【摘要】 以实验合成的联吖叮氮氧自由基分子为母体,设计了7个自由基分子.采用密度泛函理论(DFT)UB3LYP/6-31g(d,p)方法对这些自由基分子不同自旋态的稳定性和非线性光学(NLO)系数进行计算.结果表明,联吖叮氮氧自由基分子及其衍生物三重态为稳定基态,符合自旋极化规则.引入给吸电子取代基使自由基体系的极化率αs与二阶超极化率γs值有所增大,且基团的给吸电子能力越强,αs和γs值增加越明显;对于一阶超极化率βtot,自由基体系处于单重态时,取代基的影响较大.所有自由基分子三重态的NLO系数都小于单重态,表明可以通过控制体系的自旋多重度来调节体系的NLO性质.更多还原

【Abstract】 Seven radicals were designed according to di-acridine nitrogen-oxide radical which had been synthesized.Density functional theory(DFT)UB3LYP/6-31g(d,p)method was employed to calculate the stabi-lities and nonlinear optical(NLO)responses of these radicals in different spin states.The results show that the ground state of di-acridine nitrogen-oxide radicals and derivatives are stable in triplet state according with spin coupling rules.The polarizability αs and the second hyperpolarizability γs of radicals increase with donor and acceptor’s affiliation.Moreover,αs and γs increase obviously with increasing the ability to push/pull an electron.For first hyperpolarizability βtot,substituents have important influence on βtot in singlet state.The singlet radicals have the bigger NLO coefficients than the triplet radicals.Therefore,NLO property of system can be regulated by controlling spin multiplicity of system.更多还原