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采用密度泛函理论(DFT)在B3LYP/6-311G(d,p)水平上,研究2-锗萘作为亲二烯体与2,3-二甲基丁二烯的杂Diels-Alder反应的微观机理和势能剖面,考察反应的取代基效应和溶剂效应。计算结果表明,所研究反应均以协同非同步的方式进行,且C-Ge键总是先于C-C键形成。发生在C1,Ge2位上的反应中,形成2个新键的非同步性比发生在Ge2-C3位上的大,且前者在热力学和动力学上都比后者容易进行,与实验完全一致。exo进攻方式在动力学上都比相应的endo容易,但二者在热力学上的差别一般比较小。锗原子上的CCl_3和NH_2取代基,一般有利于反应,而C(CH_3)_3取代基则相反。苯溶剂对所研究反应的势能剖面影响较小。
The density functional theory (DFT) at B3LYP / 6-311G (d, p) levels, 2-germanium naphthalene as a dienophile with 2,3-dimethyl butadiene hetero Diels-Alder reaction Micro-mechanism and potential energy profile to investigate the substituent effect and solvent effect of the reaction. The calculated results show that all the reactions studied are in a synergistic non-synchronous manner, and the C-Ge bond always precedes the C-C bond. Occurred in the C1, Ge2 position on the reaction, the formation of two new key non-synchronous than occurred in the Ge2-C3 position on the large, and the former thermodynamically and kinematically easier than the latter, consistent with the experiment . exo offensive approach is more kinetic than the corresponding endo easy, but the difference between the two thermodynamics is generally relatively small. The CCl_3 and NH_2 substituents on the germanium atom generally favor the reaction, whereas the C (CH_3) __3 substituent is the opposite. Benzene solvent has little effect on the potential energy profile of the studied reaction.