene complexes containing aspartame.

Science.gov (United States)

Gray, Jennifer C; Habtemariam, Abraha; Winnig, Marcel; Meyerhof, Wolfgang; Sadler, Peter J

2008-09-01

The novel organometallic sandwich complexes [(eta(6)-p-cymene)Ru(eta(6)-aspartame)](OTf)(2) (1) (OTf = trifluoromethanesulfonate) and [(eta(6)-p-cymene)Os(eta(6)-aspartame)](OTf)(2) (2) incorporating the artificial sweetener aspartame have been synthesised and characterised. A number of properties of aspartame were found to be altered on binding to either metal. The pK(a) values of both the carboxyl and the amino groups of aspartame are lowered by between 0.35 and 0.57 pH units, causing partial deprotonation of the amino group at pH 7.4 (physiological pH). The rate of degradation of aspartame to 3,6-dioxo-5-phenylmethylpiperazine acetic acid (diketopiperazine) increased over threefold from 0.12 to 0.36 h(-1) for 1, and to 0.43 h(-1) for 2. Furthermore, the reduction potential of the ligand shifted from -1.133 to -0.619 V for 2. For the ruthenium complex 1 the process occurred in two steps, the first (at -0.38 V) within a biologically accessible range. This facilitates reactions with biological reductants such as ascorbate. Binding to and activation of the sweet taste receptor was not observed for these metal complexes up to concentrations of 1 mM. The factors which affect the ability of metal-bound aspartame to interact with the receptor site are discussed.

Rapid visual and spectrophotometric nitrite detection by cyclometalated ruthenium complex.

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Lo, Hoi-Shing; Lo, Ka-Wai; Yeung, Chi-Fung; Wong, Chun-Yuen

2017-10-16

Quantitative determination of nitrite ion (NO 2 - ) is of great importance in environmental and clinical investigations. A rapid visual and spectrophotometric assay for NO 2 - detection was developed based on a newly designed ruthenium complex, [Ru(npy)([9]aneS3)(CO)](ClO 4 ) (denoted as RuNPY; npy = 2-(1-naphthyl)pyridine, [9]aneS3 = 1,4,7-trithiacyclononane). This complex traps NO + produced in acidified NO 2 - solution, and yields observable color change within 1 min at room temperature. The assay features excellent dynamic range (1-840 μmol L -1 ) and high selectivity, and its limit of detection (0.39 μmol L -1 ) is also well below the guideline values for drinking water recommended by WHO and U.S. EPA. Practical use of this assay in tap water and human urine was successfully demonstrated. Overall, the rapidity and selectivity of this assay overcome the problems suffered by the commonly used modified Griess assays for nitrite determination. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis and reactivity of compounds containing ruthenium-carbon, -nitrogen, and -oxygen bonds

International Nuclear Information System (INIS)

Hartwig, J.F.

1990-12-01

The products and mechanisms of the thermal reactions of several complexes of the general structure (PMe 3 ) 4 Ru(X)(Y) and (DMPM) 2 Ru(X)(Y) where X and Y are hydride, aryl, and benzyl groups, have been investigated. The mechanism of decomposition depends critically on the structure of the complex and the medium in which the thermolysis is carried out. The alkyl hydride complexes are do not react with alkane solvent, but undergo C-H activation processes with aromatic solvents by several different mechanisms. Thermolysis of (PMe 3 ) 4 Ru(Ph)(Me) or (PMe 3 ) 4 Ru(Ph) 2 leads to the ruthenium benzyne complex (PMe 3 ) 4 Ru(η 2 -C 6 H 4 ) (1) by a mechanism which involves reversible dissociation of phosphine. In many ways its chemistry is analogous to that of early rather than late organo transition metal complexes. The synthesis, structure, variable temperature NMR spectroscopy and reactivity of ruthenium complexes containing aryloxide or arylamide ligands are reported. These complexes undergo cleavage of a P-C bond in coordinated trimethylphosphine, insertion of CO and CO 2 and hydrogenolysis. Mechanistic studies on these reactions are described. The generation of a series of reactive ruthenium complexes of the general formula (PMe 3 ) 4 Ru(R)(enolate) is reported. Most of these enolates have been shown to bind to the ruthenium center through the oxygen atom. Two of the enolate complexes 8 and 9 exist in equilibrium between the O- and C-bound forms. The reactions of these compounds are reported, including reactions to form oxygen-containing metallacycles. The structure and reactivity of these ruthenium metallacycles is reported, including their thermal chemistry and reactivity toward protic acids, electrophiles, carbon monoxide, hydrogen and trimethylsilane. 243 refs., 10 tabs

Synthesis and reactivity of compounds containing ruthenium-carbon, -nitrogen, and -oxygen bonds

Energy Technology Data Exchange (ETDEWEB)

Hartwig, J.F.

1990-12-01

The products and mechanisms of the thermal reactions of several complexes of the general structure (PMe{sub 3}){sub 4}Ru(X)(Y) and (DMPM){sub 2}Ru(X)(Y) where X and Y are hydride, aryl, and benzyl groups, have been investigated. The mechanism of decomposition depends critically on the structure of the complex and the medium in which the thermolysis is carried out. The alkyl hydride complexes are do not react with alkane solvent, but undergo C-H activation processes with aromatic solvents by several different mechanisms. Thermolysis of (PMe{sub 3}){sub 4}Ru(Ph)(Me) or (PMe{sub 3}){sub 4}Ru(Ph){sub 2} leads to the ruthenium benzyne complex (PMe{sub 3}){sub 4}Ru({eta}{sup 2}-C{sub 6}H{sub 4}) (1) by a mechanism which involves reversible dissociation of phosphine. In many ways its chemistry is analogous to that of early rather than late organo transition metal complexes. The synthesis, structure, variable temperature NMR spectroscopy and reactivity of ruthenium complexes containing aryloxide or arylamide ligands are reported. These complexes undergo cleavage of a P-C bond in coordinated trimethylphosphine, insertion of CO and CO{sub 2} and hydrogenolysis. Mechanistic studies on these reactions are described. The generation of a series of reactive ruthenium complexes of the general formula (PMe{sub 3}){sub 4}Ru(R)(enolate) is reported. Most of these enolates have been shown to bind to the ruthenium center through the oxygen atom. Two of the enolate complexes 8 and 9 exist in equilibrium between the O- and C-bound forms. The reactions of these compounds are reported, including reactions to form oxygen-containing metallacycles. The structure and reactivity of these ruthenium metallacycles is reported, including their thermal chemistry and reactivity toward protic acids, electrophiles, carbon monoxide, hydrogen and trimethylsilane. 243 refs., 10 tabs.

Synthesis of a ruthenium(II) bipyridyl complex coordinated by a functionalized Schiff base ligand: characterization, spectroscopic and isothermal titration calorimetry measurements of M2+ binding and sensing (M2+=Ca2+, Mg2+).

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Dixit, Namrata; Mishra, Lallan; Mustafi, Sourajit M; Chary, Kandala V R; Houjou, Hirohiko

2009-07-01

Bis-[methylsalicylidine-4'benzoic acid]-ethylene (LH2) complexed with cis-Ru(bpy)2Cl(2).2H2O provides a complex of composition [Ru(bpy)2L].2NH4PF6 (1), which has been characterized spectroscopically. Its binding behaviour towards Mg2+ and Ca2+ ions is monitored using 1H NMR titration, isothermal titration calorimetry (ITC) and luminescence microscopy. The luminescent ruthenium complex binds Ca2+ in a more selective manner as compared to Mg2+.

Intermolecular Dehydrative Coupling Reaction of Arylketones with Cyclic Alkenes Catalyzed by a Well-Defined Cationic Ruthenium-Hydride Complex: A Novel Ketone Olefination Method via Vinyl C–H Bond Activation

Science.gov (United States)

Yi, Chae S.; Lee, Do W.

2010-01-01

Summary The cationic ruthenium-hydride complex [(η6-C6H6)(PCy3)(CO)RuH]+BF4− was found to be a highly effective catalyst for the intermolecular olefination reaction of arylketones with cycloalkenes. The preliminary mechanistic analysis revealed that electrophilic ruthenium-vinyl complex is the key species for mediating both vinyl C–H bond activation and the dehydrative olefination steps of the coupling reaction. PMID:20567607

Optimization of Temperature Sensing with Polymer-Embedded Luminescent Ru(II Complexes

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Nelia Bustamante

2018-02-01

Full Text Available Temperature is a key parameter in many fields and luminescence-based temperature sensing is a solution for those applications in which traditional (mechanical, electrical, or IR-based thermometers struggle. Amongst the indicator dyes for luminescence thermometry, Ru(II polyazaheteroaromatic complexes are an appealing option to profit from the widespread commercial technologies for oxygen optosensing based on them. Six ruthenium dyes have been studied, engineering their structure for both photostability and highest temperature sensitivity of their luminescence. The most apt Ru(II complex turned out to be bis(1,10-phenanthroline(4-chloro-1,10-phenanthrolineruthenium(II, due to the combination of two strong-field chelating ligands (phen and a substituent with electron withdrawing effect on a conjugated position of the third ligand (4-Clphen. In order to produce functional sensors, the dye has been best embedded into poly(ethyl cyanoacrylate, due to its low permeability to O2, high temperature sensitivity of the indicator dye incorporated into this polymer, ease of fabrication, and excellent optical quality. Thermosensitive elements have been fabricated thereof as optical fiber tips for macroscopic applications (water courses monitoring and thin spots for microscopic uses (temperature measurements in cell culture-on-a-chip. With such dye/polymer combination, temperature sensing based on luminescence lifetime measurements allows 0.05 °C resolution with linear response in the range of interest (0–40 °C.

Mono and dinuclear iridium, rhodium and ruthenium complexes containing chelating carboxylato pyrazine ligands: Synthesis, molecular structure and electrochemistry

Czech Academy of Sciences Publication Activity Database

Govindaswamy, P.; Therrien, B.; Süss-Fink, G.; Štěpnička, P.; Ludvík, Jiří

2007-01-01

Roč. 692, č. 8 (2007), s. 1661-1671 ISSN 0022-328X R&D Projects: GA MŠk LC510; GA MŠk(CZ) LC06070 Institutional research plan: CEZ:AV0Z40400503 Keywords : dinuclear complexes * iridium * rhodium * ruthenium * electrochemistry Subject RIV: CG - Electrochemistry Impact factor: 2.168, year: 2007

Polypyridylruthenium(II complexes exert in vitro and in vivo nematocidal activity and show significant inhibition of parasite acetylcholinesterases

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Madhu Sundaraneedi

2018-04-01

Full Text Available Over 4.5 billion people are at risk of infection with soil transmitted helminths and there are concerns about the development of resistance to the handful of frontline nematocides in endemic populations. We investigated the anti-nematode efficacy of a series of polypyridylruthenium(II complexes and showed they were active against L3 and adult stages of Trichuris muris, the rodent homologue of the causative agent of human trichuriasis, T. trichiura. One of the compounds, Rubb12-mono, which was among the most potent in its ability to kill L3 (IC50 = 3.1 ± 0.4 μM and adult (IC50 = 5.2 ± 0.3 μM stage worms was assessed for efficacy in a mouse model of trichuriasis by administering 3 consecutive daily oral doses of the drug 3 weeks post infection with the murine whipworm Trichuris muris. Mice treated with Rubb12-mono showed an average 66% reduction (P = 0.015 in faecal egg count over two independent trials. The drugs partially exerted their activity through inhibition of acetylcholinesterases, as worms treated in vitro and in vivo showed significant decreases in the activity of this class of enzymes. Our data show that ruthenium complexes are effective against T. muris, a model gastro-intestinal nematode and soil-transmitted helminth. Further, knowledge of the target of ruthenium drugs can facilitate modification of current compounds to identify analogues which are even more effective and selective against Trichuris and other helminths of human and veterinary importance. Keywords: Acetylcholinesterase, Trichuris muris, Ruthenium complex, Anthelmintic

Fundamental Factors Impacting the Stability of Phosphonate-Derivatized Ruthenium Polypyridyl Sensitizers Adsorbed on Metal Oxide Surfaces.

Science.gov (United States)

Raber, McKenzie; Brady, Matthew David; Troian-Gautier, Ludovic; Dickenson, John; Marquard, Seth L; Hyde, Jacob; Lopez, Santiago; Meyer, Gerald J; Meyer, Thomas J; Harrison, Daniel P

2018-06-08

A series of 18 ruthenium(II) polypyridyl complexes were synthesized and evaluated under electrochemically oxidative conditions, which generates the Ru(III) oxidation state and mimics the harsh conditions experienced during the kinetically-limited regime that can occur in dye-sensitized solar cells (DSSCs) and dye-sensitized photoelectrosynthesis cells (DSPECs), to further develop fundamental insights into the factors governing molecular sensitizer surface stability in aqueous 0.1 M HClO4 (aq). Both desorption and oxidatively induced ligand substitution were observed on planar fluorine doped tin oxide, FTO, electrodes, with a dependence on the E1/2 Ru(III/II) redox potential dictating the comparative ratios of the processes. Complexes such as RuP4OMe (E1/2 = 0.91 vs Ag/AgCl) displayed virtually only desorption, while complexes such as RuPbpz (E1/2 > 1.62 V vs Ag/AgCl) displayed only chemical decomposition. Comparing isomers of 4,4'- and 5,5-disubstituted-2,2'-bipyridine ancillary polypyridyl ligands, a dramatic increase in the rate of desorption of the Ru(III) complexes was observed for the 5,5'-ligands. Nanoscopic indium doped tin oxide thin films, nanoITO, were also sensitized and analyzed with cyclic voltammetry, UV-Vis absorption spectroscopy, and XPS, allowing for further distinction of desorption versus ligand substitution processes. Desorption loss to bulk solution associated with the planar surface of FTO is essentially non-existent on nanoITO, where both desorption and ligand substitution are shut down with RuP4OMe. These results revealed that minimizing time spent in the oxidized form, incorporating electron donating groups, maximizing hydrophobicity, and minimizing molecular bulk near the adsorbed ligand are critical to optimizing the performance of ruthenium(II) polypyridyl complexes in dye-sensitized solar cell devices.

Mechanism of Water Oxidation Catalyzed by a Dinuclear Ruthenium Complex Bridged by Anthraquinone

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Tohru Wada

2017-02-01

Full Text Available We synthesized 1,8-bis(2,2′:6′,2″-terpyrid-4′-ylanthraquinone (btpyaq as a new dimerizing ligand and determined its single crystal structure by X-ray analysis. The dinuclear Ruthenium complex [Ru2(µ-Cl(bpy2(btpyaq](BF43 ([3](BF43, bpy = 2,2′-bipyridine was used as a catalyst for water oxidation to oxygen with (NH42[Ce(NO36] as the oxidant (turnover numbers = 248. The initial reaction rate of oxygen evolution was directly proportional to the concentration of the catalyst and independent of the oxidant concentration. The cyclic voltammogram of [3](BF43 in water at pH 1.3 showed an irreversible catalytic current above +1.6 V (vs. SCE, with two quasi-reversible waves and one irreversible wave at E1/2 = +0.62, +0.82 V, and Epa = +1.13 V, respectively. UV-vis and Raman spectra of [3](BF43 with controlled-potential electrolysis at +1.40 V revealed that [Ru(IV=O O=Ru(IV]4+ is stable under electrolysis conditions. [Ru(III, Ru(II] species are recovered after dissociation of an oxygen molecule from the active species in the catalytic cycle. These results clearly indicate that an O–O bond is formed via [Ru(V=O O=Ru(IV]5+.

γ-Sultam-cored N,N-ligands in the ruthenium(ii)-catalyzed asymmetric transfer hydrogenation of aryl ketones.

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Rast, Slavko; Modec, Barbara; Stephan, Michel; Mohar, Barbara

2016-02-14

The synthesis of new enantiopure syn- and anti-3-(α-aminobenzyl)-benzo-γ-sultam ligands 6 and their application in the ruthenium(ii)-catalyzed asymmetric transfer hydrogenation (ATH) of ketones using formic acid/triethylamine is described. In particular, benzo-fused cyclic ketones afforded excellent enantioselectivities in reasonable time employing a low loading of the syn ligand-containing catalyst. A never-before-seen dynamic kinetic resolution (DKR) during reduction of a γ-keto carboxylic ester (S7) derivative of 1-indanone is realized leading as well to excellent induction.

Incorporation of amphiphilic ruthenium(II) ammine complexes into Langmuir-Blodgett thin films with switchable quadratic nonlinear optical behavior.

Science.gov (United States)

Boubekeur-Lecaque, Leïla; Coe, Benjamin J; Harris, James A; Helliwell, Madeleine; Asselberghs, Inge; Clays, Koen; Foerier, Stijn; Verbiest, Thierry

2011-12-19

Nine nonlinear optical (NLO) chromophores with pyridinium electron acceptors have been synthesized by complexing new proligands with {Ru(II)(NH(3))(5)}(2+) electron-donor centers. The presence of long alkyl/fluoroalkyl chain substituents imparts amphiphilic properties, and these cationic complexes have been characterized as their PF(6)(-) salts by using various techniques including electronic absorption spectroscopy and cyclic voltammetry. Each complex shows three reversible/quasireversible redox processes; a Ru(III/II) oxidation and two ligand-based reductions. The energies of the intense visible d → π* metal-to-ligand charge-transfer (MLCT) absorptions correlate to some extent with the ligand reduction potentials. (1)H NMR spectroscopy also provides insights into the relative electron-withdrawing strengths of the new ligands. Single crystal X-ray structures have been determined for two of the proligand salts and one complex salt, [Ru(II)(NH(3))(5)(4-C(16)H(33)PhQ(+))]Cl(3)·3.25H(2)O (PhQ(+) = N-phenyl-4,4'-bipyridinium), showing centrosymmetric packing structures in each case. The PF(6)(-) analogue of the latter complex has been used to deposit reproducibly high-quality, multilayered Langmuir-Blodgett (LB) thin films. These films show a strong second harmonic generation (SHG) response from a 1064 nm laser; their MLCT absorbance increases linearly with the number of layers (N) and I(2ω)/I(ω)(2) (I(2ω) = intensity at 532 nm; I(ω) = intensity at 1064 nm) scales quadratically with N, consistent with homogeneous deposition. LB films on indium tin oxide (ITO)-coated glass show electrochemically induced switching of the SHG response, with a decrease in activity of about 50% on Ru(II) → Ru(III) oxidation. This effect is reversible, but reproducible over only a few cycles before the signal from the Ru(II) species diminishes. This work extrapolates our original solution studies (Coe, B. J. et al. Angew. Chem., Int. Ed.1999, 38, 366) to the first demonstration of

Synthesis of ruthenium phosphides

International Nuclear Information System (INIS)

Chernogorenko, V.B.; Lynchak, K.A.; Kulik, L.Ya.; Shkaravskij, Yu.F.; Klochkov, L.A.

1977-01-01

A method of ampoule synthesis of ruthenium phosphides, Ru 2 P, RuP, and RuP 2 , with stepwise heating of stoichimetric charges in a single-zone furnace is developed. A method for synthesizing ruthenium diphosphide by phosphidization of a ruthenium powder with phosphine at 1150 deg C is worked out. The optimum conditions of its manufacture are found by planning an extremal experiment. Interaction of PH 3 with ruthenium proceeds by the diffusion mechanism and obeys the parabolic law. An extraction-photometric method for determining phosphorus in phosphides is elaborated. Ruthenium phosphides are extremely corrosion-resistant in acids and alkalis. Ru 2 P and RuP exhibit metallic conductivity

Synthesis, characterization, and reactivity of ruthenium hydride complexes of N-centered triphosphine ligands.

Science.gov (United States)

Phanopoulos, Andreas; Brown, Neil J; White, Andrew J P; Long, Nicholas J; Miller, Philip W

2014-04-07

The reactivity of the novel tridentate phosphine ligand N(CH2PCyp2)3 (N-triphos(Cyp), 2; Cyp = cyclopentyl) with various ruthenium complexes was investigated and compared that of to the less sterically bulky and less electron donating phenyl derivative N(CH2PPh2)3 (N-triphos(Ph), 1). One of these complexes was subsequently investigated for reactivity toward levulinic acid, a potentially important biorenewable feedstock. Reaction of ligands 1 and 2 with the precursors [Ru(COD)(methylallyl)2] (COD = 1,5-cycloocatadiene) and [RuH2(PPh3)4] gave the tridentate coordination complexes [Ru(tmm){N(CH2PR2)3-κ(3)P}] (R = Ph (3), Cyp (4); tmm = trimethylenemethane) and [RuH2(PPh3){N(CH2PR2)3-κ(3)P}] (R = Ph (5), Cyp (6)), respectively. Ligands 1 and 2 displayed different reactivities with [Ru3(CO)12]. Ligand 1 gave the tridentate dicarbonyl complex [Ru(CO)2{N(CH2PPh2)3-κ(3)P}] (7), while 2 gave the bidentate, tricarbonyl [Ru(CO)3{N(CH2PCyp2)3-κ(2)P}] (8). This was attributed to the greater electron-donating characteristics of 2, requiring further stabilization on coordination to the electron-rich Ru(0) center by more CO ligands. Complex 7 was activated via oxidation using AgOTf and O2, giving the Ru(II) complexes [Ru(CO)2(OTf){N(CH2PPh2)3-κ(3)P}](OTf) (9) and [Ru(CO3)(CO){N(CH2PPh2)3-κ(3)P}] (11), respectively. Hydrogenation of these complexes under hydrogen pressures of 3-15 bar gave the monohydride and dihydride complexes [RuH(CO)2{N(CH2PPh2)3-κ(3)P}] (10) and [RuH2(CO){N(CH2PPh2)3-κ(3)P}] (12), respectively. Complex 12 was found to be unreactive toward levulinic acid (LA) unless activated by reaction with NH4PF6 in acetonitrile, forming [RuH(CO)(MeCN){N(CH2PPh2)3-κ(3)P}](PF6) (13), which reacted cleanly with LA to form [Ru(CO){N(CH2PPh2)3-κ(3)P}{CH3CO(CH2)2CO2H-κ(2)O}](PF6) (14). Complexes 3, 5, 7, 8, 11, and 12 were characterized by single-crystal X-ray crystallography.

Cationic bis-N-heterocyclic carbene (NHC) ruthenium complex: Structure and application as latent catalyst in olefin metathesis

KAUST Repository

Rouen, Mathieu

2014-09-11

An unexpected cationic bis-N-heterocyclic carbene (NHC) benzylidene ether based ruthenium complex (2 a) was prepared through the double incorporation of an unsymmetrical unsaturated N-heterocyclic carbene (U2-NHC) ligand that bore an N-substituted cyclododecyl side chain. The isolation and full characterization (including X-ray diffraction studies) of key synthetic intermediates along with theoretical calculations allowed us to understand the mechanism of the overall cationization process. Finally, the newly developed complex 2 a displayed interesting latent behavior during ring-closing metathesis, which could be "switched on" under acidic conditions.

Synthesis of phosphonic acid derivatized bipyridine ligands and their ruthenium complexes.

Science.gov (United States)

Norris, Michael R; Concepcion, Javier J; Glasson, Christopher R K; Fang, Zhen; Lapides, Alexander M; Ashford, Dennis L; Templeton, Joseph L; Meyer, Thomas J

2013-11-04

Water-stable, surface-bound chromophores, catalysts, and assemblies are an essential element in dye-sensitized photoelectrosynthesis cells for the generation of solar fuels by water splitting and CO2 reduction to CO, other oxygenates, or hydrocarbons. Phosphonic acid derivatives provide a basis for stable chemical binding on metal oxide surfaces. We report here the efficient synthesis of 4,4'-bis(diethylphosphonomethyl)-2,2'-bipyridine and 4,4'-bis(diethylphosphonate)-2,2'-bipyridine, as well as the mono-, bis-, and tris-substituted ruthenium complexes, [Ru(bpy)2(Pbpy)](2+), [Ru(bpy)(Pbpy)2](2+), [Ru(Pbpy)3](2+), [Ru(bpy)2(CPbpy)](2+), [Ru(bpy)(CPbpy)2](2+), and [Ru(CPbpy)3](2+) [bpy = 2,2'-bipyridine; Pbpy = 4,4'-bis(phosphonic acid)-2,2'-bipyridine; CPbpy = 4,4'-bis(methylphosphonic acid)-2,2'-bipyridine].

Electro-volatilization of ruthenium in nitric medium: influences of ruthenium species nature and models solutions composition

International Nuclear Information System (INIS)

Mousset, F.

2004-12-01

Ruthenium is one of the fission products in the reprocessing of irradiated fuels that requires a specific processing management. Its elimination, upstream by the PUREX process, has been considered. A process, called electro-volatilization, which take advantage of the RuO 4 volatility, has been optimised in the present study. It consists in a continuous electrolysis of ruthenium solutions in order to generate RuO 4 species that is volatilized and easily trapped. This process goes to satisfying ruthenium elimination yields with RuNO(NO 3 ) 3 (H 2 O) 2 synthetic solutions but not with fuel dissolution solutions. Consequently, this work consisted in the speciation studies of dissolved ruthenium species were carried out by simulating fuel solutions produced by hot acid attack of several ruthenium compounds (Ru(0), RuO 2 ,xH 2 O, polymetallic alloy). In parallel with dissolution kinetic studies, the determination of dissolved species was performed using voltammetry, spectrometry and spectro-electrochemistry. The results showed the co-existence of Ru(IV) and RuNO(NO 2 ) 2 (H 2 O) 3 . Although these species are different from synthetic RuNO(NO 3 ) 3 (H 2 O) 2 , their electro-oxidation behaviour are similar. The electro-volatilization tests of these dissolution solutions yielded to comparable results as the synthetic RuNO(NO 3 ) 3 (H 2 O) 2 solutions. Then, complexity increase of models solutions was performed by in-situ generation of nitrous acid during ruthenium dissolution. Nitrous acid showed a catalytic effect on ruthenium dissolution. Its presence goes to quasi exclusively RuNO(NO 2 ) 2 (H 2 O) 3 species. It is also responsible of the strong n-bond formation between Ru 2+ and NO + . In addition, it has been shown that its reducing action on RuO 4 hinders the electro-volatilization process. Mn 2+ and Ce 3+ cations also reveal, but to a lesser extent, an electro-eater behaviour as well as Pu 4+ and Cr 3+ according to the thermodynamics data. These results allow one to

A multi-target caffeine derived rhodium(i) N-heterocyclic carbene complex: evaluation of the mechanism of action.

Science.gov (United States)

Zhang, Jing-Jing; Muenzner, Julienne K; Abu El Maaty, Mohamed A; Karge, Bianka; Schobert, Rainer; Wölfl, Stefan; Ott, Ingo

2016-08-16

A rhodium(i) and a ruthenium(ii) complex with a caffeine derived N-heterocyclic carbene (NHC) ligand were biologically investigated as organometallic conjugates consisting of a metal center and a naturally occurring moiety. While the ruthenium(ii) complex was largely inactive, the rhodium(i) NHC complex displayed selective cytotoxicity and significant anti-metastatic and in vivo anti-vascular activities and acted as both a mammalian and an E. coli thioredoxin reductase inhibitor. In HCT-116 cells it increased the reactive oxygen species level, leading to DNA damage, and it induced cell cycle arrest, decreased the mitochondrial membrane potential, and triggered apoptosis. This rhodium(i) NHC derivative thus represents a multi-target compound with promising anti-cancer potential.

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

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Hasi Rani Barai

2016-06-01

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

Recent advances in the ruthenium(ii)-catalyzed chelation-assisted C-H olefination of substituted aromatics, alkenes and heteroaromatics with alkenes via the deprotonation pathway.

Science.gov (United States)

Manikandan, Rajendran; Jeganmohan, Masilamani

2017-08-08

The transition-metal-catalyzed chelation-assisted alkenylation at the inert C-H bond of aromatics with alkenes is one of the efficient methods to synthesize substituted vinylarenes in a highly regio- and stereoselective manner. Palladium, rhodium and ruthenium complexes are frequently used as catalysts for this type of transformation. The present review describes the recent advances in the ruthenium-catalyzed chelation-assisted alkenylation at the C-H bond of aromatics, alkenes and heteroaromatics with alkenes via the deprotonation pathway. Several directing groups including 2-pyridyl, carbonyl, amidine, amide, amine, imidate, sulphonic acid, triazole, cyano, oxazolidinone and hydontoin are widely used in the reaction. The scope, limitation and mechanistic investigation of the alkenylation reactions are discussed elaborately. This feature article includes all the reported ruthenium-catalyzed alkenylation reactions via the deprotonation pathway until the end of March 2017.

Ruthenium(II) tris(2,2'-bipyridine) chelate as a chemiluminophore in extrinsic lyoluminescences of aluminium and magnesium in aqueous solution

International Nuclear Information System (INIS)

Jiang Qinghong; Kotiranta, Miia; Langel, Kaarina; Suomi, Johanna; Hakansson, Markus; Spehar, Anna-Maria; Ala-Kleme, Timo; Eskola, Jarkko; Kulmala, Sakari

2005-01-01

Ruthenium(II) tris(2,2'-bipyridine) chelate shows chemiluminescence (CL) both during dissolution of metallic aluminium in alkaline conditions, and during dissolution of magnesium metal in acidic conditions. The presence of peroxodisulfate ions strongly enhances the CL. Magnesium system provides considerably better detectability of the present chelate giving linear calibration plot spanning over many orders of magnitude of concentration down to subnanomolar concentration levels. The possible primary species generated and luminescence mechanisms are shortly discussed

Polarographic determination of ruthenium

International Nuclear Information System (INIS)

Li Jifu; Duan Shirong; Wu Xi

1989-01-01

It is suggested to use 0.5 mol/l HClO 4 -0.5 mol/l NaNO 3 -0.1 mol/l NaClO 4 as supporting electrolyte for determining ruthenium. In the supporting electrolyte there is a clear polarographic wave of ruthenium (IV) at -0.8 V vs. SCE. The wave height of ruthenium(IV) is linear in the range from 0.1 to 0.4 μg. ml -1 . The effect of the component of supporting electroylte and the other ion in the samples on the measurement of ruthenium are studied. The analysis methods for measuring ruthenium in both acidic or basic imitative radioactive waste solutions which is used in study of glass solidification are worked out. Imitative samples are analysised

1H and 13C NMR coordination-induced shifts in a series of tris(α-diimine)ruthenium(II) complexes containing pyridine, pyrazine, and thiazole moieties

International Nuclear Information System (INIS)

Orellana, G.; Ibarra, C.A.; Santoro, J.

1988-01-01

1 H and 13 C NMR chemical shifts of a series of ruthenium(II) tris chelates containing the heterocyclic ligands 2,2'-bipyridine, 2-(2-pyridyl)thiazole, 2-(2-pyrazyl)thiazole, and 2,2'-bithiazole are reported and compared to those of the corresponding free ligands. Calculated coordination-induced shifts (CIS, δ complexed - δ free ) range from +0.41 to -1.00 ppM for 1 H and from +5.8 to -3.7 ppM for 13 C nuclei. These values are discussed on the basis of the various effects (charge perturbation and field interactions) that arise upon chelation: electronic σ-donation to the metallic center via the nitrogen lone pair, d-π* back-donation to the ligand, van der Waals interactions, and magnetic anisotropy of the spectator ligands. Semiquantitative values of each effect at the different positions have been proposed, taking theoretical calculations of steric and anisotropic contributions as the starting point. Shielding van der Waals interaction between proximate atoms influences only the H(3') CIS of six-membered moieties, but to a very low extent (<0.15 ppM). Magnetic anisotropy of proximate ring currents practically determines the CIS of the α positions for all the complexed ligands examined (upfield shifts from -0.8 to -1.0 ppm), has a lower influence on external β positions (< 0.2 ppM), and is negligible for γ-protons. σ-donation deshields all the positions, its contribution increasing as protons separate from the coordinated nitrogen atom (up to 0.4 ppM). Π-back-bonding is a weaker effect (< 0.2 ppM upfield contribution) that operates mainly on the γ position of the pyridine and α and β positions of the pyrazine rings. 36 refs., 3 figs., 4 tabs

A solid-state sensor based on ruthenium (II) complex immobilized on polytyramine film for the simultaneous determination of dopamine, ascorbic acid and uric acid

International Nuclear Information System (INIS)

Khudaish, Emad A.; Al-Ajmi, Khawla Y.; Al-Harthi, Salim H.

2014-01-01

A solid-state sensor based on a polytyramine (Pty) film deposited on a glassy carbon electrode doped with a tris(2,2′-bipyridyl)Ru(II) complex (Ru/Pty/GCE) was constructed electrochemically. The surface morphology of the film modified electrode was characterized using electrochemical and surface scanning techniques. A redox property represented by a [Ru(bpy) 3 ] 3+/2+ couple immobilized at the Pty moiety was characterized using typical voltammetric techniques. A distinct Ru 3d peak obtained at 280.9 eV confirms doping of the Ru species onto the Pty moiety characterized by X-ray photoelectron (XPS). Atomic force microscopy (AFM) images demonstrate that incorporation of Ru decreases the surface roughness of the native Pty film modified electrode. The Ru/Pty/GCE exhibits efficient electrochemical sensing toward the oxidation of dopamine (DA), ascorbic acid (AA) and uric acid (UA) in their mixture. Three well-defined peaks were resolved with a large peak to peak separation and the detection limits of AA, DA and UA are brought down to 0.31, 0.08 and 0.58 μM, respectively. Interference studies and application for DA determination in real samples were conducted with satisfactory results. - Highlights: • XPS data confirm doping of ruthenium onto the polytyramine moiety. • The voltammetric signals of ascorbic acid, dopamine and uric acid are well defined. • The sensor is stable and offers a large adsorption facility for all species. • The sensor is highly sensitive to dopamine oxidation. • The sensor is applied to a real sample with a satisfactory recovery percentage

A solid-state sensor based on ruthenium (II) complex immobilized on polytyramine film for the simultaneous determination of dopamine, ascorbic acid and uric acid

Energy Technology Data Exchange (ETDEWEB)

Khudaish, Emad A., E-mail: ejoudi@squ.edu.om [Sultan Qaboos University, College of Science, Chemistry Department, PO Box 36, PC 123 Muscat (Oman); Al-Ajmi, Khawla Y. [Sultan Qaboos University, College of Science, Chemistry Department, PO Box 36, PC 123 Muscat (Oman); Al-Harthi, Salim H. [Sultan Qaboos University, College of Science, Department of Physics, PO Box 36, PC 123 Muscat (Oman)

2014-08-01

A solid-state sensor based on a polytyramine (Pty) film deposited on a glassy carbon electrode doped with a tris(2,2′-bipyridyl)Ru(II) complex (Ru/Pty/GCE) was constructed electrochemically. The surface morphology of the film modified electrode was characterized using electrochemical and surface scanning techniques. A redox property represented by a [Ru(bpy){sub 3}]{sup 3+/2+} couple immobilized at the Pty moiety was characterized using typical voltammetric techniques. A distinct Ru 3d peak obtained at 280.9 eV confirms doping of the Ru species onto the Pty moiety characterized by X-ray photoelectron (XPS). Atomic force microscopy (AFM) images demonstrate that incorporation of Ru decreases the surface roughness of the native Pty film modified electrode. The Ru/Pty/GCE exhibits efficient electrochemical sensing toward the oxidation of dopamine (DA), ascorbic acid (AA) and uric acid (UA) in their mixture. Three well-defined peaks were resolved with a large peak to peak separation and the detection limits of AA, DA and UA are brought down to 0.31, 0.08 and 0.58 μM, respectively. Interference studies and application for DA determination in real samples were conducted with satisfactory results. - Highlights: • XPS data confirm doping of ruthenium onto the polytyramine moiety. • The voltammetric signals of ascorbic acid, dopamine and uric acid are well defined. • The sensor is stable and offers a large adsorption facility for all species. • The sensor is highly sensitive to dopamine oxidation. • The sensor is applied to a real sample with a satisfactory recovery percentage.

Extraction of ruthenium thiocyanate and its separation from rhodium by polyurethane foam

International Nuclear Information System (INIS)

Al-Bazi, S.J.; Chow, A.

1984-01-01

Conditions for the formation and extraction of the thiocyanate complex of ruthenium are reported. Distribution coefficients of more than 10 4 and a capacity of about 0.24 mole per kg of foam were obtained. The effect of the chloride salts of various univalent cations on the extraction of Ru(SCN) 6 3- indicated that the efficiency of ruthenium extraction depends on how well the cation fits into the polyether segment of the polyurethane foam, which agrees with the 'cation-chelation' mechanism. The separation of ruthenium and rhodium indicated that more than 95% of the rhodium remained in the aqueous phase and about 95% of the ruthenium was retained by the polyurethane foam and could be easily recovered. (author)

Ruthenium separation device from radioactive waste

International Nuclear Information System (INIS)

Ayabe, Osao.

1988-01-01

Purpose: To efficiently oxidize ruthenium in radioactive wastes and evaporize ruthenium tetraoxide after oxidization thereof, thereby improve the separation and recovery rate. Constitution: The device comprises an oxidization vessel for supplying an oxidizing agent into radioactive wastes to oxidize ruthenium in the wastes into ruthenium tetraoxide, and a distillation vessel for introducing radioactive wastes after oxidization, distillating under heating ruthenium tetraoxide leached into the wastes and evaporizing ruthenium tetraoxide. By dividing the device into the oxidizing vessel and the distillation vessel, the oxidizing treatment and the distilling treatment can individually be operated optimally to improve the separation and recovery rate of ruthenium. (Takahashi, M.)

Ruthenium removing device

International Nuclear Information System (INIS)

Kitamura, Masafumi; Shirado, Katsuyuki.

1990-01-01

A processing gas supply system and a NO x supply system for supplying NO x to be mixed with processed gases are connected to the gas plenum in the lower portion of reaction vessel. Further, a cleaning station is disposed above the gas plenum for introducing a mixed gas stream from the gas plenum into a liquid detergent thereby trapping NO x and ruthenium reduction products into the liquid detergent. Volatile ruthenium contained in the processed gases is reduced into ruthenium reduction products and formed as mists. They are trapped in the cleaning liquid and the remaining gases are discharged out of the liquid detergent to the outside of the reaction vessel. Accordingly, solid radioactive wastes are not formed and the decontaminating efficiency for volatile ruthenium can be improved. (T.M.)

Towards the Development of Functionalized PolypyridineLigands for Ru(II Complexes as Photosensitizers inDye-Sensitized Solar Cells (DSSCs

Directory of Open Access Journals (Sweden)

Adewale O. Adeloye

2014-08-01

Full Text Available A number of novel ruthenium(II polypyridine complexes have been designedand synthesized for use as photosensitizers in dye-sensitized solar cells (DSSCs due totheir rich photophysical properties such as intense absorption, long-lived lifetimes, highemission quantum yields and unique redox characteristics. Many of these complexesexhibit photophysical behavior that can be readily controlled through a careful choice ofligands and/or substituents. With this perspective, we review the design and general syntheticmethods of some polypyridine ligands based on bipyridine, phenanthroline, terpyridine andquaterpyridine with/without anchoring groups with a view to correlate functionality ofligand structures with the observed photophysical, electroredox and power conversionefficiency of some examples of Ru(II polypyridyl complexes that have been reported andparticularly used in the DSSCs applications. The main interest, however, is focused onshowing the development of new polypyridine ligand materials containing long-rangeelectron transfer motifs such as the alkenyl, alkynyl and polyaromatic donor functionalities.

Ruthenium(II)-catalyzed synthesis of pyrrole- and indole-fused isocoumarins by C-H bond activation in DMF and water

Digital Repository Service at National Institute of Oceanography (India)

Singh, K.S.; Sawant, S.G.; Dixneuf, P.H.

stream_size 26907 stream_content_type text/plain stream_name ChemCatChem_8_1046a.pdf.txt stream_source_info ChemCatChem_8_1046a.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 Author version...: ChemCatChem, vol.8(6); 2016; 1046-1050 Ruthenium(II) catalysed synthesis of pyrrole and indole fused isocoumarins via C-H bond activation in DMF and water† Keisham S. Singh*,a Sneha G. Sawanta, Pierre H. Dixneuf*,b Abstract: Pyrrole and indole...

Efficient transfer hydrogenation reaction Catalyzed by a dearomatized PN 3P ruthenium pincer complex under base-free Conditions

KAUST Repository

He, Lipeng

2012-03-01

A dearomatized complex [RuH(PN 3P)(CO)] (PN 3PN, N′-bis(di-tert-butylphosphino)-2,6-diaminopyridine) (3) was prepared by reaction of the aromatic complex [RuH(Cl)(PN 3P)(CO)] (2) with t-BuOK in THF. Further treatment of 3 with formic acid led to the formation of a rearomatized complex (4). These new complexes were fully characterized and the molecular structure of complex 4 was further confirmed by X-ray crystallography. In complex 4, a distorted square-pyramidal geometry around the ruthenium center was observed, with the CO ligand trans to the pyridinic nitrogen atom and the hydride located in the apical position. The dearomatized complex 3 displays efficient catalytic activity for hydrogen transfer of ketones in isopropanol. © 2011 Elsevier B.V. All rights reserved.

Photochromic ruthenium sulfoxide complexes: evidence for isomerization through a conical intersection.

Science.gov (United States)

McClure, Beth Anne; Mockus, Nicholas V; Butcher, Dennis P; Lutterman, Daniel A; Turro, Claudia; Petersen, Jeffrey L; Rack, Jeffrey J

2009-09-07

The complexes [Ru(bpy)(2)(OS)](PF(6)) and [Ru(bpy)(2)(OSO)](PF(6)), where bpy is 2,2'-bipyridine, OS is 2-methylthiobenzoate, and OSO is 2-methylsulfinylbenzoate, have been studied. The electrochemical and photochemical reactivity of [Ru(bpy)(2)(OSO)](+) is consistent with an isomerization of the bound sulfoxide from S-bonded (S-) to O-bonded (O-) following irradiation or electrochemical oxidation. Charge transfer excitation of [Ru(bpy)(2)(OSO)](+) in MeOH results in the appearance of two new metal-to-ligand charge transfer (MLCT) maxima at 355 and 496 nm, while the peak at 396 nm diminishes in intensity. The isomerization is reversible at room temperature in alcohol or propylene carbonate solution. In the absence of light, solutions of O-[Ru(bpy)(2)(OSO)](+) revert to S-[Ru(bpy)(2)(OSO)](+). Kinetic analysis reveals a biexponential decay with rate constants of 5.66(3) x 10(-4) s(-1) and 3.1(1) x 10(-5) s(-1). Cyclic voltammograms of S-[Ru(bpy)(2)(OSO)](+) are consistent with electron-transfer-triggered isomerization of the sulfoxide. Analysis of these voltammograms reveal E(S)(o)' = 0.86 V and E(O)(o)' = 0.49 V versus Ag/Ag(+) for the S- and O-bonded Ru(3+/2+) couples, respectively, in propylene carbonate. We found k(S-->O) = 0.090(15) s(-1) in propylene carbonate and k(S-->O) = 0.11(3) s(-1) in acetonitrile on Ru(III), which is considerably slower than has been reported for other sulfoxide isomerizations on ruthenium polypyridyl complexes following oxidation. The photoisomerization quantum yield (Phi(S-->O) = 0.45, methanol) is quite large, indicating a rapid excited state isomerization rate constant. The kinetic trace at 500 nm is monoexponential with tau = 150 ps, which is assigned to the excited S-->O isomerization rate. There is no spectroscopic or kinetic evidence for an O-bonded (3)MLCT excited state in the spectral evolution of S-[Ru(bpy)(2)(OSO)](+) to O-[Ru(bpy)(2)(OSO)](+). Thus, isomerization occurs nonadiabatically from an S-bonded (or eta(2

Reactivity of nitrido complexes of ruthenium(VI), osmium(VI), and manganese(V) bearing Schiff base and simple anionic ligands.

Science.gov (United States)

Man, Wai-Lun; Lam, William W Y; Lau, Tai-Chu

2014-02-18

Nitrido complexes (M≡N) may be key intermediates in chemical and biological nitrogen fixation and serve as useful reagents for nitrogenation of organic compounds. Osmium(VI) nitrido complexes bearing 2,2':6',2″-terpyridine (terpy), 2,2'-bipyridine (bpy), or hydrotris(1-pyrazolyl)borate anion (Tp) ligands are highly electrophilic: they can react with a variety of nucleophiles to generate novel osmium(IV)/(V) complexes. This Account describes our recent results studying the reactivity of nitridocomplexes of ruthenium(VI), osmium(VI), and manganese(V) that bear Schiff bases and other simple anionic ligands. We demonstrate that these nitrido complexes exhibit rich chemical reactivity. They react with various nucleophiles, activate C-H bonds, undergo N···N coupling, catalyze the oxidation of organic compounds, and show anticancer activities. Ruthenium(VI) nitrido complexes bearing Schiff base ligands, such as [Ru(VI)(N)(salchda)(CH3OH)](+) (salchda = N,N'-bis(salicylidene)o-cyclohexyldiamine dianion), are highly electrophilic. This complex reacts readily at ambient conditions with a variety of nucleophiles at rates that are much faster than similar reactions using Os(VI)≡N. This complex also carries out unique reactions, including the direct aziridination of alkenes, C-H bond activation of alkanes and C-N bond cleavage of anilines. The addition of ligands such as pyridine can enhance the reactivity of [Ru(VI)(N)(salchda)(CH3OH)](+). Therefore researchers can tune the reactivity of Ru≡N by adding a ligand L trans to nitride: L-Ru≡N. Moreover, the addition of various nucleophiles (Nu) to Ru(VI)≡N initially generate the ruthenium(IV) imido species Ru(IV)-N(Nu), a new class of hydrogen-atom transfer (HAT) reagents. Nucleophiles also readily add to coordinated Schiff base ligands in Os(VI)≡N and Ru(VI)≡N complexes. These additions are often stereospecific, suggesting that the nitrido ligand has a directing effect on the incoming nucleophile. M≡N is also

In vitro evaluation of ruthenium complexes for photodynamic therapy.

Science.gov (United States)

Li, Wenna; Xie, Qiang; Lai, Linglin; Mo, Zhentao; Peng, Xiaofang; Leng, Ennian; Zhang, Dandan; Sun, Hongxia; Li, Yiqi; Mei, Wenjie; Gao, Shuying

2017-06-01

Photodynamic therapy (PDT) is a promising anti-tumor treatment strategy. Photosensitizer is one of the most important components of PDT. In this work, the anticancer activities of PDT mediated by six new ruthenium porphyrin complexes were screened. The mechanisms of the most efficacious candidate were investigated. Photocytotoxicity of the six porphyrins was tested. The most promising complex, Rup-03, was further investigated using Geimsa staining, which indirectly detects reactive oxygen species (ROS) and subcellular localization. Mitochondrial membrane potential (MMP), cell apoptosis, DNA fragmentation, c-Myc gene expression, and telomerase activities were also assayed. Rup-03 and Rup-04 had the lowest IC 50 values. Rup-03 had an IC 50 value of 29.5±2.3μM in HepG2 cells and 59.0±6.1μM in RAW264.7 cells, while Rup-04 had an IC 50 value of 40.0±3.8μM in SGC-7901 cells. The complexes also induced cellular morphological changes and impaired cellular ability to scavenge ROS, and accumulated preferentially in mitochondria and endoplasmic reticulum. Rup-03 reduced MMP levels, induced apoptosis, and repressed both c-Myc mRNA expression and telomerase activity in HepG2 cells. Among six candidates, Rup-03-mediated PDT is most effective against HepG2 and RAW264.7, with a similar efficacy as that of Rup-04-mediated PDT against SGC-7901 cells. Repression of ROS scavenging activities and c-Myc expression, which mediated DNA damage-induced cell apoptosis and repression of telomerase activity, respectively, were found to be involved in the anticancer mechanisms of Rup-03. Copyright © 2017 Elsevier B.V. All rights reserved.

Organometallic Half-Sandwich Iridium Anticancer Complexes

Czech Academy of Sciences Publication Activity Database

Liu, Z.; Habtemariam, A.; Pizarro, A.M.; Fletcher, S.A.; Kisová, Anna; Vrána, Oldřich; Salassa, L.; Bruijnincx, P.C.A.; Clarkson, G.J.; Brabec, Viktor; Sadler, P. J.

2011-01-01

Roč. 54, č. 8 (2011), 3011-3026 ISSN 0022-2623 R&D Projects: GA ČR(CZ) GPP303/11/P047; GA ČR(CZ) GAP301/10/0598 Keywords : RUTHENIUM(II) ARENE COMPLEXES * CANCER-CELL CYTOTOXICITY * DNA-BINDING PROPERTIES Subject RIV: BO - Biophysics Impact factor: 5.248, year: 2011

Towards PSII analogs driven by ruthenium photophysics

International Nuclear Information System (INIS)

Olsson, Jerry

2002-01-01

A number of model complexes have been prepared in an attempt to develop models for photosystem II (PSII) in green plants. As replacement for the chlorophyll photosensitizer, we have used Ru(ll) tris-2,2-bipyridyl or Ru(ll) bis-2,2';6',2 - terpyridyl complexes linked to a pendant 2,2'-bipyridyl or 2,2';6',2''-terpyridyl moieties via spacers of varying lengths. Manganese (ll) has been covalently linked to the pendant 2,2'-bipyridyl /2,2';6',2''-terpyridyl moieties. The use of different ruthenium centres and spacers has made it possible to make assumptions about the way and how easily manganese is coordinated through self-assembly to the pendant 2,2'-bipyridyl or 2,2';6',2''-terpyridyl groups. Several polynuclear complexes containing a photoactive centre (Ru(ll) tris-2,2'-bipyridine or Ru(ll) bis-2,2';6',2''-terpyridine) or other metal ions (Co 2+ , Fe 2+ , Mn 2= ) have been prepared and characterised. The main work has been focused on organic synthesis and characterisation of polypyridine ligands and coordinated to different metal centres. The complexes have been investigated electrochemically and photophysically. Several new phenol-based ligands have been prepared by organic synthetic methods and characterised by various different methods. (author)

Light induced electron transfer reactions of metal complexes

International Nuclear Information System (INIS)

Sutin, N.; Creutz, C.

1980-01-01

Properties of the excited states of tris(2,2'-bipyridine) and tris(1,10-phenanthroline) complexes of chromium(III), iron(II), ruthenium(II), osmium(II), rhodium(III), and iridium(III) are described. The electron transfer reactions of the ground and excited states are discussed and interpreted in terms of the driving force for the reaction and the distortions of the excited states relative to the corresponding ground states. General considerations relevant to the conversion of light into chemical energy are presented and progress in the use of polypyridine complexes to effect the light decomposition of water into hydrogen and oxygen is reviewed

Amorphous carbon nanofibres inducing high specific capacitance of deposited hydrous ruthenium oxide

International Nuclear Information System (INIS)

Barranco, V.; Pico, F.; Ibanez, J.; Lillo-Rodenas, M.A.; Linares-Solano, A.; Kimura, M.; Oya, A.; Rojas, R.M.; Amarilla, J.M.; Rojo, J.M.

2009-01-01

Composites consisting of ruthenium oxide particles deposited on amorphous carbon nanofibres are prepared by a repetitive impregnation procedure. The choice of amorphous carbon nanofibres as support of amorphous ruthenium oxide leads to composites in which the deposited oxide consists of aggregates of extremely small primary particles (1-1.5 nm-size) and showing high porosity (specific surface area of 450 m 2 g -1 ). This special deposition of the oxide seems to favour: (i) high oxide capacitance (1000 Fg -1 ) at high oxide loadings (up to 20 wt%) and (ii) high capacitance retention (ca. 80% from the initial oxide capacitance) at high current densities (200 mA cm -2 ). Amorphous carbon nanofibres are suitable supports for amorphous ruthenium oxide and perhaps for other amorphous oxides acting as active electrode materials.

Ruthenium complexing during sorption by graft copolymer of polyacrylonitrile fibre with poly-2-methyl-5-vnylpyridine (PAN-MVP)

International Nuclear Information System (INIS)

Simanova, S.A.; Kolmakova, A.I.; Konovalov, L.V.; Kukushkin, Yu.N.; Lysenko, A.A.

1984-01-01

The sorption of ruthenium chlorocomplexes is studied on graft copolymer of polyacrylonitrile fibre with poly-2-methyl-5-vinylpyridine (PAN-MVP). The sorption has been performed under static conditions in the course of mixing at 20 and 98 deg from 0.1-2 OM HCl, 0.1-1 m NaCl solutions. The volume of the investigated solutions constituted 25 ml, fibre weight -0.1-0.3 g. Ruthenium concentration in solutions has been changed in the limits of 5x10 3 -2x10 -2 mol/l. The fibre has been preliminarily moistened by a solution containing no ruthenium. In all cases fresh-prepared ruthenium chlorocomplex solutions have been used. It has been found that with temperature increase the PAN-MVP sorption capacitance relative to ruthenium increases (at 20 deg-1.15 mmol/g, at 98 deg-1.70 mmol/g. The ruthenium chlorocomplex sorption by pyridine fibrous sorbent from salt-acid solutions occurs by anionoexchange mechanism and is related to the formation in the sorbent phase of onium chlorocomplexes - (RPyH) 2 [RuCl 6 ]. In the course of sorbents heating pyridine compounds are subject to Anderson regroupping with formation of compounds of diamine type-[Ru(RPy) 2 Cl 4

Electro-volatilization of ruthenium in nitric medium: influences of ruthenium species nature and models solutions composition; Electro-volatilisation du ruthenium en milieu nitrique: influence de la nature des formes chimiques du ruthenium et de la composition des solutions modeles de dissolution

Energy Technology Data Exchange (ETDEWEB)

Mousset, F

2004-12-15

Ruthenium is one of the fission products in the reprocessing of irradiated fuels that requires a specific processing management. Its elimination, upstream by the PUREX process, has been considered. A process, called electro-volatilization, which take advantage of the RuO{sub 4} volatility, has been optimised in the present study. It consists in a continuous electrolysis of ruthenium solutions in order to generate RuO{sub 4} species that is volatilized and easily trapped. This process goes to satisfying ruthenium elimination yields with RuNO(NO{sub 3}){sub 3}(H{sub 2}O){sub 2} synthetic solutions but not with fuel dissolution solutions. Consequently, this work consisted in the speciation studies of dissolved ruthenium species were carried out by simulating fuel solutions produced by hot acid attack of several ruthenium compounds (Ru(0), RuO{sub 2},xH{sub 2}O, polymetallic alloy). In parallel with dissolution kinetic studies, the determination of dissolved species was performed using voltammetry, spectrometry and spectro-electrochemistry. The results showed the co-existence of Ru(IV) and RuNO(NO{sub 2}){sub 2}(H{sub 2}O){sub 3}. Although these species are different from synthetic RuNO(NO{sub 3}){sub 3}(H{sub 2}O){sub 2}, their electro-oxidation behaviour are similar. The electro-volatilization tests of these dissolution solutions yielded to comparable results as the synthetic RuNO(NO{sub 3}){sub 3}(H{sub 2}O){sub 2} solutions. Then, complexity increase of models solutions was performed by in-situ generation of nitrous acid during ruthenium dissolution. Nitrous acid showed a catalytic effect on ruthenium dissolution. Its presence goes to quasi exclusively RuNO(NO{sub 2}){sub 2}(H{sub 2}O){sub 3} species. It is also responsible of the strong n-bond formation between Ru{sup 2+} and NO{sup +}. In addition, it has been shown that its reducing action on RuO{sub 4} hinders the electro-volatilization process. Mn{sup 2+} and Ce{sup 3+} cations also reveal, but to a lesser

Device for separating ruthenium ion from spent fuel material

International Nuclear Information System (INIS)

Izumida, Tatsuo; Sasahira, Akira; Ozawa, Yoshihiro; Kawamura, Fumio.

1988-01-01

Purpose: To separate plutonium ions efficiently and selectively from organic solvent containing tributyl phosphate used in the main step of reprocessing process. Constitution: The device comprises, as the main constituent factor, a liquid-liquid contact device for bringing not water soluble organic solvent into contact with a nitric acid solution of spent fuel substances and a liquid-liquid contact-separation device for bringing an organic solvent solution containing spent fuel substances separated with nitric acid into contact again with nitric acid. Then, a device is disposed between two liquid-liquid contact devices for staying ruthenium ions and organic solvent for a sufficient time. In this way, ruthenium ions in the organic solvent containing butyl phosphate are gradually converted into complex compounds combined with tributyl phosphate thereby enabling to separate ruthenium ions efficiently and remarkably reduce the corrosion of equipments. (Horiuchi, T.)

General synthesis of (salen)ruthenium(III) complexes via N...N coupling of (salen)ruthenium(VI) nitrides.

Science.gov (United States)

Man, Wai-Lun; Kwong, Hoi-Ki; Lam, William W Y; Xiang, Jing; Wong, Tsz-Wing; Lam, Wing-Hong; Wong, Wing-Tak; Peng, Shie-Ming; Lau, Tai-Chu

2008-07-07

Reaction of [Ru (VI)(N)(L (1))(MeOH)] (+) (L (1) = N, N'-bis(salicylidene)- o-cyclohexylenediamine dianion) with excess pyridine in CH 3CN produces [Ru (III)(L (1))(py) 2] (+) and N 2. The proposed mechanism involves initial equilibrium formation of [Ru (VI)(N)(L (1))(py)] (+), which undergoes rapid N...N coupling to produce [(py)(L (1))Ru (III) N N-Ru (III)(L (1))(py)] (2+); this is followed by pyridine substituion to give the final product. This ligand-induced N...N coupling of Ru (VI)N is utilized in the preparation of a series of new ruthenium(III) salen complexes, [Ru (III)(L)(X) 2] (+/-) (L = salen ligand; X = H 2O, 1-MeIm, py, Me 2SO, PhNH 2, ( t )BuNH 2, Cl (-) or CN (-)). The structures of [Ru (III)(L (1))(NH 2Ph) 2](PF 6) ( 6), K[Ru (III)(L (1))(CN) 2] ( 9), [Ru (III)(L (2))(NCCH 3) 2][Au (I)(CN) 2] ( 11) (L (2) = N, N'-bis(salicylidene)- o-phenylenediamine dianion) and [N ( n )Bu 4][Ru (III)(L (3))Cl 2] ( 12) (L (3) = N, N'-bis(salicylidene)ethylenediamine dianion) have been determined by X-ray crystallography.

Redox Properties of Ruthenium Nitrosyl Porphyrin Complexes with Different Axial Ligation: Structural, Spectroelectrochemical (IR, UV-VIS, EPR) and Theoretical Studies

Czech Academy of Sciences Publication Activity Database

Singh, P.; Das, A. K.; Sarkar, B.; Niemeyer, M.; Roncaroli, F.; Olabe, J. A.; Fiedler, Jan; Záliš, Stanislav; Kaim, W.

2008-01-01

Roč. 47, č. 16 (2008), s. 7106-7113 ISSN 0020-1669 R&D Projects: GA AV ČR KAN100400702; GA MŠk OC 139; GA MŠk 1P05OC068 Institutional research plan: CEZ:AV0Z40400503 Keywords : ruthenium nitrosyl porphyrin complexes * tetraphenylporphyrin dianiom * EPR Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.147, year: 2008

Synthesis, Photophysical and Electrochemical Properties of a Mixed Bipyridyl-Phenanthrolyl Ligand Ru(II Heteroleptic Complex Having trans-2-Methyl-2-butenoic Acid Functionalities

Directory of Open Access Journals (Sweden)

Adewale O. Adeloye

2011-09-01

Full Text Available In this work, two ligands: 4-(trans-2-Methyl-2-butenoic acid-2,2'-bipyridine (L1 and 5-(trans-2-methyl-2-butenoic acid-1,10-phenanthroline (L2, with the corresponding mixed-ligand heteroleptic Ru(II complex were synthesized and characterized by FT-IR, 1H-, 13C-NMR spectroscopy and elemental analysis. The influence of the mixed functionalized polypyridyl ruthenium(II complex on the photophysical and electrochemical properties were investigated and compared to individual single-ligand homoleptic complexes. Interestingly, the mixed-ligand complex formulated as [RuL1L2(NCS2] exhibits broad and intense metal-to-ligand charge transfer (MLCT absorption with a high molar extinction coefficient (λmax = 514 nm, ε = 69,700 M−1 cm−1, better than those of individual single-ligand complexes, [Ru(L12(NCS2] and [Ru(L22(NCS2], and a strong photoluminescence intensity ratio in the red region at λem = 686 nm. The electrochemical properties of the complex indicated that the redox processes are ligand-based.

Synthesis of 4‧-substituted-2,2‧;6‧,2″-terpyridine Ru(II) complexes electrochemical, fluorescence quenching and antibacterial studies

Science.gov (United States)

Ezhilarasu, Tamilarasu; Sathiyaseelan, Anbazhagan; Kalaichelvan, Pudupalayam Thangavelu; Balasubramanian, Sengottuvelan

2017-04-01

Three new Ru(II) terpyridine complexes viz. [Ru(BBtpy)2](PF6)2 [Ru(L1)] (BBtpy = 4‧-(4-benzyloxybenzaldehyde)-2,2‧:6‧,2″-terpyridine), [Ru(BMBtpy)2](PF6)2 [Ru(L2)] (BMBtpy = 4‧-(4-benzyloxy-3-methoxybenzaldehyde)-2,2‧:6‧,2″-terpyridine) and [Ru(BEBtpy)2](PF6)2 [Ru(L3)] (BEBtpy = 4‧-(4-benzyloxy-3-ethoxybenzaldehyde)-2,2‧:6‧,2″-terpyridine) have been synthesized and characterized. The MALDI-TOF/MS fragmentation pattern of [Ru(BMBtpy)2](PF6)2 complex exhibits a molecular ion peak at m/z = 987.09 [M-2PF6]2+ fragment. These Ru(II) complexes are redox active, show both metal centered oxidation and ligand centered reduction processes. The peak potential and peak current Ipa and Ipc also undergo definite shift and increase with increase in the scan rate (20-120 mV/s). The fluorescence of Ru(II) complexes [Ru(L1)], [Ru(L2)] and [Ru(L3)] are effectively quenched by 1,4-benzoquinone and 1,4-naphthoquinone in acetonitrile. The antibacterial activity of ruthenium(II) complexes were screened against four human pathogens both gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus) and gram negative bacteria (Escherichia coli, Klebsiella pneumonia) by the well diffusion method. The antibacterial activity of Ru(II) complexes is comparable to that of standard antibiotics like tetracycline.

Thermodynamic behaviour of ruthenium at high temperatures

International Nuclear Information System (INIS)

Garisto, F.

1988-01-01

Thermodynamic equilibrium calculations are used to determine the chemical speciation of ruthenium under postulated reactor accident conditions. The speciation of ruthenium is determined for various values of temperature, pressure, oxygen partial pressure and ruthenium concentration. The importance of these variables, in particular the oxygen partial pressure, in determining the volatility of ruthenium is clearly demonstrated in this report. Reliable thermodynamic data are required to determine the behaviour of ruthenium using equilibrium calculations. Therefore, it was necessary to compile a thermodynamic database for the ruthenium species that can be formed under reactor accident conditions. The origin of the thermodynamic data for the ruthenium species included in our calculations is discussed in detail in Appendix A. 23 refs

Synthesis, singlet-oxygen photogeneration, two-photon absorption, photo-induced DNA cleavage and cytotoxic properties of an amphiphilic β-Schiff-base linked Ru(II) polypyridyl–porphyrin conjugate

International Nuclear Information System (INIS)

Ke, Hanzhong; Ma, Wanpeng; Wang, Hongda; Cheng, Guoe; Yuan, Han; Wong, Wai-Kwok; Kwong, Daniel W.J.; Tam, Hoi-Lam; Cheah, Kok-Wai; Chan, Chi-Fai; Wong, Ka-Leung

2014-01-01

A novel porphyrin–polypyridyl ruthenium(II) conjugate (TPP–Ru), in which the ruthenium(II) polypyridyl moiety is linked to the β-position of the tetraphenylporphyrin via a Schiff base linkage, has been synthesized and characterized by 1 H NMR, HRMS and UV–visible spectroscopy. The relative singlet oxygen quantum yield and two-photon absorption cross-section of this conjugate, together with its photo-induced DNA cleavage and cytotoxic activities were measured. The results show that the amphiphilic ruthenium(II) polypyridyl–porphyrin conjugate is an effective DNA photocleavage agent, with potential application in one- and two-photon absorption anti-cancer photodynamic therapy. - Highlights: • New porphyrin–ruthenium(II) polypyridyl complexes (TTP–Ru) have been synthesized. • The TTP–Ru shows substantial two-photon absorption cross-section (σ 2 =391 GM). • The TTP–Ru exhibits a substantial 1 O 2 quantum yield (0.64±0.13). • The TTP–Ru exhibits a strong DNA cleavage activity upon photo-excitation. • The TTP–Ru is available for in vitro imaging and as a photodynamic therapy agent

Synthesis, singlet-oxygen photogeneration, two-photon absorption, photo-induced DNA cleavage and cytotoxic properties of an amphiphilic β-Schiff-base linked Ru(II) polypyridyl–porphyrin conjugate

Energy Technology Data Exchange (ETDEWEB)

Ke, Hanzhong, E-mail: kehanz@163.com [Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan, Hubei 430074 (China); Ma, Wanpeng; Wang, Hongda; Cheng, Guoe [Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan, Hubei 430074 (China); Yuan, Han [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR (China); Wong, Wai-Kwok, E-mail: wkwong@hkbu.edu.hk [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR (China); Institute of Advanced Materials, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR (China); Kwong, Daniel W.J. [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR (China); Tam, Hoi-Lam; Cheah, Kok-Wai [Department of Physics, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR (China); Institute of Advanced Materials, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR (China); Chan, Chi-Fai; Wong, Ka-Leung [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR (China)

2014-10-15

A novel porphyrin–polypyridyl ruthenium(II) conjugate (TPP–Ru), in which the ruthenium(II) polypyridyl moiety is linked to the β-position of the tetraphenylporphyrin via a Schiff base linkage, has been synthesized and characterized by {sup 1}H NMR, HRMS and UV–visible spectroscopy. The relative singlet oxygen quantum yield and two-photon absorption cross-section of this conjugate, together with its photo-induced DNA cleavage and cytotoxic activities were measured. The results show that the amphiphilic ruthenium(II) polypyridyl–porphyrin conjugate is an effective DNA photocleavage agent, with potential application in one- and two-photon absorption anti-cancer photodynamic therapy. - Highlights: • New porphyrin–ruthenium(II) polypyridyl complexes (TTP–Ru) have been synthesized. • The TTP–Ru shows substantial two-photon absorption cross-section (σ{sub 2}=391 GM). • The TTP–Ru exhibits a substantial {sup 1}O{sub 2} quantum yield (0.64±0.13). • The TTP–Ru exhibits a strong DNA cleavage activity upon photo-excitation. • The TTP–Ru is available for in vitro imaging and as a photodynamic therapy agent.

Phenylalanine-a biogenic ligand with flexible η6- and η6:κ1-coordination at ruthenium(ii) centres

KAUST Repository

Reiner, Thomas; Jantke, Dominik; Miao, Xiaohe; Marziale, Alexander N.; Kiefer, Florian J.; Eppinger, Jö rg

2013-01-01

The reaction of (S)-2,5-dihydrophenylalanine 1 with ruthenium(iii) chloride yields the μ-chloro-bridged dimeric η6-phenylalanine ethyl ester complex 3, which can be converted into the monomeric analogue, η6:κ1-phenylalanine ethyl ester complex 12, under basic conditions. Studies were carried out to determine the stability and reactivity of complexes bearing η6- and η6: κ1-chelating phenylalanine ligands under various conditions. Reaction of 3 with ethylenediamine derivatives N-p-tosylethylenediamine or 1,4-di-N-p-tosylethylenediamine results in the formation of monomeric η6:κ1-phenylalanine ethyl ester complexes 14 and 15, which could be saponified yielding complexes 16 and 17 without changing the inner coordination sphere of the metal centre. The structure of η6:κ1-phenylalanine complex 17 and an N-κ1-phenylalanine complex 13 resulting from the reaction of 3 with an excess of pyridine were confirmed by X-ray crystallography. © 2013 The Royal Society of Chemistry.

Increased electrochemical properties of ruthenium oxide and graphene/ruthenium oxide hybrid dispersed by polyvinylpyrrolidone

International Nuclear Information System (INIS)

Chen, Yao; Zhang, Xiong; Zhang, Dacheng; Ma, Yanwei

2012-01-01

Highlights: ► A good dispersion of RuO 2 and graphene/RuO 2 is obtained by polyvinylpyrrolidone. ► PVP as a dispersant also can prevent the formation of metal Ru in graphene/RuO 2 . ► The max capacitances of the hybrid and RuO 2 reach 435 and 597 F g −1 at 0.2 A g −1 . ► The hybrid shows the best rate capability of 39% at 50 A g −1 . - Abstract: Ruthenium oxide has been prepared by a sol–gel method. Polyvinylpyrrolidone (PVP) as an excellent polymeric dispersant is adopted to prevent aggregation of ruthenium oxide. In order to enhance the rate capability of ruthenium oxide, graphene with residual oxygen functional groups as a 2D support has been merged into ruthenium oxide. These oxygen functional groups not only favor to form stable few layers of graphene colloids, but also offer the sites to anchor ruthenium oxide nanoparticles. X-ray diffraction infers that PVP can also hinder the partial formation of Ru by blocking the direct contact between the Ru 3+ and the graphene in the sol–gel synthesis of the hybrids. The ruthenium oxide and the graphene/ruthenium oxide hybrids dispersed by PVP have superior electrochemical properties due to good dispersing and protecting ability of PVP. Especially, the hybrids using PVP exhibit the best rate capability, indicating that the composites possess an advanced structure of combining sheets and particles in nano-scale.

Electrochemical studies of ruthenium compounds

International Nuclear Information System (INIS)

Kumar Ghosh, B.; Chakravorty, A.

1989-01-01

In many ways the chemistry of transition metals is the chemistry of multiple oxidation states and the associated redox phenomena. If a particular element were to be singeld out to illustrate this viewpoint, a model choice would be ruthenium - an element that is directly or indirectly the active centre of a plethora of redox phenomena encompassing ten different oxidation states and a breathtaking diversity of structure and bonding. In the present review the authors are primarily concerned with the oxidation states of certain ligands coordinated to ruthenium. This choice is deliberate since this is one area where the unique power of electrochemical methods is splendidly revealed. Without these methods, development in this area would have been greatly hampered. A brief summary of metal oxidation states is also included as a prelude to the main subject of this review. The authors have generally emphasize the information derived which is of chemical interest leaving the details of formal electrochemical arguments in the background. The authors have reviewed the pattern and systematics of ligand redox in ruthenium complexes. The synergistic combination of electrochemical and spectroscopic methods have vastly increased our understanding of ligand phenomena during the last 15 years or so. This in turn has led to better understanding and new developments in other fields. Photophysics and photochemistry could be cited as examples. (author). 176 refs.; 10 figs.; 10 tabs

Dehydrogenation of Formic Acid Catalyzed by a Ruthenium Complex with an N,N′-Diimine Ligand

KAUST Repository

Guan, Chao

2016-12-17

We report a ruthenium complex containing an N,N′-diimine ligand for the selective decomposition of formic acid to H and CO in water in the absence of any organic additives. A turnover frequency of 12000 h and a turnover number of 350 000 at 90 °C were achieved in the HCOOH/HCOONa aqueous solution. Efficient production of high-pressure H and CO (24.0 MPa (3480 psi)) was achieved through the decomposition of formic acid with no formation of CO. Mechanistic studies by NMR and DFT calculations indicate that there may be two competitive pathways for the key hydride transfer rate-determining step in the catalytic process.

Crystal structures of bromo- and iododerivatives of ruthenium nitroso complexes K2[RuNOX5

International Nuclear Information System (INIS)

Mikhajlov, Yu.N.; Kanishcheva, A.S.; Svetlov, A.A.

1989-01-01

Method of X-ray diffraction analysis was used to interpret crystal structure of ruthenium pentahalogenonitroso complexes: K 2 [RuNOBr 5 ] (1) and K 2 [RuOI 5 ] (2). Crystals belong to rhombic syngony, sp.gr. Pcmn. Lattice parameters: (1) - a 7.236(2), b = 10.791(2), c = 13.949(3) A, V = 1089.14(1) A 3 , Z = 4; (2) - a = 7.755(1), b = 11.506(6), c = 14.951(5) A, V 133.97(8) A 3 , Z = 4. It was revealed that lengths of Ru-Br equatorial bonds in (1) exceeded the axial ones, and in the compound (2) the reverse relation was observed. The obtained results were correlated with the structural data for K 2 [RuNOF 5 ]H 2 O and K 2 [RuNOCl 5 ] complexes and similar osmium compounds

Synthesis and characterization of novel heteroleptic ruthenium sensitizer for nanocrystalline dye-sensitized solar cells

NARCIS (Netherlands)

Sivakumar, R.; Marcelis, A.T.M.; Anandan, S.

2009-01-01

A novel heteroleptic ruthenium complex of the type [Ru(bpin)(dcbpyH2)Cl]Cl (where bpin is 2,6-bis(pyrazol-1-yl)isonicotinic acid and dcbpyH2 is 4,4'-dicarboxy-2,2'-bipyridine) was synthesized and characterized for tuning the LUMO level of the ruthenium sensitizer to achieve greater stabilization in

Ruthenium complex with benznidazole and nitric oxide as a new candidate for the treatment of chagas disease.

Directory of Open Access Journals (Sweden)

Renata Sesti-Costa

2014-10-01

Full Text Available Chagas disease remains a serious medical and social problem in Latin America and is an emerging concern in nonendemic countries as a result of population movement, transfusion of infected blood or organs and congenital transmission. The current treatment of infected patients is unsatisfactory due to strain-specific drug resistance and the side effects of the current medications. For this reason, the discovery of safer and more effective chemotherapy is mandatory for the successful treatment and future eradication of Chagas disease.We investigated the effect of a ruthenium complex with benznidazole and nitric oxide (RuBzNO2 against Trypanosoma cruzi both in vitro and in vivo. Our results demonstrated that RuBzNO2 was more effective than the same concentrations of benznidazole (Bz in eliminating both the extracellular trypomastigote and the intracellular amastigote forms of the parasite, with no cytotoxic effect in mouse cells. In vivo treatment with the compound improved the survival of infected mice, inhibiting heart damage more efficiently than Bz alone. Accordingly, tissue inflammation and parasitism was significantly diminished after treatment with RuBzNO2 in a more effective manner than that with the same concentrations of Bz.The complexation of Bz with ruthenium and nitric oxide (RuBzNO2 increases its effectiveness against T. cruzi and enables treatment with lower concentrations of the compound, which may reduce the side effects of Bz. Our findings provide a new potential candidate for the treatment of Chagas disease.

Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole, 2-mercaptobenzoxazole and 2-mercaptobenzothiazole in the presence of edta

International Nuclear Information System (INIS)

Busev, A.I.; Ignat'eva, T.I.; Lomakina, L.N.

1975-01-01

Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole (2MBI), 2-mercaptobenzoxazole (2MBO) and 2-mercaptobenzothiazole (2MBT) in the presence of EDTA was studied. The interaction of ruthenium (4) and osmium (4) with EDTA was constidered. Ruthenium complex is formed with constant output at 2-4.5 pH after 30 min.heating. In the lowacid solution (pH 2-4) osmium reacts with EDTA forming soluble compound. Characteristics of ruthenium (4) compound with 2MBI, 2MBO and 2MBT produced in the presence of EDTA are presented. Osmium (4) in the presence of EDTA and above mentioned organic reagents and when heating forms lowsoluble compounds. Possibility of joint determination of ruthenium and osmium with help of 2MBI in the presence of EDTA under conditions of minimum complexing osmium with EDTA was investigated

Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole, 2-mercaptobenzoxazole and 2-mercaptobenzothiazole in the presence of EDTA

Energy Technology Data Exchange (ETDEWEB)

Busev, A I; Ignat' eva, T I; Lomakina, L N [Moskovskij Gosudarstvennyj Univ. (USSR). Kafedra Analiticheskoj Khimii

1975-05-01

Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole (2MBI), 2-mercaptobenzoxazole (2MBO) and 2-mercaptobenzothiazole (2MBT) in the presence of EDTA was studied. The interaction of ruthenium (4) and osmium (4) with EDTA was considered. Ruthenium complex is formed with constant output at 2-4.5 pH after 30 min. heating. In the low acid solution (pH 2-4) osmium reacts with EDTA forming soluble compound. Characteristics of ruthenium (4) compound with 2MBI, 2MBO and 2MBT produced in the presence of EDTA are presented. Osmium (4) in the presence of EDTA and above mentioned organic reagents and when heating forms low soluble compounds. Possibility of joint determination of ruthenium and osmium with help of 2MBI in the presence of EDTA under conditions of minimum complexing osmium with EDTA was investigated.

Electronic optimization of heteroleptic Ru(II) bipyridine complexes by remote substituents: synthesis, characterization, and application to dye-sensitized solar cells.

Science.gov (United States)

Han, Won-Sik; Han, Jung-Kyu; Kim, Hyun-Young; Choi, Mi Jin; Kang, Yong-Soo; Pac, Chyongjin; Kang, Sang Ook

2011-04-18

We prepared a series of new heteroleptic ruthenium(II) complexes, Ru(NCS)(2)LL' (3a-3e), where L is 4,4'-di(hydroxycarbonyl)-2,2'-bipyridine and L' is 4,4'-di(p-X-phenyl)-2,2'-pyridine (X = CN (a), F (b), H (c), OMe (d), and NMe(2) (e)), in an attempt to explore the structure-activity relationships in their photophysical and electrochemical behavior and in their performance in dye-sensitized solar cells (DSSCs). When substituent X is changed from electron-donating NMe(2) to electron-withdrawing CN, the absorption and emission maxima reveal systematic bathochromic shifts. The redox potentials of these dyes are also significantly influenced by X. The electronic properties of the dyes were theoretically analyzed using density functional theory calculations; the results show good correlations with the experimental results. The solar-cell performance of DSSCs based on dye-grafted nanocrystalline TiO(2) using 3a-3e and standard N3 (bis[(4,4'-carboxy-2,2'-bipyridine)(thiocyanato)]ruthenium(II)) were compared, revealing substantial dependences on the dye structures, particularly on the remote substituent X. The 3d-based device showed the best performance: η = 8.30%, J(SC) = 16.0 mA·cm(-2), V(OC) = 717 mV, and ff = 0.72. These values are better than N3-based device.

Mechanistic studies of the oxidation of soluble species of ruthenium in nitric acid solutions. Application to the removal of ruthenium from nuclear fuel dissolution solutions

International Nuclear Information System (INIS)

Carron, V.

2001-01-01

Ruthenium is one of the most troublesome fission products during nuclear fuel reprocessing. His removal from nitric acid fuel dissolution solutions, above the PUREX process, is under consideration. Electro-volatilization could be a possible way to eliminate this element. It consists in the oxidation of soluble ruthenium species coupled with the volatilization of formed RuO 4 . Soluble species are nitrate and nitro complexes of nitrosyl ruthenium RuNO 3+ . The first part of this work deals with the direct oxidation of RuNO 3+ at a golden or a platinum anode. It has been investigated by cyclic voltammetry and infrared and UV-visible reflectance spectroscopy. The oxidation of RuNO 3+ begins with an adsorption step, which precedes the formation of RuO 4 . Then a reaction between RuO 4 and RuNO 3+ occurs to produce a Ru IV compound, which is also electro-oxidized to RuO 4 . The second part concerns potentiostatic electro-volatilization experiences. The rate of electro-volatilization decreases with increasing HNO 3 concentration. At low concentrations, kinetic is controlled by the volatilization of RuO 4 . The rate-determining step is the oxidation of RuNO 3+ at concentrations higher than 1 M. In HNO 3 4 M, the addition of AgNO 3 is required to accelerate the oxidation of RuNO 3+ . The last part is devoted to the study of the indirect oxidation of RuNO 3+ . The electrocatalytic power of electro-generated Ag II is illustrated by voltammetric techniques and potentiostatic electrolysis. The existence of a limit concentration of AgNO 3 is shown (which value depends on experimental conditions) beyond which kinetic is controlled by the RuO 4 volatilization step. These results indicate that the electro-volatilization kinetic could be increased by optimizing the volatilization conditions. (author)

Complexes superstructurés mixtes Ru/Fe et Ru/Co à ligands polypyridinyles multitopiques : synthèses, caractérisations, propriétés rédox et photorédox.

OpenAIRE

Lombard , Jean

2007-01-01

This work deals with the synthesis and physico-chemical study of heterobimetallic complexes bearing ruthenium(II)-tris-bipyridine units as photosensitizers covalently linked to a polypyridinic complex unit of iron (II) or cobalt (II), in order to investigate photoinduced electron transfer in such architectures.With bis-bipyridine type ligands, we synthesized a serie of tetranuclear complexes formed by a central complex unit FeII-tris-bipyridine, covalently linked to three RuII-tris-bipyridine...

Behaviour of ruthenium (3) bromocomplexes in nonaqueous solvents

International Nuclear Information System (INIS)

Rudnitskaya, O.V.; Miroshnichenko, I.V.; Pichkov, V.N.

1989-01-01

Behaviour of K 3 [RuBr 6 ] · H 2 O and K 3 [Ru 2 Br 9 ] in solutions of dimethylsulfoxide and dimethylformamide is investigated by absorption and ESR spectroscopy. Complexes are shown to be labile in solutions, interact easily with solvents. Formation of ruthenium (3) and (2) bromide-dimethylsulfoxide complexes occurs gradually in DMSO, final product is trans-[Ru(DMSO) 4 Br 2

Utilization of ruthenium volatilization at heating of residue containing phosphates and nitrates for ruthenium separation and for its qualitative proof

International Nuclear Information System (INIS)

Holgye, Z.

1979-01-01

The volatility of ruthenium during the heating of a residue after evaporation of a solution containing ruthenium, phosphates and nitrates may be utilized for the separation of ruthenium from various substances. Sup(103,106) Ru may be rapidly, selectively, and quantitatively separated from fission products mixture. Ruthenium may be also separated in this way from various inorganic salts or from biological material. The volatility of ruthenium may be used also for its qualitative proof. (author)

Polypyridylruthenium(II complexes exert anti-schistosome activity and inhibit parasite acetylcholinesterases.

Directory of Open Access Journals (Sweden)

Madhu K Sundaraneedi

2017-12-01

Full Text Available Schistosomiasis affects over 200 million people and there are concerns whether the current chemotherapeutic control strategy (periodic mass drug administration with praziquantel (PZQ-the only licenced anti-schistosome compound is sustainable, necessitating the development of new drugs.We investigated the anti-schistosome efficacy of polypyridylruthenium(II complexes and showed they were active against all intra-mammalian stages of S. mansoni. Two compounds, Rubb12-tri and Rubb7-tnl, which were among the most potent in their ability to kill schistosomula and adult worms and inhibit egg hatching in vitro, were assessed for their efficacy in a mouse model of schistosomiasis using 5 consecutive daily i.v. doses of 2 mg/kg (Rubb12-tri and 10 mg/kg (Rubb7-tnl. Mice treated with Rubb12-tri showed an average 42% reduction (P = 0.009, over two independent trials, in adult worm burden. Liver egg burdens were not significantly decreased in either drug-treated group but ova from both of these groups showed significant decreases in hatching ability (Rubb12-tri-68%, Rubb7-tnl-56% and were significantly morphologically altered (Rubb12-tri-62% abnormal, Rubb7-tnl-35% abnormal. We hypothesize that the drugs exerted their activity, at least partially, through inhibition of both neuronal and tegumental acetylcholinesterases (AChEs, as worms treated in vitro showed significant decreases in activity of these enzymes. Further, treated parasites exhibited a significantly decreased ability to uptake glucose, significantly depleted glycogen stores and withered tubercules (a site of glycogen storage, implying drug-mediated interference in this nutrient acquisition pathway.Our data provide compelling evidence that ruthenium complexes are effective against all intra-mammalian stages of schistosomes, including schistosomula (refractory to PZQ and eggs (agents of disease transmissibility. Further, the results of this study suggest that schistosome AChE is a target of

Flotation-spectrophotometric determination of ruthenium in the Ru(IV)-chloride-rhodamine 6G-toluene system

International Nuclear Information System (INIS)

Balcerzak, M.

1985-01-01

The reduction of RuO 4 in hydrochloric acid has been examined. A sensitive flotation-spectrophotometric method of the determination of ruthenium based on the ion associate formed by the anionic chlorid complex of ruthenium RuCl 2- 6 with the basic dye Rhodamine 6G (R6G) has been developed. The solution of the ion associate obeys Beer's law up to the concentration of 0.25 μg Ru/ml. The ion associate precipitates when the aqueous solution is shaken with toluene. The separated compound is dissolved in acetone. The molar absorptivity (epsilon) at 530 nm is 5.1 x 10 5 l x mole -1 x cm -1 . The relative standard deviation is 3-7%. The mole ratio of Ru:R6G in the complex is 1:5. Osmium reacts similarly. The determination of ruthenium can be selective after the preliminary separation of osmium as OsO 4 . The method was applied to the determination of microgram amounts of ruthenium in crucible platinum. (Author)

Reaction of a (Salen)ruthenium(VI) nitrido complex with thiols. C-H bond activation by (Salen)ruthenium(IV) sulfilamido species.

Science.gov (United States)

Man, Wai-Lun; Lam, William W Y; Kwong, Hoi-Ki; Peng, Shie-Ming; Wong, Wing-Tak; Lau, Tai-Chu

2010-01-04

The reaction of [Ru(VI)(N)(L)(MeOH)](PF(6)) [1; L = N,N'-bis(salicylidene)-o-cyclohexyldiamine dianion] with a stoichiometric amount of RSH in CH(3)CN gives the corresponding (salen)ruthenium(IV) sulfilamido species [Ru(IV){N(H)SR}(L)(NCCH(3))](PF(6)) (2a, R = (t)Bu; 2b, R = Ph). Metathesis of 2a with NaN(3) in methanol affords [Ru(IV){N(H)S(t)Bu}(L)(N(3))] (2c). 2a undergoes further reaction with 1 equiv of RSH to afford a (salen)ruthenium(III) sulfilamine species, [Ru(III){N(H)(2)S(t)Bu}(L)(NCCH(3))](PF(6)) (3). On the other hand, 2b reacts with 2 equiv of PhSH to give a (salen)ruthenium(III) ammine species [Ru(III)(NH(3))(L)(NCCH(3))](PF(6)) (4); this species can also be prepared by treatment of 1 with 3 equiv of PhSH. The X-ray structures of 2c and 4 have been determined. Kinetic studies of the reaction of 1 with excess RSH indicate the following schemes: 1 --> 2a --> 3 (R = (t)Bu), 1 --> 2b --> 4 (R = Ph). The conversion of 1 to 2 probably involves nucleophilic attack of RSH at the nitrido ligand, followed by a proton shift. The conversions of 2a to 3 and 2b to 4 are proposed to involve rate-limiting H-atom abstraction from RSH by 2a or 2b. 2a and 2b are also able to abstract H atoms from hydrocarbons with weak C-H bonds. These reactions occur with large deuterium isotope effects; the kinetic isotope effect values for the oxidation of 9,10-dihydroanthracene, 1,4-cyclohexadiene, and fluorene by 2a are 51, 56, and 11, respectively.

Excited-state dynamics of a ruthenium(II) catalyst studied by transient photofragmentation in gas phase and transient absorption in solution

Energy Technology Data Exchange (ETDEWEB)

Imanbaew, D.; Nosenko, Y. [Fachbereich Chemie, Technische Universität Kaiserslautern, Erwin-Schrödinger-Str. 52–54, 67663 Kaiserslautern (Germany); Forschungszentrum OPTIMAS, Erwin-Schrödinger-Str. 46, 67663 Kaiserslautern (Germany); Kerner, C. [Fachbereich Chemie, Technische Universität Kaiserslautern, Erwin-Schrödinger-Str. 52–54, 67663 Kaiserslautern (Germany); Chevalier, K.; Rupp, F. [Fachbereich Physik, Technische Universität Kaiserslautern, Erwin-Schrödinger-Str. 46, 67663 Kaiserslautern (Germany); Riehn, C., E-mail: riehn@chemie.uni-kl.de [Fachbereich Chemie, Technische Universität Kaiserslautern, Erwin-Schrödinger-Str. 52–54, 67663 Kaiserslautern (Germany); Forschungszentrum OPTIMAS, Erwin-Schrödinger-Str. 46, 67663 Kaiserslautern (Germany); Thiel, W.R. [Fachbereich Chemie, Technische Universität Kaiserslautern, Erwin-Schrödinger-Str. 52–54, 67663 Kaiserslautern (Germany); Diller, R. [Fachbereich Physik, Technische Universität Kaiserslautern, Erwin-Schrödinger-Str. 46, 67663 Kaiserslautern (Germany)

2014-10-17

Graphical abstract: - Highlights: • Ultrafast dynamics of new Ru(II) catalysts investigated in gas phase and solution. • Catalyst activation (HCl loss) achieved in ion trap by UV photoexcitation. • Electronic relaxation proceeds by IVR and IC followed by ground state dissociation. • No triplet formation in contrast to other Ru-polypyridine complexes. • Solvent prohibits catalyst activation in solution by fast vibrational cooling. - Abstract: We report studies on the excited state dynamics of new ruthenium(II) complexes [(η{sup 6}-cymene)RuCl(apypm)]PF{sub 6} (apypm=2-NR{sub 2}-4-(pyridine-2-yl)-pyrimidine, R=CH{sub 3} (1)/H (2)) which, in their active form [1{sup +}-HCl] and [2{sup +}-HCl], catalyze the transfer hydrogenation of arylalkyl ketones in the absence of a base. The investigations encompass femtosecond pump–probe transient mass spectrometry under isolated conditions and transient absorption spectroscopy in acetonitrile solution, both on the cations [(η{sup 6}-cymene)RuCl(apypm)]{sup +} (1{sup +}, 2{sup +}). Gas phase studies on mass selected ions were performed in an ESI ion trap mass spectrometer by transient photofragmentation, unambiguously proving the formation of the activated catalyst species [1{sup +}-HCl] or [2{sup +}-HCl] after photoexcitation being the only fragmentation channel. The primary excited state dynamics in the gas phase could be fitted to a biexponential decay, yielding time constants of <100 fs and 1–3 ps. Transient absorption spectroscopy performed in acetonitrile solution using femtosecond UV/Vis and IR probe laser pulses revealed additional deactivation processes on longer time scales (∼7–12 ps). However, the formation of the active catalyst species after photoexcitation could not be observed in solution. The results from both studies are compared to former CID investigations and DFT calculations concerning the activation mechanism.

Electrooxidative Ruthenium-Catalyzed C-H/O-H Annulation by Weak O-Coordination.

Science.gov (United States)

Qiu, Youai; Tian, Cong; Massignan, Leonardo; Rogge, Torben; Ackermann, Lutz

2018-05-14

Electrocatalysis has been identified as a powerful strategy for organometallic catalysis, and yet electrocatalytic C-H activation is restricted to strongly N-coordinating directing groups. The first example of electrocatalytic C-H activation by weak O-coordination is presented, in which a versatile ruthenium(II) carboxylate catalyst enables electrooxidative C-H/O-H functionalization for alkyne annulations in the absence of metal oxidants; thereby exploiting sustainable electricity as the sole oxidant. Mechanistic insights provide strong support for a facile organometallic C-H ruthenation and an effective electrochemical reoxidation of the key ruthenium(0) intermediate. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

How phenyl makes a difference: mechanistic insights into the ruthenium( ii )-catalysed isomerisation of allylic alcohols

KAUST Repository

Manzini, Simone

2013-10-16

[RuCl(η5-3-phenylindenyl)(PPh3)2] (1) has been shown to be a highly active catalyst for the isomerisation of allylic alcohols to the corresponding ketones. A variety of substrates undergo the transformation, typically with 0.25-0.5 mol% of catalyst at room temperature, outperforming commonly-used complexes such as [RuCl(Cp)(PPh3) 2] and [RuCl(η5-indenyl)(PPh3) 2]. Mechanistic experiments and density functional theory have been employed to investigate the mechanism and understand the effect of catalyst structure on reactivity. These investigations suggest a oxo-π-allyl mechanism is in operation, avoiding intermediate ruthenium hydride complexes and leading to a characteristic 1,3-deuterium shift. Important mechanistic insights from DFT and experiments also allowed for the design of a protocol that expands the scope of the transformation to include primary allylic alcohols. © 2013 The Royal Society of Chemistry.

How phenyl makes a difference: mechanistic insights into the ruthenium( ii )-catalysed isomerisation of allylic alcohols

KAUST Repository

Manzini, Simone; Poater, Albert; Nelson, David J.; Cavallo, Luigi; Nolan, Steven P.

2013-01-01

[RuCl(η5-3-phenylindenyl)(PPh3)2] (1) has been shown to be a highly active catalyst for the isomerisation of allylic alcohols to the corresponding ketones. A variety of substrates undergo the transformation, typically with 0.25-0.5 mol% of catalyst at room temperature, outperforming commonly-used complexes such as [RuCl(Cp)(PPh3) 2] and [RuCl(η5-indenyl)(PPh3) 2]. Mechanistic experiments and density functional theory have been employed to investigate the mechanism and understand the effect of catalyst structure on reactivity. These investigations suggest a oxo-π-allyl mechanism is in operation, avoiding intermediate ruthenium hydride complexes and leading to a characteristic 1,3-deuterium shift. Important mechanistic insights from DFT and experiments also allowed for the design of a protocol that expands the scope of the transformation to include primary allylic alcohols. © 2013 The Royal Society of Chemistry.

Analysis of radioactive ruthenium

International Nuclear Information System (INIS)

1977-01-01

This manual explains the procedures of analysis of radioactive ruthenium in the drain water from atomic energy plants. The most important radioactive ruthenium is 106 Ru, and the method of measurement described in this manual is to measure the beta ray of the daughter nuclide 106 Rh. The samples to be measured are collected from seawater, marine living things, and sediment of sea bottom near atomic energy plants. In case of sea water, the ruthenium is separated by the co-precipitation with magnesium hydroxide and distillation or the extraction with carbon tetrachloride, reduction and precipitation. The beta ray of the obtained sample is measured by a gas-flow type low background β counting system. Alkali dissolution-distillation or nitric acid extraction-distillation, reduction and precipitation are applied for marine living things. The sediment of sea bottom is treated with nitric acid or strong phosphoric acid, and distilled then the ruthenium is reduced and precipitated, and the beta-counting of the precipitation is made. The method to fix radioactive ruthenium on polyethylene films after the co-precipitation is also described for reference. The detectable levels by the present methods are 0.05 pCi/l for sea water, 0.1 pCi/g for marine living things, and 20 pCi/kg for the sediment of sea bottom. (Kato, T.)

IR-doped ruthenium oxide catalyst for oxygen evolution

Science.gov (United States)

Valdez, Thomas I. (Inventor); Narayanan, Sekharipuram R. (Inventor)

2012-01-01

A method for preparing a metal-doped ruthenium oxide material by heating a mixture of a doping metal and a source of ruthenium under an inert atmosphere. In some embodiments, the doping metal is in the form of iridium black or lead powder, and the source of ruthenium is a powdered ruthenium oxide. An iridium-doped or lead-doped ruthenium oxide material can perform as an oxygen evolution catalyst and can be fabricated into electrodes for electrolysis cells.

Ruthenium chalcogenonitrosyl and bridged nitrido complexes containing chelating sulfur and oxygen ligands.

Science.gov (United States)

Ng, Ho-Yuen; Cheung, Wai-Man; Kwan Huang, Enrique; Wong, Kang-Long; Sung, Herman H-Y; Williams, Ian D; Leung, Wa-Hung

2015-11-14

Ruthenium thio- and seleno-nitrosyl complexes containing chelating sulfur and oxygen ligands have been synthesised and their de-chalcogenation reactions have been studied. The reaction of mer-[Ru(N)Cl3(AsPh3)2] with elemental sulfur and selenium in tetrahydrofuran at reflux afforded the chalcogenonitrosyl complexes mer-[Ru(NX)Cl3(AsPh3)2] [X = S (1), Se (2)]. Treatment of 1 with KN(R2PS)2 afforded trans-[Ru(NS)Cl{N(R2PS)2}2] [R = Ph (3), Pr(i) (4), Bu(t) (5)]. Alternatively, the thionitrosyl complex 5 was obtained from [Bu(n)4N][Ru(N)Cl4] and KN(Bu(t)2PS)2, presumably via sulfur atom transfer from [N(Bu(t)2PS)2](-) to the nitride. Reactions of 1 and 2 with NaLOEt (LOEt(-) = [Co(η(5)-C5H5){P(O)(LOEt)2}3](-)) gave [Ru(NX)LOEtCl2] (X = S (8), Se (9)). Treatment of [Bu(n)4N][Ru(N)Cl4] with KN(R2PS)2 produced Ru(IV)-Ru(IV)μ-nitrido complexes [Ru2(μ-N){N(R2PS)2}4Cl] [R = Ph (6), Pr(i) (7)]. Reactions of 3 and 9 with PPh3 afforded 6 and [Ru(NPPh3)LOEtCl2], respectively. The desulfurisation of 5 with [Ni(cod)2] (cod = 1,5-cyclooctadiene) gave the mixed valance Ru(III)-Ru(IV)μ-nitrido complex [Ru2(μ-N){N(Bu(t)2PS)2}4] (10) that was oxidised by [Cp2Fe](PF6) to give the Ru(IV)-Ru(IV) complex [Ru2(μ-N){N(Bu(t)2PS)2}4](PF6) ([10]PF6). The crystal structures of 1, 2, 3, 7, 9 and 10 have been determined.

Ruthenium transport experiments in air ingress accident conditions

Energy Technology Data Exchange (ETDEWEB)

Teemu, Karkele; Ulrika, Backman; Ari, Auvinen; Unto, Tapper; Jorma, Jokiniemi [VTT Technical Research Centre of Finland, Fine Particles (Finland); Riitta, Zilliacus; Maija, Lipponen; Tommi, Kekki [VTT Technical Research Centre of Finland, Accident Management (Finland); Jorma, Jokiniemi [Kuopio Univ., Dept. of Environmental Sciences, Fine Particle and Aerosol Technology Lab. (Finland)

2007-07-01

In this study the release, transport and speciation of ruthenium in conditions simulating an air ingress accident was studied. Ruthenium dioxide was exposed to oxidising environment at high temperature (1100-1700 K) in a tubular flow furnace. At these conditions volatile ruthenium species were formed. A large fraction of the released ruthenium was deposited in the tube as RuO{sub 2}. Depending on the experimental conditions 1-26 wt% of the released ruthenium was trapped in the outlet filter as RuO{sub 2} particles. In stainless steel tube 0-8.8 wt% of the released ruthenium reached the trapping bottle as gaseous RuO{sub 4}. A few experiments were carried out, in which revaporization of ruthenium deposited on the tube walls was studied. In these experiments, oxidation of RuO{sub 2} took place at a lower temperature. During revaporization experiments 35-65 % of ruthenium was transported as gaseous RuO{sub 4}. In order to close mass balance and achieve better time resolution 4 experiments were carried out using a radioactive tracer. In these experiments ruthenium profiles were measured. These experiments showed that the most important retention mechanism was decomposition of gaseous RuO{sub 3} into RuO{sub 2} as the temperature of the furnace was decreasing. In these experiments the transport rate of gaseous ruthenium was decreasing while the release rate was constant.

(II) COMPLEX COMPOUND

African Journals Online (AJOL)

user

electrochemical sensors, as well as in various chromatographic ... were carried out using Jenway pH meter Model 3320 and a conductivity ... Figure 1: the proposed molecular structure of the copper (II) Schiff base complex. M = Cu (II) or Mn (II).

Density functionalized [RuII(NO)(Salen)(Cl)] complex: Computational photodynamics and in vitro anticancer facets.

Science.gov (United States)

Mir, Jan Mohammad; Jain, N; Jaget, P S; Maurya, R C

2017-09-01

Photodynamic therapy (PDT) is a treatment that uses photosensitizing agents to kill cancer cells. Scientific community has been eager for decades to design an efficient PDT drug. Under such purview, the current report deals with the computational photodynamic behavior of ruthenium(II) nitrosyl complex containing N, N'-salicyldehyde-ethylenediimine (SalenH 2 ), the synthesis and X-ray crystallography of which is already known [Ref. 38,39]. Gaussian 09W software package was employed to carry out the density functional (DFT) studies. DFT calculations with Becke-3-Lee-Yang-Parr (B3LYP)/Los Alamos National Laboratory 2 Double Z (LanL2DZ) specified for Ru atom and B3LYP/6-31G(d,p) combination for all other atoms were used using effective core potential method. Both, the ground and excited states of the complex were evolved. Some known photosensitizers were compared with the target complex. Pthalocyanine and porphyrin derivatives were the compounds selected for the respective comparative study. It is suggested that effective photoactivity was found due to the presence of ruthenium core in the model complex. In addition to the evaluation of theoretical aspects in vitro anticancer aspects against COLO-205 human cancer cells have also been carried out with regard to the complex. More emphasis was laid to extrapolate DFT to depict the chemical power of the target compound to release nitric oxide. A promising visible light triggered nitric oxide releasing power of the compound has been inferred. In vitro antiproliferative studies of [RuCl 3 (PPh 3 ) 3 ] and [Ru(NO)(Salen)(Cl)] have revealed the model complex as an excellent anticancer agent. From IC 50 values of 40.031mg/mL in former and of 9.74mg/mL in latter, it is established that latter bears more anticancer potentiality. From overall study the DFT based structural elucidation and the efficiency of NO, Ru and Salen co-ligands has shown promising drug delivery property and a good candidacy for both chemotherapy as well as

Separation of carrier-free rhodium isotopes from ruthenium cyclotron targets by the extraction of nitrosylruthenium from hydrochloric acid solution

International Nuclear Information System (INIS)

Haasbroek, F.J.; Strelow, F.W.E.; Van der Walt, T.N.

1981-01-01

A method is presented for the separation of rhodium isotopes from ruthenium cyclotron targets. After bombardment with deuterons and dissolution of the target material, the ruthenium is converted into a nitrosyl complex by treatment with hydroxylammonium chloride. Aluminium and other elements which have been introduced in the dissolution step, are separated by cation exchange. Ruthenium is then separated by extraction with a mixture of tri-n-butyl phosphate and hexane (4:1), leaving the rhodium in the aqueous phase. No ruthenium is found in the rhodium fraction and the recovery of rhodium is better than 90 per cent [af

Microwave-Assisted Synthesis of 3,5-Dibenzyl-4-amino-1,2,4-triazole and its Diazo Ligand, Metal Complexes Along with Anticancer Activity

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Anjali Jha

2010-01-01

Full Text Available Synthesis of 3,5-dibenzyl-4-amino-1,2,4-triazole was accomplished via a conventional method as well as microwave irradiation method, followed by diazotization and coupling with 2,4-pentanedione. The dinucleating ligand was isolated and complexed with Ni(II, Cu(II and Ru(III chlorides. These complexes were screened on Jurkat, Raji & PBMC cell lines for anticancer activity. Ruthenium complexes showed potential anticancer activities.

Selective Hydrogen Generation from Formic Acid with Well-Defined Complexes of Ruthenium and Phosphorus-Nitrogen PN3-Pincer Ligand

KAUST Repository

Pan, Yupeng

2016-04-22

An unsymmetrically protonated PN3-pincer complex in which ruthenium is coordinated by one nitrogen and two phosphorus atoms was employed for the selective generation of hydrogen from formic acid. Mechanistic studies suggest that the imine arm participates in the formic acid activation/deprotonation step. A long life time of 150 h with a turnover number over 1 million was achieved. Grabbing hold: A PN3-pincer complex was employed for the selective hydrogen generation from formic acid. Mechanistic studies suggest the imine arm participates in the formic acid activation/deprotonation step. A long life time of 150 h with a turnover number over 1 million was achieved. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Iron(II) supramolecular helicates interfere with the HIV-1 Tat-TAR RNA interaction critical for viral replication

Czech Academy of Sciences Publication Activity Database

Malina, Jaroslav; Hannon, Michael J.; Brabec, Viktor

2016-01-01

Roč. 6, JUL2016 (2016) ISSN 2045-2322 R&D Projects: GA ČR(CZ) GA16-03517S Institutional support: RVO:68081707 Keywords : DINUCLEAR RUTHENIUM(II) COMPLEX * METALLOSUPRAMOLECULAR CYLINDERS * BIOLOGICAL EVALUATION Subject RIV: BO - Biophysics Impact factor: 4.259, year: 2016

Pretreatment with U(IV) solution for improving the decontamination of ruthenium

International Nuclear Information System (INIS)

Huang Haoxin; Qi Zhanshun; Zhu Guohui

1993-01-01

The ruthenium decontamination factor in Purex process falls quickly in successive TBP cycles. So, it is necessary to change the chemical states of RuNO complexes in order to improve DF Ru in the uranium purification cycle. Hydrazine nitrate is being used to transform RuNO complexes into in-extractable Ru(III)and Ru(IV). However, hydrazine nitrate may be inverted into hydrazoic acid which is dangerous and can bring an unstable factor. Pretreatment using U(IV) solution provides another method to improve the decontamination of ruthenium in Purex process. 0.02 mol/lU(IV) solution can transform RuNO complexes into inextricable species by heating in water bath. The D Ru can be decreased by a factor of 10-20. U(IV) pretreatment does not bring any harmful chemical in process. The acidity has a very large influence on the effect of pretreatment. The higher the acidity is, the worse the effect will be

Organoruthenium Complexes with CN Ligands are Highly Potent Cytotoxic Agents that Act by a New Mechanism of Action

Czech Academy of Sciences Publication Activity Database

Novohradský, Vojtěch; Yellol, J.; Stuchlíková, O.; Santana, M.D.; Kostrhunová, Hana; Yellol, G.; Kašpárková, Jana; Bautista, D.; Ruiz, J.; Brabec, Viktor

2017-01-01

Roč. 23, č. 61 (2017), s. 15294-15299 ISSN 0947-6539 R&D Projects: GA ČR(CZ) GA17-05302S Institutional support: RVO:68081707 Keywords : chemotherapeutic-agents * ruthenium(ii) complexes * iridium(iii) complexes Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 5.317, year: 2016

Cyclotron production of ruthenium-97 for radiopharmaceutical applications

International Nuclear Information System (INIS)

Music, S.; Gessner, M.

1980-01-01

Ruthenium-97 is of interest for clinical practice in nuclear medicine. The combination of the excellent physical and chemical properties of Ruthenium-97 make this isotope worth evaluating. Ruthenium-97 has been prepared by irradiation of a sheet of molybdenum with the internal alpha-beam of the Ruthenium-97 as a function of the alpha particle energy has been measured. The radiochemical separation and its possible clinical applications have been discussed. (author)

Variation of the Sterical Properties of the N-Heterocyclic Carbene Coligand in Thermally Triggerable Ruthenium-Based Olefin Metathesis Precatalysts/Initiators

KAUST Repository

Pump, Eva; Leitgeb, Anita; Kozłowska, Anna; Torvisco, Ana; Falivene, Laura; Cavallo, Luigi; Grela, Karol; Slugovc, Christian

2015-01-01

A series of ruthenium complexes based on the κ(C,N)-(2-(benzo[h]quinolin-10-yl)methylidene ruthenium dichloride fragment featuring different neutral coligands L (L = 1,3-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene (SIPr), 1,3-bis(2

Biologically active new Fe(II, Co(II, Ni(II, Cu(II, Zn(II and Cd(II complexes of N-(2-thienylmethylenemethanamine

Directory of Open Access Journals (Sweden)

C. SPÎNU

2008-04-01

Full Text Available Iron(II, cobalt(II, nickel (II, copper (II, zinc(II and cadmium(II complexes of the type ML2Cl2, where M is a metal and L is the Schiff base N-(2-thienylmethylenemethanamine (TNAM formed by the condensation of 2-thiophenecarboxaldehyde and methylamine, were prepared and characterized by elemental analysis as well as magnetic and spectroscopic measurements. The elemental analyses suggest the stoichiometry to be 1:2 (metal:ligand. Magnetic susceptibility data coupled with electronic, ESR and Mössbauer spectra suggest a distorted octahedral structure for the Fe(II, Co(II and Ni(II complexes, a square-planar geometry for the Cu(II compound and a tetrahedral geometry for the Zn(II and Cd(II complexes. The infrared and NMR spectra of the complexes agree with co-ordination to the central metal atom through nitrogen and sulphur atoms. Conductance measurements suggest the non-electrolytic nature of the complexes, except for the Cu(II, Zn(II and Cd(II complexes, which are 1:2 electrolytes. The Schiff base and its metal chelates were screened for their biological activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and the metal chelates were found to possess better antibacterial activity than that of the uncomplexed Schiff base.

Method of dissolving metal ruthenium

International Nuclear Information System (INIS)

Tsuno, Masao; Soda, Yasuhiko; Kuroda, Sadaomi; Koga, Tadaaki.

1988-01-01

Purpose: To dissolve and clean metal ruthenium deposited to the inner surface of a dissolving vessel for spent fuel rods. Method: Metal ruthenium is dissolved in a solution of an alkali metal hydroxide to which potassium permanganate is added. As the alkali metal hydroxide used herein there can be mentioned potassium hydroxide, sodium hydroxide and lithium hydroxide can be mentioned, which is used as an aqueous solution from 5 to 20 % concentration in view of the solubility of metal ruthenium and economical merit. Further, potassium permanganate is used by adding to the solution of alkali metal hydroxide at a concentration of 1 to 5 %. (Yoshihara, H.)

Influence of the π-coordinated arene on the anticancer activity of ruthenium(II carbohydrate organometallic complexes

Directory of Open Access Journals (Sweden)

Muhammad eHanif

2013-10-01

Full Text Available The synthesis and in vitro cytotoxicity of a series of RuII(arene complexes with carbohydrate-derived phosphite ligands and various arene co-ligands is described. The arene ligand has a strong influence on the in vitro anticancer activity of this series of compounds, which correlates fairly well with cellular accumulation. The most lipophilic compound bearing a biphenyl moiety and a cyclohexylidene-protected carbohydrate is the most cytotoxic with unprecedented IC50 values for the compound class in three human cancer cell lines. This compound shows reactivity to the DNA model nucleobase 9-ethylguanine, but does not alter the secondary structure of plasmid DNA indicating that other biological targets are responsible for its cytotoxic effect.

Cytotoxicity and anti-tumor effects of new ruthenium complexes on triple negative breast cancer cells.

Directory of Open Access Journals (Sweden)

Cecília P Popolin

Full Text Available Triple-negative breast cancer (TNBC is a highly aggressive breast cancer subtype. The high rate of metastasis associated to the fact that these cells frequently display multidrug resistance, make the treatment of metastatic disease difficult. Development of antitumor metal-based drugs was started with the discovery of cisplatin, however, the severe side effects represent a limitation for its clinical use. Ruthenium (Ru complexes with different ligands have been successfully studied as prospective antitumor drugs. In this work, we demonstrated the activity of a series of biphosphine bipyridine Ru complexes (1 [Ru(SO4(dppb(bipy], (2 [Ru(CO3(dppb(bipy], (3 [Ru(C2O4(dppb(bipy] and (4 [Ru(CH3CO2(dppb(bipy]PF6 [where dppb = 1,4-bis(diphenylphosphinobutane and bipy = 2,2'-bipyridine], on proliferation of TNBC (MDA-MB-231, estrogen-dependent breast tumor cells (MCF-7 and a non-tumor breast cell line (MCF-10A. Complex (4 was most effective among the complexes and was selected to be further investigated on effects on tumor cell adhesion, migration, invasion and in apoptosis. Moreover, DNA and HSA binding properties of this complex were also investigated. Results show that complex (4 was more efficient inhibiting proliferation of MDA-MB-231 cells over non-tumor cells. In addition, complex (4 was able to inhibit MDA-MB231 cells adhesion, migration and invasion and to induce apoptosis and inhibit MMP-9 secretion in TNBC cells. Complex (4 should be further investigated in vivo in order to stablish its potential to improve breast cancer treatment.

Transfer Hydro-dehalogenation of Organic Halides Catalyzed by Ruthenium(II) Complex.

Science.gov (United States)

You, Tingjie; Wang, Zhenrong; Chen, Jiajia; Xia, Yuanzhi

2017-02-03

A simple and efficient Ru(II)-catalyzed transfer hydro-dehalogenation of organic halides using 2-propanol solvent as the hydride source was reported. This methodology is applicable for hydro-dehalogenation of a variety of aromatic halides and α-haloesters and amides without additional ligand, and quantitative yields were achieved in many cases. The potential synthetic application of this method was demonstrated by efficient gram-scale transformation with catalyst loading as low as 0.5 mol %.

The biokinetics of ruthenium in the human body

International Nuclear Information System (INIS)

Leggett, Richard Wayne

2011-01-01

The biokinetics of ruthenium (Ru) in the human body is of interest due mainly to the potential for occupational or environmental exposure to 106Ru (T1/2 = 373.6 d) and 103Ru (T1/2 = 39.3 d), which typically represent a significant portion of the fission products in a reactor inventory. During reactor operations or nuclear fuel reprocessing these ruthenium isotopes may be present as ruthenium tetroxide (RuO4) vapor, a highly mobile form of ruthenium that has been involved in a number of cases of accidental exposure to 106Ru or 103Ru. This paper summarizes the biokinetic database for ruthenium and proposes a new respiratory model for inhaled RuO4 vapor, a new biokinetic for systemic (absorbed) ruthenium, and material-specific gastrointestinal absorption fractions for ruthenium. The proposed respiratory model for RuO4 differs from the current ICRP model mainly in that it depicts slower clearance of deposited activity from the respiratory tract and lower absorption to blood than depicted in the current ICRP model. The proposed systemic biokinetic model depicts more realistic paths of movement of absorbed ruthenium in the body than the current ICRP model and, in contrast to the present model, a less uniform distribution of systemic activity. Implications of the proposed models with regard to inhalation and ingestion dose coefficients for 106Ru are examined.

9,10-phenanthrenesemiquinone radical complexes of ruthenium(III), osmium(III) and rhodium(III) and redox series.

Science.gov (United States)

Biswas, Manas Kumar; Patra, Sarat Chandra; Maity, Amarendra Nath; Ke, Shyue-Chu; Weyhermüller, Thomas; Ghosh, Prasanta

2013-05-14

Reactions of 9,10-phenanthrenequinone (PQ) in toluene with [M(II)(PPh3)3X2] at 298 K afford green complexes, trans-[M(PQ)(PPh3)2X2] (M = Ru, X = Cl, 1; M = Os, X = Br, 2) in moderate yields. Reaction of anhydrous RhCl3 with PQ and PPh3 in boiling ethanol affords the dark brown paramagnetic complex, cis-[Rh(PQ)(PPh3)2Cl2] (3) in good yields. Diffusion of iodine solution in n-hexane to the trans-[Os(PQ) (PPh3)2(CO)(Br)] solution in CH2Cl2 generates the crystals of trans-[Os(PQ)(PPh3)2(CO)(Br)](+)I3(-), (4(+))I3(-)), in lower yields. Single crystal X-ray structure determinations of 1·2toluene, 2·CH2Cl2 and 4(+)I3(-), UV-vis/NIR absorption spectra, EPR spectra of 3, electrochemical activities and DFT calculations on 1, 2, trans-[Ru(PQ)(PMe3)2Cl2] (1Me), trans-[Os(PQ)(PMe3)2Br2] (2Me), cis-[Rh(PQ)(PMe3)2Cl2] (3Me) and their oxidized and reduced analogues including trans-[Os(PQ)(PMe3)2(CO)(Br)](+) (4Me(+)) substantiated that 1-3 are the 9,10-phenanthrenesemiquinone radical (PQ(˙-)) complexes of ruthenium(III), osmium(III) and rhodium(III) and are defined as trans/cis-[M(III)(PQ(˙-))(PPh3)2X2] with a minor contribution of the resonance form trans/cis-[M(II)(PQ)(PPh3)2X2]. Two comparatively longer C-O (1.286(4) Å) and the shorter C-C lengths (1.415(7) Å) of the OO-chelate of 1·2toluene and 2·CH2Cl2 and the isotropic fluid solution EPR signal at g = 1.999 of 3 are consistent with the existence of the reduced PQ(˙-) ligand in 1-3 complexes. Anisotropic EPR spectra of the frozen glasses (g11 = g22 = 2.0046 and g33 = 1.9874) and solids (g11 = g22 = 2.005 and g33 = 1.987) instigate the contribution of the resonance form, cis-[Rh(II)(PQ)(PPh3)2Cl2] in 3. DFT calculations established that the closed shell singlet (CSS) solutions of 1Me and 2Me are unstable due to open shell singlet (OSS) perturbation. However, the broken symmetry (BS) (1,1) Ms = 0 solutions of 1Me and 2Me are respectively 22.6 and 24.2 kJ mole(-1) lower in energy and reproduced the experimental bond

Electrogenerated chemiluminescence of tris(2,2'-bipyridine)ruthenium(II) using N-(3-aminopropyl)diethanolamine as coreactant.

Science.gov (United States)

Kitte, Shimeles Addisu; Wang, Chao; Li, Suping; Zholudov, Yuriy; Qi, Liming; Li, Jianping; Xu, Guobao

2016-10-01

Coreactant plays a critical role for the application of electrochemiluminescence (ECL). Herein, N-(3-aminopropyl)diethanolamine (APDEA) has been explored as a potential coreactant for enhancing tris(2,2'-bipyridyl)ruthenium(II) ECL. It is much more effective than tripropylamine at gold and platinum electrodes although it has one primary amine group besides a tertiary amine group. The presence of primary amine group and hydroxyl groups in APDEA promotes the oxidation rates of amine and thus remarkably increases ECL intensity. The ECL intensities of the Ru(bpy)3 (2+)/APDEA system are approximately 10 and 36 times stronger than that of Ru(bpy)3 (2+)/tripropylamine system and about 1.6 and 1.14 times stronger than that of Ru(bpy)3 (2+)/N-butyldiethanolamine system at Au and Pt electrodes, respectively. The ECL intensity of the Ru(bpy)3 (2+)/APDEA system is 2.42 times stronger than that of Ru(bpy)3 (2+)/N-butyldiethanolamine at glassy carbon electrodes.

Bimetallic ruthenium complexes bridged by divinylphenylene bearing oligo(ethylene glycol)methylether: synthesis, (spectro)electrochemistry and the lithium cation effect.

Science.gov (United States)

Tian, Li Yan; Liu, Yuan Mei; Tian, Guang-Xuan; Wu, Xiang Hua; Li, Zhen; Kou, Jun-Feng; Ou, Ya-Ping; Liu, Sheng Hua; Fu, Wen-Fu

2014-03-14

A series of 1,4-disubstituted ruthenium-vinyl complexes, (E,E)-[{(PMe3)3(CO)ClRu}2(μ-HC=CH-Ar-CH=CH)], in which the 1,4-diethenylphenylene bridge bears two oligo(ethylene glycol)methyl ether side chains at different positions (2,5- and 2,3-positions), were prepared. The respective products were characterized by elemental analyses and NMR spectroscopy. The structures of complexes 1b and 1e were established by X-ray crystallography. The electronic properties of the complexes were investigated by cyclic voltammetry, and IR and UV-vis/NIR spectroscopies. Electrochemical studies showed that the 2,5-substituents better stabilized the mixed-valence states; the electrochemical behavior was greatly affected by lithium cations, especially complex 1g with 2,3-substituents, which was further supported by IR and UV-vis/NIR spectra changes. Spectroelectrochemical studies showed that the redox chemistry was dominated by the non-innocent character of the bridging fragment.

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

High spectral response heteroleptic ruthenium (II) complexes as sensitizers for dye sensitized solar cells · M Chandrasekharam Ch Srinivasarao T Suresh M Anil Reddy M Raghavender G Rajkumar M Srinivasu P Yella Reddy · More Details Abstract Fulltext PDF. Heteroleptic ruthenium(II) bipyridyl complex, cis-Ru(II)(4 ...

Synthesis and spectroscopic studies of biologically active tetraazamacrocyclic complexes of Mn(II, Co(II, Ni(II, Pd(II and Pt(II

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Monika Tyagi

2014-01-01

Full Text Available Complexes of Mn(II, Co(II, Ni(II, Pd(II and Pt(II were synthesized with the macrocyclic ligand, i.e., 2,3,9,10-tetraketo-1,4,8,11-tetraazacycoletradecane. The ligand was prepared by the [2 + 2] condensation of diethyloxalate and 1,3-diamino propane and characterized by elemental analysis, mass, IR and 1H NMR spectral studies. All the complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, IR, electronic and electron paramagnetic resonance spectral studies. The molar conductance measurements of Mn(II, Co(II and Ni(II complexes in DMF correspond to non electrolyte nature, whereas Pd(II and Pt(II complexes are 1:2 electrolyte. On the basis of spectral studies an octahedral geometry has been assigned for Mn(II, Co(II and Ni(II complexes, whereas square planar geometry assigned for Pd(II and Pt(II. In vitro the ligand and its metal complexes were evaluated against plant pathogenic fungi (Fusarium odum, Aspergillus niger and Rhizoctonia bataticola and some compounds found to be more active as commercially available fungicide like Chlorothalonil.

The trans influence in mer-trichloronitridobis(triphenylarsine)ruthenium(VI)

DEFF Research Database (Denmark)

Magnussen, Magnus; Bendix, Jesper

2003-01-01

The title compound, mer-[RuCl(3)N(C(18)H(15)As)(2)], is the first structurally characterized example of a nitride complex in which ruthenium is six-coordinated to monodentate ligands only. The Ru[triple-bond]N bond length [1.6161 (15) A] is relatively long, and the trans influence of the nitride...

Volatilization and trapping of ruthenium in high temperature processes

International Nuclear Information System (INIS)

Klein, M.; Weyers, C.; Goossens, W.R.A.

1983-01-01

This experimental study has indicated the importance of moisture and NO/sub x/ vapors on the volatility and trapping conditions of ruthenium in high temperature processes. Also the process operating conditions have a great influence on the ruthenium behavior in the off-gas purification units. Of particular interest is the observation that the ruthenium release during direct vitrification of simulated high-level liquid waste is a factor of about 5 smaller than the ruthenium release during calcination of this type of waste. Moreover, in the direct vitrification case the ruthenium escapes mostly in the form of an aerosol whereas in the calcination case a volatile ruthenium compound is dominating. Consequently, a specific ruthenium filter is not needed in the off-gas line of a direct vitrifier simplifying in this way the number of units in this off-gas line and avoiding the handling and controlling problems of such a ruthenium filter. In the future, a similar program will be started on the volatility of cesium and antimony in a liquid fed melter and on the technical reliability of the liquid fed melter and its associated gas purification units on a semi-pilote scale under simulated conditions

Complexes of cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II) and dioxouranium(II) with thiophene-2-aldehydethiosemicarbazone

International Nuclear Information System (INIS)

Singh, Balwan; Misra, Harihar

1986-01-01

Metal complexes of thiosemicarbazides have been known for their pharmacological applications. Significant antitubercular, fungicidal and antiviral activities have been reported for thiosemicarbazides and their derivatives. The present study describes the systhesis and characterisation of complexes of Co II , Cu II , Zn II ,Cd II and UO II with thiosemicarbazone obtained by condensing thiophene-2-aldehyde with thiosemicarbazide. 17 refs., 2 tables. (author)

Ruthenium Dioxide Catalysts for the Selective Oxidation of Benzylamine to Benzonitrile: Investigating the Effect of Ruthenium Loading on Physical and Catalytic Properties

DEFF Research Database (Denmark)

Nordvang, Emily Catherine; Schill, Leonhard; Riisager, Anders

2017-01-01

The oxidative dehydrogenation of benzylamine to benzonitrile was studied in batch and continuous flow processes using ruthenium dioxide catalysts with varying ruthenium loadings. Increased conversions were observed in the continuous flow process compared with the batch process (up to 100% in the ......The oxidative dehydrogenation of benzylamine to benzonitrile was studied in batch and continuous flow processes using ruthenium dioxide catalysts with varying ruthenium loadings. Increased conversions were observed in the continuous flow process compared with the batch process (up to 100......% in the flow process compared with up to 92% in the batch process), with increased selectivity to benzonitrile (82 and 65%, respectively) and benzonitrile yields (84 and 58%, respectively). The major by-product was N-benzylidenebenzylamine. The ruthenium loading in the catalyst was successfully optimised...... and the most active catalyst had a ruthenium loading of 2.5-3.5 wt%....

Conductometric and voltammetric studies on the bis(triphenyl phosphine) ruthenium(II) complex, cis-[RuCl2(L)(PPh3)2], where L: 2-(2'-pyridyl)quinoxaline

Czech Academy of Sciences Publication Activity Database

Tsierkezos, Nikos; Philippopoulos, A. I.

2009-01-01

Roč. 362, č. 4 (2009), s. 3079-3087 ISSN 0020-1693 Grant - others:Kapodistrias Program(GR) 70/4/9277 Institutional research plan: CEZ:AV0Z40550506 Keywords : assocition constant * conductivity * cyclic voltammetry * ruthenium * quinoxaline Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.322, year: 2009

Recent developments in the nanostructured materials functionalized with ruthenium complexes for targeted drug delivery to tumors

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Thangavel P

2017-04-01

Full Text Available Prakash Thangavel,1 Buddolla Viswanath,1 Sanghyo Kim1,2 1Department of Bionanotechnology, Gachon University, Bokjeong-Dong, Sujeong-Gu, Seongnam-Si, Gyeonggi-Do, 2Graduate Gachon Medical Research Institute, Gil Medical Center, Incheon, Republic of Korea Abstract: In recent years, the field of metal-based drugs has been dominated by other existing precious metal drugs, and many researchers have focused their attention on the synthesis of various ruthenium (Ru complexes due to their potential medical and pharmaceutical applications. The beneficial properties of Ru, which make it a highly promising therapeutic agent, include its variable oxidation states, low toxicity, high selectivity for diseased cells, ligand exchange properties, and the ability to mimic iron binding to biomolecules. In addition, Ru complexes have favorable adsorption properties, along with excellent photochemical and photophysical properties, which make them promising tools for photodynamic therapy. At present, nanostructured materials functionalized with Ru complexes have become an efficient way to administer Ru-based anticancer drugs for cancer treatment. In this review, the recent developments in the nanostructured materials functionalized with Ru complexes for targeted drug delivery to tumors are discussed. In addition, information on “traditional” (ie, non-nanostructured Ru-based cancer therapies is included in a precise manner. Keywords: metallodrugs, nanotechnology, cancer treatment, cell apoptosis, DNA damage, toxicity

Spectrophotometric determination of ruthenium (III) and rhodium (III) with 9,10-phenanthrenequinone monoxime after extraction into molten naphthalene

International Nuclear Information System (INIS)

Wasey, A.; Bansal, R.K.; Puri, B.K.; Satake, Masatada.

1983-01-01

9,10-Phenanthrenequinone monoxime has been used as a reagent for the spectrophotometric determination of ruthenium(III) and rhodium(III) after extraction into molten naphthalene. The extracted mixture of the metal complex and naphthalene was dissolved in chloroform and ruthenium and rhodium were determined spectrophotometrically. Beer's law holds in the concentration range of 0.2-4.1 μg/cm 3 for ruthenium and 0.3-5.3 μg/cm 3 for rhodium in 10 cm 3 of the final solution. The molar absorptivities and Sandell sensitivities are calculated to be 9.70 x 10 3 l mol -1 cm -1 and 0.01 μg/cmsup(2 ) (660 nm) for ruthenium and 1.13 x 10 4 l mol -1 cm -1 and 0.009 μg/cm 2 (410 nm) for rhodium respectively. Aliquots containing 2.0 μg of ruthenium and 4.1 μg of rhodium give mean absorbances of 0.192 and 0.451 with standard deviations of 0.0017 and 0.0039, respectively. Interference of various ions has been studied and the method has been applied to the determination of ruthenium and rhodium in various synthetic mixtures. This procedure is also applied to the simultaneous determination of ruthenium and rhodium present together in a solution. (author)

Ni (II) and Cu(II) complexes of

African Journals Online (AJOL)

ADOWIE PERE

ABSTRACT: The objective of this study is to investigate the antimicrobial activity of novel. Schiff base metal complexes. The resistance of micro-organisms to classical antimicrobial compounds poses a challenge to effective management and treatment of some diseases. In line with this, copper (II), nickel (II) and cobalt (II) ...

Ruthenium Tris(2-pyridylmethyl)amine as an Effective Photocaging Group for Nitriles

Science.gov (United States)

2015-01-01

Ruthenium(II) tris(2-pyridylmethyl)amine (TPA) is an effective caging group for nitriles that provides high levels of control over the enzyme activity with light. Two caged nitriles were prepared, [Ru(TPA)(MeCN)2](PF6)2 (1) and [Ru(TPA)(3)2](PF6)2 (2), where 3 is the cathepsin K inhibitor Cbz-Leu-NHCH2CN, and characterized by various spectroscopic techniques and mass spectrometry. Both 1 and 2 show the release of a single nitrile within 20 min of irradiation with 365 nm light. Complex 2 acts as a potent, photoactivated inhibitor of human cathepsin K. IC50 values were determined for 2 and 3. Enzyme inhibition for 2 was enhanced by a factor of 89 upon exposure to light, with IC50 values of 63 nM (light) and 5.6 μM (dark). PMID:24661182

NO Exchange for a Water Molecule Favorably Changes Iontophoretic Release of Ruthenium Complexes to the Skin

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Danielle C. A. S. de Santana

2017-01-01

Full Text Available Ruthenium (Ru complexes have been studied as promising anticancer agents. Ru nitrosyl complex (Ru-NO is one which acts as a pro-drug for the release of nitric oxide (NO. The Ru-aqueous complex formed by the exchange of NO for a water molecule after NO release could also possess therapeutic effects. This study evaluates the influence of iontophoresis on enhancing the skin penetration of Ru-NO and Ru-aqueous and assesses its applicability as a tool in treating diverse skin diseases. Passive and iontophoretic (0.5 mA·cm−2 skin permeation of the complexes were performed for 4 h. The amount of Ru and NO in the stratum corneum (SC, viable epidermis (VE, and receptor solution was quantified while the influence of iontophoresis and irradiation on NO release from Ru-NO complex was also evaluated. Iontophoresis increased the amount of Ru-NO and Ru-aqueous recovered from the receptor solution by 15 and 400 times, respectively, as compared to passive permeation. Iontophoresis produced a higher accumulation of Ru-aqueous in the skin layers as compared to Ru-NO. At least 50% of Ru-NO penetrated the SC was stable after 4 h. The presence of Ru-NO in this skin layer suggests that further controlled release of NO can be achieved by photo-stimulation after iontophoresis.

Elimination of ionic interference effects in the atomic absorption spectrometric determination of ruthenium

International Nuclear Information System (INIS)

El-Defrawy, M.M.M.; Posta, J.; Beck, M.T.

1978-01-01

In connection with work on the catalytic effect of ruthenium complexes, new compounds were prepared. Atomic absorption spectrometry (a.a.s.) was to be used for their analysis. The standard methods could not be applied to the complexes studied, therefore the effect of cyanide ions for elimination of interfering effects has been studied, because of the great stability of cyanide complexes. (Auth.)

A nanogravimmetric investigation of the charging processes on ruthenium oxide thin films and their effect on methanol oxidation

International Nuclear Information System (INIS)

Santos, M.C.; Cogo, L.; Tanimoto, S.T.; Calegaro, M.L.; Bulhoes, L.O.S

2006-01-01

The charging processes and methanol oxidation that occur during the oxidation-reduction cycles in a ruthenium oxide thin film electrode (deposited by the sol-gel method on Pt covered quartz crystals) were investigated by using cyclic voltammetry, chronoamperometry and electrochemical quartz crystal nanobalance techniques. The ruthenium oxide rutile phase structure was determined by X-ray diffraction analysis. The results obtained during the charging of rutile ruthenium oxide films indicate that in the anodic sweep the transition from Ru(II) to Ru(VI) occurs followed by proton de-intercalation. In the cathodic sweep, electron injection occurs followed by proton intercalation, leading to Ru(II). The proton intercalation/de-intercalation processes can be inferred from the mass/charge relationship which gives a slope close to 1 g mol -1 (multiplied by the Faraday constant) corresponding to the molar mass of hydrogen. From the chronoamperometric measurements, charge and mass saturation of the RuO 2 thin films was observed (440 ng cm -2 ) during the charging processes, which is related to the total number of active sites in these films. Using the electrochemical quartz crystal nanobalance technique to study the methanol oxidation reaction at these films was possible to demonstrate that bulk oxidation occurs without the formation of strongly adsorbed intermediates such as CO ads , demonstrating that Pt electrodes modified by ruthenium oxide particles can be promising catalysts for the methanol oxidation as already shown in the literature

Vascular Response of Ruthenium Tetraamines in Aortic Ring from Normotensive Rats

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Ana Gabriela Conceição-Vertamatti

2015-03-01

Full Text Available Background: Ruthenium (Ru tetraamines are being increasingly used as nitric oxide (NO carriers. In this context, pharmacological studies have become highly relevant to better understand the mechanism of action involved. Objective: To evaluate the vascular response of the tetraamines trans-[RuII(NH34(Py(NO]3+, trans-[RuII(Cl(NO (cyclan](PF62, and trans-[RuII(NH34(4-acPy(NO]3+. Methods: Aortic rings were contracted with noradrenaline (10−6 M. After voltage stabilization, a single concentration (10−6 M of the compounds was added to the assay medium. The responses were recorded during 120 min. Vascular integrity was assessed functionally using acetylcholine at 10−6 M and sodium nitroprusside at 10−6 M as well as by histological examination. Results: Histological analysis confirmed the presence or absence of endothelial cells in those tissues. All tetraamine complexes altered the contractile response induced by norepinephrine, resulting in increased tone followed by relaxation. In rings with endothelium, the inhibition of endothelial NO caused a reduction of the contractile effect caused by pyridine NO. No significant responses were observed in rings with endothelium after treatment with cyclan NO. In contrast, in rings without endothelium, the inhibition of guanylate cyclase significantly reduced the contractile response caused by the pyridine NO and cyclan NO complexes, and both complexes caused a relaxing effect. Conclusion: The results indicate that the vascular effect of the evaluated complexes involved a decrease in the vascular tone induced by norepinephrine (10−6 M at the end of the incubation period in aortic rings with and without endothelium, indicating the slow release of NO from these complexes and suggesting that the ligands promoted chemical stability to the molecule. Moreover, we demonstrated that the association of Ru with NO is more stable when the ligands pyridine and cyclan are used in the formulation of the compound.

A ruthenium polypyridyl intercalator stalls DNA replication forks, radiosensitizes human cancer cells and is enhanced by Chk1 inhibition

Science.gov (United States)

Gill, Martin R.; Harun, Siti Norain; Halder, Swagata; Boghozian, Ramon A.; Ramadan, Kristijan; Ahmad, Haslina; Vallis, Katherine A.

2016-08-01

Ruthenium(II) polypyridyl complexes can intercalate DNA with high affinity and prevent cell proliferation; however, the direct impact of ruthenium-based intercalation on cellular DNA replication remains unknown. Here we show the multi-intercalator [Ru(dppz)2(PIP)]2+ (dppz = dipyridophenazine, PIP = 2-(phenyl)imidazo[4,5-f][1,10]phenanthroline) immediately stalls replication fork progression in HeLa human cervical cancer cells. In response to this replication blockade, the DNA damage response (DDR) cell signalling network is activated, with checkpoint kinase 1 (Chk1) activation indicating prolonged replication-associated DNA damage, and cell proliferation is inhibited by G1-S cell-cycle arrest. Co-incubation with a Chk1 inhibitor achieves synergistic apoptosis in cancer cells, with a significant increase in phospho(Ser139) histone H2AX (γ-H2AX) levels and foci indicating increased conversion of stalled replication forks to double-strand breaks (DSBs). Normal human epithelial cells remain unaffected by this concurrent treatment. Furthermore, pre-treatment of HeLa cells with [Ru(dppz)2(PIP)]2+ before external beam ionising radiation results in a supra-additive decrease in cell survival accompanied by increased γ-H2AX expression, indicating the compound functions as a radiosensitizer. Together, these results indicate ruthenium-based intercalation can block replication fork progression and demonstrate how these DNA-binding agents may be combined with DDR inhibitors or ionising radiation to achieve more efficient cancer cell killing.

Application of the chemical properties of ruthenium to decontamination processes; L'application des proprietes chimiques du ruthenium a des procedes de decontamination

Energy Technology Data Exchange (ETDEWEB)

Fontaine, A; Berger, D [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1965-07-01

The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [French] Les proprietes chimiques du ruthenium en solutions aqueuses nitriques et en solutions organiques de tributylphosphate, sont passees en revue. A partir de ces donnees, quelques exemples connus sont cites: ils exposent des procedes de separation ou d'elimination du ruthenium de dechets radioactifs. (auteurs)

Ruthenium complexes with phenylterpyridine derivatives target cell membrane and trigger death receptors-mediated apoptosis in cancer cells.

Science.gov (United States)

Deng, Zhiqin; Gao, Pan; Yu, Lianling; Ma, Bin; You, Yuanyuan; Chan, Leung; Mei, Chaoming; Chen, Tianfeng

2017-06-01

Elucidation of the communication between metal complexes and cell membrane may provide useful information for rational design of metal-based anticancer drugs. Herein we synthesized a novel class of ruthenium (Ru) complexes containing phtpy derivatives (phtpy = phenylterpyridine), analyzed their structure-activity relationship and revealed their action mechanisms. The result showed that, the increase in the planarity of hydrophobic Ru complexes significantly enhanced their lipophilicity and cellular uptake. Meanwhile, the introduction of nitro group effectively improved their anticancer efficacy. Further mechanism studies revealed that, complex (2c), firstly accumulated on cell membrane and interacted with death receptors to activate extrinsic apoptosis signaling pathway. The complex was then transported into cell cytoplasm through transferrin receptor-mediated endocytosis. Most of the intracellular 2c accumulated in cell plasma, decreasing the level of cellular ROS, inducing the activation of caspase-9 and thus intensifying the apoptosis. At the same time, the residual 2c can translocate into cell nucleus to interact with DNA, induce DNA damage, activate p53 pathway and enhance apoptosis. Comparing with cisplatin, 2c possesses prolonged circulation time in blood, comparable antitumor ability and importantly, much lower toxicity in vivo. Taken together, this study uncovers the role of membrane receptors in the anticancer actions of Ru complexes, and provides fundamental information for rational design of membrane receptor targeting anticancer drugs. Copyright © 2017 Elsevier Ltd. All rights reserved.

A technique for studying digestion by grasshoppers using a 103Ruthenium-labelled marker

International Nuclear Information System (INIS)

Gandar, M.V.

1981-01-01

103 Ru-labelled tris (I,10-phenanthroline) ruthenium (II) chloride has proved to be a convenient marker in investigating digestion in grasshoppers. Assimilation efficiencies and the retension time of the food in the gut were measured. It is surmised that the technique described in this paper will be applicable to studies of a variety of chewing herbivorous insects. (author)

DNA damage by the cobalt (II) and zinc (II) complexes of ...

African Journals Online (AJOL)

Using the single cell gel electrophoresis method, the tetraazamacrocycle Zn(II) complex (Zn(II)-L) and the tetraazamacrocycle Co(II) complex (Co(II)-L) were investigated focusing on their DNA damage to Tetrahymena thermophila. When the cells were treated with the 0.05, 0.25 and 0.50 mg/ml Zn(II)-L, the tail length ...

Spectroscopic and biological approach in the characterization of a novel 14-membered [N4] macrocyclic ligand and its Palladium(II), Platinum(II), Ruthenium(III) and Iridium(III) complexes

Science.gov (United States)

Rani, Soni; Kumar, Sumit; Chandra, Sulekh

2014-01-01

A novel, tetradentate nitrogen donor [N4] macrocyclic ligand, i.e. 3,5,14,16-tetramethyl-2,6,13,17-tetraazatricyclo[12,0,07-12] cosa-1(22),2,5,7,9,11,13,16,18,20-decaene(L), has been synthesized and characterized by elemental analyses, IR, Mass, and 1H NMR spectral studies. Complexes of Pd(II), Pt(II), Ru(III) and Ir(III) have been prepared and characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, Mass, electronic spectral and thermal studies. On the basis of molar conductance the complexes may be formulated as [PdL]Cl2, [PtL]Cl2, [Ru(L)Cl2]Cl and [Ir(L)Cl2]Cl. The complexes are insoluble in most common solvents, including water, ethanol, carbon tetrachloride and acetonitrile, but soluble in DMF/DMSO. The value of magnetic moment indicates that all the complexes are diamagnetic except Ru(III) complex which shows magnetic moment corresponding to one unpaired electron. The magnetic moment of Ru(III) complex is 1.73 B.M. at room temperature. The antimicrobial activities of ligand and its complexes have been screened in vitro, as growth inhibiting agents. The antifungal and antibacterial screening were carried out using Food Poison and Disc Diffusion Method against plant pathogenic fungi and bacteria Alternaria porri, Fusarium oxysporum, Xanthomonas compestris and Pseudomonas aeruginosa respectively. The compounds were dissolved in DMSO to get the required solutions. The required medium used for these activities was PDA and nutrient agar.

Spectroscopic and biological approach in the characterization of a novel 14-membered [N4] macrocyclic ligand and its palladium(II), platinum(II), ruthenium(III) and iridium(III) complexes.

Science.gov (United States)

Rani, Soni; Kumar, Sumit; Chandra, Sulekh

2014-01-24

A novel, tetradentate nitrogen donor [N4] macrocyclic ligand, i.e. 3,5,14,16-tetramethyl-2,6,13,17-tetraazatricyclo[12,0,0(7-12)] cosa-1(22),2,5,7,9,11,13,16,18,20-decaene(L), has been synthesized and characterized by elemental analyses, IR, Mass, and (1)H NMR spectral studies. Complexes of Pd(II), Pt(II), Ru(III) and Ir(III) have been prepared and characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, Mass, electronic spectral and thermal studies. On the basis of molar conductance the complexes may be formulated as [PdL]Cl2, [PtL]Cl2, [Ru(L)Cl2]Cl and [Ir(L)Cl2]Cl. The complexes are insoluble in most common solvents, including water, ethanol, carbon tetrachloride and acetonitrile, but soluble in DMF/DMSO. The value of magnetic moment indicates that all the complexes are diamagnetic except Ru(III) complex which shows magnetic moment corresponding to one unpaired electron. The magnetic moment of Ru(III) complex is 1.73 B.M. at room temperature. The antimicrobial activities of ligand and its complexes have been screened in vitro, as growth inhibiting agents. The antifungal and antibacterial screening were carried out using Food Poison and Disc Diffusion Method against plant pathogenic fungi and bacteria Alternaria porri, Fusarium oxysporum, Xanthomonas compestris and Pseudomonas aeruginosa respectively. The compounds were dissolved in DMSO to get the required solutions. The required medium used for these activities was PDA and nutrient agar. Copyright © 2013 Elsevier B.V. All rights reserved.

Electrochemical behavior of ruthenium-hexacyanoferrate modified glassy carbon electrode and catalytic activity towards ethanol electro oxidation

Energy Technology Data Exchange (ETDEWEB)

Costa, Wendell M.; Marques, Aldalea L.B., E-mail: aldalea.ufma@hotmail.com [Universidade Federal do Maranhao (UFMA), Sao Luis, MA (Brazil). Departamento de Quimica Tecnologica; Cardoso, William S.; Marques, Edmar P.; Bezerra, Cicero W.B. [Universidade Federal do Maranhao (UFMA), Sao Luis, MA (Brazil). Departamento de Qumica; Ferreira, Antonio Ap. P. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil). Instituto de Quimica; Song, Chaojie; Zhang, Jiujun [Energy, Mining and Environment Portfolio, National Research Council of Canada, Vancouver, BC (Canada)

2013-04-15

Ruthenium-based hexacyanoferrate (RuHCF) thin film modified glassy carbon electrode was prepared by drop evaporation method. The RuHCF modified electrode exhibited four redox couples in strong acidic solution (pH 1.5) attributed to Fe(CN){sub 6}{sup 3-} ion and three ruthenium forms (Ru(II), Ru(III) and Ru(IV)), characteristic of ruthenium oxide compounds. The modified electrode displayed excellent electrocatalytic activity towards ethanol oxidation in the potential region where electrochemical processes Ru(III)-O-Ru(IV) and Ru(IV)-O-Ru(VI) occur. Impedance spectroscopy data indicated that the charge transfer resistance decreased with the increase of the applied potential and ethanol concentration, indicating the use of the RuHCF modified electrode as an ethanol sensor. Under optimized conditions, the sensor responded linearly and rapidly to ethanol concentration between 0.03 and 0.4 mol L{sup -1} with a limit of detection of 0.76 mmol L{sup -1}, suggesting an adequate sensitivity in ethanol analyses. (author)

Ruthenium-modified cytochrome c: temperature dependence of the rate of intramolecular electron transfer

International Nuclear Information System (INIS)

Isied, S.S.; Kuehn, C.; Worosila, G.

1984-01-01

The ruthenium-modified horse heart cytochrome c, Ru(III)-cyt c(III), where the ruthenium is bound to the histidines-33 residue has been synthesized and characterized by ruthenium analysis, UV-vis and CD spectra, and differential pulse polarography and cyclic voltammetry. The intermediate Ru(III)-cyt c(III) has been generated by pulse-radioanalysis with use of four different radicals, CO 2 -., (CH 3 )COH., (CH 2 OH) 3 CCHOH, and -OCCH(OH)C(OH)CO 2 -. The rate of intramolecular electron transfer within the Ru(III)-cyt c(III) complex and its temperature dependence were determined over a 40 0 C temperature range with the CO 2 -. radical. At 25 0 C, these values are k/sub u/=53 +/- s/sup -1/ (pH 7.01 M phosphate buffer, 0.1 M NaHCO 2 ), ΔH/sup +/=3.5 +/- 0.2 kcal mol/sup -1/, and ΔS/sup +/=-39 +/- 1 eu

DNA damage by the cobalt (II) and zinc (II) complexes of ...

African Journals Online (AJOL)

STORAGESEVER

2008-09-03

Sep 3, 2008 ... distributed in grade 3. The results indicated that Co(II)-L induced a relatively high level of DNA damage in comparison with the level of damage induced by Zn(II)-L. Key words: Tetraazamacrocycle Zn(II) complex, tetraazamacrocycle Co(II) complex, Tetrahymena thermophila, DNA damage, the comet assay.

Development of a method for analyzing traces of ruthenium in plant materials and determination of the transfer factors soil/plant for ruthenium compounds from reprocessing plants

International Nuclear Information System (INIS)

Blasius, E.; Huth, R.; Neumann, W.

1988-01-01

In an artificial humous and sandy soil spiked with 106 Ru as RuO 2 and RuCl 3 , pasture grass was grown under artificial illumination in our laboratory. The amounts of ruthenium taken up by the plants were determined by γ-spectrometry. For open-air investigations with pasture grass, wheat and potatoes inactive ruthenium(III) chloride and ruthenium nitrosylchloride were used. Ruthenium was determined by electrothermal atomic absorption spectrometry (ETAAS) after destroying the organic material and concentrating the solution. The concentration and chemical form of the ruthenium exert an unimportant influence on the transfer factor. For the pasture-grass, the stems of wheat and the weed of potatoes it amounts to 0.00005 to 0.0015, for the ear of wheat to about 0.00005. In peeled potatoes there was no ruthenium detectable, therefore the limit of detection leads to a transfer factor ≤ 0.00001. So it is evident that ruthenium is little available for the roots of the plants. In the event of an accident in a nuclear plant the uptake of radioactive ruthenium by roots has only negligible radioecological consequences. This applies even if 50 years of ruthenium enrichment in the soil are assumed. (orig./RB)

Electrogenerated chemiluminescence of tris(2,2' bipyridine)ruthenium(II) using common biological buffers as co-reactant, pH buffer and supporting electrolyte.

Science.gov (United States)

Kebede, Noah; Francis, Paul S; Barbante, Gregory J; Hogan, Conor F

2015-11-07

A series of aliphatic tertiary amines (HEPES, POPSO, EPPS and BIS-TRIS) commonly used to buffer the pH in biological experiments, were examined as alternative, non-toxic co-reactants for the electrogenerated chemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(ii) ([Ru(bpy)3](2+)). These were found to be very attractive as "multi-tasking" reagents, serving not only as co-reactants, but also fulfiling the roles of pH buffer and supporting electrolyte within an aqueous environment; thus significantly simplifying the overall ECL analysis. Sub-nanomolar detection limits were obtained for [Ru(bpy)3](2+) in the presence of BIS-TRIS, making this species an valuable option for co-reactant ECL-based bioanalytical applications.

In Situ FTIR and NMR Spectroscopic Investigations on Ruthenium-Based Catalysts for Alkene Hydroformylation.

Science.gov (United States)

Kubis, Christoph; Profir, Irina; Fleischer, Ivana; Baumann, Wolfgang; Selent, Detlef; Fischer, Christine; Spannenberg, Anke; Ludwig, Ralf; Hess, Dieter; Franke, Robert; Börner, Armin

2016-02-18

Homogeneous ruthenium complexes modified by imidazole-substituted monophosphines as catalysts for various highly efficient hydroformylation reactions were characterized by in situ IR spectroscopy under reaction conditions and NMR spectroscopy. A proper protocol for the preformation reaction from [Ru3 (CO)12] is decisive to prevent the formation of inactive ligand-modified polynuclear complexes. During catalysis, ligand-modified mononuclear ruthenium(0) carbonyls were detected as resting states. Changes in the ligand structure have a crucial impact on the coordination behavior of the ligand and consequently on the catalytic performance. The substitution of CO by a nitrogen atom of the imidazolyl moiety in the ligand is not a general feature, but it takes place when structural prerequisites of the ligand are fulfilled. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of the chemical properties of ruthenium to decontamination processes; L'application des proprietes chimiques du ruthenium a des procedes de decontamination

Energy Technology Data Exchange (ETDEWEB)

Fontaine, A.; Berger, D. [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1965-07-01

The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [French] Les proprietes chimiques du ruthenium en solutions aqueuses nitriques et en solutions organiques de tributylphosphate, sont passees en revue. A partir de ces donnees, quelques exemples connus sont cites: ils exposent des procedes de separation ou d'elimination du ruthenium de dechets radioactifs. (auteurs)

p-chloro- and p-bromo-benzoylacetoneoxime as the spectrophotometric reagents for palladium and ruthenium(III)

International Nuclear Information System (INIS)

Yeole, V.V.; Langade, A.D.; Shinde, V.M.

1980-01-01

A procedure is described for the extractive spectrophotometric determination of palladium or ruthenium(III) using p-chloro or p-bromobenzoylacetoneoxime as the reagent. The yellow palladium complexes which are extracted into chloroform from an aqueous solution of pH 3.5, absorb as 400 nm and conform to Beer's law in the range of 10 to 100 μg of Pd/10 ml of organic phase. The orange-red ruthenium complexes which are extracted into ethylacetate from an aqueous solution of pH 5.0, absorbs at 475 nm and conforms to Beer's law in the range of 20 to 200 μg of Ru/10 ml of organic phase. The molar absorptivities, Sandell's sensitivities and instability constants are reported. (author)

η6-Arene complexes of ruthenium and osmium with pendant donor functionalities

KAUST Repository

Reiner, Thomas

2010-11-01

Conversion of 4′-(2,5-dihydrophenyl)butanol or N-trifluoroacetyl-2,5- dihydrobenzylamine with MCl3·n H2O (M = Ru, Os) affords the corresponding dimeric η6-arene complexes in good to excellent yields. Under similar reaction conditions, the amine functionalized arene precursor 2,5-dihydrobenzylamine yields the corresponding Ru(II) complex. For osmium, HCl induced oxidation leads to formation of [OsCl6] 2- salts. However, under optimized reaction conditions, conversion of the precursor 2,5-dihydrobenzylamine chloride results in clean formation of η6-arene Os(II) complex. X-ray structures of [(η6- benzyl ammonium)(dmso)RuCl2] and (2,5-dihydrobenzyl ammonium) 4[OsCl6]2confirm the spectroscopic data. High stability towards air and acid as well as enhanced solubility in water is observed for all η6-arene complexes. © 2010 Elsevier B.V. All rights reserved.

Analysis of uranium and its compounds. Ruthenium spectrographic determination

International Nuclear Information System (INIS)

Anon.

Ruthenium determination in uranium and its compounds, suitable for content greater than 0.1 ppm with respect to uranium, by dissolution in sulfuric acid and addition of palladium as an internal standard, separation of the precipitated ruthenium, in the presence of gold, by reduction with zinc, the precipitate is calcined and ruthenium is determined by spectrography [fr

The effects of linear assembly of two carbazole groups on acid-base and DNA-binding properties of a ruthenium(II) complex

Science.gov (United States)

Chen, Xi; Xue, Long-Xin; Ju, Chun-Chuan; Wang, Ke-Zhi

2013-07-01

A novel Ru(II) complex of [Ru(bpy)2(Hbcpip)](ClO4)2 {where bpy = 2,2-bipyridine, Hbcpip = 2-(4-(9H-3,9'-bicarbazol-9-yl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline} is synthesized and characterized. Calf-thymus DNA-binding properties of the complex were studied by UV-vis absorption and luminescence titrations, steady-state emission quenching by [Fe(CN)6]4-, DNA competitive binding with ethidium bromide, thermal denaturation and DNA viscosity measurements. The results indicate that the complex partially intercalated into the DNA with a binding constant of (5.5 ± 1.4) × 105 M-1 in buffered 50 mM NaCl. The acid-base properties of the complex were also studied by UV-visible and luminescence spectrophotometric pH titrations, and ground- and excited-state acidity ionization constant values were derived.

Spectroscopic and thermal degradation behavior of Mg(II, Ca(II, Ba(II and Sr(II complexes with paracetamol drug

Directory of Open Access Journals (Sweden)

Moamen S. Refat

2017-05-01

Full Text Available Complexes of Mg(II, Ca(II, Ba(II and Sr(II with paracetamol drug were synthesized and characterized by elemental analysis, conductivity, UV–Vis, IR, and 1H NMR spectroscopy and thermal analysis, as well as screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as paracetamol behaves as a neutral bidentate ligand coordinated to the metal ions via the lone pair of electrons of nitrogen and carbonyl-O atoms of the amide group. From the microanalytical data, the stoichiometry of the complexes reacts with Mg(II, Ca(II, Ba(II and Sr(II by molar ratios (2:1 (paracetamol:metal ion. The thermal behavior (TG/DTG of the complexes was studied. The ligand and their metal complexes were screened against both of antibacterial and fungicidal activities.

Ruthenium-catalyzed reactions--a treasure trove of atom-economic transformations.

Science.gov (United States)

Trost, Barry M; Frederiksen, Mathias U; Rudd, Michael T

2005-10-21

The demand for new chemicals spanning the fields of health care to materials science combined with the pressure to produce these substances in an environmentally benign fashion pose great challenges to the synthetic chemical community. The maximization of synthetic efficiency by the conversion of simple building blocks into complex targets remains a fundamental goal. In this context, ruthenium complexes catalyze a number of non-metathesis conversions and allow the rapid assembly of complex molecules with high selectivity and atom economy. These complexes often exhibit unusual reactivity. Careful consideration of the mechanistic underpinnings of the transformations can lead to the design of new reactions and the discovery of new reactivity.

Electronic Interplay between TTF and Extended-TCNQ Electrophores along a Ruthenium Bis(acetylide) Linker.

Science.gov (United States)

Vacher, Antoine; Auffray, Morgan; Barrière, Frédéric; Roisnel, Thierry; Lorcy, Dominique

2017-11-17

A bis(TTF-butadiynyl) ruthenium D-D'-D complex, with intramolecular electronic interplay between the three electron-donating electrophores, was easily converted through a cycloaddition-retroelectrocyclization with TCNQ into a D-A-D'-A-D pentad complex, which exhibits an intense intramolecular charge transfer together with an electronic interplay between the two acceptors along the conjugated organometallic bridge.

Mechanism of ruthenium dioxide crystallization during high level waste vitrification

International Nuclear Information System (INIS)

Boucetta, H.

2012-01-01

Ruthenium, arising from the reprocessing of spent uranium oxide fuel, has a low solubility in glass melt. It crystallizes in the form of particles of RuO 2 of acicular or polyhedral morphology dispersed in fission product and actinides waste containment glass. Since the morphology of these particles strongly influences the physico-chemical properties, the knowledge and the control of their mechanism of formation are of major importance. The goal of this work is to determine the chemical reactions responsible for the formation of RuO 2 particles of acicular or polyhedral shape during glass synthesis. Using a simplification approach, the reactions between RuO 2 -NaNO 3 , and more complex calcine RuO 2 -Al 2 O 3 -Na 2 O and a sodium borosilicate glass are studied. In situ scanning electron microscopy and XANES at increasing temperatures are used to follow changes in composition, speciation and morphology of the ruthenium intermediate species. Those compounds are thoroughly characterised by SEM, XRD, HRTEM, and ruthenium K-edge X-ray absorption spectroscopy. This combined approach allows us to show that the ruthenium speciation modification during vitrification is the key of control of the morphology of RuO 2 particles in the glass. In particular, the formation of a specific intermediate compound (Na 3 RuO 4 ) is one of the main steps that lead to the precipitation of needle-shaped RuO 2 particles in the melt. The formation of polyhedral particles, on the contrary, results from the direct incorporation of RuO 2 crystals in the melt followed by an Ostwald ripening mechanism. (author) [fr

Ruthenium(II)-catalyzed direct addition of indole/pyrrole C2-H bonds to alkynes.

Science.gov (United States)

Liang, Libo; Fu, Shaomin; Lin, Dongen; Zhang, Xiao-Qi; Deng, Yuanfu; Jiang, Huanfeng; Zeng, Wei

2014-10-17

A ruthenium-catalyzed C2-hydroindolation of alkynes has been achieved. This protocol provides a rapid and concise access to kinds of 2-alkenyl-substituted N-(2-pyridyl)indoles in which the pyridyl moiety can be easily removed to afford free (N-H) indoles under mild conditions. Various arenes and alkynes, including electron-deficient and electron-rich internal alkynes and terminal alkynes, allow for this transformation.

Scaling-resistance of ruthenium- and ruthenium phosphides powders in argon and air

International Nuclear Information System (INIS)

Chernogorebko, V.B.; Semenov-Kobzar', A.A.; Kulik, L.Ya.

1976-01-01

The thermal stability of ruthenium phosphides in air diminishes as the content of phosphorus in the compound increases. The temperatures at which active oxidation of the powders starts are as follows: Ru-600, Ru 2 P-590, RuP-390, and RuP 2 -270 0 C. The oxidation of phosphorus in the phosphides proceeds in steps. The atoms of phosphorus which are most accessible to oxygen are first oxidated. Phosphorus atoms in the octahedral spaces are oxidated less easily, simultaneously with the oxidation of the ruthenium atoms. When heated in argon, Ru 2 P and RuP fuse congruently at 1,500 and 1,555 0 C respectively, while RuP 2 dissociates at 950 0 C. (author)

Deprotonation/protonation of coordinated secondary thioamide units of pincer ruthenium complexes: modulation of voltammetric and spectroscopic characterization of the pincer complexes.

Science.gov (United States)

Teratani, Takuya; Koizumi, Take-aki; Yamamoto, Takakazu; Tanaka, Koji; Kanbara, Takaki

2011-09-21

New pincer ruthenium complexes, [Ru(SCS)(tpy)]PF(6) (1) (SCS = 2,6-bis(benzylaminothiocarbonyl)phenyl), tpy = 2,2':6',2''-terpyridyl) and [Ru(SNS)(tpy)]PF(6) (2) (SNS = 2,5-bis(benzylaminothiocarbonyl)pyrrolyl), having κ(3)SCS and κ(3)SNS pincer ligands with two secondary thioamide units were synthesized by the reactions of [RuCl(3)(tpy)] with N,N'-dibenzyl-1,3-benzenedicarbothioamide (L1) and N,N'-dibenzyl-2,5-1H-pyrroledicarbothioamide (L2), respectively, and their chemical and electrochemical properties were elucidated. The structure of 1 was determined by X-ray crystallography. The complexes 1 and 2 showed a two-step deprotonation reaction by treatment with 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU), and the addition of DBU led to a shift of the metal-centered redox couples to a lower potential by 720 and 550 mV, respectively. The di-deprotonated complexes were also studied by (1)H-NMR and UV-vis spectroscopy. The addition of methanesulfonic acid (MSA) to the di-deprotonated complexes enabled the recovery of 1 and 2, indicating that the thioamide moiety underwent a reversible deprotonation-protonation process, which resulted in regulating the redox potentials of the metal center. The Pourbaix diagram of 1 revealed that 1 underwent a one-proton/one-electron transfer process in the pH range of 5.83-10.35, and a two-proton/one-electron process at a pH of over 10.35, indicating that the deprotonation/protonation process of the complexes is related to proton-coupled electron transfer (PCET). This journal is © The Royal Society of Chemistry 2011

Experiments on the behaviour of ruthenium in air ingress accidents

International Nuclear Information System (INIS)

Kaerkelae, T.; Backman, Ul; Auvinen, A.; Zilliacus, R.; Lipponen, M.; Kekki, T.; Tapper, U.; Jokiniemi, J.

2007-03-01

During routine nuclear reactor operation, ruthenium will accumulate in the fuel in relatively high concentrations. In a severe accident in a nuclear power plant it is possible that air gets into contact with the reactor core. In this case ruthenium may oxidise and form volatile ruthenium species, RuO3 and RuO4, which can be transported into the containment. In order to estimate the amount of gaseous ruthenium species, it is of interest to know, how they are formed and how they behave. In our experiments the formation and transport of volatile ruthenium oxides was studied by exposing RuO2 powder to diverse oxidising atmospheres at a relatively high temperature. Transport of gaseous RuO4 was further investigated by injecting it into the facility in similar conditions. Upon cooling of the gas flow RuO2 aerosol particles were formed in the system. They were removed from the gas stream with plane filters. Gaseous ruthenium species were trapped in 1M NaOH-water solution, which is capable of trapping RuO4 totally. Ruthenium in the solution was filtered for analysis. The determination of ruthenium both in aerosol and in liquid filters was made using instrumental neutron activation analysis (INAA). In order to close the mass balance and to achieve better time resolution seven experiment were carried out using radioactive tracer. In this report, the facility for the ruthenium behaviour study and results from experiments are presented. Preliminary conclusions from the experiments are reported as well. Final conclusions will be made after modelling of the facility is completed in a continuation work of this study. (au)

Experiments on the behaviour of ruthenium in air ingress accidents

Energy Technology Data Exchange (ETDEWEB)

Kaerkelae, T.; Backman, Ul; Auvinen, A.; Zilliacus, R.; Lipponen, M.; Kekki, T.; Tapper, U.; Jokiniemi, J. [Technical Research Centre of Finland VTT (Finland)

2007-03-15

During routine nuclear reactor operation, ruthenium will accumulate in the fuel in relatively high concentrations. In a severe accident in a nuclear power plant it is possible that air gets into contact with the reactor core. In this case ruthenium may oxidise and form volatile ruthenium species, RuO3 and RuO4, which can be transported into the containment. In order to estimate the amount of gaseous ruthenium species, it is of interest to know, how they are formed and how they behave. In our experiments the formation and transport of volatile ruthenium oxides was studied by exposing RuO2 powder to diverse oxidising atmospheres at a relatively high temperature. Transport of gaseous RuO4 was further investigated by injecting it into the facility in similar conditions. Upon cooling of the gas flow RuO2 aerosol particles were formed in the system. They were removed from the gas stream with plane filters. Gaseous ruthenium species were trapped in 1M NaOH-water solution, which is capable of trapping RuO4 totally. Ruthenium in the solution was filtered for analysis. The determination of ruthenium both in aerosol and in liquid filters was made using instrumental neutron activation analysis (INAA). In order to close the mass balance and to achieve better time resolution seven experiment were carried out using radioactive tracer. In this report, the facility for the ruthenium behaviour study and results from experiments are presented. Preliminary conclusions from the experiments are reported as well. Final conclusions will be made after modelling of the facility is completed in a continuation work of this study. (au)

Two Discrete RuCp* (Cp*=Pentamethylcyclopentadienyl) Binding Modes of N-Confused Porphyrins: Peripheral π Complex and Sitting Atop Ruthenocenophane Complex by Skeletal Transformation.

Science.gov (United States)

Yamamoto, Takaaki; Mitsuno, Koki; Mori, Shigeki; Itoyama, Shuhei; Shiota, Yoshihito; Yoshizawa, Kazunari; Ishida, Masatoshi; Furuta, Hiroyuki

2018-05-07

Complexation of a RuCp* cation with N-confused tetraarylporphyrins (NCPs) forms directly bound ruthenium(II) pentamethylcyclopentadienyl (Cp*) π-complex on a specific meso-aryl group (e.g., phenyl) neighboring peripheral imino nitrogen of NCPs in high yields. In contrast, in the case of NCPs bearing bulky meso-substituents (e.g., 3,5-di-tert-butylphenyl), new ruthenocenophane-like complex embedded on an N-confused calix[4]phyrin was formed through multiple C-H bond activation of methyl groups of Cp* ligand. The mechanistic insight into the formation of the ruthenocenophane was derived from DFT calculations. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Crystal structure of a mononuclear Ru(II) complex with a back-to-back terpyridine ligand: [RuCl(bpy)(tpy-tpy)](.).

Science.gov (United States)

Rein, Francisca N; Chen, Weizhong; Scott, Brian L; Rocha, Reginaldo C

2015-09-01

We report the structural characterization of [6',6''-bis-(pyridin-2-yl)-2,2':4',4'':2'',2'''-quaterpyridine](2,2'-bi-pyridine)-chlorido-ruthenium(II) hexa-fluorido-phosphate, [RuCl(C10H8N2)(C30H20N6)]PF6, which contains the bidentate ligand 2,2'-bi-pyridine (bpy) and the tridendate ligand 6',6''-bis-(pyridin-2-yl)-2,2':4',4'':2'',2'''-quaterpyridine (tpy-tpy). The [RuCl(bpy)(tpy-tpy)](+) monocation has a distorted octa-hedral geometry at the central Ru(II) ion due to the restricted bite angle [159.32 (16)°] of the tridendate ligand. The Ru-bound tpy and bpy moieties are nearly planar and essentially perpendicular to each other with a dihedral angle of 89.78 (11)° between the least-squares planes. The lengths of the two Ru-N bonds for bpy are 2.028 (4) and 2.075 (4) Å, with the shorter bond being opposite to Ru-Cl. For tpy-tpy, the mean Ru-N distance involving the outer N atoms trans to each other is 2.053 (8) Å, whereas the length of the much shorter bond involving the central N atom is 1.936 (4) Å. The Ru-Cl distance is 2.3982 (16) Å. The free uncoordinated moiety of tpy-tpy adopts a trans,trans conformation about the inter-annular C-C bonds, with adjacent pyridyl rings being only approximately coplanar. The crystal packing shows significant π-π stacking inter-actions based on tpy-tpy. The crystal structure reported here is the first for a tpy-tpy complex of ruthenium.

Analysis of flow fields, temperatures and ruthenium transport in the test facility

International Nuclear Information System (INIS)

Kaerkelae, T.; Pyykoenen, J.; Auvinen, A.; Jokiniemi, J.

2008-03-01

Ruthenium transport experiments were conducted at VTT during years 2002- 2006. Experiments gave information about ruthenium behaviour in air ingress accident conditions. This study complements those experiments with an analysis of the flows and thermal fields in the test system. Temperature profiles were measured at the walls of the experimental facility. Computational fluid dynamics (CFD) simulations used the measured profiles and provided predictions of flows and temperatures inside the furnace. Ruthenium transport was also modelled with CFD. Thermal characterisation of the reactor demonstrated that buoyancy has a significant role during the cooling after the furnace. A hypothesis of the dominant role of RuO2 and RuO3 condensation on reactor walls gave simulation results that are in accordance with radiotracer measurements of deposition in experiments conducted with furnace at 1500K. Actually, RuO3 does not condensate, but it thermal decomposes to RuO2. This does not seem to have effect on result. Particle formation around the furnace exit could be detected from the comparison of modelling results with the measured profiles. In several other experiments ruthenium behaviour is dominated by other issues. These are related to the complex ruthenium chemistry that includes various surface reactions. Thermal equilibrium indicates significant gaseous RuO4 concentration around 1300 K. It seems that seed particles decreased the catalytic decomposition activity of RuO4 to RuO2 around this temperature pushing the gas concentration towards the equilibrium, and further give rise to gaseous RuO4 transport to low temperatures. At higher temperature increasing mass flow rate of RuO2 particles is likely to catalyse (decomposition) reaction of RuO4 to RuO2. (au)

Analysis of flow fields, temperatures and ruthenium transport in the test facility

Energy Technology Data Exchange (ETDEWEB)

Kaerkelae, T.; Pyykoenen, J.; Auvinen, A.; Jokiniemi, J. [Technical Research Centre of Finland VTT (Finland)

2008-03-15

Ruthenium transport experiments were conducted at VTT during years 2002- 2006. Experiments gave information about ruthenium behaviour in air ingress accident conditions. This study complements those experiments with an analysis of the flows and thermal fields in the test system. Temperature profiles were measured at the walls of the experimental facility. Computational fluid dynamics (CFD) simulations used the measured profiles and provided predictions of flows and temperatures inside the furnace. Ruthenium transport was also modelled with CFD. Thermal characterisation of the reactor demonstrated that buoyancy has a significant role during the cooling after the furnace. A hypothesis of the dominant role of RuO2 and RuO3 condensation on reactor walls gave simulation results that are in accordance with radiotracer measurements of deposition in experiments conducted with furnace at 1500K. Actually, RuO3 does not condensate, but it thermal decomposes to RuO2. This does not seem to have effect on result. Particle formation around the furnace exit could be detected from the comparison of modelling results with the measured profiles. In several other experiments ruthenium behaviour is dominated by other issues. These are related to the complex ruthenium chemistry that includes various surface reactions. Thermal equilibrium indicates significant gaseous RuO4 concentration around 1300 K. It seems that seed particles decreased the catalytic decomposition activity of RuO4 to RuO2 around this temperature pushing the gas concentration towards the equilibrium, and further give rise to gaseous RuO4 transport to low temperatures. At higher temperature increasing mass flow rate of RuO2 particles is likely to catalyse (decomposition) reaction of RuO4 to RuO2. (au)

A Proton-Switchable Bifunctional Ruthenium Complex That Catalyzes Nitrile Hydroboration.

Science.gov (United States)

Geri, Jacob B; Szymczak, Nathaniel K

2015-10-14

A new bifunctional pincer ligand framework bearing pendent proton-responsive hydroxyl groups was prepared and metalated with Ru(II) and subsequently isolated in four discrete protonation states. Stoichiometric reactions with H2 and HBPin showed facile E-H (E = H or BPin) activation across a Ru(II)-O bond, providing access to unusual Ru-H species with strong interactions with neighboring proton and boron atoms. These complexes were found to promote the catalytic hydroboration of ketones and nitriles under mild conditions, and the activity was highly dependent on the ligand's protonation state. Mechanistic experiments revealed a crucial role of the pendent hydroxyl groups for catalytic activity.

DNA interactions of dinuclear RuII arene antitumor complexes in cell-free media

Czech Academy of Sciences Publication Activity Database

Nováková, Olga; Nazarov, A.A.; Hartinger, Ch.G.; Keppler, B.K.; Brabec, Viktor

2009-01-01

Roč. 77, č. 3 (2009), s. 364-374 ISSN 0006-2952 R&D Projects: GA MŠk(CZ) LC06030; GA MŠk(CZ) ME08017; GA MŠk(CZ) OC08003; GA AV ČR(CZ) 1QS500040581; GA AV ČR(CZ) KAN200200651 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : dinuclear ruthenium complex * DNA * cross-links Subject RIV: BO - Biophysics Impact factor: 4.254, year: 2009

Ruthenium(ii)-catalyzed olefination via carbonyl reductive cross-coupling† †Electronic supplementary information (ESI) available: Experimental details. See DOI: 10.1039/c7sc04207h

Science.gov (United States)

Wei, Wei; Dai, Xi-Jie; Wang, Haining; Li, Chenchen; Yang, Xiaobo

2017-01-01

Natural availability of carbonyl groups offers reductive carbonyl coupling tremendous synthetic potential for efficient olefin synthesis, yet the catalytic carbonyl cross-coupling remains largely elusive. We report herein such a reaction, mediated by hydrazine under ruthenium(ii) catalysis. This method enables facile and selective cross-couplings of two unsymmetrical carbonyl compounds in either an intermolecular or intramolecular fashion. Moreover, this chemistry accommodates a variety of substrates, proceeds under mild reaction conditions with good functional group tolerance, and generates stoichiometric benign byproducts. Importantly, the coexistence of KOtBu and bidentate phosphine dmpe is vital to this transformation. PMID:29568466

Synthesis, Characterization, and Biological Activity of Mn(II, Fe(II, Co(II, Ni(II, Cu(II, Zn(II, and Cd(II Complexes of N-Thiophenoyl-N′-Phenylthiocarbohydrazide

Directory of Open Access Journals (Sweden)

M. Yadav

2013-01-01

Full Text Available Mn(II, Fe(II, Co(II, Ni(II, Cu(II, Zn(II, and Cd(II complex of N-thiophenoyl -N′-phenylthiocarbohydrazide (H2 TPTH have been synthesized and characterized by elemental analysis, magnetic susceptibility measurements, infrared, NMR, electronic, and ESR spectral studies. The complexes were found to have compositions [Mn(H TPTH2], [Co(TPTH (H2O2], [Ni(TPTH (H2O2], [Cu(TPTH], [Zn(H TPTH], [Cd(H TPTH2], and [Fe(H TPTH2(EtOH]. The magnetic and electronic spectral studies suggest square planar geometry for [Cu(TPTH], tetrahedral geometry for [Zn(TPTH] and [Cd(H TPTH2], and octahedral geometry for rest of the complexes. The infrared spectral studies of the 1 : 1 deprotonated complexes suggest bonding through enolic oxygen, thiolato sulfur, and both the hydrazinic nitrogens. Thus, H2TPTH acts as a binegative tetradentate ligand. H2 TPTH and its metal complexes have been screened against several bacteria and fungi.

Method of suppressing evaporation loss of ruthenium

International Nuclear Information System (INIS)

Muromura, Tadazumi; Sato, Tadashi.

1987-01-01

Purpose: To prevent evaporation loss of ruthenium from liquid wastes by adding an aluminum compound upon applying evaporating and drying to solid treatment to reprocessing liquid wastes for spent fuels. Method: An aluminum compound such as aluminum nitrate or aluminum hydroxide to reprocessing liquid wastes of spent fuels such that aluminum/ruthenium mixing ratio corresponds to 1.3 - 70.0 by g/atom ratio (0.34 - 187 by weight ratio), and the liquid mixture is heated to a temperature of about 130 deg C to be evaporated and dried to solidness. This enables to recover ruthenium without settling and depositing insoluble matters in the liquid wastes and without decomposing nitric acid. (Yoshino, Y.)

Synthesis, characterization and thermal studies of nickel (II), copper (II), zinc (II) and cadmium (II) complexes with some mixed ligands

International Nuclear Information System (INIS)

Mitra, Samiran; Kundu, Parimal; Singh, Rajkumar Bhubon

1998-01-01

Dichloro-(DCA) and trichloroacetate(TCA) -cyclic ligand morpholine (Morph)/thiomorpholine (Tmorph)/methylmorpholine (Mmorph)/dimethyl-piperazine (DMP) complexes of nickel (II), copper (II), zinc (II) and cadmium (II) with the compositions [Ni(tmorph) 2 (DCA) 2 ], [Ni(tmorph) 2 (TCA) 2 ].2H 2 O, [Cu(DMP) 2 (TCA) 2 ],[ML 2 X 2 ].nH 2 O where M=Zn II or Cd II , L=Morph, DMP or tmorph and X=DCA or TCA and n=O except in case of [Cd (Morph) 2 (TCA) 2 ] where n=1 have been synthesised. Some intermediate complexes have been isolated by temperature arrest technique (pyrolysis) and characterised. Configurational and conformational changes have been studied by elemental analyses, IR and electronic spectra, magnetic moment data (in the case of Ni(II) and Cu(II) complexes) and thermal analysis. E a * , ΔH, and ΔS for the decomposition reaction of these complexes are evaluated and the stability of the complexes with respect to activation energy has also been compared. The linear correlation has been found between E a * and ΔS for the decomposition of the complexes. (author)

Titrimetric determination of ruthenium

International Nuclear Information System (INIS)

Velichko, V.V.; Belyaeva, T.I.; Kudinova, V.K.; Usatenko, Yu.I.

1978-01-01

Titration of ruthenium(4) hydrochloric-acid solutions with Mohr's salt, hydroquinone, and thiourea has been studied with the use of biampero- and potentiometric indication of the titration end point (t.e.p.) Potentiometric and amperometric indication of the t.e.p. is applicable when Ru(4) concentration is from 20 to 6000 mkg in 20 ml of the titrated solution; biamperometric indication can be used at a concentration of 5-1000 mkg in the same volume. It has been established that titration of Ru(4) (in the form of the Na 2 RuCl 6 solution) with Mohr's salt is not hindered by the presence of 1000-fold excess of alkaline and alkali-earth metals, Al, Ti(4), Mn(2), Cr(3), Fe(3), Co, Ni, Cu, Zn, Ga, Ge(4), As, Se, Mo(6), Cd, In, and Te; 100-fold excess of Rh, Pd, W, Bi, and Sn; 10-fold excess of Ag, Au, Pt, Hg, Os. Along with Ru(4) titrated are Ir(4), Te(3), V(5), and Ce(4). Selectivity of hydroquinone and thiourea is lower. Titrimetric procedure of determining ruthenium has been tested for ruthenium alloy containing cobalt tungsten. It cannot be recommended for analysis of the samples which dissolve in aqua regia

Complexes cobalt(II, zinc(II and copper(II with some newly synthesized benzimidazole derivatives and their antibacterial activity

Directory of Open Access Journals (Sweden)

S. O. PODUNAVAC-KUZMANOVIC

1999-05-01

Full Text Available The preparation and properties of some complexes of cobalt(II, zinc(II and copper(II with several newly synthesized benzimidazole derivatives (L are reported. The complexes, of the general formula [MCl2L2] (M=Co(II, Zn(II and [CuCl2L(H2O], have a tetrahedral structure. The complexes were characterized by elemental analysis, molar conductivity, magnetic susceptibility measurements, IR and absorption electronic spectra. The antibacterial activitiy of the benzimidazoles and their complexes was evaluated against Erwinia carotovora subsp. carotovora and Erwinia amylovora. The complexes were found to be more toxic than the ligands.

Synthesis and studies on Cu(II), Co(II), Ni(II) complexes of Knoevenagel β-diketone ligands

Science.gov (United States)

Sumathi, S.; Tharmaraj, P.; Sheela, C. D.; Anitha, C.

2012-11-01

Transition metal complexes of various acetylacetone based ligands of the type ML [where M = Cu(II), Ni(II), Co(II); L = 3-(aryl)-pentane-2,4-dione] have been synthesized. The structural features have been derived from their elemental analysis, magnetic susceptibility, molar conductance, IR, UV-Vis, 1H NMR, Mass and ESR spectral studies. Conductivity measurements reveal that all the complexes are non-electrolytic in nature. Spectroscopic and other analytical data of the complexes suggest octahedral geometry for other metal(II) complexes. The redox behavior of the copper(II) complexes have been studied by cyclic voltammetry. The free ligands and their metal complexes have been screened for their in vitro biological activities against the bacteria Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus as well as the fungus Candida albicans by well diffusion method. The zone of inhibition value indicates that the most of the metal(II) complexes are found to possess increased activities compared to those of the free ligands. All synthesized compounds may serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic generation (SHG) efficiency of the ligands (L1-L3) was found to be considerable effect than that of urea and KDP (potassium dihydrogen phosphate).

Experiments on the behaviour of ruthenium in air ingress accidents - Progress report

International Nuclear Information System (INIS)

Kaerkelae, T.; Backman, U.; Auvinen, A.; Ziliacus, R.; Lipponen, M.; Kekki, T.; Tapper, U.; Jokiniemi, J.

2006-02-01

During routine nuclear reactor operation, ruthenium will accumulate in the fuel in relatively high concentrations. In an accident in a nuclear power plant it is possible that air gets into contact with the reactor core. In this case ruthenium can oxidise and form volatile ruthenium species, RuO3 and RuO4, which can be transported into the containment. In order to estimate the amount of gaseous ruthenium species it is of interest to know, how it is formed and how it behaves. In our experiments RuO2 is exposed to diverse oxidising atmospheres at a relatively high temperature. In this report, the experimental system for the ruthenium behaviour study is presented. Also preliminary results from experiments carried out during year 2005 are reported. In the experiments gaseous ruthenium oxides were produced in a furnace. Upon cooling RuO2 aerosol particles were formed in the system. They were removed with plane filters from the gas stream. Gaseous ruthenium species were trapped in 1M NaOH-water solution, which is capable of trapping RuO4 totally. Ruthenium in the solution was filtered for analysis. The determination of ruthenium both in aerosol and in liquid filters was made using instrumental neutron activation analysis (INAA). In order to close mass balance and achieve better time resolution three experiment using radioactive tracer were carried out. (au)

Experiments on the behaviour of ruthenium in air ingress accidents - Progress report

Energy Technology Data Exchange (ETDEWEB)

Kaerkelae, T.; Backman, U.; Auvinen, A.; Ziliacus, R.; Lipponen, M.; Kekki, T.; Tapper, U.; Jokiniemi, J. [VTT Technical Research Centre of Finland (Finland)

2006-02-15

During routine nuclear reactor operation, ruthenium will accumulate in the fuel in relatively high concentrations. In an accident in a nuclear power plant it is possible that air gets into contact with the reactor core. In this case ruthenium can oxidise and form volatile ruthenium species, RuO3 and RuO4, which can be transported into the containment. In order to estimate the amount of gaseous ruthenium species it is of interest to know, how it is formed and how it behaves. In our experiments RuO2 is exposed to diverse oxidising atmospheres at a relatively high temperature. In this report, the experimental system for the ruthenium behaviour study is presented. Also preliminary results from experiments carried out during year 2005 are reported. In the experiments gaseous ruthenium oxides were produced in a furnace. Upon cooling RuO2 aerosol particles were formed in the system. They were removed with plane filters from the gas stream. Gaseous ruthenium species were trapped in 1M NaOH-water solution, which is capable of trapping RuO4 totally. Ruthenium in the solution was filtered for analysis. The determination of ruthenium both in aerosol and in liquid filters was made using instrumental neutron activation analysis (INAA). In order to close mass balance and achieve better time resolution three experiment using radioactive tracer were carried out. (au)

Determination of gold osmium and ruthenium through iodine-azide reaction in presence of 2- or 6- mercaptopurine

International Nuclear Information System (INIS)

Matusiewicz, H.; Kurzawa, Z.

1978-01-01

The composition of osmium and ruthenium complexes with 6-mercaptopurine has been determined. The sensitivity of the method was enhanced due to a proper choice of the optimal time of the formation of these complexes and the time of equilibrium attainment in the presence of excess of azide. Also the gold complex with 2-mercaptopurine was investigated. (author)

Mixed ligand complexes of alkaline earth metals: Part XII. Mg(II, Ca(II, Sr(II and Ba(II complexes with 5-chlorosalicylaldehyde and salicylaldehyde or hydroxyaromatic ketones

Directory of Open Access Journals (Sweden)

MITHLESH AGRAWAL

2002-04-01

Full Text Available The reactions of alkaline earth metal chlorides with 5-chlorosalicylaldehyde and salicylaldehyde, 2-hydroxyacetophenone or 2-hydroxypropiophenone have been carried out in 1 : 1 : 1 mole ratio and the mixed ligand complexes of the type MLL’(H2O2 (where M = Mg(II, Ca(II, Sr(II and Ba(II, HL = 5-chlorosalicylaldehyde and HL’ = salicylaldehyde, 2-hydroxyacetophenone or 2-hydroxypropiophenone have been isolated. These complexes were characterized by TLC, conductance measurements, IR and 1H-NMR spectra.

Cd(II and Pb(II complexes of the polyether ionophorous antibiotic salinomycin

Directory of Open Access Journals (Sweden)

Tanabe Makoto

2011-09-01

Full Text Available Abstract Background The natural polyether ionophorous antibiotics are used for the treatment of coccidiosis in poultry and ruminants. They are effective agents against infections caused by Gram-positive microorganisms. On the other hand, it was found that some of these compounds selectively bind lead(II ions in in vivo experiments, despite so far no Pb(II-containing compounds of defined composition have been isolated and characterized. To assess the potential of polyether ionophores as possible antidotes in the agriculture, a detailed study on their in vitro complexation with toxic metal ions is required. In the present paper we report for the first time the preparation and the structure elucidation of salinomycin complexes with ions of cadmium(II and lead(II. Results New metal(II complexes of the polyether ionophorous antibiotic salinomycin with Cd(II and Pb(II ions were prepared and structurally characterized by IR, FAB-MS and NMR techniques. The spectroscopic information and elemental analysis data reveal that sodium salinomycin (SalNa undergoes a reaction with heavy metal(II ions to form [Cd(Sal2(H2O2] (1 and [Pb(Sal(NO3] (2, respectively. Abstraction of sodium ions from the cavity of the antibiotic is occurring during the complexation reaction. Salinomycin coordinates with cadmium(II ions as a bidentate monoanionic ligand through the deprotonated carboxylic moiety and one of the hydroxyl groups to yield 1. Two salinomycin anions occupy the equatorial plane of the Cd(II center, while two water molecules take the axial positions of the inner coordination sphere of the metal(II cation. Complex 2 consists of monoanionic salinomycin acting in polydentate coordination mode in a molar ratio of 1: 1 to the metal ion with one nitrate ion for charge compensation. Conclusion The formation of the salinomycin heavy metal(II complexes indicates a possible antidote activity of the ligand in case of chronic/acute intoxications likely to occur in the stock

Cd(II) and Pb(II) complexes of the polyether ionophorous antibiotic salinomycin

Science.gov (United States)

2011-01-01

Background The natural polyether ionophorous antibiotics are used for the treatment of coccidiosis in poultry and ruminants. They are effective agents against infections caused by Gram-positive microorganisms. On the other hand, it was found that some of these compounds selectively bind lead(II) ions in in vivo experiments, despite so far no Pb(II)-containing compounds of defined composition have been isolated and characterized. To assess the potential of polyether ionophores as possible antidotes in the agriculture, a detailed study on their in vitro complexation with toxic metal ions is required. In the present paper we report for the first time the preparation and the structure elucidation of salinomycin complexes with ions of cadmium(II) and lead(II). Results New metal(II) complexes of the polyether ionophorous antibiotic salinomycin with Cd(II) and Pb(II) ions were prepared and structurally characterized by IR, FAB-MS and NMR techniques. The spectroscopic information and elemental analysis data reveal that sodium salinomycin (SalNa) undergoes a reaction with heavy metal(II) ions to form [Cd(Sal)2(H2O)2] (1) and [Pb(Sal)(NO3)] (2), respectively. Abstraction of sodium ions from the cavity of the antibiotic is occurring during the complexation reaction. Salinomycin coordinates with cadmium(II) ions as a bidentate monoanionic ligand through the deprotonated carboxylic moiety and one of the hydroxyl groups to yield 1. Two salinomycin anions occupy the equatorial plane of the Cd(II) center, while two water molecules take the axial positions of the inner coordination sphere of the metal(II) cation. Complex 2 consists of monoanionic salinomycin acting in polydentate coordination mode in a molar ratio of 1: 1 to the metal ion with one nitrate ion for charge compensation. Conclusion The formation of the salinomycin heavy metal(II) complexes indicates a possible antidote activity of the ligand in case of chronic/acute intoxications likely to occur in the stock farming

Characterization of ultrasonic spray pyrolysed ruthenium oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Patil, P.S.; Ennaoui, E.A.; Lokhande, C.D.; Mueller, M.; Giersig, M.; Diesner, K.; Tributsch, H. [Hahn-Meitner-Institut Berlin GmbH (Germany). Bereich Physikalische Chemie

1997-11-21

The ultrasonic spray pyrolysis (USP) technique was employed to deposit ruthenium oxide thin films. The films were prepared at 190 C substrate temperature and further annealed at 350 C for 30 min in air. The films were 0.22 {mu} thick and black grey in color. The structural, compositional and optical properties of ruthenium oxide thin films are reported. Contactless transient photoconductivity measurement was carried out to calculate the decay time of excess charge carriers in ruthenium oxide thin films. (orig.) 28 refs.

Surface and sub-surface thermal oxidation of thin ruthenium films

Energy Technology Data Exchange (ETDEWEB)

Coloma Ribera, R.; Kruijs, R. W. E. van de; Yakshin, A. E.; Bijkerk, F. [MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Kokke, S.; Zoethout, E. [FOM Dutch Institute for Fundamental Energy Research (DIFFER), P.O. Box 1207, 3430 BE Nieuwegein (Netherlands)

2014-09-29

A mixed 2D (film) and 3D (nano-column) growth of ruthenium oxide has been experimentally observed for thermally oxidized polycrystalline ruthenium thin films. Furthermore, in situ x-ray reflectivity upon annealing allowed the detection of 2D film growth as two separate layers consisting of low density and high density oxides. Nano-columns grow at the surface of the low density oxide layer, with the growth rate being limited by diffusion of ruthenium through the formed oxide film. Simultaneously, with the growth of the columns, sub-surface high density oxide continues to grow limited by diffusion of oxygen or ruthenium through the oxide film.

Molecular mass spectrometry in metallodrug development: A case of mapping transferrin-mediated transformations for a ruthenium(III) anticancer drug

Energy Technology Data Exchange (ETDEWEB)

Jarosz, Maciej [Chair of Analytical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego St. 3, 00-664 Warsaw (Poland); Matczuk, Magdalena, E-mail: mmatczuk@ch.pw.edu.pl [Chair of Analytical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego St. 3, 00-664 Warsaw (Poland); Pawlak, Katarzyna [Chair of Analytical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego St. 3, 00-664 Warsaw (Poland); Timerbaev, Andrei R. [Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Kosygin St. 19, 119991 Moscow (Russian Federation)

2014-12-03

Highlights: • Extra- and intra-cellular interactions of Ru(III) anticancer drug candidate. • ESI-TOF-MS mapping of the ruthenium species bound to transferring. • ESI-QqQ-MS identification of released Ru species under cytosol simulated conditions. - Abstract: Electrospray ionization mass spectrometry (ESI-MS) techniques have been used to characterize the speciation of a Ru(III) anticancer drug, indazolium trans-[tetrachloridobis(1H-indazole) ruthenate(III)], upon its binding to transferrin and the impact of cellular reducing components on drug–transferrin adducts. Using time-of-flight ESI-MS, the polymorphism of apo- (iron-free) and holo-form (iron-saturated) of the protein was confirmed. While the ruthenium moieties bound to each of five isoforms under simulated extracellular conditions are essentially identical in numbers for apo- and holo-transferrin, distinct differences were found in the composition of Ru(III) species attached to either of the protein forms, which are dominated by differently coordinated aquated complexes. On the other hand, at least one of the Ru-N bonds in metal-organic framework remains intact even after prolonged interaction with the protein. Triple quadrupole tandem ESI-MS measurements demonstrated that the ruthenium species released from drug adducts with holo-transferrin in simulated cancer cytosol are underwent strong ligand exchange (as compared to the protein-bound forms) but most strikingly, they contain the metal center in the reduced Ru(II) state. In vitro probing the extra- and intracellular interactions of promising Ru(III) drug candidate performed by ESI-MS is thought to shed light on the transportation to tumor cells by transferrin and on the activation to more reactive species by the reducing environment of solid tumors.

Rare earth-ruthenium-magnesium intermetallics

Energy Technology Data Exchange (ETDEWEB)

Stein, Sebastian; Kersting, Marcel; Heletta, Lukas; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie

2017-07-01

Eight new intermetallic rare earth-ruthenium-magnesium compounds have been synthesized from the elements in sealed niobium ampoules using different annealing sequences in muffle furnaces. The compounds have been characterized by powder and single crystal X-ray diffraction. Sm{sub 9.2}Ru{sub 6}Mg{sub 17.8} (a=939.6(2), c=1779(1) pm), Gd{sub 11}Ru{sub 6}Mg{sub 16} (a=951.9(2), c=1756.8(8) pm), and Tb{sub 10.5}Ru{sub 6}Mg{sub 16.5} (a=942.5(1), c=1758.3(4) pm) crystallize with the tetragonal Nd{sub 9.34}Ru{sub 6}Mg{sub 17.66} type structure, space group I4/mmm. This structure exhibits a complex condensation pattern of square-prisms and square-antiprisms around the magnesium and ruthenium atoms, respectively. Y{sub 2}RuMg{sub 2} (a=344.0(1), c=2019(1) pm) and Tb{sub 2}RuMg{sub 2} (a=341.43(6), c=2054.2(7) pm) adopt the Er{sub 2}RuMg{sub 2} structure and Tm{sub 3}Ru{sub 2}Mg (a=337.72(9), c=1129.8(4) pm) is isotypic with Sc{sub 3}Ru{sub 2}Mg. Tm{sub 3}Ru{sub 2}Mg{sub 2} (a=337.35(9), c=2671(1) pm) and Lu{sub 3}Ru{sub 2}Mg{sub 2} (a=335.83(5), c=2652.2(5) pm) are the first ternary ordered variants of the Ti{sub 3}Cu{sub 4} type, space group I4/mmm. These five compounds belong to a large family of intermetallics which are completely ordered superstructures of the bcc subcell. The group-subgroup scheme for Lu{sub 3}Ru{sub 2}Mg{sub 2} is presented. The common structural motif of all three structure types are ruthenium-centered rare earth cubes reminicent of the CsCl type. Magnetic susceptibility measurements of Y{sub 2}RuMg{sub 2} and Lu{sub 3}Ru{sub 2}Mg{sub 2} samples revealed Pauli paramagnetism of the conduction electrons.

Ruthenium-Catalyzed Dehydrogenative Decarbonylation of Primary Alcohols

DEFF Research Database (Denmark)

Mazziotta, Andrea; Madsen, Robert

2017-01-01

Dehydrogenative decarbonylation of a primary alcohol involves the release of both dihydrogen and carbon monoxide to afford the one-carbon shorter product. The transformation has now been achieved with a ruthenium-catalyzed protocol by using the complex Ru(COD)Cl2 and the hindered monodentate ligand...... P(o-tolyl)3 in refluxing p-cymene. The reaction can be applied to both benzylic and long chain linear aliphatic alcohols. The intermediate aldehyde can be observed during the transformation, which is therefore believed to proceed through two separate catalytic cycles involving first dehydrogenation...... of the alcohol and then decarbonylation of the resulting aldehyde....

Photocleavage of DNA by copper (II) complexes

Indian Academy of Sciences (India)

The chemistry of ternary and binary copper(II) complexes showing efficient visible lightinduced DNA cleavage activity is summarized in this article. The role of the metal in photo-induced DNA cleavage reactions is explored by designing complex molecules having a variety of ligands. Ternary copper(II) complexes with amino ...

Photocleavage of DNA by copper(II) complexes

Indian Academy of Sciences (India)

The chemistry of ternary and binary copper(II) complexes showing efficient visible lightinduced DNA cleavage activity is summarized in this article. The role of the metal in photo-induced DNA cleavage reactions is explored by designing complex molecules having a variety of ligands. Ternary copper(II) complexes with amino ...

Contribution to the study of ruthenium fluorides, oxyfluorides and oxides

International Nuclear Information System (INIS)

Corbin, Odile.

1982-08-01

Studies on the dry processing of spent fuels reveal a poor ruthenium decontamination of plutonium. For a better understanding of this result a study of ruthenium fluorides, oxyfluorides and oxides is carried out here as follows: - bibliographical review; - thermochromatographic identification of the number and nature of compounds formed by fluorination of microquantities of ruthenium; - confirmation of the thermochromatographic results by two other analytical methods: thermogravimetry and infrared spectroscopy [fr

Coordination behavior of tetraaza [N4] ligand towards Co(II), Ni(II), Cu(II), Cu(I) and Pd(II) complexes: Synthesis, spectroscopic characterization and anticancer activity

Science.gov (United States)

El-Boraey, Hanaa A.

2012-11-01

Novel eight Co(II), Ni(II), Cu(II), Cu(I) and Pd(II) complexes with [N4] ligand (L) i.e. 2-amino-N-{2-[(2-aminobenzoyl)amino]ethyl}benzamide have been synthesized and structurally characterized by elemental analysis, spectral, thermal (TG/DTG), magnetic, and molar conductivity measurements. On the basis of IR, mass, electronic and EPR spectral studies an octahedral geometry has been proposed for Co(II), Ni(II) complexes and Cu(II) chloride complex, square-pyramidal for Cu(I) bromide complex. For Cu(II) nitrate complex (6), Pd(II) complex (8) square planar geometry was proposed. The EPR data of Cu(II) complexes in powdered form indicate dx2-y2 ground state of Cu(II) ion. The antitumor activity of the synthesized ligand and some selected metal complexes has been studied. The palladium(II) complex (8) was found to display cytotoxicity (IC50 = 25.6 and 41 μM) against human breast cancer cell line MCF-7 and human hepatocarcinoma HEPG2 cell line.

Beryllium(II), manganese(II) and uranyl(VI)-salicylamide complexes

Energy Technology Data Exchange (ETDEWEB)

Maurya, P L; Agarwala, B V; Dey, A K [Allahabad Univ. (India)

1977-01-01

The preparation, composition, general properties and i.r. absorption spectra of the solid chelates formed by salicylamide with beryllium(II), manganese(II) and uranyl(VI) are described. The complexes have been synthesized by refluxing a mixture of ethanolic solutions of the reactants (metal:ligand :: 1:2) for several hours in the presence of alkali. Attempts to isolate the complexes by the interaction of ethanolic solutions of the metal salts and the ligand in the absence of alkali did not succeed.

Influence of Proton Acceptors on the Proton-Coupled Electron Transfer Reaction Kinetics of a Ruthenium-Tyrosine Complex.

Science.gov (United States)

Lennox, J Christian; Dempsey, Jillian L

2017-11-22

A polypyridyl ruthenium complex with fluorinated bipyridine ligands and a covalently bound tyrosine moiety was synthesized, and its photo-induced proton-coupled electron transfer (PCET) reactivity in acetonitrile was investigated with transient absorption spectroscopy. Using flash-quench methodology with methyl viologen as an oxidative quencher, a Ru 3+ species is generated that is capable of initiating the intramolecular PCET oxidation of the tyrosine moiety. Using a series of substituted pyridine bases, the reaction kinetics were found to vary as a function of proton acceptor concentration and identity, with no significant H/D kinetic isotope effect. Through analysis of the kinetics traces and comparison to a control complex without the tyrosine moiety, PCET reactivity was found to proceed through an equilibrium electron transfer followed by proton transfer (ET-PT) pathway in which irreversible deprotonation of the tyrosine radical cation shifts the ET equilibrium, conferring a base dependence on the reaction. Comprehensive kinetics modeling allowed for deconvolution of complex kinetics and determination of rate constants for each elementary step. Across the five pyridine bases explored, spanning a range of 4.2 pK a units, a linear free-energy relationship was found for the proton transfer rate constant with a slope of 0.32. These findings highlight the influence that proton transfer driving force exerts on PCET reaction kinetics.

Spectroscopic evaluation of Co(II), Ni(II) and Cu(II) complexes derived from thiosemicarbazone and semicarbazone

Science.gov (United States)

Chandra, Sulekh; Kumar, Anil

2007-12-01

Co(II), Ni(II) and Cu(II) complexes were synthesized with thiosemicarbazone (L 1) and semicarbazone (L 2) derived from 2-acetyl furan. These complexes were characterized by elemental analysis, molar conductance, magnetic moment, mass, IR, electronic and EPR spectral studies. The molar conductance measurement of the complexes in DMSO corresponds to non-electrolytic nature. All the complexes are of high-spin type. On the basis of different spectral studies six coordinated geometry may be assigned for all the complexes except Co(L) 2(SO 4) and Cu(L) 2(SO 4) [where L = L 1 and L 2] which are of five coordinated square pyramidal geometry.

Structural characterization and antioxidant properties of Cu(II) and Ni(II) complexes derived from dicyandiamide

Science.gov (United States)

Kertmen, Seda Nur; Gonul, Ilyas; Kose, Muhammet

2018-01-01

New Cu(II) and Ni(II) complexes derived from dicyandiamide were synthesized and characterised by spectroscopic and analytical methods. Molecular structures of the complexes were determined by single crystal X-ray diffraction studies. In the complexes, the Cu(II) or Ni(II) ions are four-coordinate with a slight distorted square planar geometry. The ligands (L-nPen and L-iPen) derived from dicyandiamide formed via nucleophilic addition of alcohol solvent molecule in the presence Cu(II) or Ni(II) ions. Complexes were stabilised by intricate array of hydrogen bonding interactions. Antioxidant activity of the complexes was evaluated by DPPH radical scavenging and CUPRAC methods. The complexes exhibit antioxidant activity, however, their activities were much lower than standard antioxidants (Vitamin C and trolox).

Adsorption of aliphatic alcohols on ruthenium

International Nuclear Information System (INIS)

Shapovalova, L.B.; Zakumbaeva, G.D.

1977-01-01

The adsorption is studied of allyl-, propyl- and propargyl alcohols on a ruthenium catalyst-electrode at 20, 30 and 40 deg C in H 2 SO 4 in helium. Above adsorption has been found to grow with increased concentration of the alcohols in the solution. In solutions with the same concentration, propargyl alcohol has been noted to show highest sorptive capacity, followed by that of allyl- and propyl alcohols. With variations in the ruthenium electrode potential, alcohol adsorption occurs via maximum at potential = 0.18

Nitric oxide production by visible light irradiation of aqueous solution of nitrosyl ruthenium complexes.

Science.gov (United States)

Sauaia, Marília Gama; de Lima, Renata Galvão; Tedesco, Antonio Claudio; da Silva, Roberto Santana

2005-12-26

[Ru(II)L(NH(3))(4)(pz)Ru(II)(bpy)(2)(NO)](PF(6))(5) (L is NH(3), py, or 4-acpy) was prepared with good yields in a straightforward way by mixing an equimolar ratio of cis-[Ru(NO(2))(bpy)(2)(NO)](PF(6))(2), sodium azide (NaN(3)), and trans-[RuL(NH(3))(4)(pz)] (PF(6))(2) in acetone. These binuclear compounds display nu(NO) at ca. 1945 cm(-)(1), indicating that the nitrosyl group exhibits a sufficiently high degree of nitrosonium ion (NO(+)). The electronic spectrum of the [Ru(II)L(NH(3))(4)(pz)Ru(II)(bpy)(2)(NO)](5+) complex in aqueous solution displays the bands in the ultraviolet and visible regions typical of intraligand and metal-to-ligand charge transfers, respectively. Cyclic voltammograms of the binuclear complexes in acetonitrile give evidence of three one-electron redox processes consisting of one oxidation due to the Ru(2+/3+) redox couple and two reductions concerning the nitrosyl ligand. Flash photolysis of the [Ru(II)L(NH(3))(4)(pz)Ru(II)(bpy)(2)(NO)](5+) complex is capable of releasing nitric oxide (NO) upon irradiation at 355 and 532 nm. NO production was detected and quantified by an amperometric technique with a selective electrode (NOmeter). The irradiation at 532 nm leads to NO release as a consequence of a photoinduced electron transfer. All species exhibit similar photochemical behavior, a feature that makes their study extremely important for their future application in the upgrade of photodynamic therapy in living organisms.

Sol-gel-immobilized Tris(2,2'-bipyridyl)ruthenium(II) electrogenerated chemiluminescence sensor for high-performance liquid chromatography

International Nuclear Information System (INIS)

Choi, Han Nim; Cho, Sung-Hee; Park, Yu-Jin; Lee, Dai Woon; Lee, Won-Yong

2005-01-01

The sol-gel-immobilized Tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy) 3 2+ ] electrogenerated chemiluminescence (ECL) sensor was applied to the reversed-phase high-performance liquid chromatography (HPLC) determination of phenothiazine derivatives (promazine, chlorpromazine, triflupromazine, thioridazine, and trifluoperazine) and erythromycin in human urine samples. In this method, Ru(bpy) 3 2+ was immobilized in sol-gel-derived titania (TiO 2 )-Nafion nanocomposite films coated on a dual platinum electrode. This method eliminates an extra pump needed for the delivery of Ru(bpy) 3 2+ reagent into a reaction/observation zone in front of photomultiplier tube because the immobilized-Ru(bpy) 3 2+ is recycled on the electrode surface by an applied potential at +1.3 V versus Ag/AgCl (3 M NaCl) reference electrode. The resulting analytical performances such as detection limit, working range, sensitivity, and measurement precision were slightly worse than those obtained with the conventional post-column Ru(bpy) 3 2+ addition approach. The lack of significant interferences and the low detection limits for phenothiazine derivatives and erythromycin indicate that the proposed HPLC-Ru(bpy) 3 2+ ECL detection method is suitable for the determination of those compounds in biological fluids

Characterization of self-assembled monolayers on a ruthenium surface

NARCIS (Netherlands)

Shaheen, Amrozia; Sturm, Jacobus Marinus; Ricciardi, R.; Huskens, Jurriaan; Lee, Christopher James; Bijkerk, Frederik

2017-01-01

We have modified and stabilized the ruthenium surface by depositing a self-assembled monolayer (SAM) of 1-hexadecanethiol on a polycrystalline ruthenium thin film. The growth mechanism, dynamics, and stability of these monolayers were studied. SAMs, deposited under ambient conditions, on

Optimization of screen-printed ruthenium dioxide electrodes for pH measurements

International Nuclear Information System (INIS)

Wyzkiewicz, I.

2002-01-01

Optimization of disposable, screen-printed pH-sensors based on ruthenium dioxide is described in this paper. The electrodes were prepared with the use of thick-film technology. The pH-sensitive layers were deposited onto polyester foil. Polymer graphite paste containing ruthenium dioxide from 0% to 90% has been investigated. The dependence of the pH-sensitive layers related to ruthenium dioxide content is presented. The investigation proved that the electrodes containing 40-60% ruthenium dioxide exhibit linear high sensitivity (∼ 50 mV/pH) in the wide range of pH (2 - 11) as well as very good reproducibility. (author)

Nanoengineering of Ruthenium and Platinum-based Nanocatalysts by Continuous-Flow Chemistry for Renewable Energy Applications

KAUST Repository

AlYami, Noktan Mohammed

2017-04-15

This thesis presents an integrated study of nanocatalysts for heterogenous catalytic and electrochemical processes using pure ruthenium (Ru) with mixed-phase and platinum-based nanomaterials synthesized by continuous-flow chemistry. There are three major challenges to the application of nanomaterials in heterogenous catalytic reactions and electrocatalytic processes in acidic solution. These challenges are the following: (i) controlling the size, shape and crystallography of nanoparticles to give the best catalytic properties, (ii) scaling these nanoparticles up to a commercial quantity (kg per day) and (iii) making stable nanoparticles that can be used catalytically without degrading in acidic electrolytes. Some crucial limitations of these nanostructured materials in energy conversion and storage applications were overcome by continuous-flow chemistry. By using a continuous-flow reactor, the creation of scalable nanoparticle systems was achieved and their functionality was modified to control the nanoparticles’ physical and chemical characteristics. The nanoparticles were also tested for long-term stability, to make sure these nanoparticles were feasible under realistic working conditions. These nanoparticles are (1) shape- and crystallography-controlled ruthenium (Ru) nanoparticles, (2) size-controlled platinum-metal (Pt-M= nickel (Ni) & copper (Cu)) nanooctahedra (while maintaining morphology) and (3) core-shell platinum@ruthenium (Pt@Ru) nanoparticles where an ultrathin ruthenium shell was templated onto the platinum core. Thus, a complete experimental validation of the formation of a scalable amount of these nanoparticles and their catalytic activity and stability towards the oxygen evolution reaction (OER) in acid medium, hydrolysis of ammonia borane (AB) along with plausible explanations were provided.

Synthesis and properties of complexes of copper(II), nickel(II), cobalt(II) and uranyl ions with 3-(p-tolylsulphonamido)rhodamine

International Nuclear Information System (INIS)

El-Bindary, A.A.; El-Sonbati, A.Z.

2000-01-01

Metal complexes of copper(II), nickel(II), cobalt(II) and uranyl ions with 3-(p-tolylsulphonamido)rhodamine (HL) have been prepared and characterized by chemical and thermal analyses, molar conductivity , magnetic susceptibility measurements, and infrared, electronic and EPR spectra. The visible and EPR spectra indicated that the Cu(II) complex has a tetragonal geometry. From EPR spectrum of the Cu(II) complex,various parameters were calculated. The crystal field parameters of Ni(II) complex were calculated and were found to agree fairly well with the values reported for known square pyramidal complexes. The infrared spectral studies showed a monobasic bidentate behaviour with the oxygen and nitrogen donor system. Thermal stabilities of the complexes are also reported. (author)

An XPS study on ruthenium compounds and catalysts

International Nuclear Information System (INIS)

Bianchi, C.L.; Ragaini, V.; Cattania, M.G.

1991-01-01

The binding energy (BE) of the relevant peaks of several ruthenium compounds have been measured with a monochromatic small spot XPS. The BE of the 3d 5/2 level of ruthenium is in the range 279.91-282.88 eV. The variation of BE is due either to the variation of the oxidation state or to the different counter-ion. A series of catalysts with varying amounts of ruthenium supported on alumina and prepared using different precursors was also analyzed. The presence of more ruthenium species other than the metal was observed. On the basis of the values previously obtained on unsupported compounds, the species with higher BE were assigned to oxides. On all the samples prepared from RuCl 3 , an additional peak at a very high BE (283.79 eV) has been observed. This peak is related to the presence of chlorine on the surface: it is suggested that it is related to a charge transfer interaction. The influence of this species on the CO reactivity in the Fischer-Tropsch reaction is discussed. (orig.)

Oxidation of ruthenium thin films using atomic oxygen

Energy Technology Data Exchange (ETDEWEB)

McCoy, A.P.; Bogan, J.; Brady, A.; Hughes, G.

2015-12-31

In this study, the use of atomic oxygen to oxidise ruthenium thin films is assessed. Atomic layer deposited (ALD) ruthenium thin films (~ 3 nm) were exposed to varying amounts of atomic oxygen and the results were compared to the impact of exposures to molecular oxygen. X-ray photoelectron spectroscopy studies reveal substantial oxidation of metallic ruthenium films to RuO{sub 2} at exposures as low as ~ 10{sup 2} L at 575 K when atomic oxygen was used. Higher exposures of molecular oxygen resulted in no metal oxidation highlighting the benefits of using atomic oxygen to form RuO{sub 2}. Additionally, the partial oxidation of these ruthenium films occurred at temperatures as low as 293 K (room temperature) in an atomic oxygen environment. - Highlights: • X-ray photoelectron spectroscopy study of the oxidation of Ru thin films • Oxidation of Ru thin films using atomic oxygen • Comparison between atomic oxygen and molecular oxygen treatments on Ru thin films • Fully oxidised RuO{sub 2} thin films formed with low exposures to atomic oxygen.

Reactions of ruthenium and osmium cluster carbonyls with heteroatom-substituted and functionalized alkynes

International Nuclear Information System (INIS)

Koridze, A.A.

2000-01-01

The results of studies of the reactions of ruthenium and osmium cluster carbonyls with metal (M = Re, Mn, Fe) alkynes, silylalkynes, propargyl alcohols and their derivatives, diynes, enynes, and ferrocenylacetylene are summarized. Intramolecular rearrangements in the cluster complexes including migrations of carbonyl, hydride, and hydrocarbon ligands and the metal core reorganization are considered [ru

Electrogenerated chemiluminescence: An oxidative-reductive mechanism between quinolone antibiotics and tris(2,2'-bipyridyl)ruthenium(II)

International Nuclear Information System (INIS)

Burkhead, Matthew S.; Wang, Heeyoung; Fallet, Marcel; Gross, Erin M.

2008-01-01

The cyclic voltammetry and electrogenerated chemiluminescent (ECL) reactions of a series of quinolone and fluoroquinolone antibiotics were investigated in a flow injection analysis (FIA) system. 7-Piperazinyl fluoroquinolone antibiotics were found to participate as a coreactant in an oxidative-reductive ECL mechanism with tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy) 3 2+ ) as the luminescent reagent. The reaction mechanism was investigated in order to understand and optimize the processes leading to light emission. The optimal conditions included a solution pH ∼7 at a flow rate of 3.0 mL min -1 with no added organic modifier and application of 1.2 V vs. a Pt quasi-reference electrode (QRE). Fluoroquinolones containing a tertiary distal nitrogen on the piperazine ring, such as enrofloxacin and ofloxacin, reacted to produce more intense ECL than those with a secondary nitrogen, such as ciprofloxacin and norfloxacin. The method linear range, precision, detection limits, and sensitivity for the detection of enrofloxacin and ciprofloxacin were compared to that of tripropylamine. The method was applied to the determination of the ciprofloxacin content in a pharmaceutical preparation. The assay is discussed in terms of its analytical figures of merit, ease of use, speed, accuracy and application to pharmaceutical samples

Thermodynamic properties of gaseous ruthenium species.

Science.gov (United States)

Miradji, Faoulat; Souvi, Sidi; Cantrel, Laurent; Louis, Florent; Vallet, Valérie

2015-05-21

The review of thermodynamic data of ruthenium oxides reveals large uncertainties in some of the standard enthalpies of formation, motivating the use of high-level relativistic correlated quantum chemical methods to reduce the level of discrepancies. The reaction energies leading to the formation of ruthenium oxides RuO, RuO2, RuO3, and RuO4 have been calculated for a series of reactions. The combination of different quantum chemical methods has been investigated [DFT, CASSCF, MRCI, CASPT2, CCSD(T)] in order to predict the geometrical parameters, the energetics including electronic correlation and spin-orbit coupling. The most suitable method for ruthenium compounds is the use of TPSSh-5%HF for geometry optimization, followed by CCSD(T) with complete basis set (CBS) extrapolations for the calculation of the total electronic energies. SO-CASSCF seems to be accurate enough to estimate spin-orbit coupling contributions to the ground-state electronic energies. This methodology yields very accurate standard enthalpies of formations of all species, which are either in excellent agreement with the most reliable experimental data or provide an improved estimate for the others. These new data will be implemented in the thermodynamical databases that are used by the ASTEC code (accident source term evaluation code) to build models of ruthenium chemistry behavior in severe nuclear accident conditions. The paper also discusses the nature of the chemical bonds both from molecular orbital and topological view points.

Synthesis of PVP-stabilized ruthenium colloids with low boiling point alcohols.

Science.gov (United States)

Zhang, Yuqing; Yu, Jiulong; Niu, Haijun; Liu, Hanfan

2007-09-15

A route to the preparation of poly(N-vinyl-2-pyrrolidone) (PVP)-stabilized ruthenium colloids by refluxing ruthenium(III) chloride in low boiling point alcohols was developed. Deep purple colloids with shuttle-like ruthenium particles were also synthesized. XPS measurement verified the nanoparticles were in the metallic state. The morphology of metal nanoparticles was characterized by UV-visible absorption spectrophotometry, TEM and XRD.

Activity of iridium-ruthenium and iridium-rhodium adsorption catalysts in decomposition of hydrogen peroxide

Energy Technology Data Exchange (ETDEWEB)

Zubovich, I A; Mikhaylov, V A; Migulina, N N [Yaroslavskij Politekhnicheskij Inst. (USSR)

1976-06-01

Experimental data for the activities of iridium-ruthenium and iridium-rhodium adsorption catalysts in the decomposition of hydrogen peroxide are considered and the results of magnetic susceptibility measurements are presented. It is concluded that surface structures (complexes) may be formed and that micro-electronic feaures play a role in heterogeneous catalysis.

Method of removing clogging materials due to ruthenium precipitates and sealing them in device

International Nuclear Information System (INIS)

Hoshikawa, Tadahiro; Sasahira, Akira.

1994-01-01

In a facility, such as a reprocessing facility, for processing a solution containing a great amount of ruthenium, precipitates due to evaporated ruthenium and cooled NO x are brought into contact with each other to decompose the precipitates due to the evaporated ruthenium. Precipitates due to ruthenium evaporated from the solution are reacted with cooled NO x , and the precipitates of ruthenium are decomposed and returned to the solution in the form of extremely fine particles together with recycling flow from the inner wall of the device. Since the precipitates of ruthenium returned to the solution are stable, they are no more evaporated and precipitated on the inner wall of the device. In the solution processing device having a possibility of clogging, clogging can be prevented and the precipitates of ruthenium can be sealed by decomposing them. (T.M.)

A thermodynamic/mass-transport model for the release of ruthenium from irradiated fuel

International Nuclear Information System (INIS)

Garisto, F.; Iglesias, F.C.; Hunt, C.E.L.

1990-01-01

Some postulated nuclear reactor accidents lead to fuel failures and hence release of fission products into the primary heat transport system (PHTS). To determine the consequences of such accidents, it is important to understand the behavior of fission products both in the PHTS and in the reactor containment building. Ruthenium metal has a high boiling point and is nonvolatile under reducing conditions. However, under oxidizing conditions ruthenium can form volatile oxides at relatively low temperatures and, hence, could escape from failed fuel and enter the containment building. The ruthenium radioisotope Ru-106 presents a potentially significant health risk if it is released outside the reactor containment building. Consequently, it is important to understand the behavior of ruthenium during a nuclear reactor accident. The authors review the thermodynamic behavior of ruthenium at high temperatures. The qualitative behavior of ruthenium, predicted using thermodynamic calculations, is then compared with experimental results from the Chalk River Nuclear Laboratories (CRNL). Finally, a simple thermodynamic/mass-transport model is proposed to explain the release behavior of ruthenium in a steam atmosphere

Preparation of Schiff s base complexes of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) and their spectroscopic, magnetic, thermal, and antifungal studies

International Nuclear Information System (INIS)

Parekh, H.M.; Patel, M.N.

2006-01-01

The potassium salt of salicylidene-DL-alanine (KHL), bis(benzylidene)ethylenediamine (A 1 ), thiophene-o-carboxaldene-p-toluidine (A 2 ), and its metal complexes of the formula [(M II (L)(A)(H 2 O)] (M=Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II); A = A 1 or A 2 ) are prepared. They are characterized by elemental analysis, magnetic susceptibility measurements, thermogravimetric analysis, and infrared and electronic spectral studies. The electronic spectral and magnetic moment data suggest an octahedral geometry for the complexes. All of these complexes, metal nitrates, fungicides (bavistin and emcarb), and ligands are screened for their antifungal activity against Aspergillus niger, Fusarium oxysporum, and Aspergillus flavus using a plate poison technique. The complexes show higher activity than those of the free ligands, metal nitrate, and the control (DMSO) and moderate activity against bavistin and emcarb [ru

Ruthenium based redox flow battery for solar energy storage

International Nuclear Information System (INIS)

Chakrabarti, Mohammed Harun; Roberts, Edward Pelham Lindfield; Bae, Chulheung; Saleem, Muhammad

2011-01-01

Research highlights: → Undivided redox flow battery employing porous graphite felt electrodes was used. → Ruthenium acetylacetonate dissolved in acetonitrile was the electrolyte. → Charge/discharge conditions were determined for both 0.02 M and 0.1 M electrolytes. → Optimum power output of 0.180 W was also determined for 0.1 M electrolyte. → 55% voltage efficiency was obtained when battery was full of electrolytes. -- Abstract: The technical performance for the operation of a stand alone redox flow battery system for solar energy storage is presented. An undivided reactor configuration has been employed along with porous graphite felt electrodes and ruthenium acetylacetonate as electrolyte in acetonitrile solvent. Limiting current densities are determined for concentrations of 0.02 M and 0.1 M ruthenium acetylacetonate. Based on these, operating conditions for 0.02 M ruthenium acetylacetonate are determined as charging current density of 7 mA/cm 2 , charge electrolyte superficial velocity of 0.0072 cm/s (through the porous electrodes), discharge current density of 2 mA/cm 2 and discharge electrolyte superficial velocity of 0.0045 cm/s. An optimum power output of 35 mW is also obtained upon discharge at 2.1 mA/cm 2 . With an increase in the concentration of ruthenium species from 0.02 M to 0.1 M, the current densities and power output are higher by a factor of five approximately (at same superficial velocities) due to higher mass transport phenomenon. Moreover at 0.02 M concentration the voltage efficiency is better for battery full of electrolytes prior to charging (52.1%) in comparison to an empty battery (40.5%) due to better mass transport phenomenon. Voltage efficiencies are higher as expected at concentrations of 0.1 M ruthenium acetylacetonate (55% when battery is full of electrolytes and 48% when empty) showing that the all-ruthenium redox flow battery has some promise for future applications in solar energy storage. Some improvements for the

Synthesis, spectral, thermal and antimicrobial studies on cobalt(II), nickel(II), copper(II), zinc(II) and palladium(II) complexes containing thiosemicarbazone ligand

Science.gov (United States)

El-Sawaf, Ayman K.; El-Essawy, Farag; Nassar, Amal A.; El-Samanody, El-Sayed A.

2018-04-01

The coordination characteristic of new N4-morpholinyl isatin-3-thiosemicarbazone (HL) towards Co(II), Ni(II), Cu(II), Zn(II) and Pd(II) has been studies. The structures of the complexes were described by elemental analyses, molar conductivity, magnetic, thermal and spectral (IR, UV-Vis, 1H and 13C NMR and ESR) studies. On the basis of analytical and spectral studies the ligand behaves as monobasic tridentate ONS donor forming two five membered rings towards cobalt, copper and palladium and afforded complexes of the kind [M(L)X], (Mdbnd Co, Cu or Pd; Xdbnd Cl, Br or OAc). Whereas the ligand bound to NiCl2 as neutral tridentate ONS donor and with ZnCl2 as neutral bidentate NS donor. The newly synthesized thiosemicarbazone ligand and some of its complexes were examined for antimicrobial activity against 2 gram negative bacterial strains (Escherichia coli Pseudomonas and aeruginosa), 2 gram positive bacterial strains (Streptococcus pneumoniae and Staphylococcus aureus)} and two Pathogenic fungi (Aspergillus fumigatus and Candida albicans). All metal complexes possess higher antimicrobial activity comparing with the free thiosemicarbazone ligand. The high potent activities of the complexes may arise from the coordination and chelation, which tends to make metal complexes act as more controlling and potent antimicrobial agents, thus hindering the growing of the microorganisms. The antimicrobial results also show that copper bromide complex is better antimicrobial agent as compared to the Schiff base and its metal complexes.

Solventless synthesis of ruthenium nanoparticles

Energy Technology Data Exchange (ETDEWEB)

García-Peña, Nidia G. [Departmento de Tecnociencias, Universidad Nacional Autónoma de México, Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Cd. Universitaria A.P. 70-186, C.P. 04510 Coyoacán, México D.F. (Mexico); Redón, Rocío, E-mail: rredon@unam.mx [Departmento de Tecnociencias, Universidad Nacional Autónoma de México, Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Cd. Universitaria A.P. 70-186, C.P. 04510 Coyoacán, México D.F. (Mexico); Herrera-Gomez, Alberto [Estudios Avanzados del Instituto Politécnico Nacional, Campus Juriquilla, Querétaro (Mexico); Fernández-Osorio, Ana Leticia [FES-Cuautitlán, Universidad Nacional Autónoma de México, Edo. de Mexico (Mexico); Bravo-Sanchez, Mariela; Gomez-Sosa, Gustavo [Estudios Avanzados del Instituto Politécnico Nacional, Campus Juriquilla, Querétaro (Mexico)

2015-06-15

Graphical abstract: - Highlights: • Successful synthesis of Ru nanoparticles by a cheap, fast and solventless approach was achieved. • The zero-valent state as well as the by-product/impurity free of the mechanochemical obtained Ru nanoparticles was proven by XPS, TEM and XRD. • Compared to two other synthesis strategies, the above-mentioned synthesis was more suitable to obtain smaller particles with fewer impurities in shorter time. - Abstract: This paper presents a novel solventless method for the synthesis of zero-valent ruthenium nanoparticles Ru(0). The proposed method, although not entirely new in the nanomaterials world, was used for the first time to synthesize zero-valent ruthenium nanoparticles. This new approach has proved to be an environmentally friendly, clean, cheap, fast, and reproducible technique which employs low amounts of solvent. It was optimized through varying amounts of reducing salt on a determined quantity of precursor and measuring the effect of this variation on the average particle size obtained. The resulting products were fully characterized by powder XRD, TEM, HR-TEM, and XPS studies, all of which corroborated the purity of the nanoparticles achieved. In order to verify the advantages of our method over other techniques, we compared our nanoparticles with two common colloidal-synthesized ruthenium nanoparticles.

Antibacterial Co(II, Ni(II, Cu(II and Zn(II complexes with biacetyl-derived Schiff bases

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MUHAMMAD IMRAN

2010-08-01

Full Text Available The condensation reactions of biacetyl with ortho-hydroxyaniline and 2-aminobenzoic acid to form bidendate NO donor Schiff bases were studied. The prepared Schiff base ligands were further utilized for the formation of metal chelates having the general formula [ML2(H2O2] where M = Co(II, Ni(II, Cu(II and Zn(II and L = HL1 and HL2. These new compounds were characterized by conductance measurements, magnetic susceptibility measurements, elemental analysis, and IR, 1H-NMR, 13C-NMR and electronic spectroscopy. Both Schiff base ligands were found to have a mono-anionic bidentate nature and octahedral geometry was assigned to all metal complexes. All the complexes contained coordinated water which was lost at 141–160 °C. These compounds were also screened for their in vitro antibacterial activity against four bacterial species, namely: Escherichia coli, Staphylococcus aureus, Salmonella typhi and Bacillus subtilis. The metal complexes were found to have greater antibacterial activity than the uncomplexed Schiff base ligands.

Studying the effect of Ruthenium on High Temperature Mechanical Properties of Nickel Based Superalloys and Determining the Universal Behavior of Ruthenium at Atomic Scale with respect to alloying elements, Stress and Temperature

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Sriswaroop Dasari

2016-10-01

Full Text Available Any property of a material is a function of its microstructure and microstructure is a function of material composition. So, to maximize the desired properties of a material, one has to understand the evolution of microstructure which in turn is nothing but the reflection of the role of alloying elements. Research has not been done to understand the universal behavior of a certain base/alloying element. Let’s take the example of Cl- ion in HCl, we all know that in general, chloride ion can only be replaced by Fluoride or oxygen ion and that no other ion can replace it. But when you consider a metal like Ni, Co, Cr, Fe etc. there is no establishment that it behaves only in a certain way. Though I concord to the fact that discovery of universal behavior of Ni is lot complex than chloride ion, I think that future research should be focused in this direction also. Superalloys are the candidate materials required to improve thermal efficiency of a gas turbine by allowing higher turbine inlet gas temperatures. Gas turbines are the heart of local power systems, next generation jet engines and high performance space rockets. Recent research in superalloys showed that addition of some alloying elements in minor quantities can result in drastic change in properties. Such an alloying element is Ruthenium (Ru. Addition of Ruthenium to superalloys has shown improvement in mechanical properties by an order of magnitude. However reasons for such improvement are not known yet. Hence, there is a need to identify its role and discover the universal behavior of ruthenium to utilize it efficiently. In this proposal, we study materials with different compositions that are derived based on one ruthenium containing superalloy, and different thermomechanical history. Based on the evolution of microstructures and results of mechanical testing, we plan to determine the exact role of Ruthenium and prediction of its behavior with respect to other elements in the material

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.

Arene ruthenium(II) azido complexes incorporating N intersection O chelate ligands: Synthesis, spectral studies and 1,3-dipolar-cycloaddition to a coordinated azide in ruthenium(II) compounds

Digital Repository Service at National Institute of Oceanography (India)

Singh, K.S.; Kaminsky, W.

showed a slightly different spectra pattern for p- cymene ligand as compared to the rest of the complexes. For instant, the complex 1 exhibits two doublets for diastereotopic methyl protons of the isopropyl group at around δ 1.12-0.99 (Fig. 1). Likewise... formed are exclusively N(2) bound isomer which is supported by their NMR spectral data. For instant, the proton NMR spectrum of 8 displayed a, singlet at δ 3.75 assignable to the protons of a methoxy carbonyl group while for complex 9 a quartet...

Complexes of Cu(II), Ni(II), Co(II), oxovanadium(IV) and dioxouranium(VI) with N,N'-ethylenebis (2-hydroxy-4-methylpropiophenoneimine)

International Nuclear Information System (INIS)

Patel, M.M.; Patel, M.R.; Patel, M.N.; Patel, R.P.

1982-01-01

Complexes of Cu(II), Ni(II), Co(II), oxovanadium(IV) and dioxouranium(VI) with the schiff base, N,N'-ethylenebis(2-hydroxy-4-methylpropiophenoneimine)(4-MeOHPEN), have been synthesised and characterised on the basis of elemental analyses, conductivity, magnetic moment, electronic and infrared spectral data. Square-planar structures are suggested for Cu(II), Ni(II) and Co(II) complexes while a distorted square-pyramidal structure is suggested for the oxovanadium(IV) complex. (author)

Study of the formation of complexes of nitrosyl-rhutenium nitrates with thiourea

International Nuclear Information System (INIS)

Floh, B.

1977-01-01

A method for the treatment of spent uranium fuel is presented, based on the Purex process using thiourea to increase the ruthenium decontamination factor. Thiourea exhibits a strong tendency for the formation of coordination compounds in acidic media. This tendency serves as a basis to transform nitrosyl-ruthenium species into Ru/SC(NH)(NH 2 )/ 2+ and Ru/SC(NH)(NH 2 )/ 3 complexes which are unextractable by TBP-varsol. The best conditions for the ruthenium-thiourea complex formation were found to be: thiourea-ruthenium ratio (mass/mass) close to 42, at 75 0 C, 30 minutes reaction time and aging period of 60 minutes. The ruthenium decontamination factor for a single uranium extraction are ca. 80-100, not interfering with extraction of actinides. These values are rather high in comparison to those obtained using the conventional Purex process (e.g. F.D. sub(Ru)=10). For this reason, the method developed here is suitable for the treatment of spent uranium fuels. Thiourea (100 g/l) scrubbing experiments of ruthenium, partially co-extracted with actinides, confirmed the possibility of its removal from the extract. With this procedure a decontamination greater than 83,5% for ruthenium as fission product is obtained in two stages [pt

Metalloantibiotic Mn(II)-bacitracin complex mimicking manganese superoxide dismutase

International Nuclear Information System (INIS)

Piacham, Theeraphon; Isarankura-Na-Ayudhya, Chartchalerm; Nantasenamat, Chanin; Yainoy, Sakda; Ye Lei; Buelow, Leif; Prachayasittikul, Virapong

2006-01-01

Superoxide dismutase (SOD) activities of various metallobacitracin complexes were evaluated using the riboflavin-methionine-nitro blue tetrazolium assay. The radical scavenging activity of various metallobacitracin complexes was shown to be higher than those of the negative controls, e.g., free transition metal ions and metal-free bacitracin. The SOD activity of the complex was found to be in the order of Mn(II) > Cu(II) > Co(II) > Ni(II). Furthermore, the effect of bacitracin and their complexation to metals on various microorganisms was assessed by antibiotic susceptibility testing. Moreover, molecular modeling and quantum chemical calculation of the metallobacitracin complex was performed to evaluate the correlation of electrostatic charge of transition metal ions on the SOD activity

Electrogenerated chemiluminescence: An oxidative-reductive mechanism between quinolone antibiotics and tris(2,2'-bipyridyl)ruthenium(II)

Energy Technology Data Exchange (ETDEWEB)

Burkhead, Matthew S.; Wang, Heeyoung; Fallet, Marcel [Department of Chemistry, Creighton University, Omaha, NE 68178 (United States); Gross, Erin M. [Department of Chemistry, Creighton University, Omaha, NE 68178 (United States)], E-mail: eringross@creighton.edu

2008-04-21

The cyclic voltammetry and electrogenerated chemiluminescent (ECL) reactions of a series of quinolone and fluoroquinolone antibiotics were investigated in a flow injection analysis (FIA) system. 7-Piperazinyl fluoroquinolone antibiotics were found to participate as a coreactant in an oxidative-reductive ECL mechanism with tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy){sub 3}{sup 2+}) as the luminescent reagent. The reaction mechanism was investigated in order to understand and optimize the processes leading to light emission. The optimal conditions included a solution pH {approx}7 at a flow rate of 3.0 mL min{sup -1} with no added organic modifier and application of 1.2 V vs. a Pt quasi-reference electrode (QRE). Fluoroquinolones containing a tertiary distal nitrogen on the piperazine ring, such as enrofloxacin and ofloxacin, reacted to produce more intense ECL than those with a secondary nitrogen, such as ciprofloxacin and norfloxacin. The method linear range, precision, detection limits, and sensitivity for the detection of enrofloxacin and ciprofloxacin were compared to that of tripropylamine. The method was applied to the determination of the ciprofloxacin content in a pharmaceutical preparation. The assay is discussed in terms of its analytical figures of merit, ease of use, speed, accuracy and application to pharmaceutical samples.

DNA binding and biological activity of mixed ligand complexes of Cu(II, Ni(II and Co(II with quinolones and N donor ligand

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S.M M Akram

2015-10-01

Full Text Available  AbstractMixed ligand complexes of  Cu(II, Ni(II and Co(II have been synthesized by using levofloxacin and bipyridyl and characterized using spectral and analytical techniques. The binding behavior of the Ni(II and Cu(II complexes with herring sperm DNA(Hs-DNA were determined using electronic absorption titration, viscometric measurements and cyclic voltammetry measurements. The binding constant calculated  for Cu(II and Ni(II complexes are 2.0 x 104 and 4.0 x 104 M-1 respectively. Detailed analysis reveals that these metal complexes interact with DNA through intercalative binding mode. The nuclease activity of  Cu(II and Ni(II complexes with ct-DNA was carried out using agarose gel electrophoresis technique. The antioxidant activities for the synthesized complexes have been tested and the antibacterial activity for Ni(II complex was also checked.Key words: Intercalation, hypochromism, red shift and  peak potential.

New Mn(II, Ni(II, Cd(II, Pb(II complexes with 2-methylbenzimidazole and other ligands. Synthesis, spectroscopic characterization, crystal structure, magnetic susceptibility and biological activity studies

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Shayma A. Shaker

2016-11-01

Full Text Available Synthesis and characterization of Mn(II, Ni(II, Cd(II and Pb(II mixed ligand complexes of 2-methylbenzimidazole with other ligands have been reported. The structure of the ligands and their complexes was investigated using elemental analysis, IR, UV–Vis, (1H, 13C NMR spectroscopy, molar conductivity and magnetic susceptibility measurements. In all the studies of complexes, the 2-methylbenzimidazole behaves as a neutral monodentate ligand which is coordinated with the metal ions through the N atom. While benzotriazole behaves as a neutral bidentate ligand which is coordinated with the Ni(II ion through the two N atoms. Moreover, the N-acetylglycine behaves as a bidentate ligand which is coordinated with the Mn(II, Ni(II and Pb(II ions through the N atom and the terminal carboxyl oxygen atom. The magnetic and spectral data indicate the tetrahedral geometry for Mn(II complex, irregular tetrahedral geometry for Pb(II complex and octahedral geometry for Ni(II complex. The X-ray single crystal diffraction method was used to confirm a centrosymmetric dinuclear Cd(II complex as each two metal ions are linked by a pair of thiocyanate N = S bridge. Two 2-methylbenzimidazole N-atom donors and one terminal thiocyanate N atom complete a highly distorted square pyramid geometry around the Cd atom. Besides, different cell types were used to determine the inhibitory effect of Mn(II, Ni(II, Cd(II and Pb(II complexes on cell growth using MTT assay. Cd(II complex showed cytotoxic effect on various types of cancer cell lines with different EC50 values.

A High Molar Extinction Coefficient Ru(II Complex Functionalized with cis-Dithiocyanato-bis-(9-anthracenyl-10-(2-methyl-2-butenoic acid-1,10-phenanthroline: Potential Sensitizer for Stable Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Adewale O. Adeloye

2014-01-01

Full Text Available New heteroleptic ruthenium(II complex was formulated as [Ru(L12(NCS2], where L1 = 9-anthracenyl-10-(2-methyl-2-butenoic acid-1,10-phenanthroline was synthesized and its photophysical properties were studied and compared to previously reported analogue complex containing no anthracene moiety [Ru(L22(NCS2], L2 = (2-methyl-2-butenoic acid-1,10-phenanthroline. The two complexes though exhibit very strong molar extinction coefficient values; however, [Ru(L12(NCS2] shows better characteristic broad and intense metal-to-ligand charge transfer (MLCT absorption band and higher molar absorptivity coefficient at (λmax=522 nm, ε=6.60×104 M−1 cm−1 than that of [Ru(L22(NCS2] complex, (λmax=446 nm, ε=4.82×104 M−1 cm−1. At room temperature, long wavelength emissions with strong intensity ratio centered at 660 nm were recorded for [Ru(L12(NCS2] complex with a bathochromic shift (λem=700 nm for [Ru(L22(NCS2] complex. It was shown that the luminescence wavelength characteristic of the complexes may be a function relating to the increasing length of π-conjugation and/or molecular weight. A preliminary cyclic voltammetry of [Ru(L12(NCS2] complex also exhibits good electroredox activity with oxidation potential of about 1.04 V, significantly better than other Ru(II polypyridine complexes containing bidentate ligands.

Photodynamic effect of light-harvesting, long-lived triplet excited state Ruthenium(II)-polyimine-coumarin complexes: DNA binding, photocleavage and anticancer studies.

Science.gov (United States)

Nomula, Raju; Wu, Xueyan; Zhao, Jianzhang; Munirathnam, Nagegownivari R

2017-10-01

Two coumarin based Ru II -polyimine complexes (Ru-1 and Ru-2) showing intense absorption of visible light and long-lived triplet excited states (~12-15μs) were used for study of the interaction with DNA. The binding of the complexes with CT-DNA were studied by UV-vis, fluorescence and time-resolved nanosecond transient absorption (ns-TA) spectroscopy. The results suggesting that the complexes interact with CT-DNA by intercalation mode of binding, showing the binding constants (K b ) 6.47×10 4 for Ru-1 and 5.94×10 4 M -1 for Ru-2, in contrast no such results were found for Ru-0. The nanosecond transient absorption spectra of these systems in the presence of CT-DNA showing a clear perturbation in the bleaching region was observed compare to buffer alone. Visible light photoirradiation DNA cleavage was investigated for these complexes by treating with the supercoiled pUC19 DNA and irradiated at 450nm. The reactive species produced upon irradiation of current agents is singlet oxygen ( 1 O 2 ), which results in the generation of other reactive oxygen species (ROS). The complexes shown efficient cleavage activity, converted complete supercoiled DNA to nicked circular at as low as 20μM concentration in 30min of light irradiation time. Significant amount of linear form was generated by Ru-1 at the same conditions. Even though Ru-0 has significant 1 O 2 quantum yield but shown lower cleavage activity compared to other two analogs is due the miserable interaction (binding) with DNA. The cytotoxicity in vitro of the complexes toward HeLa, BEL-7402 and MG-63 cells was assessed by MTT assay. The cellular uptake was observed on BEL-7402 cells under fluorescence microscope. The complexes shown appreciable cytotoxicity towards the cancer cell lines. Copyright © 2017 Elsevier B.V. All rights reserved.

Interpretation of electronic spectra of ruthenium nitroso complexes with N-heterocyclic ligands

International Nuclear Information System (INIS)

Sizova, O.V.; Ivanova, N.V.; Lyubimova, O.O.; Nikol'skij, A.B.

2004-01-01

Relaying on ab initio and semiempirical CINDO/CI calculations of free ligands L and complexes trans-[Ru(NO)(NH 3 ) 4 (L)] 3+ (L=pyridine, pyrazine, nicotinamide, l-histidine, imidazole), electronic absorption spectra of nitroso complexes with nitrogen-containing heterocyclic ligands L have been analyzed. Spectral manifestations of strong covalent bond Ru-NO was pointed out and the conclusion was made about advisability of presentation of Ru and NO oxidation states in grouping RuNO 3+ as Ru(III) and NO 0 . Introduction of nitroso group into inner coordination sphere of Ru(II) complexes with nitrogen-containing heterocyclic ligands results in essential rearrangement of the entire structure and deprives ligands L of their ability to manifest chromophore properties [ru

Crystal structure and physical properties of a ruthenium(II) bipyridine dimethylsulfoxide complex

International Nuclear Information System (INIS)

Wang, Y.; Eichhorn, D.M.; Goswami, N.; Zhao, Q.; Rillema, D.P.

1999-01-01

The complex [Ru(bpy) 2 (DMSO)C1]PF 6 , where bpy is 2,2prime-bipyridine and DMSO is dimethyl-sulfoxide, crystallizes in the triclinic space group Pbar 1 (number s ign2) with a = 8.873 (2), b = 12.805 (4), c = 12.864 (4) angstrom, α = 97.76(3), β = 106.45(2), γ = 107.88(2); Z = 2, and d calc = 1.75 mg/m 3 . The coordination geometry is that of a distorted octahedron with a cis-RuN 4 SCl arrangement of coordinating atoms. The four Ru-N distances to the bpy ligands are 2.082(5), 2.092(4), 2.044(4), and 2.078(5) angstrom. The Ru-Cl distance is 2.421(2) angstrom and the Ru-S distance to DMSO is 2.260(1) angstrom. The Ru-N bond distance trans to Cl is the shortest; the Ru-N bond distance trans to S is the longest. The complex is oxidized and reduced reversibly at 1.13 and minus1.37 V vs. SSCE, respectively. It displays electronic absorptions at 515, 480 (1.5 x 10 4 ), 342 (1.5 X 10 4 ), 292 (1.2 X 10 5 ), and 240 nm (6.2 x 10 4 ) and has a broad emission band centered at 607 nm at 77 K in a 4:1 ethanol/methanol glass. The emission lifetime at room temperature is less than the pulse width of the laser, τ < 20 ns

Ruthenium determination in new composite materials by coulometric titration with generated iron(2)

International Nuclear Information System (INIS)

Butakova, N.A.; Oganesyan, L.B.

1983-01-01

A coulometric technique is developed for ruthenium (4) titration with generated iron (2) in a mixture of hydrochloric-, sulfuric- and phosphoric acids with potentiometric and biammetric indication of the final titration point. Bi (3), Pd (2), Nb (5), Pt (4) Pb (2), Rh (3) do not interfere with the titration. Together with Ru (4) titrated are Ir (4), V (5), Au (3). The method is applied to analyze commercial samples of ruthenium dioxides, lead- and bismuth ruthenites, ruthenium pentafluorides containing 30-80% of ruthenium. The Ssub(r) values do not exceed 0.002

New complexes of Co(II, Ni(II, Cu(II with Schiff base N,N’-bis-(3-methoxy-saliciliden-3,3’-dimethylbenzidine

Directory of Open Access Journals (Sweden)

Alan Ionela

2013-01-01

Full Text Available The new N,N’-bis-(3-methoxy-saliciliden-3,3’-dimetilbenzidine (H2L Schiff base and complexes with Co(II, Ni(II and Cu(II of type [M(HLCl(H2O] (M=Co(II, Cu(II [M2L(H2O4]X2 (M=Co(II, X=ClO4 and M=Cu(II, X=NO3 and [M2L(CH3COO2] (M=Co(II, Ni(II, Cu(II were synthesised. The ligand and complexes were characterized by elemental analysis, conductibility measurements, magnetic moments at room temperature, IR, NMR, UV-VIS-NIR, EPR spectra and thermogravimetric analysis. A molar ratio of 1:1 or 1:2 between ligand and metal was determined from the elemental analysis. Except for perchlorate complex that behave as electrolyte, the rest of complexes are non-electrolytes. The spectral data suggest a tetrahedral, pseudo-tetrahedral or square-planar stereochemistry respectively, data confirmed by magnetic behaviour of complexes. The antimicrobial tests indicate a fungicide effect both for ligand and complexes.

Synthesis, characterization and biological studies of metal complexes of Co (II), Ni (II), Cu (II), Zn (II) with sulphadimidine-benzylidene

International Nuclear Information System (INIS)

Tahira, F.; Imran, M.; Iqbal, J.

2009-01-01

Some novel complexes of Co (II), Ni (II), Cu (II), and Zn (II) have been synthesized with a Schiff base ligand derived from sulphadimidine and benzaldehyde. The structural features of the complexes have been determined by elemental analysis, magnetic susceptibility, conductance measurement, UV/ Vis. and infrared spectroscopy. IR studies revealed that the Schiff base ligand Sulphadimidine-benzylidene has monoanionic bidendate nature and coordinate with metal ions through nitrogen atom of azomethine (>C = N) and deprotonated -NH group. All the complexes were assigned octahedral geometry on the basis of magnetic moment and electronic spectroscopic data. Low value of conductance supports their non-electrolytic nature. The ligand, as well as its complexes were checked for their in vitro antimicrobial activities against two gram positive bacterial strains, Bacillus subtillus. Staphylococcus aureus and one gram negative Salmonella typhae and five fungal strains, Nigrospora oryzae, Curvularia lunata, Drechslera rostrata, Aspergillus niger and Candida olbicans by disc diffusion method and agar plate technique, respectively. Both the antibacterial and antitungal activities of the synthesized metal complexes were found to be more as compared to parent drug and uncomplexed ligand. All the complexes contain coordinated water, which is lost at 141-160 degree C. (author)

Towards a rational design of ruthenium CO2 hydrogenation catalysts by Ab initio metadynamics.

Science.gov (United States)

Urakawa, Atsushi; Iannuzzi, Marcella; Hutter, Jürg; Baiker, Alfons

2007-01-01

Complete reaction pathways relevant to CO2 hydrogenation by using a homogeneous ruthenium dihydride catalyst ([Ru(dmpe)2H2], dmpe=Me2PCH2CH2PMe2) have been investigated by ab initio metadynamics. This approach has allowed reaction intermediates to be identified and free-energy profiles to be calculated, which provide new insights into the experimentally observed reaction pathway. Our simulations indicate that CO2 insertion, which leads to the formation of formate complexes, proceeds by a concerted insertion mechanism. It is a rapid and direct process with a relatively low activation barrier, which is in agreement with experimental observations. Subsequent H2 insertion into the formate--Ru complex, which leads to the formation of formic acid, instead occurs via an intermediate [Ru(eta2-H2)] complex in which the molecular hydrogen coordinates to the ruthenium center and interacts weakly with the formate group. This step has been identified as the rate-limiting step. The reaction completes by hydrogen transfer from the [Ru(eta2-H2)] complex to the formate oxygen atom, which forms a dihydrogen-bonded Ru--HHO(CHO) complex. The activation energy for the H2 insertion step is lower for the trans isomer than for the cis isomer. A simple measure of the catalytic activity was proposed based on the structure of the transition state of the identified rate-limiting step. From this measure, the relationship between catalysts with different ligands and their experimental catalytic activities can be explained.

Flow injection chemiluminescent determination of N-nitrosodimethylamine using photogenerated tris(2,2'-bipyridyl) ruthenium (III)

International Nuclear Information System (INIS)

Perez-Ruiz, Tomas; Martinez-Lozano, Carmen; Tomas, Virginia; Martin, Jesus

2005-01-01

A flow injection configuration was developed and evaluated for the chemiluminescent determination of N-nitrosodimethylamine. The method is based on the on-line cleavage of the N-NO bond of the nitrosamine by irradiation with ultraviolet light. The dimethylamine generated was subsequently reacted with tris(2,2'-bipyridyl) ruthenium (III), which was generated through the on-line photo-oxidation of tris(2,2'-bipyridyl) ruthenium (II) with peroxydisulfate. After selecting the best operating parameters, the emitted light showed a linear relationship with the concentration of N-nitrosodimethylamine between 1.5 and 148 ng ml -1 , with a detection limit of 0.29 ng ml -1 . The repeatability was 1.6% expressed as relative standard deviation (n = 10) and the reproducibility, studied on five consecutive days, was 3.2%. The sample throughput was 50 injections per hour. The method was applied to studying the recoveries of N-nitrosodimethylamine in water and different cured meat products

Dendrimer-Encapsulated Ruthenium Nanoparticles as Catalysts for Lithium-O2 Batteries

Energy Technology Data Exchange (ETDEWEB)

Bhattacharya, Priyanka; Nasybulin, Eduard N.; Engelhard, Mark H.; Kovarik, Libor; Bowden, Mark E.; Li, Shari; Gaspar, Daniel J.; Xu, Wu; Zhang, Jiguang

2014-12-01

Dendrimer-encapsulated ruthenium nanoparticles (DEN-Ru) have been used as catalysts in lithium-O2 batteries for the first time. Results obtained from UV-vis spectroscopy, electron microscopy and X-ray photoelectron spectroscopy show that the nanoparticles synthesized by the dendrimer template method are ruthenium oxide instead of metallic ruthenium reported earlier by other groups. The DEN-Ru significantly improve the cycling stability of lithium (Li)-O2 batteries with carbon black electrodes and decrease the charging potential even at low catalyst loading. The monodispersity, porosity and large number of surface functionalities of the dendrimer template prevent the aggregation of the ruthenium nanoparticles making their entire surface area available for catalysis. The potential of using DEN-Ru as stand-alone cathode materials for Li-O2 batteries is also explored.

Fe (III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of schiff bases based-on glycine and phenylalanine: Synthesis, magnetic/thermal properties and antimicrobial activity

Science.gov (United States)

Sevgi, Fatih; Bagkesici, Ugur; Kursunlu, Ahmed Nuri; Guler, Ersin

2018-02-01

Zinc (II), copper (II), nickel (II), cobalt (II) and iron (III) complexes of Schiff bases (LG, LP) derived from 2-hydroxynaphthaldehyde with glycine and phenylalanine were reported and characterized by 1H NMR, 13C NMR, elemental analyses, melting point, FT-IR, magnetic susceptibility and thermal analyses (TGA). TGA data show that iron and cobalt include to the coordinated water and metal:ligand ratio is 1:2 while the complex stoichiometry for Ni (II), Cu (II) and Zn (II) complexes is 1:1. As expected, Ni (II) and Zn (II) complexes are diamagnetic; Cu (II), Co (II) and Fe (III) complexes are paramagnetic character due to a strong ligand of LG and LP. The LG, LP and their metal complexes were screened for their antimicrobial activities against five Gram-positive (Staphylococcus aureus, Methicillin resistant Staphylococcus aureus (MRSA), Bacillus cereus, Streptococcus mutans and Enterococcus faecalis) and three Gram-negative (Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa) and one fungi (Candida albicans) by using broth microdilution techniques. The activity data show that ligands and their metal complexes exhibited moderate to good activity against Gram-positive bacteria and fungi.

Application of the chemical properties of ruthenium to decontamination processes

International Nuclear Information System (INIS)

Fontaine, A.; Berger, D.

1965-01-01

The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [fr

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

International Nuclear Information System (INIS)

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

2004-01-01

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

Electron transfer across multiple hydrogen bonds: the case of ureapyrimidinedione-substituted vinyl ruthenium and osmium complexes.

Science.gov (United States)

Pichlmaier, Markus; Winter, Rainer F; Zabel, Manfred; Zális, Stanislav

2009-04-08

Ruthenium and osmium complexes 2a,b and 3a,b featuring the N-4,6-dioxo-5,5-dibutyl- or the N-4,6-dioxo-5,5-di-(2-propenyl)-1,4,5,6-tetrahydropyrimidin-2-yl-N'(4-ethenylphenyl)-urea ligand dimerize by a self-complementary quadruply hydrogen-bonding donor/donor/acceptor/acceptor (DDAA) motif. We provide evidence that the dimeric structures are maintained in nonpolar solvents and in 0.1 M NBu(4)PF(6)/CH(2)Cl(2) supporting electrolyte solution. All complexes are reversibly oxidized in two consecutive two-electron oxidations (DeltaE(1/2) approximately = 500 mV) without any discernible potential splitting for the oxidation of the individual hydrogen-bridged redox active moieties. IR and UV/vis/NIR spectroelectrochemistry show a one-step conversion of the neutral to the dication without any discernible features of an intermediate monooxidized radical cation. Oxidation-induced IR changes of the NH and CO groups that are involved in hydrogen bonding are restricted to the styryl-bonded urea NH function. IR band assignments are aided by quantum chemical calculations. Our experimental findings clearly show that, at least in the present systems, the ureapyrimidinedione (Upy) DDAA hydrogen-bonding motif does not support electron transfer. The apparent reason is that neither of the hydrogen-bonding functionalities contributes to the occupied frontier levels. This results in nearly degenerate pairs of MOs representing the in-phase and out-of-phase combinations of the individual monomeric building blocks.

Graphene/Ruthenium Active Species Aerogel as Electrode for Supercapacitor Applications.

Science.gov (United States)

Gigot, Arnaud; Fontana, Marco; Pirri, Candido Fabrizio; Rivolo, Paola

2017-12-30

Ruthenium active species containing Ruthenium Sulphide (RuS₂) is synthesized together with a self-assembled reduced graphene oxide (RGO) aerogel by a one-pot hydrothermal synthesis. Ruthenium Chloride and L-Cysteine are used as reactants. The hydrothermal synthesis of the innovative hybrid material occurs at 180 °C for 12 h, by using water as solvent. The structure and morphology of the hybrid material are fully characterized by Raman, XRD, XPS, FESEM and TEM. The XRD and diffraction pattern obtained by TEM display an amorphous nanostructure of RuS₂ on RGO crystallized flakes. The specific capacitance measured in planar configuration in 1 M NaCl electrolyte at 5 mV s -1 is 238 F g -1 . This supercapacitor electrode also exhibits perfect cyclic stability without loss of the specific capacitance after 15,000 cycles. In summary, the RGO/Ruthenium active species hybrid material demonstrates remarkable properties for use as active material for supercapacitor applications.

Activity and selectivity regulation of synthesis gas reaction over supported ruthenium catalysts

Energy Technology Data Exchange (ETDEWEB)

Fujimoto, K; Nobusawa, T; Fukushima, T; Tominaga, H

1985-01-01

The catalytic activities of supported ruthenium for synthesis-gas conversion to hydrocarbons was found to be in the following order: TiOS > Nb2O3 > ZrO2 > SiO2 > Ta2O5 > Al2O3 > V2O5 > MoO3 > WO3 > MnO2 > ZnO. Turnover frequencies of the supported ruthenium increased with decrease in dispersion of the metal particles for every carrier material. Even the activities per unit weight of metals were higher for low-dispersion ruthenium of Al2O3, TiO2, and ZrO2. The chain-growth probability of a hydrocarbon product, which is characterized by the Schulz-Flory distribution, increased markedly with decrease in the metal dispersion irrespective of the carrier material. The catalytic activity of ruthenium particles with a dispersed ruthenium increased almost linearly with an increase in reaction pressure (up to at least 2.0 MPa). 23 references, 10 figures, 3 tables.

Synthesis and characterization of chromium(III), manganese(II), iron(III), cobalt(II), nickel(II), copper(II), cadmium(II) and dioxouranium(VI) complexes of 4(2-pyridyl)-1-(2,4-dihydroxybenzaldehyde)-3-thiosemicarbazone

International Nuclear Information System (INIS)

Abu El-Reash, G.M.; Ibrahim, M.M.; Kenawy; El-Ayaan, Usama; Khattab, M.A.

1994-01-01

A few complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and dioxouranium(VI) with 4(2-pyridyl)-1-(2,4-dihydroxybenzaldehyde)-3-thiosemicarbazone have been synthesised and characterized on the basis of elemental analysis, IR, electronic NMR, and magnetic moment data. An octahedral structure is proposed for the Cr(III), Fe(III), Co(II) and Ni(H 3 PBT) 2 Cl 2 .2H 2 O complexes; a tetrahedral structure for the Mn(II) and Ni 2 (PBT)OAc.H 2 0 complexes and a square planar structure for the Cu(II) complexes. The antimicrobial and antifungal activities of H 3 PBT and of its metal(II) complexes are investigated. The results reveal that H 3 PBT exhibits greater antimicrobial activities than its complexes. (author). 34 refs., 4 figs., 2 tabs

Hydrothermal synthesis and physicochemical properties of ruthenium(0) nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Dikhtiarenko, A., E-mail: dikhtiarenkoalla@uniovi.es [Departamento de Quimica Organica e Inorganica, Universidad de Oviedo - CINN, 33006 Oviedo (Spain); Khainakov, S.A.; Garcia, J.R.; Gimeno, J. [Departamento de Quimica Organica e Inorganica, Universidad de Oviedo - CINN, 33006 Oviedo (Spain); Pedro, I. de; Fernandez, J. Rodriguez [CITIMAC, Facultad de Ciencias, Universidad de Cantabria, 39005 Santander (Spain); Blanco, J.A. [Departamento de Fisica, Universidad de Oviedo, 33007 Oviedo (Spain)

2012-09-25

Highlights: Black-Right-Pointing-Pointer Ruthenium nanoparticles were synthesized by hydrothermal technique. Black-Right-Pointing-Pointer The average size of the nanoparticles are depend on the reducing agent used. Black-Right-Pointing-Pointer The magnetic response seems to be dominated by a paramagnetic contribution characteristic of the band electronic magnetism of the ruthenium(0) nanoparticles. - Abstract: The synthesis of ruthenium nanoparticles in hydrothermal conditions using mild reducing agents (succinic acid, ascorbic acid and sodium citrate) is reported. The shape of the nanoparticles depends on the type of the reducing agent, while the size is more influenced by the pH of the medium. The magnetic response seems to be dominated by a paramagnetic contribution characteristic of the band electronic magnetism of the nanoparticles.

Surface and sub-surface thermal oxidation of thin ruthenium films

NARCIS (Netherlands)

Coloma Ribera, R.; van de Kruijs, Robbert Wilhelmus Elisabeth; Kokke, S.; Zoethout, E.; Yakshin, Andrey; Bijkerk, Frederik

2014-01-01

A mixed 2D (film) and 3D (nano-column) growth of ruthenium oxide has been experimentally observed for thermally oxidized polycrystalline ruthenium thin films. Furthermore, in situ x-ray reflectivity upon annealing allowed the detection of 2D film growth as two separate layers consisting of low

Thermodynamic data bases for multivalent elements: An example for ruthenium

International Nuclear Information System (INIS)

Rard, J.A.

1987-11-01

A careful consideration and understanding of fundamental chemistry, thermodynamics, and kinetics is absolutely essential when modeling predominance regions and solubility behavior of elements that exhibit a wide range of valence states. Examples of this are given using the ruthenium-water system at 298.15 K, for which a critically assessed thermochemical data base is available. Ruthenium exhibits the widest range of known aqueous solution valence states. Known solid anhydrous binary oxides of ruthenium are crystalline RuO 2 , RuO 4 , and possibly RuO 3 (thin film), and known hydroxides/hydrated oxides (all amorphous) are Ru(OH) 3 . H 2 O, RuO 2 . 2H 2 O, RuO 2 . H 2 O, and a poorly characterized Ru(V) hydrous oxide. Although the other oxides, hydroxides, and hydrous oxides are generally obtained as precipitates from aqueous solutions, they are thermodynamically unstable with regard to RuO 2 (cr) formation. Characterized aqueous species of ruthenium include RuO 4 (which slowly oxidizes water and which dissociates as a weak acid), RuO 4 - and RuO 4 2- (which probably contain lesser amounts of RuO 3 (OH) 2 - and RuO 3 (OH) 2 2- , respectively, and other species), Ru(OH) 2 2+ , Ru 4 (OH) 12 4+ , Ru(OH) 4 , Ru 3+ , Ru(OH) 2+ , Ru(OH) 2 + , Ru 2+ , and some hydroxytetramers with formal ruthenium valences of 3.75 ≥ Z ≥ 2.0. Potential pH diagrams of the predominance regions change significantly with concentration due to polymerization/depolymerization reactions. Failure to consider the known chemistry of ruthenium can yield large differences in predicted solubilities

Antibacterial, antimalarial and leishmanicidal activities of Cu (II) and nickel (II) complexes of diclofenac sodium

International Nuclear Information System (INIS)

Rehman, F.U.; Khan, M.F.; Khan, G.M.; Khan, H.; Khan, I.U.

2010-01-01

Metal complexes are famous for a wide array of chemotherapeutic effects. The current study was designed to synthesize and evaluate unexplored chemotherapeutic effects of Cu (II) and Nickel (II) complexes of the non-steroidal anti-inflammatory drug diclofenac. Nickel complex exhibited significant leishmanicidal activity against Lieshmania major, while the copper complex was found to possess low activity against the same pathogen. Both of the complexes revealed low antibacterial activities and were interestingly failed to produce any considerable antimalarial activity against Plasmodium falciparum 3D7. Selective leishmanicidal activities of Nickel (II) complex of diclofenac needs further improvement to be developed as potential new metal-based leishmanicidal agent.(author)

Antibacterial, antimalarial and leishmanicidal activities of Cu (II) and nickel (II) complexes of diclofenac sodium

Energy Technology Data Exchange (ETDEWEB)

Rehman, F U; Khan, M F; Khan, G M; Khan, H [Gomal University, D.I. Khan (Pakistan). Dept. of Faculty of Pharmacy; Khan, I U [University of Peshawar (Pakistan). Dept. of Faculty of Pharmacy

2010-08-15

Metal complexes are famous for a wide array of chemotherapeutic effects. The current study was designed to synthesize and evaluate unexplored chemotherapeutic effects of Cu (II) and Nickel (II) complexes of the non-steroidal anti-inflammatory drug diclofenac. Nickel complex exhibited significant leishmanicidal activity against Lieshmania major, while the copper complex was found to possess low activity against the same pathogen. Both of the complexes revealed low antibacterial activities and were interestingly failed to produce any considerable antimalarial activity against Plasmodium falciparum 3D7. Selective leishmanicidal activities of Nickel (II) complex of diclofenac needs further improvement to be developed as potential new metal-based leishmanicidal agent.(author)

Synthesis and characterization of zinc(II), cadmium(II) and mercury(II) complexes with bis(bidentate) Schiff bases

International Nuclear Information System (INIS)

Das, Mrinal Kanti; Ghosh, Shyamali

1998-01-01

A few Zn(II), Cd(II) and Hg(II) complexes of the bis(bidentate) Schiff bases derived from p-phenylenediamine and salicylaldehyde (H 2 Salpphen), and o-phenylenediamine and o-vanillin (H 2 Vanophen), of the type MCl 2 .H 2 L(H 2 L = H 2 Salpphen or H 2 Vanophen) have been synthesised. The complexes have been characterized by elemental analysis, infrared, 1 H and 13 C NMR and mass spectra. (author)

Ruthenium(II)-Catalyzed C-H Activation of Imidamides and Divergent Couplings with Diazo Compounds: Substrate-Controlled Synthesis of Indoles and 3H-Indoles.

Science.gov (United States)

Li, Yunyun; Qi, Zisong; Wang, He; Yang, Xifa; Li, Xingwei

2016-09-19

Indoles are an important structural motif that is commonly found in biologically active molecules. In this work, conditions for divergent couplings between imidamides and acceptor-acceptor diazo compounds were developed that afforded NH indoles and 3H-indoles under ruthenium catalysis. The coupling of α-diazoketoesters afforded NH indoles by cleavage of the C(N2 )-C(acyl) bond whereas α-diazomalonates gave 3H-indoles by C-N bond cleavage. This reaction constitutes the first intermolecular coupling of diazo substrates with arenes by ruthenium-catalyzed C-H activation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hazards and control of ruthenium in the nuclear fuel cycle

International Nuclear Information System (INIS)

Eichholz, G.G.

1978-01-01

A review is presented of present information on the possible hazards of radioruthenium in the nuclear fuel cycle and its behaviour in nuclear operations and in the environment. The subject is dealt with under the following headings: basic chemical and nuclear properties of ruthenium; chemistry (including the ruthenium-nitric acid system, electrochemistry, extraction processes); ruthenium toxicity; generation of radioruthenium (fallout sources, reactor sources, fuel reprocessing operations); waste treatment (cementation and bitumenization, calcining processes, vitrification); movement in the environment (movement of airborne effluents, liquid effluents and the freshwater environment, marine environment, bottom sediments, marine organisms, terrestrial environments, uptake in vegetation and animals); conclusion. (U.K.)

Preparation and Spectral Properties of Mixed-Ligand Complexes of VO(IV, Ni(II, Zn(II, Pd(II, Cd(II and Pb(II with Dimethylglyoxime and N-acetylglycine

Directory of Open Access Journals (Sweden)

Shayma A. Shaker

2010-01-01

Full Text Available A number of mixed-ligand complexes of the general formula [M(D(G] where D=dimethylglyoximato monoanion, G=N-acetylglycinato and M=VO(IV, Ni(II, Zn(II, Pd(II, Cd(II and Pb(II were prepared. Each complex was characterized by elemental analysis, determination of metal, infrared spectra, electronic spectra, (1H and 13C NMR spectra, conductivity and magnetic moments. All these complexes were not soluble in some of the organic solvent but highly soluble in dimethylformamide. The conductivity data showed the non-electrolytic nature of the complexes. The electronic spectra exhibited absorption bands in the visible region caused by the d-d electronic transition such as VO(IV, Ni(II and Pd(II. The IR and (1H, 13C NMR spectra which have indicate that the dimethylglyoxime was coordinated with the metal ions through the N and O atoms of the oxime group and N-acetylglycine was coordinated with metal ions through the N atom and terminal carboxyl oxygen atom.

Density functional theory based QSAR study of ruthenium (II) antitumor drugs and their interactions with xanthine oxidoreductase

International Nuclear Information System (INIS)

Mondal, Paritosh; Das, Dharitri

2013-01-01

Transition metal containing drugs have been used intensely for their potential anticancer activities. Platinum drugs have been used successfully for the treatment of cancer. However, these drugs have severe drawbacks including unwanted side effects, drug resistance and ineffectiveness towards some of cancers. Therefore scientists are searching for new drugs to solve these problems, and Ruthenium coordination compounds have been found effective alternatives to platinum coordination drugs

Coordination chemistry of sugar-phosphate complexes with palladium(II), rhenium(V) and zinc(II)

Energy Technology Data Exchange (ETDEWEB)

Steinborn, Christian Martin

2013-05-21

As described before, some studies dealing with coordination chemistry of sugar phosphates are available but no analogous complexes of Zn{sup II} have been investigated yet. The primary goal of this work is, therefore, to fill this gap. In order to stay close to the active sites of enzymes such as class-II-aldolase, the simple metal fragment Zn{sup II}(dien) is used. NMR spectroscopy is used primarily as analytical method since it enables the investigation of both complex equilibria in solution and pH dependence of metal-binding sites. Since this approach is challenging due to the fast metal-ligand exchange and the absence of CIS values, it is necessary to improve the significance of NMR data collected from sugar-phosphate complexes with Zn{sup II}. Hence, further experiments are performed with molecules similar to sugar phosphates such as reducing and methylated sugars or polyols. Beside NMR spectroscopy, crystal-structure analysis will be used to get more detailed information about the binding pattern of the complexes. Additionally, sugar-phosphate complexes of Pd{sup II} are investigated. Further experiments are conducted, on the one hand, to synthesise more sugarphosphate complexes with ReVON2 fragments, and, on the other hand, to grow crystals confirming the theory about mixed sugar-core-phosphate chelation.

Ruthenium determination by the method of inversion voltammetry on graphite electrode

Energy Technology Data Exchange (ETDEWEB)

Dominova, I G; Kolpakova, N A; Stromberg, A G [Tomskij Politekhnicheskij Inst. (USSR)

1978-12-01

Optimal conditions for determining ruthenium by inversion voltammetry on a graphite electrode are 0.1 M KCl or KNO/sub 3/, pH 2-3, electrolysis potential - 1.0 V. A linear dependence of ruthenium electrodissolution current on its concentration in the solution makes it possible to use inversion voltammetry for determining 5x10/sup -7/ - 1x10/sup -4/ g-ion Ru/l. Ruthenium can be determined in the presence of a large excess of nickel and copper but commensurable amounts of mercury adn platinum metals interfere.

[1,4-Bis(diphenylphosphanylbutane-κ2P,P′]chlorido(η5-indenylruthenium(II

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Hui-Ling Sung

2011-05-01

Full Text Available Facile ligand substitution is observed when the ruthenium chloride complex [Ru(η5-C9H7Cl(PPh32] is treated with 1,4-bis(diphenylphosphanylbutane in refluxing toluene yielding the title compound, [Ru(C9H7Cl(C28H28P2]. The RuII atom has a typical piano-stool coordination, defined by the indenyl ligand, one Cl atom and two phosphanyl P atoms. The Ru—P bond lengths are 2.2502 (9 and 2.2968 (8 Å.

Synthesis, Characterization and Antimicrobial Activity of Cu(II, Co(II and Ni(II Complexes with O, N, and S Donor Ligands

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Vidyavati Reddy

2008-01-01

Full Text Available The complexes of the type ML2 [where M = Cu(II, Co(II, and Ni(II] L = 1-phenyl-1-ene-3-(2-hydroxyphenyl-prop-2-ene with 3- substituted-5-mercapto-4-amino-1,2,4-triazoles. Schiff base ligands have been prepared by reacting 3-(2-hydroxyphenyl-1-phenylprop-2-en-1-one and 3-phenyl/pyridyl-4-amino-5-mercapto-1,2,4-triazoles in an alcoholic medium. The complexes are non-electrolytes in DMF. The resulting complexes were characterized by elemental analysis, magnetic measurements, conductivity measurements and spectral studies. The Schiff base acts as a tridentate dibasic and coordinating through the deprotonated oxygen, thioenolic sulphur and azomethine nitrogen atoms. It is found that Cu(II, Co(II, and Ni(II complexes exhibited octahedral geometry. The antimicrobial activities of ligands and its complexes were screened by cup plate method.

Processing of radioactive ruthenium with aluminosilicate gels

International Nuclear Information System (INIS)

Kanno, Takuji; Ichinose, Yasuhiro; Ito, Katsuo

1979-01-01

Coprecipitation of radioactive Ru with hydroxides has been studied for the purpose of the management of the high level waste from the nuclear fuel reprocessing. Aluminosilicate gel used as coprecipitant was prepared by addition of aqueous sodium hydroxide to sodium aluminate-sodium silicate solution containing ruthenium nitrate. Ruthenium quantitatively precipitates under the conditions, aluminate > 4 x 10 -2 M, Al/Si 0 C. However, volatilization rate of Ru is suppressed by coating with mullite phase into which aluminosilicate gel transformes above 900 0 C. The amount of Ru volatilized in Ar-flow was reduced to about 10% of that in air-flow. (author)

Ruthenium release from thermally overheated nitric acid solution containing ruthenium nitrosyl nitrate and sodium nitrate to solidify

Energy Technology Data Exchange (ETDEWEB)

Sawada, Kayo; Ueda, Yasuyuki; Enokida, Youichi [Nuclear Chemical Engineering Laboratory, Nagoya University, Nagoya 4648603 (Japan)

2016-07-01

Radioactive ruthenium (Ru) is one of the dominant elemental species released into the environment from a fuel reprocessing plant in a hypothetical design accident due to its relatively higher fission yield and longer half-life. After the hypothetical accident assuming the loss of all electric power and cooling functions, high-level liquid waste (HLLW) may be overheated by the energetic decays of many fission products in it, and Ru may be oxidized to the volatile tetroxide, RuO{sub 4}, which is released through the off-gas pathway. At a reprocessing plant in Japan, alkaline solution from the solvent scrubbing stream is sometimes mixed with the HLLW followed by vitrification, which can be influenced by the addition of sodium nitrate to a simulated HLLW containing ruthenium nitrosyl nitrate that was experimentally evaluated on a small scale using the overheated nitric acid solution of 2 mol/dm{sup 3}, which was kept at 180 Celsius degrees in a glass evaporator placed in a thermostatic bath. The release fraction of Ru increased by approximately 30% by the addition of sodium nitrate. This may be partially explained by the existence of relatively highly concentrated nitrate ions in the liquid phase that oxidize the ruthenium species to RuO{sub 4} during the drying process. (authors)

Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of N'-(furan-3-ylmethylene)-2-(4-methoxyphenylamino)acetohydrazide.

Science.gov (United States)

Emam, Sanaa M; El-Saied, Fathy A; Abou El-Enein, Saeyda A; El-Shater, Heba A

2009-03-01

Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of furan-2-carbaldehyde 4-methoxy-N-anilinoacetohydrazone were synthesized and characterized by elemental and thermal (TG and DTA) analyses, IR, UV-vis and (1)H NMR spectra as well as magnetic moment and molar conductivity. Mononuclear complexes are obtained with 1:1 molar ratio except complexes 3 and 9 which are obtained with 1:2 molar ratios. The IR spectra of ligand and metal complexes reveal various modes of chelation. The ligand behaves as a neutral bidentate one and coordination occurs via the carbonyl oxygen atom and azomethine nitrogen atom. The ligand behaves also as a monobasic tridentate one and coordination occurs through the enolic oxygen atom, azomethine nitrogen atom and the oxygen atom of furan ring. Moreover, the ligand behaves as a neutral tridentate and coordination occurs via the carbonyl oxygen, azomethine nitrogen and furan oxygen atoms as well as a monobasic bidentate and coordination occurs via the enolic oxygen atom and azomethine nitrogen atom. The electronic spectra and magnetic moment measurements reveal that all complexes possess octahedral geometry except the copper complex 10 possesses a square planar geometry. The thermal studies showed the type of water molecules involved in metal complexes as well as the thermal decomposition of some metal complexes.

Gamma radiolysis of Cu(II) complex of metronidazole

International Nuclear Information System (INIS)

Mandal, P.C.; Bardhan, D.K.; Bhattacharyya, S.N.

1990-01-01

Aqueous solutions of Cu(II)Metronidazole (Cu(II)M) at neutral pH were irradiated with 60 Co γ-rays under different conditions of radiolysis. The radiolytic formation of HNO 2 and Cu(I) was followed. The radiolytic yields of chromophore loss of Cu(II)M were also determined under different conditions. The OH radicals attack the metal complex to give the OH adducts of the ligand at C 2 , C 4 , and C 5 either directly or through the formation of Cu(III) species. The C 5 -OH adduct, however, undergoes oxidative denitration and as a result the metal complex is decomposed. The OH adducts also undergo electron transfer to Cu(II) ion to give reduced complex. No denitration was observed due to the reaction of e eq - with the metal complex. On the other hand, the nitro group of the ligand in the complex undergoes successive 4-electron reduction to give hydroxylamino derivative. From the competition kinetics using t-butyl alcohol as the scavenger of OH in N 2 O saturated solution of the metal complex, the rate constant for the reaction of OH with complex was evaluated to be ca. 2.1x10 9 dm 3 mol -1 s -1 which is of the same order as that observed in the case of free metronidazole. (author)

Interaction of Cr (III), Ni (II), Pb (II) with DTPA complexes of essential metal ions

International Nuclear Information System (INIS)

Gulzar, S.; Zahida; Maqsood, T.; Naqvi, R.R.

2002-01-01

With the increase of anthropogenic activities in the environment, heavy metal toxicity (Chromium, Nickel and Lead) is more common now. DTPA (diethylene triamine pentaacetic acid) a polyamino carboxylic acid is widely used to form hydrophilic and stable complexes with most of the metal ions. In this spectrophotometric study, concentration of Cr(III), Ni(II) and Pb(II) (toxic metal ions) exchanged with Fe(III), Zn(II) and Ca(II) from their DTPA complexes were estimated at pH 4,7 and 9. Concentration of added metal was varied from 1-4 times to that of complexed metal. (author)