Reactions of trimethylphosphine or diphosphines with SbCl(3) in the presence of AlCl(3) or Me(3)SiSO(3)CF(3) give ligand stabilized stibenium and stibinidenium cations. The geometry at each antimony center reveals a variety of environments for antimony that describes new bonding and highlights new directions in the chemistry of the pnictogen elements.

The bis(triphenylarsane) complex of the [P4]2+ dication has been formed in a high‐yielding one‐pot synthesis. X‐ray crystallography reveals a butterfly structure of the bicyclo[1.1.0]‐tetraphosphane‐1,4‐diium core, with two triphenylarsane ligands in an exo,exo configuration (see picture). The reaction of [(Ph3As)2P4]2+ with Ph3P results in the quantitative formation of [(Ph3P)2P4]2+ and Ph3As.

Arsine and stibine ligands stabilize bismuthenium cations and bismuthetidinium dications to give compounds containing As-Bi bonds and Sb-Bi bonds. The first enium-onium bonding environments in dications of the form [R'BiPnR(3)](2+) (Pn = As, Sb) contain the first definitive examples of carbenoid bismuth centers.