http://nopr.niscpr.res.in/handle/123456789/803 Sat, 10 Oct 2026 08:15:24 GMT 2026-10-10T08:15:24Z http://nopr.niscpr.res.in/handle/123456789/2235 Title: Physicochemical behaviour of copper(II) complexes of chelated dianune ligands: Catalytic role of diaquabis(ethylenediamine)copper(II) perchlorate in acylal formation Authors: Sarmah, Purabi; Singha, Sunita; Chakrabarty, Rajesh; Bora, Sanchay J; Das, Birinchi K Abstract: Preparation and propertics of a few chelated diarnine complexes of copper(II) are reported. Thc compounds, [Cu(en)₂(H₂O)₂](C lO₄)₂ (1), [Cu(tmen)₂(H₂O)₂](C lO₄)₂ (2), [Cu(en)₂Cl₄]ո (3) and [Cu(en)₂(SO₄)₂(H₂O)₄].2H₂O (4) have been prepared in moderate to excellent yields and characterized by various physicochemical techniques. The structure of [Cu₂(en)₂Cl₄]n (3) has been determined by single crystal X-ray diffraction. Complex 3 crystallizes in monoclinic space group P2l/m, with unit cell parameters a = 6.7850 (14) Aº, b = 5.7600(12)Aº, c = 8.2240(l6)Aº, β = 93.75(3)º, V = 320.7(1)Aº³. The structurc has been solved by direct method and refined by full-matrix least squares to final R₁ = 0.0460, wR₂ = 0.1249 and GooF = 1.135 for all 8 I 8 reflections. Each copper atom in complex 3 is present in a distorted octahedral environment creatcd by a chelating ethylenediamine ligand and four chlorine atoms. Two adjacent parallel -Cu-Cl-Cu- chains joined by short Cu-C1 bonds give rise to a zigzag ribbon-like polymer. Complex 1has been studied as a catalyst 1'01' thc conversion of aromatic aldehydes to acylals under solvent-free conditions at room temperature. Page(s): 1929-1937 Sat, 01 Dec 2007 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/2235 2007-12-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/2230 Title: Excess transport properties of binary mixtures of methanol and pyridine through ultrasonic measurements at different temperatures Authors: Rao, G V Rama; Sarma, A Viswanatha; Ramachandran, D; Rambabu, C Abstract: The viscosities, densities and ultrasonic velocities of binary liquid mixtures of methanol with piperidine and morpholine and pyridine with piperidine and morpholine have been determined at 303.15 to 318.15K over the entire composition range. These data have been utilized to estimate the excess free volume, excess internal pressure, excess enthalpy, excess velocity, excess acoustic impedance and excess Gibb’s free energy of activation of flow. The results obtained have been discussed in the light of existing theories of molecular interaction involved and chemical constitution of the liquid components. Analysis of these parameters indicates that there are intermolecular interactions among components of the binary mixtures that lead to possible hydrogen bond formation (of the type N…H-O) between unlike molecules. Page(s): 1972-1978 Sat, 01 Dec 2007 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/2230 2007-12-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/2229 Title: Kinetics and mechanism of visible light induced oxidation of hydrazine by peroxodisulphate in aqueous solution containing tris-(2,2′-bipyridine) ruthenium(II) Authors: Bansal, Savita; Soni, N K; Khandelwal, C L; Sharma, P D Abstract: The rate of visible light induced oxidation of hydrazine by peroxodisulphate in the presence of tris-(2,2´-bipyridine)-ruthenium(II) [Ru(bipy)₃²⁺] in aqueous solution is independent of the substrate concentration but increases with the intensity of light absorbed as follows: where ki is the initial rate and other the terms have their usual meaning. Page(s): 1969-1971 Sat, 01 Dec 2007 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/2229 2007-12-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/2228 Title: Complexes of ruthenium(III), rhodium(III) and iridium(III) with ligands bearing 2,6-diacetylpyridine bis(S-alkylisothiosemi-carbazones): Synthesis, spectral studies and structural elucidation Authors: Sharma, Vinod K; Srivastava, Ankita Abstract: Reactions of the ligands, 2,6-diacetylpyridine bis(S-methylisothiosemicarbazone) and 2,6-diacetylpyridine bis(S-butylisothiosemicarbazone) with ruthenium(III), rhodium(III) and iridium(III) have been studied and their structures have been proposed based on elemental analyses, molar conductance, magnetic moment, spectral data (IR, ¹H NMR, FAB mass) and thermal investigations. The ligands behave as pentacoordinated and give acyclic complexes of the general formula [M(H₂L)Cl₂]Cl and macrocyclic complexes, [M(L’)Cl₂]Cl•H₂O, which are formed by template condensation by using β-diketones. Pentagonal bipyramidal geometries are observed for acyclic and macrocyclic complexes. In both types of complexes, the ligands coordinate in their amino form. The thermal stability and mode of decomposition of the various complexes have been studied by TGA techniques. Conductance measurements reveal 1:1 electrolytic nature of the complexes. Page(s): 1963-1968 Sat, 01 Dec 2007 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/2228 2007-12-01T00:00:00Z