量子化学计算苄嘧磺隆的晶体结构  

Quantum chemical calculation of the crystal structure of bensulfuron-methyl

作　　者：李壹[1] 夏金云 李方实[1] 

机构地区：[1]南京工业大学理学院应用化学系,江苏南京210009

出　　处：《计算机与应用化学》2009年第11期1503-1508,共6页Computers and Applied Chemistry

摘　　要：制备苄嘧磺隆的单晶并用x射线衍射测定晶体结构。苄嘧磺隆晶体属于单斜晶系，C2／c空间群。晶胞参数为：a=33．831（7）A，b=6．9020（14）A，c=16．021（3）A，α=90．00（3）°，β=104．48（3）°，γ=90．00（3）°，V=3622．1（13）A^3。晶体分子内通过N-H…N氢键和C-H…O氢键形成2个六元环，使分子结构较稳定。苯环平面和嘧啶环平面之间的夹角为50．00（15）°。晶体以1中心对称二聚体为基本重复单元。2个分子间以N-H…O氢键和C-H…O氢键连接。晶体由这些二聚体以范德华作用力堆积而成。使用Gaussian 03程序，用B3LYP／6-31G（d，p）法计算分子的优化结构、电荷分布、稳定性、前沿轨道布居分析和3D示意图。算得分子的键长键角数据和X射线衍射的晶体结构数据基本相符。键长和键角的计算值与X射线衍射数据之差证实晶体中分子间的氢键。The single crystal of bensulfuron-methyl was cultured and the crystal structure was determined by X-ray diffraction. The crystal belongs to monoclinic C2/c, with a=33.831（7）A,b=6.9020（14）A,c=16.021（3）A,α=90.00（3）°,β=104.48（3）°,γ=90.00（3）°,V=3622.1（13）A^3. In the crystal, the intramolecular N-H…N and C-H…O hydrogen bonds result in the formation of two six-membered tings, which may be effective in the stabilization of the structure. The dihedral angle between the benzene and pyrimidine tings is 50. 00 （ 15 ）°. Between two molecules, there are intermolecular N-H…O and C-H…O hydrogen bonds to form centrosymmetric dimers. The optimized structure, charge distribution, molecular stability, HOMO, LUMO, composition of frontier orbitals, population analysis and three-dimensional schematic diagram were calculated by B3LYP/6-31G （d, p） method. The result shows that the bond lengths and bond angles obtained by quantum chemical calculation were almost the same with the values of X-ray diffraction. The difference between the two methods confirmed the intermolecular hydrogen bonds in the crystal structure.

关 键 词：苄嘧磺隆 晶体结构 量子化学计算 

分 类 号：O641[理学—物理化学] TQ015.9[理学—化学]