标题：Synthesis, Crystal Structure, and DFT Study of Ethyl 1-(2-(Hydroxyimino)-2-phenylethyl)-3-phenyl-1H-pyrazole-5-carboxylate
作者：Zhou, Jin-Hui; Zheng, Liang-Wen; Yan, Mao-Cai; Shi, Mao-Jian; Liu, Jing; Shangguan, Guo-Qiang
作者机构：[Zhou, Jin-Hui; Yan, Mao-Cai; Shi, Mao-Jian; Liu, Jing; Shangguan, Guo-Qiang] Jining Med Univ, Coll Pharm, Rizhao 276826, Peoples R China.; [Zhou, J 更多
通讯作者地址：[Shangguan, GQ]Jining Med Univ, Coll Pharm, Rizhao 276826, Peoples R China.
来源：JOURNAL OF CHEMISTRY
摘要：The crystal structure of ethyl 1-(2-(hydroxyimino)-2-phenylethyl)-3-phenyl-1H-pyrazole-5-carboxylate has been determined by X-ray single crystal diffraction. The crystal of the title compound is the monoclinic space group P2/c with unit cell parameters of a = 8.634(2) angstrom, b = 9.616(2) angstrom, c = 22.190(3) angstrom, beta = 99.265(2)degrees, V = 1818.3(4) angstrom(3), and Z = 4. The dihedral angles formed by the planes of the central pyrazole ring and the adjacent benzene rings are 73.60(7)degrees and 3.55(7)degrees, respectively. The combination of the weak intermolecular C-H center dot center dot center dot O andN-H center dot center dot center dot O hydrogen-bonding interactions stabilizes the crystal packing. The geometries of its Z and E isomers and the corresponding transition state (TS), aswell as the dimer of its Z isomer, are optimized using the B3LYP hybrid functional coupled with def-TZVP triple-zeta polarized basis set. The bond angles and bond lengths of the optimized structure of Z dimer are very consistent with those of its single crystal parameters. Double-hybrid functional PWPB95-D3 in combination with very highly accurate basis set def2-QZVP is employed to evaluate accurate energy of each isomer and TS. The calculated equilibrium constant between Z and E isomers corresponds to the [ Z]/[ E] ratio of 4.29. Mulliken atomic charges and electrostatic potential (ESP) on molecular van derWaals (vdW) surface are calculated in order to study and predict the intermolecular interactions. The molecular total energies and frontier orbital analysis are also discussed.