http://nopr.niscpr.res.in/handle/123456789/46224 Fri, 09 Oct 2026 12:42:49 GMT 2026-10-09T12:42:49Z http://nopr.niscpr.res.in/handle/123456789/46319 Title: X-Ray photoelectron spectroscopic studies of modified zeolite catalysts Authors: Kulkarni, S J; Badrinarayanan, S Abstract: The X-ray photoelectron spectra of the modified FeNaY, mordenite (zeolon) and HZSM5 catalysts have been studied. The effects of per cent ferric exchange, thermal activation and coking on binding energies and the (Si/AI) atomic ratios in the external surfaces have been evaluated. The multiple structure of Si(2<em>s</em>) peak in XPS of coked zeolites indicates that the coke deposit interacts strongly with SiO₄ tetrahedra. The splitting of the O(1<em>s</em>) peak in the XPS of the coked FeNaY zeolite and the occurrence of a peak at 527.0 eV are characteristics of the dehydrogenating catalyst. Page(s): 201-204 Thu, 01 Mar 1990 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/46319 1990-03-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/46318 Title: Determination of inductive effect parameter of methyl group from trends in fluorescence maxima of some charge-transfer complexes of N-ethyltetrachlorophthalimide with methyl benzenes and methoxybenzenes using graph theoretical technique Authors: Roy, M; Mukherjee, A K; Seal, B K Abstract: From trends in fluorescence maxima (hv_CT(f)) of charge transfer complexes of N-ethyltetrachlorophthalimide with methylbenzenes and methoxybenzenes the inductive effect PMO parameter of the methyl group has been calculated using Coulson-Longuet-Higgins perturbation theory. For complexes of methylbenzenes h_Me is found to be ~ 0.175 while for methoxybenzenes a value of -0.2855 has been estimated for the same. The agreement with literature data is good. The necessary perturbational coefficients and eigenvalues have been calculated using some recently developed graph theoretical techniques which reduce the entire computation to a paper-and-pencil work. Page(s): 205-209 Thu, 01 Mar 1990 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/46318 1990-03-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/46317 Title: Standard electrode potential of Br<img src='/image/spc_char/3_bar.gif' border=0>/Br^-, Br₂/ Br<img src='/image/spc_char/3_bar.gif' border=0> and B₂/Br redox couples and related formation constants of Br<img src='/image/spc_char/3_bar.gif' border=0> in some dipolar aprotic solvents Authors: Dutta, Jayati; Kundu, Kiron K Abstract: Standard potentials of Br<img src='/image/spc_char/3_bar.gif' border=0>/Br^-, Br₂/ Br<img src='/image/spc_char/3_bar.gif' border=0> and B₂/Br redox couples have been determined in dipolar aprotic solvents like acetonitrile (AN), N,N-dimethylformamide (DMF) and propylene carbonate (PC) at 25ᵒC by potentiometric method, The standard potentials of the redox couple Br₂/Br^- as well as the related formation constants (<em>K</em>_f) of Br<img src='/image/spc_char/3_bar.gif' border=0> in the solvents have also been derived thereof. These values help derive transfer free energies, <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0>G<img src='http://www.niscair.res.in/jinfo/zerov.gif' border=0>, Br<img src='/image/spc_char/3_bar.gif' border=0> and Br₂ from water to the solvents, as the corresponding values of Br^- based on TATB reference electrolyte are already known in the literature. <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0>G<img src='http://www.niscair.res.in/jinfo/zerot.gif' border=0> values of different Br-species have also been examined in the light of various types of interactions, such as cavity, Born, ion-dipole, ion-induced dipole and the rest 'chemical' as guided chiefly by dispersion-type soft-soft interactions. Page(s): 210-214 Thu, 01 Mar 1990 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/46317 1990-03-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/46316 Title: Solvent effect on electronic absorption spectra of some chlorophenols: Part II - Application of Bakhshiev's theoretical model for elucidating excited state dipole moments and specific solute-solvent interaction energies Authors: Prabhumirashi, L S; Kunte, S S Abstract: A systematic and simple procedure employing Bakhshiev's expression for solvatochromic frequency shifts in electronic absorption spectra for estimating the excited state dipole moments and specific solute-solvent interaction energies is developed. The results for several chlorophenols based on this method are found to be in close agreement with those obtained by applying the more commonly used McRae's expression-for solvent-induced frequency shifts. The method described herein can be employed as an alternative approach for studying solute-solvent interactions. Page(s): 215-219 Thu, 01 Mar 1990 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/46316 1990-03-01T00:00:00Z