【摘要】 用溶液法测定三甲基羟基硅烷、三苯基羟基硅烷、二甲基二羟基硅烷和二苯基二羟基硅烷的偶极矩,实验数据按 Guggenheim 法计算得到的结果分别是1.53,1.51,1.94,1.74 D。与 Grubb-Osthoff 所给两种羟基硅烷的偶极矩值相差甚大。而 Malatesta-Pizzotti 的结果是与本工作的结果相协调的。偶极矩数据指出:在二羟基硅烷的结构中,两个羟基的内旋转是受阻的,其择优排布使两个 RSi-OH 基团极矩矢量间约成102°的夹角。更多还原

【Abstract】 The dipole moments of trimethylsilanol,triphenylsilanol,dimethylsilandiol and diphenylsilandiol have been determined by the solution method in dioxane,and the results are 1.53,1.51,1.94,and 1.74D respectively.The experimental data were treated according to the method of Guggenheim.For comparison,the dipole moments were also evaluated according to the procedure of Halverstadt and Kumler which gave higher values than Guggenheim moments,and the deviation increases with the number of phenyl gioups in the molecule,apparently resulted from the noglect of atomic polarization.The dipole moment values obtained for the silanols are compared to those appeared in literature,supporting the measurement of Malatosta and Pizzotti,while in wide disagreement with the values reported by Grubb and Osthoff.The experimental results indicate that the internal rotation of two hydroxyl groups in the silandiols appears to be hindered and the preferred confi-guration of the silandiols shows an average angle between the vectors of two RSiOH group moments of ca.102°.更多还原