Departamento de Química Orgánica e Inorgánica/IUQOEM, Universidad de Oviedo, E-33071, Oviedo, Spain.
Chemistry. 2018 Jul 5;24(38):9504-9507. doi: 10.1002/chem.201801944. Epub 2018 May 30.
The high unsaturation of the title complex enabled it to react with a wide variety of molecules under mild conditions, whereby the agostic methyl ligand underwent unusual or unprecedented processes. Methane elimination occurred in the reactions with PPh H and SiPh H , this being followed in the latter case by Si-H bond oxidative addition to give the hydride silylene derivative [Mo Cp H(μ-PtBu )(μ-SiPh )(CO)]. Dehydrogenation, however, was the dominant process in the room temperature reaction with [Fe (CO) ], to give the unsaturated methylidyne cluster [Mo FeCp (μ -CH)(μ-PtBu )(CO) ] (Mo-Mo=2.6770(8) Å). In contrast, PMe elimination took place in the reaction with P , to give the unsaturated triphosphorus complex [Mo Cp (μ-η :η -P )(μ-PtBu )] (Mo-Mo=2.6221(3) Å). Yet a most remarkable reaction occurred with BH ⋅THF, involving insertion of two BH units and dehydrogenation to yield [Mo Cp (μ-B H Me)(μ-PtBu )(CO)], with the novel methyldiboranyl ligand acting as a 5-electron donor due to the presence of two 3-centre, 2-electron B-H-Mo interactions, according to spectroscopic data and DFT calculations (Mo-Mo ca. 2.65 Å).
标题配合物的高不饱和性使其能够在温和条件下与各种分子反应，从而使桥连甲基配体经历了不寻常或前所未有的过程。甲烷消除发生在与 PPhH 和 SiPhH 的反应中，在后一种情况下，Si-H 键发生氧化加成，得到氢化物甲硅烷基衍生物 [MoCpH(μ-PtBu)(μ-SiPh)(CO)]。然而，在与 [Fe(CO)]的室温反应中，脱氢是主要过程，得到不饱和亚甲基簇 [MoFeCp(μ-CH)(μ-PtBu)(CO)]（Mo-Mo=2.6770(8)Å）。相比之下，PMe 消除发生在与 P 的反应中，得到不饱和三膦配合物 [MoCp(μ-η:η-P)(μ-PtBu)]（Mo-Mo=2.6221(3)Å）。然而，与 BH ⋅THF 的反应最为显著，涉及两个 BH 单元的插入和脱氢，生成 [MoCp(μ-BHMe)(μ-PtBu)(CO)]，新型甲基二硼基配体由于存在两个 3 中心、2 电子 B-H-Mo 相互作用，充当 5 电子供体，根据光谱数据和 DFT 计算（Mo-Mo 约为 2.65Å）。
