Quantum Mechanical Study on Hydrogen Bonds between 3‐Aminophenol and CHxCl4 − x (x = 1, 2, 3): Effect of the Number of Halogen Atoms#

摘要

Hydrogen bonds between 3a??aminophenol and three chlorinea??substituted methanes (CHCl3, CH2Cl2, and CH3Cl) were quantum mechanically studied at MP2/auga??cca??pVDZ level. Several lowa??energy structures with a hydrogen bond were identified for all chlorinated methanes, and the properties of their C?￡?H stretching vibrations were investigated. When it is hydrogena??bonded to 3a??aminophenol (3AP), the C?￡?H stretching frequency of CHCl3 is bluea??shifted by 18a??54a??cma??1, and its IR absorption intensity is 48a??74 times increased, depending on the isomer. The symmetric and antisymmetric C?￡?H stretches of CH2Cl2 and CH3Cl are shifted in either direction by a few cma??1 upon hydrogena??bonding to 3AP, and their IR intensity was increased by a few times. It is concluded that all chlorinated methanes can make a ??a??hydrogen bond to 3AP but only CHCl3, the one with the most chlorine atoms, makes a bluea??shifting hydrogen bond, or an a??antihydrogen bonda??.