高等学校化学研究 ›› 2010, Vol. 26 ›› Issue (6): 1016-1019.
Prediction of the 13C NMR Chemical Shifts of Stilbene Analogues by GIAO Method
XIE Hui-ding, LI Yu-peng*, QIU Kai-xiong, LIU Bo and CHEN Ya-ping
- Department of Chemistry, School of Pharmaceutical Sciences, Kunming Medical College, Kunming 650500, P. R. China
Prediction of the 13C NMR Chemical Shifts of Stilbene Analogues by GIAO Method
XIE Hui-ding, LI Yu-peng*, QIU Kai-xiong, LIU Bo and CHEN Ya-ping
- Department of Chemistry, School of Pharmaceutical Sciences, Kunming Medical College, Kunming 650500, P. R. China
摘要： After the geometry optimization at B3LYP/6-31+G(d,p) level, the calculations of the NMR chemical shifts of a series of stilbene analogues were carried out by means of Gauge Including Atomic Orbitals(GIAO) method at HF/6-31+G(d) level and B3LYP/6-311G+(2d,p) level, respectively. The 13C NMR chemical shifts calculated at both HF/6-31+G(d) and B3LYP/6-31+G(d,p) levels are in agreement with the observed values. By virtue of a series of linear correction equations(δpred. =a+bδcalcd.) of the 13C chemical shifts, accurate prediction of 13C chemical shifts was achieved for the new stilbene compounds. For the 13C NMR chemical shifts calculated at HF/6-31+G(d) level, the linear correlation of δpred. with δexptl. is excellent, and the square of correlation coefficient, r2, is 0.9985. The maximum absolute difference between δpred. and δexptl., Δδ, is 2.3, and the root-mean-square error between δpred. and δexptl. is 0.98. In the meantime, for those obtained at B3LYP/6-31+G(d,p) level, the linear correlation of δpred. with δexptl. is also excellent, and the square of correlation coefficient, r2, is up to 0.9987. The maximum absolute difference between δpred. and δexptl., Δδ, is 2.2, and the root-mean-square error between δpred. and δexptl. is only 0.88.