摘要
在密度泛函(DFT)B3LYP/6-311++G**理论水平上,全自由度优化气相和水相中3-(CHO/COF)-吲唑两种反应途径(Path A:分子内质子迁移;Path B:水助质子迁移)质子迁移的各异构体的几何构型,得其气相和水相中的几何结构和电子结构,并将PCM(极化连续介质模型)反应场溶剂模型用于水相计算.在气相和水相中,3-(CHO/COF)-吲唑的N1-H形式比N2-H形式稳定.进一步研究3-(CHO/COF)-吲唑质子迁移的反应机理.研究结果显示:不同的3C取代基对反应物、产物及过渡态的分子几何构型影响不大,但是不同构象的3C取代基对反应物、产物的几何结构和质子迁移的热力学参数有较大影响;溶剂化效应和氢键的形成对质子转移反应的热力学参数有很大影响;Path B所需的活化能较低,约为Path A途径的一半.
The molecular structures of 3-CHO-indazole and 3-COF-indazole tautomers were calculated by the B3LYP method at the 6-311＋＋G＊＊ level,both in the gaseous and aqueous phases,with full geometry optimization.The geometry and electronic structure of the tautomers of 3-（CHO/COF）-indazole and their transition states were obtained.The PCM（polarized continuum model） solvate theory model was employed for the aqueous solution calculations.The influences of the different 3C substituents,the different constellations of the same 3C substituent and the solvent effects on the geometry,energy,charge and activation energy were discussed.In this paper,there were two paths of proton transfer,viz.Path A was intramolecular proton transfer;while Path B was waster-assisted intermolecular proton transfer.The calculation results indicate that Path B has lower activation energies than Path A.The molecular structure of transition states of Path B is a five-member ring and that of Path A is a three-member ring.
出处
《武汉大学学报（理学版）》
CAS
CSCD
北大核心
2011年第1期23-28,共6页
Journal of Wuhan University:Natural Science Edition
基金
江苏盐城师范学院自然科学基金(10YCKL003)资助项目
