Syntheses and structures of [Me2Si{As(PBu)3}2] and [(CyP)3SiMe2] (Cy = cyclohexyl, C6H11)

The reaction of the anion (^tBuP)₃As]⁻ (1) with Me₂SiCl₂ results in nucleophilic substitution of the Cl⁻ anions, giving the di- and mono-substituted products Me₂Si{As(P^tBu)₃}₂] (3a) and Me₂Si(Cl){As(P^tBu)₃}] (3b). Analogous reactions of the pre-isolated (CyP)₄As]⁻ anion (2) (Cy = cyclohexyl) with Me₂SiCl₂ produced mixtures of products, from which no pure materials could be isolated. However, reaction of 2 generated in situ from CyPHLi and As(NMe₂)₃] gives the heterocycle (CyP)₃SiMe₂] (4). The X-ray structures of 3a and 4 are reported.