Estimates of hydride ion stability in condensed systems: energy of formation and solvation in aqueous and polar-organic solvents

Fundamental to its chemical and electrochemical-especially electrochromic-r eactions, energies of formation of the hydride anion in several solvents (a nd concomitant solvation energies) were re-evaluated via a radius estimate derived from differing theoretical approaches of satisfactory mutual consis tency. The values (Gibbs free energies-ions at the standard 1 mol dm(-3), g ases at 100 kPa; 25 degreesC) with subscripted error-estimates were, in kJ mol(-1), for water 141(4), acetonitrile 207(9), N,N-dimethylformamide 228(1 4), dimethyl sulfoxide 219(11), methanol 156(9) (a first estimate), and nit robenzene 183(11) (a first estimate). The aqueous, acetonitrile and N,N-dim ethylformamide values are substantial revisions.