SINGLE-ION ENTHALPIES OF TRANSFER FOR CONJUGATE-BASE ANIONS OF IMIDESIN ACETONITRILE-METHANOL MIXTURES - EMPIRICAL CORRELATION WITH SEMIEMPIRICAL MOLECULAR-ORBITAL CALCULATIONS

Single-ion enthalpies of transfer for conjugate-base anions of imides have been determined in acetonitrile-methanol mixtures and partitioned into constituent terms, the 'physical' interaction enthalpy, Delta(tr ,ph,AN-->MeOH)H and the specific interaction enthalpy, Delta(tr,SI,AN- ->MeOH)H. The latter enthalpies have been found to be linearly correla ted with atomic charges on the carbonyl oxygen which have been determi ned through semi-empirical molecular orbital calculations, MNDO/PM3, a nd this has the physical consequence that imidide ions form hydrogen b onds with methanol at the carbonyl oxygen of the imidide ion.