摘要
应用量子化学基本原理，对两种固体化合物席夫碱类的１５Ｎ化学位移的分子内氢键效应进行了研究．为简化计算，本文在计算过程中采用一种简化模型．其分子几何结构参数采用优化值．本文结果表明：理论值成功地再现了两种固体化合物的１５Ｎ化学屏蔽值，证实了１５Ｎ在分子内氢键形成过程中的屏蔽行为．本文证实当有分子内氢键形成时（大约为０．２ｎｍ），１５Ｎ化学位移向高频区大约移动５０ｐｐｍ．本文结果对理论上定量估计氢键强度可能会有重要作用．
Ab initio calculations of the 15 N chemical shifts are reported for two Schiff bases. The calculations were performed with the gauge invariant atomic orbital (GIAO) quantum chemical approach. Optimized geometrical parameters were used. The predicted results successfully reproduce the observed 15 N shielding values for the two compounds taken in the solid state. It is demonstrated that the calculation reasonably confirms the 15 N chemical shielding behavior due to the formation of an intramolecular hydrogen bond.
出处
《波谱学杂志》
CAS
CSCD
北大核心
1998年第4期341-346,共6页
Chinese Journal of Magnetic Resonance
关键词
化学位移
席夫碱
氢键
氮15
量子化学
Ab initio method, 15 N chemical shift, GIAO approach, Schiff base
