Synthesis of Platinum group metal cluster complexes with redox active ligands.

商业加氢脱硫（HDS）催化剂通常包含负载在γ-氧化铝上的金属硫化物。钼或钨是必需组分，但通过添加其它过渡金属如Ni、Co、Ru、Ir、Rh、Pt、Pd、Os、Re作为促进剂，催化活性显著提高。这些促进者所起的作用仍然是未知的。虽然在脱硫步骤之前形成的中间物种的分离和表征吸引了很多关注，但是这样的模型络合物仍然远离催化剂表面的结构。在研究吡啶硫醚双核铂配合物[Pt_2Cl_2（5-mpyt）_4]与四硫代钨酸盐[WS_4]的反应过程中<2->，意外地发现了[{ ClPt_2（5-mpyt）_4}_2S_4]的生成。由四硫代钨酸盐形成四硫阴离子（S_4^<2->）是非常罕见的，因为我们只知道一个例子，其中四硫代金属酸盐阴离子作为二硫阴离子（S_2^）的来源<2->。[{ClPt_2（5-mpyt）_4}_2S_4]可在室温下转化为起始化合物[Pt_2Cl_2（5-mpyt）_4]。该化合物的分离使我们了解了WS_4 ~<2->+经S_4 ~+转化为单质硫的整个反应过程<2->。[（ClPt_2（5-mpyt）_4）_2S_4]的分离对应于该反应的中间体化合物的鉴定。

The commercial hydrodesulfurization (HDS) catalysts generally comprise metal sulfides supported on gamma-alumina. Molybdenum or tungsten are essential components but the catalytic activity increases remarkably by addition of other transition metals such as Ni, Co, Ru, Ir, Rh, Pt, Pd, Os, Re as promoters. The role playd by these promoters is still unknown. Although the isolation and characterization of the intermediate species that is formed prior to the desulfurization step are attracting much attention, such model complexes are still far from the structure of the surface of the catalysts. It is very important to study and understand the reaction of thiometallate anions with metal complexes which can be promoters.In the course of our study of the reaction of dinuclear Pt (III) complexes of pyridinethiol, [Pt_2Cl_2(5-mpyt)_4] , With tetrathiotungstate, WS_4^<2->, we unexpectedly found the formation of tetrasulfido bridged dimer of the "Pt_2" unit, [{ ClPt_2(5-mpyt)_4}_2S_4]. The formation of tetrasulfide anion (S_4^<2->) from tetrathiotungstate is very unusual, since we know only one example in which tetrathiometallate anions act as a source of disulfide anion (S_2^<2->). [{ClPt_2(5-mpyt)_4}_2S_4] Can be converted to the starting compound, [Pt_2Cl_2(5-mpyt)_4] , by exposing the CHCl_3 solution toward room light. The isolation of this compound enabled us to know whole the reaction in which WS_4^<2-> was converted to elemental sulfur via S_4^<2-> ion. The isolation of [(ClPt_2(5-mpyt)_4)_2S_4] corresponds to the identification of the intermediate compound of this reaction.