摘要
采用X射线分析测定了标题化合物的晶体结构和分子结构。化合物C_(20)H_(22)-O_2N_4P_2S4(1)为反式构型,M_r=540.63,正交晶系,空间群Pcab,a=7.255(2),b=18.297(3),c=18.576(2),V=2465.9 ~3,Z=4,D_c=1.456g/cm^(-3),最终偏离因子R=0.058,R_ω=0.049;化合物(2)为顺式构型,单斜晶系,空间群Ic,a=14.649(5),b=7.009(2),c=22.694(8),β=100.60(3)°,V=2290.1 ~3,Z=4,D_c=1.643g/cm^(-3),最终偏离因子R=0.061,R_ω=0.065。晶体结构测定结果表明,这对顺反异构体的构象明显不同:反式异构体的分子本身有对称中心且与晶体学对称中心重合,氧,氮,磷杂六员环为椅式构象,磷硫单键为轴向键,磷硫双键为平伏键;顺式异构体的分子本身无对称中心,两个氧氮磷杂六员环分别为椅式和船式构象,环上的磷硫单键为平伏键,磷硫双键为轴向键,与反式异构体恰恰相反。
The crystal structures of the title compounds (1) and (2) have been determined using x-ray analysis. The crystal data are as follows:(1): Trans-compound, Orthofhombic, Space group Pcab, a = 7. 255(2), b = 18.297(3), c= 18. 576(2)(?), V=2465. 9(?)3, Z = 4, Dc=1. 456g. cm-3, final discrepancy factors R = 0. 058, Rw = 0. 049; (2) : Cis-Compound, Monoclinic, Space group Ic, a = 14. 649(5), b = 7. 009(2), c=22. 694(8) (?) , β= 100. 60(3)°, V =2290. 1(?)3, Z = 4, Dc=1. 643g.cm-3, final discrepancy factors R = 0. 061, Rw = 0. 065.The results of crystal structure determination indicate: The molecule of the Trans-compound is centrosymmetric. The six-membered oxazaphosphorinan ring has a chair conformation, the P =S double bond is equatorial and the P-S single bond is axial. In the molecule of the Cis-com-pound, one oxazaphosphorinan ring has a chair conformation and the P=S, P-S bonds are very like those of the Trans-compound, but the other oxazaphosphorinan ring has a boat conformation and the P=S double bond is axial and the P-S bond is equatouial.
