title: Synthesis, characterization, crystal structure and ab initio studies on 5-ethoxycarbonly-6-methyl-4-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine.
abstract: The title compound, 5-ethoxycarbonly-6-methyl-4-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine, has been synthesized and characterized by elemental analysis, IR, UV-vis and X-ray single crystal diffraction. Ab initio calculations have been carried out for the title compound by using B3LYP and HF methods at 6-31G* basis set. The calculated results show that the predicted geometries can reproduce the structural parameters, although the intermolecular interactions have some influences on the molecular geometry in the solid state. Predicted vibrational frequencies by two methods are consistent with each other. They have been assigned and compared with experimental IR spectra. The theoretical electronic absorption spectra have been calculated by both TD-DFT and HF-CIS methods, and the results indicate that only the former can approximately predict the electronic spectra for the title compound. Molecular orbital coefficients analyses suggest that the electronic transitions are mainly assigned to n-->pi* and pi-->pi* electronic transitions. On the basis of vibrational analyses, the thermodynamic properties of the title compound at different temperatures have been calculated, revealing the correlations between C(p,m)(0), S(m)(0), H(m)(0) and temperatures.
authors.affiliation: Jiangsu Key Laboratory for Chemistry of Low-Dimensional Materials, Huaiyin Teachers College, Huaian, Jiangsu 223300, PR China. zhaopusu@163.com
authors.forename: Pusu
authors.initials: P
authors.lastname: Zhao
authors.forename: Rongchang
authors.initials: R
authors.lastname: Shangguan
authors.forename: Hongyan
authors.initials: H
authors.lastname: Wang
authors.forename: Yongqi
authors.initials: Y
authors.lastname: Qing
authors.forename: Fangfang
authors.initials: F
authors.lastname: Jian
mesh_terms: D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008956:Models, Chemical; D008958:Models, Molecular; D011743:Pyrimidines / Q000138:chemical synthesis* / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013816:Thermodynamics; D013871:Thiones / Q000138:chemical synthesis* / Q000737:chemistry*; D014732:Vibration
chemical_list: C539727:5-ethoxycarbonyl-6-methyl-4-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine; D011743:Pyrimidines; D013871:Thiones; C030986:pyrimidine