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6849156 
Journal Article 
TRANSFER ENTHALPIES OF TERT-BUTYL CHLORIDE IN SOME AQUO-ORGANIC SOLVENTS 
Datta, M; Datta, M; Das, ML; Das, ML; Datta, J; Datta, J; Kundu, KK; Kundu, KK 
1993 
1 
Indian Journal of Chemistry. Section A
ISSN: 0376-4710
EISSN: 0975-0975 
32 
6 
472-477 
WOS:A1993LF25900002 
Transfer enthalpies, DELTAH(t)0, of tert-butyl chloride (t-BuCl) from water to aqueous mixtures of various cosolvents viz., protic ethanol (EtOH), tert-butanol (t-BuOH), ethanediol (EG) and methoxyethanol (ME), aprotic 1,2-dimethoxyethane (DME) and 1,4-dioxane (D) and dipolar aprotic N,N-dimethylformamide (DMF) and dimethyl sulphoxide (DMSO), have been determined at 25-degrees-C by measuring the partial molal heats of solution at infinite dilution (DELTAH(s)0)BAR with a rapid response Tronac (model 458) recording titration calorimeter by avoiding the uncertainties from hydrolysis of t-BuCl in the solvents. These DELTAH(s)0BAR values on extrapolation to zero cosolvent composition in each of the aqueous cosolvent systems lead to a common value for that of water ((w)DELTAH(s)0BAR), which is equal to 6.27 +/- 0.25 kJ mol-1. DELTAH(t)0 values of the initial state (IS) of T-BuCl (= (s)DELTAH(s)0BAR-(w)DELTAH(s)0BAR) on subtraction from the corresponding transfer activation energies partial derivative DELTAH(not-equal) (= (s)DELTA(not-equal) - (w)DELTAH(double dagger)) as obtained from parallel kinetic studies of the hydrolysis/solvolysis of t-BuCl in the solvents at different temperatures, and reported elsewhere, helped determine the transfer enthalpies DELTAH(t)0(TS) of the transition state (TS). A comparative view of the composition profiles of DELTAH(s)0BAR, as well as of partial derivative DELTAH(not-equal) and DELTAH(t)0 (TS) in the solvent systems reflects that while the variations in DELTAH(t)0BAR values are guided by complex structural and interaction effects in the respective solvents, DELTAH(t)0 (IS) values are fairly small as compared to partial-derivative DELTAH(not-equal) values. Evidently, partial-derivative DELTAH(not-equal) values are guided by the contributions of DELTAH(t)0 of TS rather than that of IS, contrary to what has been concluded by Arnett et al. from the corresponding studies only in aqueous ethanol system.<