Angular Arenediethynyl Complexes of Gold(I)

Abstract

Alkynylgold(I) complexes have been prepared from the angular bis(alkyne) MeC6H3-3,5-(CCH)2, in which the alkyne units are rigidly fixed at an angle of 120° to each other. Reaction with [AuCl(SMe2)] and base yields the shock-sensitive, insoluble compound [{MeC6H3-3,5-(CCAu)2}n] (2), which reacts with isocyanide, phosphine, or phosphite ligands (L) to give [MeC6H3-3,5-(CCAuL)2] (3; L = P(OPh)3, P(OMe)3, PPh3, PMePh2, t-BuNC, MeNC). The complexes with L = P(OMe)3, PMePh2 exist in the solid state as infinite one-dimensional ribbon structures in which neighboring molecules are associated through secondary gold−gold bonding. Complexes with diisocyanide ligands 1,4-C6R4(NC)2 (R = H, Me) have the formula [{MeC6H3-3,5-(CCAu)2(μ-LL)}n] and are insoluble in organic solvents; they are suggested to have a zigzag polymeric structure. In contrast, complexes with diphosphine ligands (CH2)n(PPh2)2 (n = 1−6) are soluble and are suggested to be the cyclic tetragold(I) complexes of formula [{MeC6H3-3,5-(CCAu)2(μ-LL)}2]; the ...