DFT investigation on the differences in the geometrical parameters of trans-cis and cis-trans conformations of methyl substituted benzoyl pyridylthiourea

Five single molecules of pyridylthiourea compounds,benzoylpyridylthiourea derivatives were theoretically studied in order to understand their conformational preference,flexibility and stability. the calculation is made by gaussian 09w at b3lyp/6-311g(d,p). the positional of methyl substituent group brought major effect to the conformations of the molecule that prone to form cis-trans conformation. in cis-trans conformation,n-benzoyl-n'-(6-methyl-2-pyridyl)thiourea,the positional of methyl substituent indicates that this molecule has relatively high intermolecular hydrogen bonding compared to the other studied molecules. nevertheless,hyperconjugation of methyl with pseudo six-membered ring has been observed in cis-trans conformation. © 2017 penerbit umt.