The radical-cation of hydrogen sulfide

A centre formed in KCl crystals doped with KSH has been identified as the H2S.- radical-anion (A. Hausmann, Z. Phys., 1966, 192, 313). The EPR parameters for the centre are examined herein and it is suggested that this assignment is incorrect. Also, comparison with the results for authentic H2S.- anions in an argon matrix (J. E. Bennett, B. Mile and P. Thomas, J. Chem. Soc., Chem. Commun., 1966, 192) shows that the centre in KCl crystals cannot be H2S.-. Analysis of the EPR parameters leads firmly to the conclusion that this centre is the previously unknown radical-cation, H2S.+.