Unpaired and Bond Electrons as H, Cl, and Li Bond Acceptors: An Anomalous One-Electron Blue-Shifting Chlorine Bond
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- 作者：B. Raghavendra ; E. Arunan
- 刊名：Journal of Physical Chemistry A
- 出版年：2007
- 出版时间：October 4, 2007
- 年：2007
- 卷：111
- 期：39
- 页码：9699 - 9706
- 全文大小：111K
- 年卷期：v.111,no.39(October 4, 2007)
- ISSN：1520-5215
文摘
Ab initio, DFT, and AIM theoretical studies on H-, Cl-, and Li-bonded complexes have been carried out withtypical lone pair (H2O), (C2H4) and (H2) bonded pairs, and unpaired (CH3) electrons as acceptors andHF, ClF, and LiF as donors. Optimization and frequency calculations have been carried out at reasonablyhigh levels (MP2, DFT(B3LYP), and QCISD) with large basis sets up to aug-cc-pVTZ. Not surprisingly, allHF complexes show red shift in stretching frequency and the shift is correlated to the binding energy. However,the FCl···CH3 complex shows a large blue shift (about 200 cm-1), which appears to be the largest blue shiftpredicted for any weakly bound complex yet. Analysis of the normal modes of the complex indicates that theshift is due to the mixing of modes between donor and acceptor and it is qualitatively different from the blueshifts reported thus far in hydrogen-bonded complexes. For Cl- and Li-bonded complexes, a correlation betweenfrequency shift and binding energy is not found. However, AIM theoretical analysis shows the similarity inall these interactions. The electron density at the bond critical point shows a strong correlation with thebinding energy for H-, Cl-, and Li-bonded complexes. This appears to be the first report on a one-electronchlorine bond.