Conformational and electronic interaction studies of some para-substituted S-phenyl α-ethylsulfonylthioacetates
作者:P.R. Olivato、M.L.T. Hui、A. Rodrigues、R. Ruiz Filho、R. Rittner、J. Zukerman-Schpector、G. Distefano、M. Dal Colle
DOI:10.1016/s0022-2860(02)00570-7
日期:2003.1
The preferred conformations of some p-substituted S-phenyl α-ethylsulfonylthioacetates, p-X-Ph-SC(O)CH2SO2Et (X=NO21, Cl 2, Br 3, H 4, Me 5 and OMe 6) are determined through νCO infrared analysis and ab initio HF/6-31G** calculations, which show the occurrence of two stable conformations, i.e. the gauche2(syn) and the gauche1(anti), with the former being the most stable. The lower frequency and more
通过νCO红外分析确定了一些对位取代的S-苯基α-乙基磺酰基硫代乙酸酯,pX-Ph-SC(O)CH2SO2Et (X=NO21, Cl 2, Br 3, H 4, Me 5 和 OMe 6) 的优选构象和ab initio HF/6-31G**计算,显示出两种稳定构象的出现,即gauche2(syn)和gauche1(anti),其中前者最稳定。羰基吸收双峰的较低频率和较强烈的成分归因于 gauche2(syn),而较高频率和较弱的成分归因于 gauche1(anti) 构象异构体。相应的对位取代-S-苯基硫代乙酸酯(X=NO210、Cl 11、Br 12、H 13、Me 14 和 OMe 15)(不带有 α-乙基磺酰基)的实验和理论数据得出类似的结果,证实频率分配。化合物 1-6 的 gauche2(syn)/gauche1(s-anti) 红外布居比逐渐增加,从对位的吸电子取代基到给电子取代基,以及更大的负羰基频移