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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 structure and molecular structure of the title compound were determined by X-ray analysis. The compound C_ (20) H_ (22) -O_2N_4P_2S4 (1) has the trans configuration with M_r = 540.63, orthorhombic space group Pcab, a = 7.255 (2), b = 18.297 (3) and c = 18.576 (2), V = 2465.9-3, Z = 4, D_c = 1.456g / cm -3, the final deviation factor R = 0.058, R_ω = 0.049. Compound (2) A = 14.649 (5) b = 7.009 (2) c = 22.694 (8) β = 100.60 (3) ° V = 2290.1-3 Z = 4 D c = 1.643 g / cm -3, the final deviation factor R = 0.061, R_ω = 0.065. The results of the crystal structure determination show that the conformations of cis-trans isomers are obviously different: the trans isomer has its own center of symmetry and coincides with the center of crystallographic symmetry, and the six rings of oxygen, nitrogen and phosphorus are the chair conformation , The single bond of phosphorous and sulfur is the axial bond, and the double bond of phosphorous and sulfur is equatorial; the molecule of cis-isomer has no center of symmetry itself. The two oxygen-nitrogen-phosphorus six-membered rings are chair-type and boat- Of the phosphorus and sulfur single bonds are equatorial bonds, phosphorus and sulfur double bonds are axial bonds, and trans isomers exactly the opposite.