Tetranuclear organometallic complexes based on 1,2-ethanedithiolate ligands as potential precursors for CuMS2 (M = Ga, In)

Abstract

The synthesis and characterization of a series of homologous tetranuclear complexes [(ⁱPr₃PCu)₂(MR₂)₂(SCH₂CH₂S)₂] (MR₂ = GaMe₂ (2), GaEt₂ (3), GaⁱPr₂ (4), GaⁿBu₂ (5) and InMe₂ (6), InEt₂ (7), InⁱPr₂ (8), InⁿBu₂ (9)) and of related compounds [(ⁱPr₃PCu)₃(MR₂)(SCH₂CH₂S)₂] (MR₂ = GaMe₂ (10), GaEt₂ (11), GaⁱPr₂ (12), GaⁿBu₂ (13) and InMe₂ (14), InEt₂ (15), InⁱPr₂ (16), InⁿBu₂ (17)) are presented. The molecular structures of these were determined by single crystal X-ray diffraction. Thermolysis processes of all the representatives of 2–9 were investigated by simultaneous thermal analysis and thermal decomposition in a nitrogen atmosphere in a quartz glass tube. According to powder X-ray diffraction studies these thermolysis residues predominantly consist of CuMS₂ (M = Ga, In), which mainly occurred in the well known tetragonal chalcopyrite-type structure and partially in the hexagonal wurtzite-type structure. As expected from their composition, representatives of 10–17 form mixtures of CuMS₂ and large amounts of Cu_2−xS upon thermolysis.