The Lewis-base behavior of Bunsen's cacodyl disulfide, Me₂As(S)‒S‒AsMe₂, toward molecular halides of group 13

Abstract

Molecular halides of group 13 in chloroform solutions interact but do not split Bunsen's cacodyl disulfide, Me₂As(S)‒S‒AsMe₂. With BF₃ · Et₂O cacodyl disulfide gives an equilibrated mixture of Me₂As(S)‒S‒AsMe₂ and Me₂As‒SS‒AsMe₂, whereas AlCl₃ causes complete isomerization to Me₂As‒SS‒AsMe₂ which is stabilized by complexation to AlCl₃. GaCl₃ and InCl₃ do not isomerize Me₂As(S)‒S‒AsMe₂ but only bind to it. Thallium(III) acetate, splits Me₂As(S)‒S‒AsMe₂ giving initially the unstable thallium(III) complex, (Me₂AsS₂)₃Tl, which is spontaneously converted to Me₂AsS₂Tl. The electrons for the reduction Tl(III) → Tl(I) most likely come from two of the ‒ ⁻ sulfur anions bound to the initially formed (Me₂AsS₂)₃Tl.

Keywords:

• dimethylarsino dimethyldithioarsinate
• boron trifluoride etherate
• aluminum(III), gallium(III), indium(III) chlorides
• thallium(III) acetate
• thallium(I) dimethyldithioarsinate