01967nas a2200289 4500008004100000022001400041245008100055210006900136260006700205300001200272490000700284520110000291653000601391653000601397653002501403653000901428653000801437653000901445653000901454653000801463653001701471653001401488100002301502700001701525700002401542856011101566 2013 eng d a0749-158100aGIAO/DFT studies on 1,2,4-triazole-5-thiones and their propargyl derivatives0 aGIAODFT studies on 124triazole5thiones and their propargyl deriv a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcDEC a767-7740 v513 a
Density functional theory (DFT)/Becke-Lee-Yang-Parr (B3LYP) and gauge-including atomic orbital (GIAO) calculations were performed on a number of 1,2,4-triazole derivatives, and the optimized structural parameters were employed to ascertain the nature of their predominant tautomers. C-13 and N-15 NMR chemical shifts of 3-substituted 1,2,4-triazole-5-thiones and their propargylated derivatives were calculated via GIAO/DFT approach at the B3LYP level of theory with geometry optimization using a 6-311++G** basis set. A good agreement between theoretical and experimental C-13 and N-15 NMR chemical shifts could be found for the systems investigated. The data generated were useful in predicting N-15 chemical shifts of all the nitrogen atoms of the triazole ring, some of which could not be obtained in solution state N-15 HMBC/HSQC NMR measurements. The energy profile computed for the dipropargylated derivatives was found to follow the product distribution profile of regioisomers formed during propargylation of 1,2,4-triazole thiones. Copyright (c) 2013 John Wiley & Sons, Ltd.
10a110a210a4-triazole-5-thiones10aC-1310aDFT10aGIAO10aN-1510aNMR10aRegioisomers10atautomers1 aPhalgune, Usha, D.1 aVanka, Kumar1 aRajamohanan, P., R. uhttp://library.ncl.res.in/content/giaodft-studies-124-triazole-5-thiones-and-their-propargyl-derivatives-0