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

Abstract

Fundamental to its chemical and electrochemical—especially electrochromic—reactions, energies of formation of the hydride anion in several solvents (and concomitant solvation energies) were re-evaluated ia a radius estimate derived from differing theoretical approaches of satisfactory mutual consistency. The values (Gibbs free energies—ions at the standard 1 mol dm⁻³, gases at 100 kPa; 25°C) with subscripted error-estimates were, in kJ mol⁻¹, for water 141₄, acetonitrile 207₉, N,N-dimethylformamide 228₁₄, dimethyl sulfoxide 219₁₁, methanol 156₉ (a first estimate), and nitrobenzene 183₁₁ (a first estimate). The aqueous, acetonitrile and N,N-dimethylformamide values are substantial revisions.