http://nopr.niscpr.res.in/handle/123456789/46227 Fri, 09 Oct 2026 13:23:05 GMT 2026-10-09T13:23:05Z http://nopr.niscpr.res.in/handle/123456789/46370 Title: A novel single-pot conversion of 2-diphenylarsinobenzoic acid into 2-phenylchloroarsino benzophenone by PCl3 or MeCOCl Authors: Parmar, Swam S; Bathla, Harinder K; Saluja, Harveen K Abstract: The acyl chloride intermediate (<strong>8a</strong>)/(<strong>8b</strong>) formed in the reaction of 2-diphenylarsinobenzoic acid (4) with PCl₃ or MeCOCl, undergoes a sigmatropic exchange of Cl and Ph groups to yield 2-phenylchloroarsinobenzophenone (<strong>5</strong>) which contains a heterocyclic ring. The heterocyclic ring is formed due to intramolecular coordination of carbonyl oxygen to arsenic(III). Page(s): 405-406 Tue, 01 May 1990 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/46370 1990-05-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/46369 Title: Modification of the SOCl₂-RCO₂H reaction route by a vicinal arsenic(III): A novel conversion of 2-carboxyphenyldi-phenylarsine into the first stable acyloxy-chloroarsorane Authors: Parmar, Swarn S; Saluja, Harveen K Abstract: 2-Carboxyphenyldiphenylarsine (4) reacts with SOCl₂ to yield the first stable monocyclic acyloxy-chloroarsorane, 1-chloro-1, 1-diphenyl-2,1 A 5-benzoxarsol-3-one [(1), E ;= As] through the successive intermediate formation of 2-dichlorodiphenylarsoranobenzolc acid (<strong>5c</strong>)/(<strong>5d</strong>), 2-hydroxychlorodiphenylarsoranobenzoyl chloride (<strong>5a</strong>)/(<strong>5b</strong>) and the HCl adduct (5e) of [(<strong>1</strong>), E = As]. Page(s): 407-408 Tue, 01 May 1990 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/46369 1990-05-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/46368 Title: A molecular level interpretation of ion exchange selectivity Authors: Gupta, AR Abstract: A molecular level interpretation of ion exchange selectivity has to be based on various types of interactions in the exchanger phase and the corresponding interactions in the solution phase. The various interactions in the resin phase, i.e. ionogenic group-water, ionogenic group counterion, counterion-water, and water-water interactions have been discussed in the light of available information in the literature on alkali metal cation/ lithium ion exchanges on Dowex 50W resins of different cross linking. Recently developed technique for studying counterion-water and water-water interactions in these resins (which uses hydrogen isotope effects in the dehydration of these resins as a probe for studying these interactions) has been described in some detail. Selectivity sequence for the alkali metal cations in these resins as well as the effect of cross linking on the selectivity have been interpreted in terms of the various molecular interactions involved. Selectivity sequence arises because of the greater hydration of more preferred cation in the resin phase compared to that in the solution phase. As the crosslinking decreases and the resins imbibe more water, the hydration shells of the preferred cations are progressively destroyed by the normal water structure formed by the free water present in the resins thus selectivity decreases with decreasing cross linking. Page(s): 409-417 Tue, 01 May 1990 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/46368 1990-05-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/46367 Title: Fluorescence quenching of tryptophan, 4-methyl- 2,6-diformylphenol and 5-hydroxytetracycline by ethylene trithiocarbonate at high pH Authors: Ray, R; Mukherjee, S Abstract: Ethylene trithiocarbonate (ETTC) s shown to quench the fluorescence of tryptophan (Trp), 4-methyl-2,6-diformylphenol (Mfp) and 5-hydroxytetracycline (Htc) in aqueous alkaline medium at 300K. Rate constant measurements indicate that in all the three cases the quenching process is not entirely deactivation of the excited state, but in part may be due to association between fluorescers and quencher in its ground state, as shown by positive curvatures in Stern-Volmer plots. Bimolecular rate constants (<em>k</em>_q) are obtained from steady-state measurements leading to a modified form of the Stern-Volmer equation. Page(s): 418-421 Tue, 01 May 1990 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/46367 1990-05-01T00:00:00Z