前线轨道理论认为 :分子在反应过程中是分子轨道起变化 ,优先起作用的是前线轨道 ,即分子中的最高被电子占有分子轨道 (HOMO)和最低空分子轨道 (LUMO) ,分子轨道的对称性特别是前线轨道的对称性在反应历程中起决定作用

The theory of the frontier orbital thinks that the molecular orbital makes a change in the reaction process of the molecule, in which the frontier orbital makes a great effect first, that is the HOMO and the LUMO. The symmetry of the molecular orbital especially the symmetry of the frontier orbital in the reaction.