Synthesis, spectroscopic characterization, crystal structures, and theoretical studies of (E)-2-(2,4-dimethoxybenzylidene)thiosemicarbazone and (E)-2-(2,5-dimethoxybenzylidene)thiosemicarbazone
作者:Aliakbar Dehno Khalaji、Gholamhossein Grivani、Samaneh Jalali Akerdi、Kazuma Gotoh、Hiroyuki Ishida、Hossein Mighani
DOI:10.1007/s11224-010-9637-3
日期:2010.10
Two thiosemicarbazones, (E)-2-(2,4-dimethoxybenzylidene)thiosemicarbazone (24-MBTSC (1)) and (E)-2-(2,5-dimethoxybenzylidene)thiosemicarbazone (25-MBTSC (2)), derived from 2,4-dimethoxybenzaldehyde and 2,5-dimethoxybenzaldehyde, respectively, with thiosemicarbazide have been synthesized and their structures were characterized by elemental analyses, FT-IR, 1H NMR spectroscopy, and X-ray single-crystal diffraction analysis. Molecular orbital calculations have been carried out for 1 and 2 by using an ab initio method (HF) and also density functional method (B3LYP) at 6-31G basis set. Compound 1 crystallizes in the monoclinic system, space group P21/c, with a = 8.1342(5) Å, b = 18.1406(10) Å, c = 8.2847(6) Å, β = 109.7258(17)°, V = 1150.75(12) Å3, and Z = 4, whereas compound 2 crystallizes in the orthorhombic system, space group Pbca, with a = 11.0868(6) Å, b = 13.1332(6) Å, c = 15.9006(8) Å, V = 2315.2(2) Å3, and Z = 8. The compounds 1 and 2 displays a trans-configuration about the C=N double bond.
合成了两种硫半肟,分别为(E)-2-(2,4-二甲氧基苯甲叉)硫半肟(24-MBTSC (1))和(E)-2-(2,5-二甲氧基苯甲叉)硫半肟(25-MBTSC (2)),它们分别由2,4-二甲氧基苯甲醛和2,5-二甲氧基苯甲醛与硫半肟反应得到,结构通过元素分析、傅里叶变换红外光谱(FT-IR)、^1H NMR光谱以及X射线单晶衍射分析进行表征。对化合物1和2进行了分子轨道计算,使用了从头算方法(HF)和密度泛函方法(B3LYP),采用6-31G基组。化合物1在单斜晶系中结晶,空间群为P21/c,晶格参数为a = 8.1342(5) Å,b = 18.1406(10) Å,c = 8.2847(6) Å,β = 109.7258(17)°,体积V = 1150.75(12) ų,Z = 4,而化合物2则在正交晶系中结晶,空间群为Pbca,晶格参数为a = 11.0868(6) Å,b = 13.1332(6) Å,c = 15.9006(8) Å,体积V = 2315.2(2) ų,Z = 8。化合物1和2在C=N双键处显示出顺式构型。