Synthesis, spectroscopy and structures of palladium(II) and platinum(II) complexes containing mercapto-o-carborane

The reactions of [M2Cl2(μ-Cl)2(PMe2Ph)2] with mercapto-o-carboranes in the presence of pyridine afforded mono-nuclear complexes of composition, [MCl(SCb°R)(py)(PMe2Ph)] (M = Pd or Pt; Cb° = o-C2B10H10; R = H or Ph). The treatment of [PdCl2(PEt3)2] with PhCb°SH yielded trans-[Pd(SCb°Ph)2(PEt3)2] (4) which when left in solution in the presence of pyridine gave another substitution product, [Pd(SCb°Ph)2(py)(PEt3)] (5). The structures of [PdCl(SCb°Ph)(py)(PMe2Ph)] (1), [Pd(SCb°Ph)2(PEt3)2] (4) and [Pd(SCboPh)2(py)(PEt3)] (5) were established unambiguously by X-ray crystallography. The palladium atom in these complexes adopts a distorted square-planar configuration with neutral donor atoms occupying the trans positions. Thermolysis of [PdCl(SCb°)(py)(PMe2Ph)] (2) in TOPO (trioctylphosphine oxide) at 200 °C gave nanocrystals of TOPO capped Pd4S which were characterized by XRD pattern and SEM.