A Series of Dimeric Cobalt Complexes Bridged by N-Heterocyclic Phosphido Ligands
A Series of Dimeric Cobalt Complexes Bridged by N-Heterocyclic Phosphido Ligands
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一系列由 N-杂环磷脂配体桥联的二聚钴配合物
DOI：
10.1021/acs.inorgchem.9b03790
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发表时间：
2020
影响因子：
4.6
通讯作者：
Thomas, Christine M.
中科院分区：
文献类型：
--
作者：
Poitras, Andrew M.;Bezpalko, Mark W.;Moore, Curtis E.;Dickie, Diane A.;Foxman, Bruce M.;Thomas, Christine M.
一个三叉[PPP]配体已经被用来构建一系列二聚钴配合物，并探索了金属和配体中心的合作多电子氧化还原过程。过量镁还原（PPClP）CoCl2(1)得到coicoin -杂环磷酸（NHP -）桥接对称二聚体[(μ-PPP)Co]2(2)。2与fcpf6的双电子氧化产生不对称桥接[(μ-PPP)Co]2[PF6]2(3)，其中氧化在整个Co2P2core中以离域方式发生。相比之下，[(μ-PPP)Co]2+(5)具有不对称的几何结构和局域混合价，可以用fcpf6单电子氧化2或由2和3组成。用较温和的还原剂cocp2和KBEt3H处理1不会生成2,3或5，而是生成二聚体[(PPP)CoCl]2(6)和[(PPP)CoH]2(7)。与2 - 5不同的是，其中三叉戟[PPP]配体的膦侧臂跨越两个Co中心，而络合物6和7仅由连接两个（PPP）Co片段的npp配体连接。
A tridentate [PPP] ligand has been used to construct a series of dimeric cobalt complexes and explore cooperative multielectron redox processes that are both metal- and ligand-centered. Reduction of (PPClP)CoCl2(1) with excess magnesium affords the CoICoIN-heterocyclic phosphido (NHP–)-bridged symmetric dimer [(μ-PPP)Co]2(2). Two-electron oxidation of2with FcPF6generates an asymmetrically bridged dication [(μ-PPP)Co]2[PF6]2(3) in which the oxidation has occurred in a delocalized fashion throughout the Co2P2core. In contrast, [(μ-PPP)Co]2+(5), which can be generated either by one-electron oxidation of2with FcPF6or comportionation of2and3, features an asymmetric geometry and localized mixed valence. Treatment of1with the milder reductants CoCp2and KBEt3H does not lead to formation of2,3, or5but instead generates dimeric species [(PPP)CoCl]2(6) and [(PPP)CoH]2(7). Unlike2–5, where the phosphine side arms of the tridentate [PPP] ligand span the two Co centers, complex6and7are connected solely by NHP–ligands that bridge the two (PPP)Co fragments.