Acetylacetonates of Nickel( 11) and Copper( 11) as Accelerators for the Epoxy Resin System

The acetylacetonates of nickel(II) and copper(II) serve as accelerators for the anhydride-curable epoxy resin system. An appreciable lowering in the cure gel time and a substantial increase in the rate of curing is observed with enhanced concentrations of the metal chelates. Cure kinetic studies and cure schedules have been followed using a differential scanning calorimeter. The thermal and electrical insulation characteristics of the cured epoxy system are little affected by the variation of temperature, voltage, and aging under UV radiation. (C) 1994 John Wiley & Sons, Inc

Complexes of ruthenium(II) and ruthenium(III) with tertiary arsines

Ruthenium trichloride reacts with stoichiometric amounts of tertiary arsines in boiling ethanol to give paramagnetic complexes, RuCl3(Ph2RAs)3 (R = Me, Et, Pr, Bu), which react further with 2,2′-bipyridyl(bipy) and o-phenanthroline(phen) to yield brick red crystalline products, RuCl3 (N-N)(Ph2RAs) (N-N = bipy, phen). In the presence of excess arsine Ru(III) is reduced to Ru(II), and trichloro-bridged complexes of the formula [Ru2Cl3(Ph2RAs)6]Cl are formed. These on treatment with carbonylated solutions of rhodium chloride produce yellow crystals of [Ru2Cl3(Ph2RAs)6][RhCl2(CO)2] containing Ru(II) and Rh(I). Several dicarbonyl complexes cis-RuX2(CO)2(Ph2RAs)2 (X = Cl, Br; R = Pr, Bu) have also been isolated. © 1977

arbonyl complexes of rhodium and iridium with tricyclohexyl arsine

Tricyclohexylarsine (L) complexes of Ir and Rh carbonyls were prepd. Thus, treating the carboxylation mixt. from Rh halides with L gave RhXL2(CO) (X = Br, Cl) which added X2 to give RhX3L2(CO)​. Treating the Ir analogs with HX gave IrHX2(CO)​L2, which by dehydrohalogenation gave mixed IrX(CO)​L2 and IrX(CO)​(O)​2L2

Hydrogenation of nitroarenes using polybenzimidazole-supported rhodium catalyst

Polybenzimidazole (PBI)-supported rhodium PBI-Rh(I) catalyst was prepared and characterised by chemical analysis, IR, TGA and X-ray photoelectron spectroscopy. Sodium borohydride was used to produce active species of the catalyst. The anchored catalyst PBI-Rh(I) was found to be effective for the reduction of nitrophenols, nitrobenzoic acids and nitroanilines in methanol at room temperature and at 1 atm hydrogen. The influence of temperature, concentrations of the catalyst and substrate and nature of the solvent on the reaction rates was investigated. The recycling efficiency of the catalyst was found to be good. A probable mechanism for the catalytic reaction has been suggested. © 2004 Elsevier B.V. All rights reserved

Complexes of osmium with tertiary arsines and carbonmonoxide

Osmium halides (Cl and Br) react with monotertiary arsines Ph2RAs (R=Me, Et, Pr and Bu) in alcoholic medium to give paramagnetic octahedral complexes of the type OsX3L3 (X=Cl, Br; L=Ph2RAs) which further react with carbonmonoxide to give dihalo dicarbonyl complexes of osmium(II) of the type OsX2 (CO)2 L2. Similarly, osmium halides react with tertiary arsines in the presence of formaldehyde to give monocarbonyl complexes of osmium(II) of the type OsX2 (CO)L3. Structures have been assigned to all these compounds on the basis of IR and NMR studies. © 1980 Indian Academy of Sciences

Structural investigation, spectroscopic and energy level studies of Schiff base: 2-(3�-N-salicylidenephenyl)benzimidazole using experimental and DFT methods

The Schiff base 2-(3�-N-salicylidenephenyl)benzimidazole (Spbzl) was characterized by FT-Raman, 1H NMR, 13C NMR and single crystal X-ray diffraction technique. Crystallographic studies reveal the presence of two water molecules in the asymmetry unit which aid the intermolecular hydrogen bonding with imidazole ring, and the trans-conformation of the azomethine bond. Theoretical computations conducted using density functional theory (DFT) analysis support the experimental facts. Energy levels estimated by DFT studies are in good agreement with the values obtained from cyclic voltammetry technique. Frontier molecular orbital analysis shows that charge transfer has taken place from donor to acceptor moiety, which is also supported by the high hyperpolarizability values in both gaseous and solution phases, indicating high charge transfer capability of the molecule. A comparative theoretical study of Spbzl with derivative 4-((3-(1H-benzimidazol-2-yl)phenylimino)methyl)-3-hydroxybenzoic acid (Pbzlb) having an added anchor group COOH substituted at para position in the acceptor ring has been made. The result shows the feasibility of charge transfer to the semiconductor surface in dye sensitized solar cell (DSSC) applications for Pbzlb. © 2017 Elsevier B.V

Monochelates and bischelates of nickel(II) with bis-benzimidazolyl derivatives

The reaction of the hydrated halides/perchlorate of nickel(II) with bis-benzimidazolyl derivatives (I), namely, 1,3-bis(benzimidazol-2-yl) benzene (bbzlH2bzH; L1), 1,3-bis(1-methylbenzimidazol-2-yl) benzene (bbzlMe2bzH; L2) and 2.6-bis(1-methylbenzimidazol-2-yl)pyridine (bbzlMe2py; L 3) in stoichiometric amounts in absolute ethanol-teof and acetone has afforded a series of nickel(II) complexes with the formulae NiX 2L.nH2O (X = Cl or Br, L = L1 or L 2, n = 2; X = I, L = L2. n = 1; X = Cl, Br or I, L = L3, n = 0), NiI2L1H2O.(CH 3)2CO and Ni(L)2(ClO4) 2.nH2O (L = L1 or L2, n = 0; L = L3, n = 2. The brown iodo complex, NiI2L3 turns green on exposure to atmosphere, giving NiI2L 3.2H2O. The complexes have been characterised by elemental analyses, conductivity and magnetic measurements, infrared and electronic spectral studies as well as thermal analysis

Reactions of zinc salts with bis(Benzimidazolyl) derivatives

Zinc complexes of the formulae ZnX2L·nH2O X = Cl or Br, n = 2, X = I, n = 1, L - L1, 1,3-bis(benzimidazol-2-yl)benzene; X = Cl, Br or I, n = 0, L = L2, 1,3-bis(1-methylbenzimidazol-2-yl)benzene and Zn(L)2(ClO 4)2·2H2O (L = L1 and L 2) were obtained by the reactions of zinc halides/perchlorate with N-heterocycles in ethanol. The complexes have been characterized based on elemental analyses, molar conductance measurements, IR, 1H and 13C NMR spectral studies and thermal analysis