Synthesis and characterization of coinage metal aluminum sulfur species.

The synthesis of heterobimetallic cluster with the Al-S-M (M = Cu and Ag) structural unit has been realized for the first time by the reaction of aluminum-dithiol LAl(SH)2 (L = HC[C(Me)N(Ar)]2, Ar = 2,6-iPr2C6H3) with (MesCu)4 and (MesAg)4 (Mes = 2,4,6-Me3C6H2), respectively. The isolated clusters exhibit core structures of Al2Cu4S4 and Al4Ag8S8, respectively. During the formation of the [LAl(SAg)2]4, a side product of LAlS6 is formed. However, the reaction of LAl(SH)2 with excess of sulfur and (MesAg)4 resulted in the formation of LAlS4 as the only product soluble in organic solvents. Both of them represent rare examples of aluminum polysulfides. All compounds were characterized by spectroscopic methods and single crystal X-ray diffraction studies.