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溶剂化效应对6-亚甲基环戊二烯酮与HCN的反应机理影响的理论研究
Theoretical Study of Effect of Solvent on the Mechanism of Reaction of Pentafulvenone with Hydrocyanic Acid
【摘要】 在B3LYP/6-311+G**计算水平上,采用导体极化连续模型研究了溶剂化效应对6-亚甲基环戊二烯酮与HCN反应生成主要产物b类酸的反应机理的影响.计算结果表明,在溶剂中的反应机理与在气相中的反应机理一致.溶剂化效应使反应路径中各驻点的自由能降低,稳定化了各物质.溶液中的活化自由能与气相相比也有所降低,反应更容易发生,其中CC进攻方式的活化自由能降低得更多.
【Abstract】 Theoretical investigation of the solvent effects on the mechanism of the reaction of pentafulvenone with hydrocyanic acid to produce the main product of acid of type b was carried out at B3LYP/6-311+G level via the conductor-like polarizable continuum model(CPCM). The calculation results show that the reaction mechanism in solvent is consistent with that in gas phase. The free energies of each point in channel decrease,which was caused by the solvent effects. The solvent effects stabilize each species. The activating free energies in solution phase fall down,which was comparative to that in gas phase. The reaction proceeds easier and the activating free energies decrease more in the C=C attacking channel.
【Key words】 Pentafulvenone； HCN； Conductor-like polarizable continuum model； Solvation effectXCHI Shao-Ming1,2,WANG Ning1,MA Li-Ying1,FANG Fang2,TIAN Guo-Cai2,LI Guo-Bao2,XU Si-Chuan1(1. Key Lab of Medicinal Chemistry for Natural Resource of Education Ministry,College of Chemical Science and Technology,Lab on the Origin of Life,Yunnan University,Kunming 650091,China； 2. College of Chemistry and Chemical Engineering,Yunnan Normal University,Kunming 650092,China)Abstract The reaction potential surfaces(PESes) for the ion-molecule reaction of NO-3+Cl2 → ClONO2+Cl-were calculated at the B3LYP/6-311+G(d) level in the mode of three dimensions. Three original three-dimensional PESes prove that in the reaction there are no transition state and energy barrier,but there exists a potential energy well. The depth of the potential energy well is -55.0 kJ/mol(relative to NO-3 and Cl2 completely be separated) calculated with CCSD(T)/6-311+G(d)// B3LYP/6-311+G(d). At the bottom of the well,there is a compound called Potential Well Compound(PWC),existing stably with the help of the well. The calculated theoretical infrared spectra predict that the PWC would be examined in low temperature infrared spectra. Our work shows that at low temperatures(~180 K) the reaction is dominated by its thermal dynamics. When the temperature going up,the PWC decomposes through reaction of(O2NOClCl)-→ NO-3+Cl2,dominated by its chemical dynamics. Our study indicates that ClONO2 with Cl-cannot produce Cl2 at low temperatures in the gas-phase reaction.Keywords Chlorine nitrate； Potential energy surface； Potential energy well； Potential well compound； Chemical dynamics；
- 【文献出处】 高等学校化学学报 ,Chemical Journal of Chinese Universities , 编辑部邮箱 ,2008年06期
- 【分类号】O643.12
- 【被引频次】6
- 【下载频次】320