Hydrides and Thiolates as Compatible Ligands in Transition Metal Complexes. Heterolytic Bond Activations

该奖项授予德克萨斯农工大学化学系的Marcetta Y.Darensburg博士，以表彰他在含氢和含硫配体的过渡金属络合物化学方面所做的基础工作。这项研究的目标是找到镍、铁和钴激活S-H、C-S和C-H的一些单独步骤的直接证据。具体地说，达伦斯堡计划研究四种类型的反应的机制：金属氢化物与有机硫试剂；从铁和镍的氢硫酸盐络合物中释放二氢；与不同配体环境的硫结合镍络合物的氧化-还原；以及过渡金属促进金属-接近的C-H键的异解。在硫结合镍络合物的研究中，将研究硫和磷配体的存在对氧化电位和氢的氧化加成的依赖关系。这些实验结果与产甲烷细菌和多相加氢脱硫催化剂中氢酶的作用有关，并提出了硫和氢同时成键的反应机理。

This award in the Inorganic, Bioinorganic and Organometallic Program is made to Dr. Marcetta Y. Darensbourg of the Chemistry Department, Texas A&M University, for fundamental work on the chemistry of transition metal complexes containing both hydrogen and sulfur-containing ligands. The goal of the research is to find direct evidence for some of the individual steps in S-H, C-S and C-H activation by nickel, iron, and cobalt. Specifically Darensbourg plans to investigate the mechanism of four types of reactions: metal hydrides with organosulfur reagents; dihydrogen release from hydrido-thiolate complexes of iron and nickel; oxidation-reduction of sulfur-bound nickel complexes with various ligand environments; and transition metal promoted heterolysis of metal-proximate C-H bonds. In the studies of sulfur-bound nickel complexes, dependence of the oxidation potential and of the oxidative addition of hydrogen on the presence of sulfur and phosphorus ligands will be investigated. %%% The results of these experiments are relevant to the action of hydrogenase enzymes in methanogenic bacteria and heterogeneous hydrodesulfurization catalysts, in which reaction mechanisms involving simultaneous bonding of sulfur and hydrogen have been proposed.