Theorical Study of Intermolecular and Inter-Ionic molecular Hydrogen Bonding in Amines Comparing System

• Main Authors: Long Shing Wu, 吳龍興
• Other Authors: Chen Cheng
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/52093114401543887101

碩士 === 國防大學中正理工學院 === 應用化學研究所 === 91 === In this article we studied the amines (N(CH3)nH3-n) combined with different kinds of molecule to create the intermolecular hydrogen bonding and inter-ionic hydrogen bonding complex, from that way, discussing the influence of molecular structure stability by two kinds of hydrogen bonding systems. In the intermolecular hydrogen bonding system, we chosen amines combined with nitric acid (HNO3) or hydrogen halide (HX,X=F, Cl or Br) complex, to compare and analyze the affect of hydrogen bonding by methyl group and steric effect. However, in the part of ionic-inter hydrogen bonding, selected the amines combined with hydrogen halide complex for researching object, to discuss the distinction of intermolecular hydrogen bonding and inter-ionic hydrogen bonding. As the result of calculation, we found that methyl group really could strength the stability at intermolecular hydrogen bonding. Along with the addition of temperature because of steric effect and entropy, the stability sequence of Gibbs free energy (△G) would have different variations. In the amines combined with hydrogen halide complex, when methyl group added gradually and atomic number of halogen atom became augmented (Cl or Br), contrasted the migration of hydrogen atom position in hydrogen bonding system, we could find the tendency of total system transferred from intermolecular hydrogen bonding to inter-ionic hydrogen bonding. In the case of inter-ionic hydrogen bonding system, its binding energy between ions including both the coulombic attraction energy and hydrogen bonding energy. In this system, the overall energy between this ionic pairs is decreased whenever the number of CH3 is increasing due to proton accept or electron donor effect of methyl group.