Aurophilicity in gold(I) thiosemicarbazone clusters

The reaction of the phosphine thiosemicarbazone ligands HLPH and HLPMe with Au(I) ions yields the gold complexes [Au-3(HLPH)(2)Cl-2]Cl center dot 2MeOH(1 center dot 2MeOH) and [Au-2(HLPMe)Cl-2] (2). The structures determined by X Ray diffraction, [Au-3(HLPH)(2)Cl-2]Cl center dot 4MeOH (1 center dot 4MeOH) and [Au-2(HLPMe)Cl-2](2) (2), are the first examples of gold(I) thiosemicarbazone clusters showing aurophilicity. The structure of the trinuclear cation 1 contains the Au(1) atom located in an inversion centre, being connected to another gold(I) atom, Au(2), through a phosphino thiosemicarbazone molecule which acts as a S, P-bridging ligand. Additionally, every gold(I) atom in the trinuclear cation 1 assembles into trinuclear linear cluster units by means of close gold-gold interactions, being connected through the crystal cell in a 2D zigzag mode. The crystal structure of [Au-2(HLPMe)Cl-2](2) (2) contains one discrete molecule [(AuCl)(2)(HLPMe)] in the asymmetric unit, which is further assembled into tetranuclear [(AuCl)(2)(HLPMe)](2) units by means of close gold-gold interactions. Both clusters are highly luminescent in solution.