RIGID-ROD COMPOUNDS - MONOMERIC AND OLIGOMERIC COMPLEXES WITH GOLD(I) CENTERS BRIDGED BY (ISOCYANOARYL)ACETYLIDES

The new ligands 4-CNC6H4CCH (1a) and 3-Me-4-CNC6H3CCH (1b), which contain 4-isocyano-1-ethynylbenzene units designed to act as bridging ligands in rigid-rod, conjugated organometallic polymers, have been prepared. They react with [AUCl(SMe2)] and with [(AuCC-t-Bu)4] to give the corresponding isocyanide complexes [ClAuC=N-AR-C=CH] (2) and [t-BuC=CAuC=N-Ar-C=CH] (5) (Ar = C6H4, Me-C6H3), respectively. The structures of 2a and 5b have been determined by single-crystal X-ray diffraction studies. Complexes 5, when heated in benzene solution, eliminate t-BuCCH to give the rigid-rod, conjugated oligomers [t-BuC=C(AuC=N-Ar-C=C)(x)H] (6a, Ar = C6H4; 6b, R = MeC6H3).