The reactions of triethylamine-activated octasulfur with thioarsinites, L₂As‒SPh (L = Me, Ph), Bunsen's cacodyl disulfide, Me₂As(S)‒S‒AsMe₂, and triphenylarsine

Abstract

The reactions of L₂As‒SPh (L = Me or Ph) with varying amounts of octasulfur, activated by triethylamine, aiming at the preparation of L₂As‒S‒AsL₂ and L₂As(S)‒S‒AsL₂ were slow and very complex in the sense that the composition in solution changed on work up. Generally, the disulfide L₂As(S)‒S‒AsL₂ was formed admixed with L₂As‒S‒NEt₃ ⁺ and L₂As‒S⁻. The disulfide Ph₂As(S) ‒S‒AsPh₂ was not stable during chromatography giving sulfur (S₈) and Ph₂As‒S‒AsPh₂ which was autoxidized to Ph₂AsO₂H·Ph₂As(S)OH. Bunsen's cacodyl disulfide, Me₂As(S)‒S‒AsMe₂, was electrophilic toward activated octasulfur reacting at As˭S sulfur. Triphenylarsine was oxidized to pure triphenylarsine sulfide in boiling ethanol by octasulfur in the presence of a catalytic amount of triethylamine in short time and with excellent yields.

Keywords:

• thioarsinites
• bis(dimethylarsenic) sulfide
• bis(diphenylarsenic) sulfide
• dimethylarsino dimethyldithioarsinate
• diphenylarsino diphenyldithioarsinate
• triphenylarsine sulfide
• octasulfur