论文部分内容阅读
采用量子化学密度泛函理论(DFT)在B3LYP/6-311++G~* *水平上对环戊二烯与2(5H)-呋喃酮、丁烯二酸酐和2,5-二氢呋喃的Diels-Alder反应机理进行了理论研究,并且考虑了溶剂化效应和取代基效应对反应机理及能垒的影响.结果表明,本文所涉及的环戊二烯与二氢呋喃类化合物的Diels-A1der加成反应是以协同方式进行的;羰基取代基的吸电子作用是造成产物中C(1)-C(2)、C(3)-C(4)键键长增加的主要原因;反应所涉及到的FMO相互作用主要是环戊二烯的HOMO与二氢呋喃类化合物的LUMO之间的相互作用,羰基对反应活化能的影响主要是通过降低呋喃类化合物的LUMO能级,减小与环戊二烯的HOMO的能级差异,从而有利于反应进行的;反应2的活化能垒最低,从动力学的角度考虑在室温下可以进行.
Quantum chemical density functional theory (DFT) was used to investigate the effect of cyclopentadiene and 2 (5H) -furanone, maleic anhydride and 2,5-dihydrofuran on the B3LYP / 6-311 ++ G ~ * * Diels-Alder reaction mechanism has been studied theoretically and the effects of solvation effect and substituent effect on the reaction mechanism and energy barrier have been considered.The results show that the Diels-Alder reaction mechanism of Diels- A1der addition reaction is carried out in a synergistic manner. The electron-withdrawing effect of carbonyl substituents is the main reason for the increase of C (1) -C (2) and C (3) -C (4) The involved FMO interactions are mainly the interaction between HOMO of cyclopentadiene and the LUMO of dihydrofuran compounds. The influence of carbonyl on the activation energy of the reaction mainly decreases by decreasing the LUMO energy level of the furan compounds And HOMO cyclopentadienyl level difference, which is conducive to the reaction; Reactive 2 minimum energy barrier, from a kinetic point of view can be carried out at room temperature.