Density functional theory(DFT)-B3LYP/6-311G** method was used to study the mechanism and potential energy surface of[2+2] ,[4+2] and[4+4] dimerization reactions of 1-germaanthracene and[2+2] dimerization reactions of 2-germaanthracene and 9-germaphenanthrene. The influence of benzene solvent on the potential energy surface of reactions was explored. The obtained results were compared with those of dimerization reactions of germabenzene, 1 -germanaphthalene and 2-germanaphthalene studied previously. The results show that[2+2] and[4+4] reactions occur in a concerted and synchronous way, while[4+2] reactions proceed in a concerted but nonsynchronous way. [4+2] Reactions of 1-germaanthracene are the most favorable both thermodynamically and kinetically,while[4+4]reactions are the most unfavorable. It seems that the difference between exo and endo approaches is not obvious both in the thermodynamic and kinetic properties. Benzene,as a poor polar solvent,has only trivial influence on the potential energy surface of the studied reactions. l-Germaanthracene(2-germaanthraeene)has higher reactivity than gennabenzene and 1 -germanaphthalene ( 2-germanaphthalene ).%采用密度泛函B3LYP/6-311G*方法研究了1-锗蒽的[2+2]、[4+2]及[4+4]二聚反应、2-锗蒽及9-锗菲的[2+2]二聚反应的微观机理和势能剖面,考察了苯溶剂对反应势能剖面的影响,并与锗苯、1-锗萘及2-锗萘的类似反应进行了比较.计算结果表明,[2+2]和[4+4]反应为同步的协同过程,而[4+2]反应为非同步的协同过程.无论从热力学还是从动力学来看,1-锗蒽的[4+2]反应最有利,而[4+4]反应最不利.两种不同的进攻方式(endo进攻与exo进攻)在热力学和动力学上的差别不大.苯溶剂对所研究反应的势能剖面影响较小.1-锗蒽(2-锗蒽)的反应性高于锗苯和1-锗萘(2-锗萘).
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