Stereochemical non-rigidity in germylcyclopentadiene and related derivatives of germane
作者:Philip C. Angus、Stephen R. Stobart
DOI:10.1039/dt9730002374
日期:——
at 175 °C. For compounds (I) and (II), spin coupling between protons at Ge and on the C5 ring could be resolved (a) below –20 °C. establishing the identity of the species present at the slow-exchange limit in each case, and (b) above 50 °C, providing novel evidence for an intramolecular, metallotropic shift as the mechanism for rearrangement. I.r. and Raman spectra for compounds (I)–(V) have been partly
化合物锗烷基环戊二烯(I),锗烷基(甲基)环戊二烯(II),甲基锗烷基环戊二烯(III),双(环戊二烯基)锗烷(IV)和锗烷基茚(V)是通过卤代锗烷与适当的烃阴离子反应合成的。使用可变温度1 H nmr光谱,发现化合物(I)-(IV)在35°C时具有通量,而(V)的类似行为仅在175°C时才发生。对于化合物(I)和(II),在–20°C以下,可以解决Ge和C 5环上质子之间的自旋耦合(a)。在每种情况下均确定存在于慢交换极限处的物种的身份,并且(b)在50°C以上的温度下,为分子内成金属位移作为重排机制提供了新的证据。化合物(I)–(V)的Ir和拉曼光谱已被部分分配,ν[Ge–C(ring)]在370 cm –1附近;质谱显示碎片模式,表明H从Ge大量转移到有机基团。加热化合物(I)导致部分质子重排成2-和3-胚芽基异构体。已经研究了(I)的几种反应,包括与HCl和Me 3 SnH的反应。