Bond formation and coupling between germyl and bridging germylene ligands in dinuclear palladium(I) complexes.
Bond formation and coupling between germyl and bridging germylene ligands in dinuclear palladium(I) complexes.
复制标题
双核钯 (I) 配合物中甲锗烷基和桥联甲锗烷基配体之间的键形成和偶联。
作者：
M. Tanabe;Shumpei Omine;N. Ishikawa;K. Osakada;Y. Hayashi;S. Kawauchi
双核钯(I)配合物 [L(Ar2 HGe)Pd(μ-GeAr2 )2 Pd(GeHAr2 )L] (Ar=Ph, p-Tol; L=PMe3 , tBuNC) 含有末端甲锗基和桥接甲锗烷基配体，实验观察到 Ge⋅⋅⋅Ge 键长为 2.8263(4) Å (L=PMe3 ) 和2.928(1) Å (L=tBuNC)，接近迄今为止报道的最长Ge-Ge键[2.714(1) Å]。 DFT 计算、Wiberg 键指数 (WBI) 和自然键轨道 (NBO) 分析支持甲锗烷基和甲锗基配体（PMe3 配合物 > tBuNC 配合物）之间显着的 Ge⋅⋅⋅Ge 相互作用。将 tBuNC 替换为 PMe3 配体会增加 Ge⋅⋅⋅Ge 相互作用，并同时激活两个 Pd-Ge 键。将螯合二膦 1,2-双（二乙基膦基）乙烷 (depe) 添加到 PMe3 配合物中，导致甲锗烷基和甲亚甲基配体发生分子内偶联，然后挤出二甲锗烷。
The dinuclear palladium(I) complexes [L(Ar2 HGe)Pd(μ-GeAr2 )2 Pd(GeHAr2 )L] (Ar=Ph, p-Tol; L=PMe3 , tBuNC) contain terminal germyl and bridging germylene ligands with the experimentally observed Ge⋅⋅⋅Ge bond lengths of 2.8263(4) Å (L=PMe3 ) and 2.928(1) Å (L=tBuNC), which are close to the longest Ge-Ge bond reported to date [2.714(1) Å]. Significant Ge⋅⋅⋅Ge interactions between the germylene and germyl ligands (PMe3 complexes > tBuNC complexes) are supported by DFT calculations, Wiberg bond indices (WBI), and natural bond orbital (NBO) analyses. Exchanging tBuNC for PMe3 ligands increases the Ge⋅⋅⋅Ge interaction, and simultaneously activates two Pd-Ge bonds. Adding the chelating diphosphine 1,2-bis(diethylphosphino)ethane (depe) to the PMe3 complexes results in the intramolecular coupling of germyl and germylene ligands followed by extrusion of a digermane.