are declined away from the plane E−C−N. These facts are interpreted in terms of the absence of an earlier postulated α-effect, which should lead to an attractive interaction between E and N centers. The structures, energies, and orbital interactions in the natural bond orbital (NBO) model for three possible conformations of the SiCH2NC2 skeleton (lone pairs at N vs Si atom) of H3SiCH2NMe2 have been
为了确定它们的分子结构,已经制备了三种化合物H 3 SiCH 2 NMe 2,Me 3 GeCH 2 NMe 2和Me 3 SnCH 2 NMe 2。H 3 SiCH 2 NMe 2的气相结构已经通过电子衍射(GED)和从头算到MP2 / 6-311G **理论
水平的计算建立。Me 3 GeCH 2 NMe 2的几何结构只能通过理论方法研究,而Me 3 SnCH 2的结构NMe 2已通过单晶X射线衍射(XRD)和计算方法确定。所有三种化合物中的E-C-N单元(E = Si,Ge,Sn)所采用的角度均大于四面体角(H 3 SiCH 2 NMe 2 GED 114.7(3)°,MP2 / 6-311G ** 111.4°; Me 3 GeCH 2 NMe 2 SCF / 6-31G * 116.1°; Me 3 SnCH 2 NMe 2XRD 113.0(2)°,SCF / dzp 115.4