定量共振论与MO的关系——奇共轭烃的激发态

A Quantiflde Resonance Theory and its Relation to Mo—Excited State Behaviour of Odd Conjugated Hydrocarbons

最近我们引进考虑共振结构权重差别的系统处理,指出按此定量化后的共振论（QRT）对大量共轭分子的基态和激发态性质得出和PMO或HMO广泛一致的结果。另一方面适当参数化后的QRT数值结果和实验值的符合,在很多情况下则优于HMO,而和SCF-MO相当。注意到至今尚无对共轭烃自由基及离子π→π*激发态的具体共振结构式描述,本文首先指出对所论的奇共轭体系的电离势和电子亲合势等QRT和PMO或HMO间存在密切的对应关系,从在而此基础上导出π→π*激发态的共振结构式（RS）,并表明QRT结果仍和MO广泛一致。 QRT的基本原则是:（1）由共振结构计数（SC）的对数计算共振能（RE）,由迭加RS得出电荷密度qr和键序Pr3。

Quantified resonance theory (QRT) involving the use of weighting has been applied to ionization potential, electron affinity, energy of the lowest π→π~* transiton, charge density and bond order in excited state for odd π hydrocarbon radicals, anions and cations, the QRT results are in remarkable agreement with HMO, the heteroatom effects on these properties obtained by QRT are in full accord with PMO. Moreover QRT gives a simple rule for estimating whether odd nonalternant hydrocarbons containing a 5-or 7-membered ring have NBMO or not.