NOPR Collection:

A quantum chemical study of hydrogen abstraction from silane by methyl radical

Thu, 01 Jul 1993 00:00:00 GMT

Title: A quantum chemical study of hydrogen abstraction from silane by methyl radical Authors: Malar, E J Padma Abstract: The potential profile for the hydrogen abstraction reaction from silane by methyl radical is computed quantum chemically. The all-valence electrons semiempirical SCF MO methods SINDOI and MNDO predict comparable activation barriers of 68.5 and 75.2 kJ mol^-1 respectively. The lower activation barrier of the title reaction as compared to that of the thermoneutral reaction CH₃ + CH₄ → CH₄ + CH₃ reflects the greater ease of abstracting a hydrogen atom from silane than that from methane. This is in agreement with the lower bond dissociation energy in silane (377.5 kJ mol^-1) than that in methane (431.4 kJ mol^-1). Page(s): 557-560

Interaction of egg lecithin with, π-electron acceptors

Thu, 01 Jul 1993 00:00:00 GMT

Title: Interaction of egg lecithin with, π-electron acceptors Authors: Chatterjee, Ira; Sen-Varma, Chirasree; Bhowmik, Benoy B. Abstract: Spectral studies show that egg lecithin forms 1:1 molecular complexes with different π-electron > acceptors such as picric acid, tetracyanoethylene and chloranil in chloroform. In water the π-electron acceptors are already complexed and the spectra of these π-electron acceptors are not further perturbed in the presence of egg lecithin. Thermodynamic and spectrophotometric properties of the complexes show that the acceptor strengths of the π-electron acceptors studied are in the order, picric acid > tetracyanoethylene > chloranil. The exact site of interaction of electron acceptor in egg lecithin has also been identified. Page(s): 561-564

Thermodynamics of transfer of polar nonelectrolytes from water to aqueous salt solutions

Thu, 01 Jul 1993 00:00:00 GMT

Title: Thermodynamics of transfer of polar nonelectrolytes from water to aqueous salt solutions Authors: Sugunan, S; Thomas, Benny Abstract: The Setschenow parameter and thermodynamic parameters of transfer of a number of mono substituted benzoic acids from water to different salt solutions have been reported. The data have been rationalized by considering the structure breaking effects of the ions of the salts, the localized hydrolysis model, the internal pressure theory and Symons' theory of water structure. Page(s): 565-567

lnteraction of some pyridinol azo dyes with chlorite mineral

Thu, 01 Jul 1993 00:00:00 GMT

Title: lnteraction of some pyridinol azo dyes with chlorite mineral Authors: Srivastava, S K; Gupta, V K; Mohan, Dinesh Abstract: The adsorption of two anionic pyridinol azo dyes on chlorite mineral has been observed as a function of pH and temperature. The orientation of dye molecules on edge surface has been envisaged by observing the exchange site dimensions etc., and the same has been supported by X-ray measurements. Thermodynamic parameters of the process have also been evaluated. Page(s): 568-571