Gold complexes with thiosemicarbazones: reactions of bi- and tridentate thiosemicarbazones with dichloro[2-(dimethylaminomethyl)phenyl-C 1,N ]gold(III), [Au(damp-C 1,N )Cl2]

Abstract

Dichloro[2-(N,N-dimethylaminomethyl)phenyl-C1,N]gold(III), [Au(damp-C1,N)Cl2] (1), reacts with salicylaldehyde thiosemicarbazone (H2saltsc), vanilline thiosemicarbazone (Hvantsc), N-methylpyrrole aldehyde thiosemicarbazone (Hmepyrtsc), pyridoxal methylthiosemicarbazone (H2pydoxmetsc), 2-diphenylphosphinobenzaldehyde thiosemicarbazone (HPtsc) or variously substituted acetylpyridine thiosemicarbazones (HapRtsc; R = H, Me, Ph) with cleavage of the Au–N bond and protonation of the dimethylamino group. Compounds of general formulae [Au(Hdamp-C1)Cl(L)]+ (L = Hsaltsc−, vantsc−, mepyrtsc−), [Au(Hdamp-C1)Cl(L)]2+ (L = H2pydoxmetsc) or [Au(Hdamp-C1)(L)]2+ (L = Ptsc−, apRtsc−, R = H, Me, Ph) have been isolated and characterized. The presence of the σ-bonded 2-(dimethylaminomethyl)phenyl ligand is mandatory to prevent reduction of the gold(III) centre. The crystal structures of [Au(Hdamp-C1)Cl(Hsaltsc)](PF6) (3a), [Au(Hdamp-C1)Cl(mepyrtsc)]Cl (3c), [Au(Hdamp-C1)Cl(H2pydoxmetsc)]Cl2·MeOH (4), [Au(Hdamp-C1)(apPhtsc)]Cl2·2 MeOH (5c) and [Au(Hdamp-C1)(Ptsc)]Cl2· 1.5MeOH (6) have been elucidated, showing the gold atoms in distorted square-planar co-ordination environments.