Gigantic Blue Shift of the H−Ar Stretch Vibration in π Hydrogen-Bonded C2H2···HArCCF Complex

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• 作者：Jianbo Cheng ; Yilei Wang ; Qingzhong Li ; Zhenbo Liu ; Wenzuo Li ; Baoan Gong
• 刊名：Journal of Physical Chemistry A
• 出版年：2009
• 出版时间：April 30, 2009
• 年：2009
• 卷：113
• 期：17
• 页码：5235-5239
• 全文大小：130K
• 年卷期：v.113,no.17(April 30, 2009)
• ISSN：1520-5215

文摘

Quantum chemical calculations have been performed to study the structure and properties of the π hydrogen-bonded complex formed between acetylene and HArCCF at the MP2/6-311++G(2d,2p) level. The C₂H₂···HCCF and C₂H₂···HCCArF complexes were also studied for comparison with the C₂H₂···HArCCF complex. The basis set superposition errors (BSSE)-counterpoise corrected potential-energy surface (PES) has a larger influence on the structure and properties of the C₂H₂···HArCCF complex than those of the C₂H₂···HCCF and C₂H₂···HCCArF complexes. The C₂H₂···HArCCF complex exhibits a very large harmonic vibrational frequency blue shift of 574 cm⁻¹ for the H−Ar stretch, whereas the C₂H₂···HCCF and C₂H₂···HCCArF complexes exhibit a small red shift of 35 and 47 cm⁻¹ for the H−C stretch, respectively; upon complexation the IR intensity decreases in the former, whereas it increases in the latter. The origin of the frequency shift and nature of the hydrogen bond in these complexes have been unveiled with the natural bond orbital analysis and energy decomposition.