of the heterocycles have been proved by the multinuclear (1H, 13C, 29Si, 125Te) NMR spectroscopy, 2D NOESY NMR spectroscopy and mass-spectrometry. Z-Isomers are characterized by a long-range spin–spin interaction of protons through five bonds with 5JHH 0.2–0.5 Hz lacking in E-isomers. In the mass spectra the heterocycles manifest themselves as the fragment ions [M−Cl2]+.
在室温下,TeCl 4与二有机基二
乙炔基
硅烷RR 1 Si(CCH)2在CHCl 3中的反应导致区域和立体选择性形成一类新的不饱和五元杂环4,4-二有机基-1,1, 3,6-tetrachloro-1,4-tellura(IV)silafulvenes,高产。在
硅原子上有二烷基取代基的情况下,反应以100%的立体选择性进行,仅提供E-异构体,而对于环状二
乙炔基
硅烷,形成的螺杂环具有Z-和E-构型,其中E-异构体占优势。杂环的结构已被多核(1H,13 C,29 Si,125 Te)NMR光谱,2D NOESY NMR光谱和质谱。Z-异构体的特征是质子通过5个键具有5 J HH 0.2-0.5 Hz的E-异构体缺乏长距离自旋自旋相互作用。在质谱图中,杂环表现为碎片离子[M-Cl 2 ] +。