Pressure-enhanced C－H…O interactions in aqueous tert-Butyl Alcohol

• Main Authors: Ching-Wei Chuang, 莊經緯
• Other Authors: Hai-Chou Chang
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/02777537912494953256

碩士 === 國立東華大學 === 化學系 === 93 === We have investigated pressure-enhanced C–H•••O interactions in tert-butyl alcohol (TBA)/D2O mixtures. Based on its responses to changes in pressure and concentration, TBA appears to be the ideal candidate to study the variations in structural and dynamical properties of C–H•••O interactions. For dilute aqueous TBA, the pressure dependence of the C–H bands yielded blue frequency shifts at pressures below 0.3 GPa, but dramatic red frequency shifts occurred at pressures above this value. This discontinuity in frequency shift is related to enhanced C–H•••O interactions. The frequency of the C–H stretching modes that characterize C–H•••O hydrogen bonding undergoes a blue shift with pressure. This behavior is in contrast with the general trend of red shifts observed in strongly hydrogen-bonded systems that occur through O–H•••O and C=O•••H interactions. We discuss the results of ab initio calculations that predict the frequency shift of the C–H stretching vibrations.