Gold(I) Phosphido Complexes: Synthesis, Structure, and Reactivity

Deprotonation of the phosphine complexes Au(PHR2)Cl with aqueous ammonia gave the gold(I) phosphido complexes [Au(PR2)]n (PR2 = PMes2 (1), PCy2 (2), P(t-Bu)2 (3), PIs2 (4), PPhMes (5), PHMes* (6); Mes = 2,4,6-Me3C6H2, Is = 2,4,6-(i-Pr)3C6H2, Mes* = 2,4,6-(tBu)3C6H2, Cy = cyclo-C6H11). 31P NMR spectroscopy showed that these complexes exist in solution as mixtures, presumably oligomeric rings of different sizes. X-ray crystallographic structure determinations on single oligomers of 1-4 revealed rings of varying size (n = 4, 6, 6, and 3, respectively) and conformation. Reactions of 1-3 and 5 with PPN[AuCl2] gave PPN[(AuCl)2((mu)-PR2)] (9-12, PPN = (PPh3)2N+). Treatment of 3 with the reagents HI, I2, ArSH, LiP(t-Bu)2, and [PH2(t-Bu)2]BF4 gave respectively Au(PH(t-Bu)2)(I) (14), Au(PI(t-Bu)2)(I) (15), Au(PH(t-Bu)2)(SAr) (16, Ar = p-t-BuC6H4), Li[Au(P(t-Bu)2)2] (17), and [Au(PH(t-Bu)2)2]BF4 (19).