Theoretical Study on Intermolecular Interactions and Thermodynamic Properties of Dimethylnitroamine Clusters
Theoretical Study on Intermolecular Interactions and Thermody-namicProperties of Dimethylnitroamine Clusters作者机构:DepartmentofChemistryNanjingUniversityofScienceandTechnologyNanjing210094China
出 版 物:《Chinese Journal of Chemistry》 (中国化学(英文版))
年 卷 期:2002年第20卷第3期
页 面:629-637页
核心收录:
学科分类:081704[工学-应用化学] 07[理学] 070304[理学-物理化学(含∶化学物理)] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学]
主 题:dimethylnitroamine cluster intermolecular interaction ah initio thermodynamic property
摘 要:Ab initio SCF and Moller-Plesset correlation correction methods incombination with counterpoise procedure for BSSE correction have been applied to the theroeticalstudying of dimethylnitroamine and its dimers and trimers. Three optimized stable dimers and twotrimers have been obtained. The corrected binding energies of the most stable dimer and trimer werepredicted to be - 24.68 kJ/mol and - 47.27 kJ/mol, respectively at the MP2/6-31G ~*//HF/6-31G~*level. The proportion of correlated interaction energies to their total interaction energies for allclusters was at least 29.3 percent, and the BSSE of ΔE(MP2) was at least 10.0 kJ/mol. Dispersionand/ or electrostatic force were dominant in all clusters. There exist cooperative effects in boththe chain and the cyclic trimers. The vibrational frequencies associated with N―O stretches or wagsexhibit slight red shifts, but the modes associated with the motion of hydrogen atoms of the methylgroup show somewhat blue shifts with respect to those of monomer. Thermodynamic properties ofdimethylnitroamine and its clusters at different temperatures have been calculated on the basis ofvibrational analyses. The changes of the Gibbs free energies for the aggregation from monomer to themost stable dimer and trimer were predicted to be 14.37 kJ/mol and 30.40 kJ/mol, respectively, at 1atm and 298.15 K.