Ligand Influences on the Supramolecular Chemistry of Simple Gold(I) Complexes: Mononuclear (Isonitrile)gold(I) Complexes

A series of (isonitrile)gold(I) complexes has been synthesized: (MeNC)AuX (X = Cl 1a, 1 1c), (t-BuNC)AuBr 2b, (PhNC)AuX (X = Cl 3a, Br 3b, 1 3c, SCN 3d), (MesNC)AuCl 4a [mes=mesityl], and (MeOC(O)CH₂NC)AuX (X = Cl 5a, Br 5b, I 5c, SCN 5d). The chlorides were prepared by the reaction of (Me₂S)AuCl with equimolur amounts (or with an excess) of the corresponding isonitrile. The bromides, iodides and thiocyanates were obtained from the reaction of (RNC)AuCl with K⁺K^- (X = Br, I, SCN) in the two-phase system H₂O/CH₂Cl₂. The molecular and crystal structures of 1a, 2b, 3a-c, 4a, and 5a-c have been determined by X-ray diffraction methods. In the solid state the molecules are aggregated through short Au-Au contacts into dimers (4a and 5c), chains (1a, 2b and 3a-c) or sheets (5a and 5b). The influence of the isonitrile and halide ligands on the type and strength of the intermolecular Au-Au contacts is discussed.