Synthesis, X-ray crystal structure, and reactivity of Pd2(μ-dotpm)2 (dotpm=bis(di-ortho-tolylphosphino)methane)
作者:Eleazar Lumbreras、Elizabeth M. Sisler、Quinetta D. Shelby
DOI:10.1016/j.jorganchem.2009.10.010
日期:2010.1
produces the binuclear Pd(0) complex Pd2(μ-dotpm)2 and the elimination byproducts 1-butene, cis-2-butene, trans-2-butene, butane, and octane. The dibutyl complex, Pd(dotpm)(n-Bu)2, is presumed to be the reaction intermediate. The crystal structure of Pd2(μ-dotpm)2 reveals that the methylene groups of the bridging dotpm ligands are located on opposite sides of the Pd2P4 unit, forming an 8-membered ring
的PdCl的烷基化2(dotpm)(dotpm =双(二-邻-tolylphosphino)甲烷)与Ñ丁基锂产生双核的Pd(0)配合物的Pd 2(μ -dotpm)2和消除副产物1-丁烯,顺式- 2-丁烯,反式-2-丁烯,丁烷和辛烷。推测二丁基络合物Pd(dotpm)(n- Bu)2是反应中间体。Pd 2(μ- dotpm)2的晶体结构表明,桥接dotpm配体的亚甲基位于Pd 2 P 4的相对侧。单元,形成一个细长的椅子构型的八元环。四个磷原子不是共面的,P1-P2-P3-P4环的扭转角为13.8°,这使邻甲苯基环之间的空间相互作用最小化。Pd-Pd的键距为2.8560(6)Å,表明d 10 -d 10金属中心之间存在弱的“闭壳”键相互作用。每个钯原子都具有近似线性的几何形状,dotpm配体的八个甲基保护了金属中心上的开放配位点。四个甲基屏蔽了Pd 2 P 4环腔上方和下方的金属原子,四个甲基阻塞了Pd