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

工业加氢脱硫（HDS）催化剂一般由γ -氧化铝负载的金属硫化物组成。钼或钨是催化活性的基本成分，但加入其他过渡金属如Ni、Co、Ru、Ir、Rh、Pt、Pd、Os、Re作为促进剂，催化活性显著提高。这些发起人所起的作用尚不清楚。虽然脱硫步骤之前形成的中间物的分离和表征引起了人们的广泛关注，但这种模型配合物与催化剂表面的结构仍然相去甚远。研究和了解硫金属酸阴离子与金属配合物的反应具有重要的意义。在研究吡啶硫醇双核Pt （III）配合物[Pt_2Cl_2(5-mpyt)_4]与四硫钨酸盐WS_4^<2->的反应过程中，我们意外地发现了“Pt_2”单元的四硫桥接二聚体[{ClPt_2(5-mpyt)_4}_2S_4]。由四硫钨酸盐形成四硫阴离子（S_4^<2->）是非常不寻常的，因为我们只知道一个四硫金属酸阴离子作为二硫阴离子（S_2^<2->）来源的例子。[{clt_2 (5-mpyt)_4}_2S_4]将CHCl_3溶液暴露在室内光照下，可转化为起始化合物[Pt_2Cl_2(5-mpyt)_4]。该化合物的分离使我们能够完整地了解WS_4^<2->通过S_4^<2->离子转化为单质硫的反应过程。[(ClPt_2(5-mpyt)_4)_2S_4]的分离对应于该反应中间化合物的鉴定。

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.