http://nopr.niscair.res.in/handle/123456789/11697 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/11704 Title: Dielectric measurements of nematic and smectic A phases in a binary system <br/> <br/>Authors: Bamezai, Rajinder K; Sharma, Meena; Gupta, Monika; Gupta, Ankush; Soni, Arti <br/> <br/>Abstract: The phase diagram of a binary mixture of 4-<i>n</i>-octyloxy- phenyl–4′-<i>n</i>-heptylcyclohexane carboxylate (molecule having weak polar terminal group) and 4-nitrophenyl-4′-<i>n</i>-pentylbenzoate (molecule having strong polar terminal group) has been studied using polarizing microscope and differential scanning calorimeter. The phase diagram shows an enhancement in smectic A phase over a wide composition range and intermediate nematic phase in a narrow composition range. The dielectric properties of these phases are investigated in the frequency range of 100 Hz to 1 MHz. <br/> <br/>Page(s): 680-684 Thu, 28 Apr 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/11703 Title: Synthesis, spectral characterization and DNA cleavage studies of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) complexes with benzofuran-2-carbohydrazide schiff bases <br/> <br/>Authors: Halli, M B; Patil, Vijayalaxmi B <br/> <br/>Abstract: New schiff bases have been synthesized from benzofuran-2-carbohydrazide and 1-naphthaldehyde [NMBC] or 6-methoxy-2-naphthaldehyde [MNMBC]. Complexes of the type MLX₂, where M = Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II), L = NMBC or MNMBC and X = Cl, have been synthesized and characterized on the basis of analytical data, IR, UV-vis, ¹H NMR, DART-MS and ESR spectral data and magnetic studies. All the complexes are soluble in DMF and DMSO. The measured molar conductance values indicate that the complexes are non-electrolytic in nature. The DNA cleavage activities of the schiff bases and their Co(II), Ni(II) and Cu(II) complexes have been studied by agarose gel electrophoresis method. The Cu(II), Ni(II) and Co(II) complexes have also been studied for their plasmid (pBR322) DNA cleavage activity. <br/> <br/>Page(s): 664-669 Thu, 28 Apr 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/11702 Title: Oxidation of substituted alkynes catalyzed by a non-heme iron(III) bis benzimidazole diamide complex as catalyst under ambient conditions <br/> <br/>Authors: Bakshi, Ruchi; Kumar, Ravinder; Mathur, Pavan <br/> <br/>Abstract: Bis-benzimidazole diamide ligand,<b style=""> </b>N,N′- bis(2-methylbenzimidazolyl) hexanediamide [GBHA = L], and its Fe(III) complexes have been synthesized. The Fe(III) complexes have been analyzed for the composition [Fe(L)X₃].nH₂O where X is an exogenous anionic ligand (X=Cl¯, NO_3­¯) and characterized by IR, UV-visible, cyclic voltammetry and EPR spectroscopy. Low temperature EPR spectra have been obtained for the complexes that indicate rhombic geometry environment in solution state. Oxidation of substituted alkynes has been investigated using these Fe(III) complexes as catalyst with TBHP and H₂O₂ as an alternate source of oxygen. The isolated products have been characterized by GC-MS. <br/> <br/>Page(s): 658-663 Thu, 28 Apr 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/11701 Title: Mechanistic studies of aquachlororhodium(III) catalysis in potassium iodate oxidation of 1,2-propanediol in acidic medium: A kinetic approach <br/> <br/>Authors: Singh, Bharat; Singh, Aniruddh Kumar; Singh, Anamika <br/> <br/>Abstract: The kinetics of homogeneously Rh(III) catalysed oxidation of 1, 2-propanediol by acidic solution of potassium iodate at constant ionic strength of the medium has been investigated at 308 K. The reaction follows complex kinetics, being first order in [KIO₃], zero order in 1, 2-propanediol and inverse fractional order in both [H⁺] and [Cl^¯]. The first order rate constant increases linearly with increase in [Rh(III)] in its lower concentration range but as the concentration of Rh(III) is increased towards the higher range, the rate constant becomes almost constant, indicating positive fractional order in [Rh(III)]. Variation of ionic strength of the medium and successive addition of mercuric acetate (used as I^¯ ions scavenger) has a positive effect on the rate of the reaction. IO₃^¯ and [RhCl₅(H₂O)]^-2 have been postulated as the reactive species of KIO₃ and Rh(III), respectively. Activation parameters for the slow and rate determining step of the proposed mechanism, which involves the formation of the most activated complex, [Cl₅Rh(HO→Hg)]^¯, prior to the slowest step, have been obtained from rate measurements at 30, 35, 40 and 45 °C. The rate law conforming to the observed kinetic results has been derived as <img src='http://www.niscair.res.in/jinfo/IJCA/IJCA 50A(5) 650-657-image.gif'>. The main oxidation products have been identified as acetic acid and formic acid <br/> <br/>Page(s): 650-657 Thu, 28 Apr 2011 22:58:59 GMT