Angular arenediethynyl complexes of gold(I)

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 degrees 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)(mu-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)(mu-LL)}(2)]; the ring size varies from 24 to 34, depending on n.