Crystal and molecular structure of dinuclear palladium(II) complex containing nitrogen and phosphorus donor ligands, [Pd2(N3)4(PPh3)2(μ-ted)]

The dinuclear azido-palladium(II) complex [Pd2(N3)4(PPh3)2(μ-ted)], where PPh3 = triphenylphosphine and ted = triethylenediamine, was synthesized and characterized by single-crystal X-ray diffraction. The title compound was crystallized in a triclinic system, space group P1 with a = 11.5875(2)Å, b = 13.0817(3)Å, c = 15.2618(3)Å, α = 93.306(2)°, β =110.040(1)°, γ = 98.486(1)°, V = 2134.95(8)Å3, Z = 2. Each Pd(II) center displays a distorted squareplanar coordination environment formed by two N atoms from two trans terminally coordinated azido groups, one P atom from the phosphine and one N atom from the bridging ted ligand. 2008 © The Japan Society for Analytical Chemistry.

New ruthenium(II)/phosphines/diimines complexes: Promising antitumor (human breast cancer) and Mycobacterium tuberculosis fighting agents

The synthesis and characterization of ruthenium compounds of the type [RuCl2(P)2(N-N)] [(P)2 = (PPh3) 2, dppb = 1,4-bis(diphenylphosphino)butano; dppp = 1,3-bis(diphenylphosphino)propane; N-N = 5,5′-dimethyl-2,2′dipyridyl (5,5′-mebipy) or 4,4′-dimethyl-2,2′dipyridyl (4,4′-mebipy)] are described. The complexes were characterized using elemental analysis, UV-Vis and infrared spectroscopies, cyclic voltammetry, and X-ray crystallography. In vitro evaluation of the complexes, using the MTT methodology, revealed their cytotoxic activities in a range of 5.4-15.7 μM against the MDA-MB-231 breast tumor cells and showed that, in this case, they are more active than the reference metallodrug cisplatin. The in vitro antimycobacterial activities of the complexes had their Minimum Inhibitory Concentration (MIC) for MTB cell growth measured, by the REMA method. The MICs for these complexes were found to be between 12.5 and 25.0 μg/mL. The results are comparable with the second line drug cycloserine (MIC = 12.5-50.0 μg/mL), commonly used in the treatment of TB. © 2013 Elsevier Ltd. All rights reserved.

Nanostructured Lipid Systems as a Strategy to Improve the in Vitro Cytotoxicity of Ruthenium(II) Compounds

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação toxicogenética e atividade antitumoral in vitro de complexos heterolépticos de Rutênio(II): Atividades citotóxicas, genotóxicas e interação com biomoléculas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Bifunctional silica nanoparticles for the exploration of biofilms of Pseudomonas aeruginosa

Luminescent silica nanoparticles are frequently employed for biotechnology applications mainly because of their easy functionalization, photo-stability, and biocompatibility. Bifunctional silica nanoparticles (BSNPs) are described here as new efficient tools for investigating complex biological systems such as biofilms. Photoluminescence is brought about by the incorporation of a silylated ruthenium(II) complex. The surface properties of the silica particles were designed by reaction with amino-organosilanes, quaternary ammonium-organosilanes, carboxylate-organosilanes and hexamethyldisilazane. BSNPs were characterized extensively by DRIFT, 13C and 29Si solid state NMR, XPS, and photoluminescence. Zeta potential and contact angle measurements exhibited various surface properties (hydrophilic/hydrophobic balance and electric charge) according to the functional groups. Confocal laser scanning microscopy (CLSM) measurements showed that the spatial distribution of these nanoparticles inside a biofilm of Pseudomonas aeruginosa PAO1 depends more on their hydrophilic/hydrophobic characteristics than on their size. CLSM observations using two nanosized particles (25 and 68 nm) suggest that narrow diffusion paths exist through the extracellular polymeric substances matrix. © 2013 Copyright Taylor and Francis Group, LLC.

Electrochemical investigation of the dimeric oxo-bridged ruthenium complex in aqueous solution and its incorporation within a cation-exchange polymeric film on the electrode surface for electrocatalytic activity of hydrogen peroxide oxidation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nitrosyl ruthenium complexes with general formula [RuCl3,(NO)(P-P)] (P-P={PPh(2)(CH2)(n)PPh(2)},n=1-3 and {PPh(2)-CH=CH-PPh(2)}). X-ray structure of [RuCl3(NO){PPh(2)(CH2)(3)PPh(2)}]

Ruthenium(II) complexes with general formula [RuCl3(NO)(P-P)] were obtained in the solid state, where P-P = PPh(2)(CH2)(n)PPh(2) (n = 1-3) and PPh(2)-CH = CH-PPh(2). The P-31 NMR spectra of these compounds measured in CH2Cl2 showed only singlets, consistent with a fac configuration containing two equivalent phosphorus atoms, However the X-ray diffraction data show that the [RuCl3(NO){PPh(2)(CH2)(3)PPh(2)}] complex crystallizes in a met configuration, where one of the phosphorus atoms is trans to the NO group, in a slightly distorted octahedral geometry. Copyright (C) 1996 Elsevier B.V. Ltd

A NOVEL SYNTHETIC ROUTE FOR SUPPORTING RUTHENIUM COMPLEXES ON FUNCTIONALIZED SILICA-GEL

The immobilization of the ruthenium moiety Ru(NH3)4SO3 by reaction of trans-[Ru(NH3)4SO2(H2O)]2+ with silica gel functionalized with 3-(1-imidazolyl)propyl groups is reported. A 60% surface coverage was obtained in the proportion of the resulting material [=Si(CH2)3imN-Ru(NH3)4SO3]. The anchored Ru(II) complex was characterized and its reactivity investigated. Derivatives of CO, pyrazine, and isonicotinamide have been prepared and characterized by electronic and vibrational spectroscopies, as well as by chemical means. The [=Si(CH2)3imN-Ru(NH3)4SO4]Cl, obtained through oxidation of the corresponding ruthenium(II) sulfite species, has been characterized and the aquo and the oxalate derivative have been synthesized.

Synthesis, crystal structure, spectroscopic and electrochemical characterization of the dinuclear complex {tetra-mu-[(+/-)-2-(p-methoxyphenoxy)-propionato-O,O']bis(aqua)dicopper(II)}

Structural, electrochemical and spectroscopic data of a new dinuclear copper(II) complex with (+/-)-2-(p- methoxyphenoxy) propionic acid are reported. The complex {tetra-mu-[(+/-)-2-(p-methoxyphenoxy)propionato-O,O']-bis( aqua) dicopper(II)} crystallizes in the monoclinic system, space group P2(1)/n with a = 14.149(1) angstrom, b = 7.495(1) angstrom, c = 19.827(1) angstrom, beta = 90.62(1) and Z = 4. X-ray diffraction data show that the two copper(II) ions are held together through four carboxylate bridges, coordinated as equatorial ligands in square pyramidal geometry. The coordination sphere around each copper ion is completed by two water molecules as axial ligands. Thermogravimetric data are consistent with such results. The ligand has an L' type shape due to the angle formed by the beta-carbon of the propionic chain and the linked p-methoxyphenoxy group. This conformation contributes to the occurrence of a peculiar structure of the complex. The complex retains its dinuclear nature when dissolved in acetonitrile, but it decomposes into the corresponding mononuclear species if dissolved in ethanol, according to the EPR measurements. Further, cyclic voltammograms of the complex in acetonitrile show that the dinuclear species maintains the same structure, in agreement with the EPR data in this solvent. The voltammogram shows two irreversible reduction waves at E-pc = -0.73 and -1.04 V vs. Ag/AgCl assigned to the Cu(II)/ Cu(I) and Cu(I)/Cu degrees redox couples, respectively, and two successive oxidation waves at E-pa = -0.01 and +1.41 V vs. Ag/AgCl, assigned to the Cu degrees/Cu(I) and Cu( I)/Cu( II) redox couples, respectively, in addition to the oxidation waves of the carboxylate ligand.

H-1-N-15 NMR studies of the complex bis(S-allyl-L-cysteinate)palladium(II)

H-1-N-15 2D NMR data for S-allyl-L-cysteine (deoxyalliin) and for bis(S-allyl-L-cysteinate)palladium(II) complex are presented in this manuscript. Large upfield N-15 NMR shift of the amine nitrogen in the spectrum of the complex when compared to the spectrum of the ligand shows clearly coordination of S-allyl-L-cysteine, in the anion form, to palladium(II) through the NH2 group. (c) 2005 Elsevier B.V. All rights reserved.

fac-[RuCl3(no)(dppb)] (I) and mer-[RuCl3(NO)(diop)] (II) complexes: Syntheses, characterization and x-ray structures

The fac-[RuCl3(NO)(dppb)] complex I has been prepared from solution of the correspondent mer isomer in refluxing methanol (dppb = 1,4-bis(diphenylphosphino)butane). The mer-[RuCl3(NO)(diop)] (II) has been obtained from the mer-[RuCl3(diop)(H2O)] by bubbling NO for 1 h in dichloromethane (diop = 2S,3S-O-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)butane). The complexes have been characterized by microanalysis, cyclic voltammetry (CV), IR and 31P{1H} NMR spectroscopies. The crystal and molecular structures of these two compounds have been determined from X-ray studies. The mer-[RuCl3(NO)(dppb)] isomer III was characterized in solution by NMR spectra (31P{1H}, 1H{31P}, 31P-1H HETCORR, COSY 1H-1H, HMQC 1H-13C and HMBC 1H-13C). © 2002 Elsevier Science Ltd. All rights reserved.

Complexos de rutênio (II) contendo ligantes nitrogenados como fotossensibilizadores em células solares

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Inhibition of myotoxic activity of Bothrops asper myotoxin II by the anti-trypanosomal drug surarnin

Suramin, a synthetic polysulfonated compound, developed initially for the treatment of African trypanosomiasis and onchocerciasis, is currently used for the treatment of several medically relevant disorders. Suramin, heparin, and other polyanions inhibit the myotoxic activity of Lys49 phospholipase A(2) analogues both in vitro and in vivo, and are thus of potential importance as therapeutic agents in the treatment of viperid snake bites. Due to its conformational flexibility around the single bonds that link the central phenyl rings to the secondary amide backbone, the symmetrical suramin molecule binds by an induced-fit mechanism complementing the hydrophobic surfaces of the dimer and adopts a novel conformation that lacks C2 symmetry in the dimeric crystal structure of the suramin-Bothrops asper myotoxin II complex. The simultaneous binding of suramin at the surfaces of the two monomers partially restricts access to the nominal active sites and significantly changes the overall charge of the interfacial recognition face of the protein, resulting in the inhibition of myotoxicity. (c) 2005 Elsevier Ltd. All rights reserved.

REDUCTION OF THE AMIDO-BONDED (2-PICOLINAMIDO)PENTAAMMINERUTHENIUM(III) FOLLOWED BY FORMATION OF CIS-(2-PICOLINAMIDE)TETRAAMMINERUTHENIUM(II)

[(NH3)(5)Ru-III(2-NCpy)], obtained from electrochemical oxidation of the Ru(II) complex, undergoes hydrolysis to the amido-bonded [Ru-III(NHC(O)-2-py)]. The electrochemical reduction of this latter complex to Ru(II) is followed by an aquation reaction to form [R(II)(NH3)(5)(OH2)] and free picolinamide and a chelation reaction to form cis-[R(II)-(NH3)(4)(2-pica)] with the displacement of one cis ammonia.

Synthesis and spectroscopic characterization of new metal(II) complexes with methionine sulfoxide

Methionine sulfoxide complexes of iron(II) and copper(II) were synthesized and characterized by chemical and spectroscopic techniques. Elemental and atomic absorption analyses fit the compositions K2[Fe(metSO) 2]SO4 · H2O and [Cu(metSO)2] · H2O. Electronic absorption spectra of the complexes are typical of octahedral geometries. Infrared spectroscopy suggests coordination of the ligand to the metal through the carboxylate and sulfoxide groups. An EPR spectrum of the Cu(II) complex indicates tetragonal distortion of its octahedral symmetry. 57Fe Mössbauer parameters are also consistent with octahedral stereochemistry for the iron(II) complex. The complexes are very soluble in water.