The formally zero-valent Mn dimer [(^Ph2PEtPDI)Mn]₂ has been synthesized upon reducing (^Ph2PEtPDI)MnCl₂ with excess Na/Hg. Single crystal X-ray diffraction analysis has revealed that [(^Ph2PEtPDI)Mn]₂ possesses a κ⁴-PDI chelate about each Mn center, as well as η²-imine coordination across the dimer. The chelate metrical parameters suggest single electron PDI reduction and EPR spectroscopic analysis afforded a signal consistent with two weakly interacting S = ¹/₂ Mn centers. At ambient temperature in the absence of solvent, [(^Ph2PEtPDI)Mn]₂ has been found to catalyze the hydrosilylation of aldehydes at loadings as low as 0.005 mol % (0.01 mol % relative to Mn) with a maximum turnover frequency of 9,900 min^–1 (4,950 min^–1 per Mn). Moreover, the [(^Ph2PEtPDI)Mn]₂-catalyzed dihydrosilylation of formates has been found to proceed with turnover frequencies of up to 330 min^–1 (165 min^–1 relative to Mn). These metrics are comparable to those described for the leading Mn catalyst for this transformation, the propylene-bridged variant (^Ph2PPrPDI)Mn; however, [(^Ph2PEtPDI)Mn]₂ is more easily inhibited by donor functionalities. Carbonyl and carboxylate hydrosilylation is believed to proceed through a modified Ojima mechanism following dimer dissociation.

中文翻译：

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使用二聚锰预催化剂对醛和甲酸酯进行氢化硅烷化

通过用过量的Na / Hg还原（^Ph2PEt PDI）MnCl ₂可以合成形式上为零价的Mn二聚体[（^Ph2PEt PDI）Mn] ₂。单晶X射线衍射分析表明，[（^Ph2PEt PDI）的Mn] ₂具有一个κ ⁴有关每个锰中心-PDI螯合物，以及η ²横跨二聚体-亚胺协调。螯合韵律参数建议单电子还原PDI和EPR光谱分析，得到具有两个弱相互作用相一致的信号小号= ¹ / ₂的Mn中心。在无溶剂的环境温度下，[（^Ph2PEt已发现PDI）Mn] ₂以低至0.005 mol％（相对于Mn为0.01 mol％）的负载量催化醛的氢化硅烷化，最大转换频率为9,900 min ^–1（每Mn 4,950 min ^–1）。此外，已发现[（^Ph2PEt PDI）Mn] ₂催化的甲^酸酯的二氢^{硅烷化反应}以高达330 min ^–1的转换频率（相对于Mn为165 min ^–1）进行。这些量度可与用于该转化的主要Mn催化剂的丙烯桥连变体（^{Ph 2 PPr} PDI）Mn所描述的量度相媲美。但是，[（^Ph2PEt PDI）Mn] ₂被供体的功能更容易抑制。据信二聚体解离后，羰基和羧酸酯的氢化硅烷化通过修饰的Ojima机理进行。