Crystal Structure of 2—[（P,P—Diphenoxy）phosphono（p—methyl）benzyl]—1,2—

The crystal structure of the title compound 2-[(P, P-Diphenoxy)phosphono(p-methyl)benzyl]-1, 2-benzisoselenazol-3(2H)-one, C27H22NO4PSe, was determined by single crystal X-ray diffraction. It crystallizes in the triclinic system, space group P(No. 2) with Mr=534.41, a=9.761(2), b=10.304(2), c=13.396(3), α=110.97(3), β=107.70(3). γ=90.02(3)°, V=1190(1) 3, Z=2, Dx=1.492 g/cm3, λ=0.71073, μ=1.6596 mm-1 and F(000)=544. The structure was solved by direct methods. The final R factor is 0.068 and Rw is 0.074 for 2500 unique observed reflections [I≥3σ(I)]. The results presented herein indicate that the selenium-containing bicyclic moiety is a coplanar structure and that two adjacent molecules are symmetrically linked to each other forming a dimer through the Se(1c)...O=P(1) bonding interaction with an intermolecular Se(1c)...O distance of 2.797 .     

3—（p—甲苯基）磺酰氨基—2，6—哌啶二酮（C12H14O4N2S）的晶体结构和分子

采用X－射线单晶衍射和INDO量子化学计算法研究了标题化合物的晶体和分子结构，标题化合物的分子式C12H14O4N2S，Mr=282.31，三斜晶系，空间群P1，a=7.229(2),b=8.7922(9),c=11.242(1)A;A=70.339(8),β＝71。15（2），γ＝87．88（2）°，V=634.8(7)A^3,Z=2,Dc=1.476g/cm^3,R=0.037,Rw=0.037(W=1),分子的哌啶二酮环中C＝0和C－N键与多肽分子和相应键长相一致，根据INDO计算结果讨论了标题化合物的水解反应活性。     

Crystal Structure of cis—2—[P,P—Diethoxy） phosphono（m—nitro）benzyloxy]

The crystal structure of the title compound cis-2-[(P, P-Diethoxy)phosphono(m-nitro)benzyloxy]-4-Phenyl-5,5-Dimethyl-1,3,2-Dioxaphosphorinane 2-Sulfide, C22H29NO8P2S, was determined by single crystal X-ray diffraction. It crystallizes in the monoclinic system, space group P21/c, with Mr=529.49, a=9.888(2), b=20.831(4), c=12.797(3) , β=94.42(3)°, V=2628(1) 3, Z=4, Dx=1.338 g/cm3, λ=0.71073, μ=0.2796 mm-1 and F(000)=556. The structure was solved by direct methods. The final R factor is 0.052 and Rw is 0.057 for 1793 unique observed reflections [I≥3σ(I)]. A cis-configuration and a preferred chair conformation for the molecule have been established by X-ray diffraction analysis. The results presented also give a good explanation to the correlation between the configurational assignments and the regularity in the chemical shifts of C4-H and 31P NMR.