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Complexes with general formulap,t-[Ru(CO)(PR3)(tren)]X2[R = Ph (1) orp-tol (2); tren = tris(2-aminoethyl)amine; X = Cl−or] were prepared from [RuCl2(CO)(dmf)(PR3)] by direct reaction with tren. The complexes were fully characterized by NMR (1H,31P{1H}, HMBC1H–31P), FTIR and ESI-MS spectroscopy, elemental analysis, and the structures ofp,t-[Ru(CO)(PPh3)(tren)](PF6)2(1•PF6) andp,t-[Ru(CO)(P{p-tol}3)(tren)]Cl2(2•Cl) were determined by X-ray diffraction. The water soluble complexes1•Cland2•Clwere tested as antimicrobial agents against Gram (+) and Gram (−) bacteria with the latter showing superior activity than the approved antimicrobial agent chloramphenicol in one of the strains. [ABSTRACT FROM AUTHOR]

Abstract: Ruthenium(II) carbonyl complexes containing triarylphosphines and hybrid ligands PPh2-X (X= o-dimethylaniline – P–N, o-pyridine – P-Py, or o-anisole – P–O) were synthesized and characterized. Six new complexes with the formula cis,trans-[RuCl2(CO)(PPh2-X)(PR3)] (X= o-dimethylaniline, R=Ph 1a; X= o-pyridine, R=Ph 2a; X= o-anisole, R=Ph 3a; X= o-dimethylaniline, R= p-tol 1b; X= o-pyridine, R= p-tol 2b; and X= o-anisole, R= p-tol 3b) were obtained by starting from the appropriate precursors, [RuCl2(CO)(DMF)(PPh3)2] or [RuCl2(CO)(DMF)(P{p-tol}3)2]. The two chlorine atoms are in cis position to each other, and the monophosphine (PPh3 or P{p-tol}3) is in trans position to the nitrogen or oxygen of the PPh2-X ligand. The synthesized complexes were characterized by 1D–1H, 31P{1H} and 2D-correlations HMBC 31P–1H NMR, vibrational spectroscopy, elemental analysis, and X-ray diffraction structural determination (for complexes 1a, 2a·CH2Cl2 , 3a, and 3b·CH2Cl2 ). Only the complexes containing the P–O ligand (3a and 3b) reacted with carbon monoxide (at 1atm and room temperature). The NMR (31P{1H}, 1H) data was compatible with carbon monoxide coordination at the OCH3 position, which led to the formation of dicarbonyl complexes [RuCl2(CO)2(P–O)(PR3)] (R=Ph 4a or p-tol 4b), and proved the hemilabile behavior of the P–O ligand. In addition, the complexes underwent isomerization in solution when exposed to ambient light, and the products were analyzed by 31P{1H} NMR. The X-ray structures and the chemical shift in the 31P NMR spectra were correlated and discussed. [Copyright &y& Elsevier]

Abstract: Complex fac-[RuCl3(NO)(P–N)] (1) was synthesized from the reaction of [RuCl3(H2O)2(NO)] and the P–N ligand, o-[(N,N-dimethylamino)phenyl]diphenylphosphine) in refluxing methanol solution, while complex mer,trans-[RuCl3(NO)(P–N)] (2) was obtained by photochemical isomerization of (1) in dichloromethane solution. The third possible isomer mer,cis-[RuCl3(NO)(P–N)] (3) was never observed in direct synthesis as well as in photo- or thermal-isomerization reactions. When refluxing a methanol solution of complex (2) a thermally induced isomerization occurs and complex (1) is regenerated. The complexes were characterized by NMR (31P{1H}, 15N{1H} and 1H), cyclic voltammetry, FTIR, UV–Vis, elemental analysis and X-ray diffraction structure determination. The 31P{1H} NMR revealed the presence of singlet at 35.6 for (1) and 28.3ppm for (2). The 1H NMR spectrum for (1) presented two singlets for the methyl hydrogens at 3.81 and 3.13ppm, while for (2) was observed only one singlet at 3.29ppm. FTIR Ru–NO stretching in KBr pellets or CH2Cl2 solution presented 1866 and 1872cm−1 for (1) and 1841 and 1860cm−1 for (2). Electrochemical analysis revealed a irreversible reduction attributed to RuII–NO+ →RuII–NO0 at −0.81V and −0.62V, for (1) and (2), respectively; the process RuII →RuIII, as expected, is only observed around 2.0V, for both complexes. Studies were conducted using 15NO and both complexes were isolated with 15N-enriched NO. Upon irradiation, the complex fac-[RuCl3(NO)(P–N)] (1) does not exchange 14NO by 15NO, while complex mer,trans-[RuCl3(NO)(P–N)] (2) does. Complex mer,trans-[RuCl3(15NO)(P–N)] (2′) was obtained by direct reaction of mer,trans-[RuCl3(NO)(P–N)] (2) with 15NO and the complex fac-[RuCl3(15NO)(P–N)] (1′) was obtained by thermal-isomerization of mer,trans-[RuCl3(15NO)(P–N)] (2′). DFT calculation on isomer energies, electronic spectra and electronic configuration were done. For complex (1) the HOMO orbital is essentially Ru (46.6%) and Cl (42.5%), for (2) Ru (57.4%) and Cl (39.0%) while LUMO orbital for (1) is based on NO (52.9%) and is less extent on Ru (38.4%), for (2) NO (58.2%) and Ru (31.5%). [Copyright &y& Elsevier]

Abstract: The complex mer-[RuCl3(dppb)(H2O)] [dppb=1,4-bis(diphenylphosphino)butane] was used as a precursor in the synthesis of the complexes tc-[RuCl2(CO)2(dppb)], ct-[RuCl2(CO)2(dppb)], cis-[RuCl2(dppb)(Cl-bipy)], [RuCl(2Ac4mT)(dppb)] (2Ac4mT=N(4)-meta-tolyl-2-acetylpyridine thiosemicarbazone ion) and trans-[RuCl2(dppb)(mang)] (mang=mangiferin or 1,3,6,7-tetrahydroxyxanthone-C2-β-D-glucoside) complexes. For the synthesis of RuII complexes, the RuIII atom in mer-[RuCl3(dppb)(H2O)] may be reduced by H2(g), forming the intermediate [Ru2Cl4(dppb)2], or by a ligand (such as H2Ac4mT or mangiferin). The X-ray structures of the cis-[RuCl2(dppb)(Cl-bipy)], tc-[RuCl2(CO)2(dppb)] and [RuCl(2Ac4mT)(dppb)] complexes were determined. [ABSTRACT FROM AUTHOR]

Abstract: The “Ru(P–P)” unit (P–P=diphosphine) is recognized to be an important core in catalytic species for hydrogenation of unsaturated organic substrates. Thus, in this study we synthesized six new complexes containing this core, including the binuclear complex [(dppb)(CO)Cl2Ru-pz-RuCl2(CO)(dppb)] (pz=pyrazine) which can be used as a precursor for the synthesis of cationic carbonyl species of general formula [RuCl(CO)(dppb)(N–N)]PF6 (N–N=diimine). Complexes with the formula [RuCl(py)(dppb)(N–N)]PF6 were synthesized by exhaustive electrolysis of these carbonyl compounds or from the precursors [RuCl2(dppb)(N–N)]. The new complexes were characterized by microanalysis, conductivity measurements, IR and 31P{1H} NMR spectroscopy, cyclic voltammetry and X-ray crystallography. [Copyright &y& Elsevier]