Structural investigation of bis(isonitrile)gold(I) complexes

The reaction of (MeNC)-, (PhNC)- and (MesNC) AuCl in tetrahydrofuran with an equimolar amount of the corresponding isonitrile ligand and one equivalent of Ag(+)X(-) (X(-) = BF4- or CF3SO3-) leads to the formation of the bis(isonitrile)gold(I) complexes (MeNCAu+ CF3SO3- (1), (PhNCAu+ BF4- (2) and (MesNCAu+ BF4- (3). The crystal structures of 1, 2 and 3 have been determined. In compound 1 there are rod-like cations with a parallel packing into meandering puckered layers, in which the gold atoms have alternating Au-Au contacts of 3.611 and 3.624 Angstrom. In complex 2 the cations form long double-paddles, with the two paddles at an angle of 77.5 degrees. The individual cations are well separated and have no sub-van-der-Waals Au-Au contacts. The crystal structure of 3 is similar, but with a smaller dihedral angle between the planes of the two mesityl rings (56.0 degrees).