Arsolidinium Cations

A series of cyclic thia- and amino- arsenium cations have been prepared and structurally characterised and represent rare examples of cationic environments for arsenic (III). Novel structural arrangements are observed, which illustrate the instability of di-coordinate environments for arsenic. The 1,3-dimethyl-1,3-diaza-2-arsolidinium cation and the 1,3-dithia-2-arsolidinium cation both exist as dimers in the solid state. The dithiaarsolidinium cation is also observed as a component of an unusual bicyclic cationic complex. A genuine dicoordinate environment for arsenic has been isolated as a heteronaphthalenic system, which relies on Huckel features for stabiliaation.