Reactions of dichloro[2-(dimethylaminomethyl)phenyl-C1,N]gold(III), [Au(damp-C1,N)Cl2], with heterocyclic thiols.: Evidence for Au-N bond cleavage and protonation of the dimethylamino group

Dichloro[2-(dimethylaminomethyl)phenyl-C-1,N]gold(III) [Au(damp-C-1,N)Cl-2], reacts with 2-mercapto-1,3-thiazoline (HSthiaz), 2-mercaptopyridine (HSpy), sodium 1-methylmercaptotetrazolate (NaSmetetraz), 4-methyl-3-mercapto-1,2,4-triazole (HSmetriaz) or 6-mercaptopurine (HSpur) under cleavage of the Au-N bond and protonation of the dimethylamino group. Compounds of general formulae [Au(Hdamp-C-1)Cl(HL)(2)](2+) (HL = HSthiaz or HSpy), [Au(Hdamp-C-1)Cl(L)] (L = Spur(-)) or [Au(Hdamp-C-1)(L)(3)] (L = Smetetraz(-)) have been isolated and characterized. The reaction with HSmetriaz leads to a rapid reduction of the metal and the formation of the gold(I) complex [Au(HSmetriaz) (2)](+). The crystal structures of [Au(Hdamp-C-1)Cl(HSthiaz)(2)]Cl-2 . Me2CO, [Au(Hdamp-C-1)Cl(HSpy)(2)]. H2O, [Au(Hdamp-C-1)(Smetetraz)(3)] and [Au(Hdamp-C-1)Cl(Spur)]Cl have been elucidated showing the gold atoms in distorted square-planar co-ordination environments. Generally, one or more hydrogen atoms of the heterocyclic ligands and/or the NMe2H+ group form hydrogen bonds in the solid-state structures. The reaction of Na[AuCl4] with Na(Smetetraz) and [NEt4]Br yields bright red crystals of [NEt4][Au(Smetetraz)(4)], the first structurally characterized gold(III) complex with four monodentate thiolate ligands. The structure of the complex shows well separated [Au(Smetetraz)(4)](-) anions with Au-S distances of 2.354(4) Angstrom.