Transfer free energies of trimethylammonium hydrochloride-a precursor to a potential model transition state for S_Nl-type hydrolysis of <em>tert-</em>butyl chloride in some aquo-organic solvents

Abstract

Transfer free energies, <img src='/image/spc_char/delta.gif' border=0><em>G</em>, of trimethylammonium hydrochloride (Me₃NHCl)-a precursor to a potential model for the transition state (TS) for <em>S</em>_Nl-type hydrolysis of <em>tert-</em>butylchloride (<em>t</em>-BuCI), have been determined in aqueous mixtures of various organic co solvents viz protic ten-butanol (<i>t</i>-BuOH), ethylene glycol (EG), glycerol (GL) and methoxyethanol (ME), aprotic dimethoxyethane (DME) and dioxane (D) and dipolar aprotic 1,2-dimethylformamide (DMF) and dimethyl sulphoxide (DMSO). These have been determined by measuring the solubilities of sparingly soluble salt Me₃NHBPh₄ (Ph = phenyl) at 25ᵒC in the solvents and by using the relation:<br> <img src='/image/spc_char/delta.gif' border=0><em>G</em><img src='http://www.niscair.res.in/jinfo/zerot.gif' border=0> (Me₃NHCl) = <img src='/image/spc_char/delta.gif' border=0><em>G</em><img src='http://www.niscair.res.in/jinfo/zerot.gif' border=0> ( Me₃NHBPh)₄ - <img src='/image/spc_char/delta.gif' border=0><em>G</em><img src='http://www.niscair.res.in/jinfo/zerot.gif' border=0> (Ph₄B^-) + <img src='/image/spc_char/delta.gif' border=0><em>G</em><img src='http://www.niscair.res.in/jinfo/zerot.gif' border=0> (Cl^-).