论文部分内容阅读
利用MNDO哈密顿中PM-3方法计算了三个系列D-A化合物的偶极矩(μ),极化系数(α),一阶(β)和二阶(σ)超极化系数。计算结果与实验值相符。计算显示β和ν与推、拉电子基团强弱有关,利用电荷转移可以提高β和ν值。计算结果证明杂原子对超极化度的影响是显著的。通过对双取代-二苯基多烯的β和ν计算,证实在共轭键上引入C=C双键是提高β和ν的有效方法。双键数对ν的影响可以表示成:ν=(n)=ν(0)+70n+9.4n~2。
The dipole moment (μ), polarization coefficient (α), first order (β) and second order (σ) hyperpolarizability of the three series of D-A compounds were calculated using the PM-3 method in MNDO Hamiltonian. The calculated results are consistent with the experimental values. Calculations show that β and ν are related to the strength of electron groups pushed and pulled, and the β and ν values can be increased by charge transfer. The calculated results show that the influence of heteroatoms on hyperpolarizability is significant. By calculating β and ν of disubstituted-diphenyl polyene, it was confirmed that the introduction of C = C double bonds on the conjugated bond is an effective method to increase β and ν. The effect of double bond number on ν can be expressed as: ν = (n) = ν (0) + 70n + 9.4n ~ 2.