氢键复合物中键长变化与振动频率移动相关性重访(英文)

X―H···Y(Y为电子供体)型氢键形成时,X―H键长伸长或缩短与相应的X―H伸缩振动频率红移或蓝移存在较强的相关性,这也是氢键光谱检测和研究的基础.但是,最近的理论研究却推翻了这一观点,认为X―H键长变化和相应的X―H伸缩振动频率移动在有些氢键体系中并不存在相关性(McDowell,S.A.C.;Buckingham,A.D.J.Am.Chem.Soc.2005,127,15515.).本文中,我们采用更为可信的计算方法,对这一问题进行再研究.结果表明是错误的计算方法导致了McDowell和Buckingham得出错误的结论.在McDowell和Buckingham所研究的氢键体系中,X―H键长变化和相应的X―H伸缩振动频率移动仍存在较强的相关性.

Correlation between Bond-Length Change and Vibrational Frequency Shift in Hydrogen-Bonded Complexes Revisited

The correlation between the X―H bond-length change and the corresponding X―H stretching frequency shift upon X―H···Y(Y is an electron donor)hydrogen bond formation is the basis for the spectroscopic detection and investigation of the hydrogen bond.However,this view has been questioned in a recent report,suggesting that the widely accepted correlation between the bond-length change and the frequency shift in hydrogen-bonded complexes is unreliable(McDowell,S.A.C.;Buckingham,A.D.J.Am. Chem.Soc.2005,127,15515.).In this work,several robust computational methods have been used to investigate this issue.The results clearly show that a computational artifact leads to the conclusion incorrectly reported by McDowell and Buckingham and that the correlation between the X―H bond-length change and the corresponding X―H stretching frequency shift is still very good in the hydrogen-bonded complexes studied.