Goodbye to S2- in aqueous solution

Abstract

New Raman spectra of Na2S dissolved in hyper-concentrated NaOH(aq) and CsOH(aq) cast serious doubt on the widely-assumed existence of S2-(aq). To avoid conceptual and practical problems with sulfide equilibria in numerous applications, S2-(aq) should be expunged from the chemical literature. Thermodynamic databases involving sulfide minerals also need careful revision.