超共轭
化学
粘结长度
自然键轨道
配网
蓝移
结晶学
分子轨道
密度泛函理论
计算化学
分子
晶体结构
光学
物理
光致发光
基准集
有机化学
作者
Yong Yang,Weijun Zhang,Xiaoming Gao
标识
DOI:10.1002/cjoc.200690169
摘要
Abstract A theoretical study on the blue‐shifted H‐bond N–H···O and red‐shifted H‐bond O–H···O in the complex HNO···H 2 O 2 was conducted by employment of both standard and counterpoise‐corrected methods to calculate the geometric structures and vibrational frequencies at the MP2/6‐31G(d), MP2/6‐31+G(d,p), MP2/6‐311++G(d,p), B3LYP/6‐31G(d), B3LYP/6‐31+G(d,p) and B3LYP/6‐311++G(d,p) levels. In the H‐bond N–H···O, the calculated blue shift of N–H stretching frequency is in the vicinity of 120 cm −1 and this is indeed the largest theoretical estimate of a blue shift in the X–H···Y H‐bond ever reported in the literature. From the natural bond orbital analysis, the red‐shifted H‐bond O–H···O can be explained on the basis of the dominant role of the hyperconjugation. For the blue‐shifted H‐bond N–H···O, the hyperconjugation was inhibited due to the existence of significant electron density redistribution effect, and the large blue shift of the N–H stretching frequency was prominently due to the rehybridization of sp n N–H hybrid orbital.
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