Department of Chemistry, National Institute of Technology Durgapur, Mahatma Gandhi Avenue, Durgapur, 713 209 (WB), India.
Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
Angew Chem Int Ed Engl. 2020 Jun 2;59(23):9177-9185. doi: 10.1002/anie.202001363. Epub 2020 Mar 30.
According to the well-accepted mechanism, methyl-coenzyme M reductase (MCR) involves Ni-mediated thiolate-to-disulfide conversion that sustains its catalytic cycle of methane formation in the energy saving pathways of methanotrophic microbes. Model complexes that illustrate Ni-ion mediated reversible thiolate/disulfide transformation are unknown. In this paper we report the synthesis, crystal structure, spectroscopic properties and redox interconversions of a set of Ni complexes comprising a tridentate N S donor thiol and its analogous N S donor disulfide ligands. These complexes demonstrate reversible Ni -thiolate/Ni -disulfide (both bound and unbound disulfide-S to Ni ) transformations via thiyl and disulfide monoradical anions that resemble a primary step of MCR's catalytic cycle.
根据公认的机制，甲基辅酶 M 还原酶（MCR）涉及 Ni 介导的硫醇到二硫键的转换，从而维持甲烷形成的催化循环，这是甲烷营养微生物节能途径中的关键步骤。目前还没有说明 Ni 离子介导的可逆硫醇/二硫键转换的模型配合物。在本文中，我们报告了一组 Ni 配合物的合成、晶体结构、光谱性质和氧化还原转化，这些配合物包含一个三齿 N S 供体硫醇及其类似的 N S 供体二硫键配体。这些配合物通过类似于 MCR 催化循环的初始步骤的硫基和二硫键单自由基阴离子，证明了 Ni-硫醇/Ni-二硫键（均结合和未结合的二硫键-S 到 Ni）的可逆转化。
