外型-1,4-氧桥-环己基-2,3-二羧酸的晶体及分子结构

外型-1,4-氧桥-环己基-2,3-二羧酸晶体属单斜晶系,空间群为P2_1/n;晶胞参数为:α=5.594(3)A,b=11.178(7)A,c=14.675(11)A,β=91.46(5)°;Ζ=4.从直接法得到结构的初始模型,经块矩阵最小二乘修正后,最后的R值为0.072.在晶体中,分子间的O—H…O氢键将分子连接成层型氢键体系.使用自编的CNDO/2程序,计算得电子的能量、分子的总能量、偶极矩及各原子的电荷密度和净电荷.

The crystal and molecular structure of exo-1, 4-epoxy-cyclohexyl-2, 3-dicarboxylic acid monohydrate

The crystal of exo-1, 4-epoxy-cyclohexyl-2, 3-liearboxylic acid in monohydrate (C8H10O5.H2O) belongs to monoclinic system, space group P21/n. There are four molecules in an unit cell with parameters α=5.594(3)A, b=11.178(7)A, c=14.675(11)A, β=91.46(5). The three dimensional intensity data were obtained with a Syntex R3 four-circle diffractometer, and the number of the independent diffractions amounted to 1626. The structure was solved by direct method and refined by block-diagonal least-squares method. The final R is 0.072. In the crystal, there are O--H. . .O hydrogen bonds between molesules, to form layer hydrogen bond system. We use the CNDO/2 programmes written by ourselves on Nova-Eclipse computer to compute the electron energy, molecular total energy, dipole moment, the charge density and net charge of each atom of the molecule C8H10O5.