类杂芪染料分子第一超极化率的溶剂效应研究

Solvents Effects on Molecular First - Hyperpolarizabilities of Stilbazolium - like Dyes

从实验上证明了反式-(2-N-甲基吡咯基)-(4-N-甲基吡啶基)杂芪碘(MPPSI),反式-(2-吡咯基)-(4-N-甲基吡啶基)杂芪碘(PPSl),反式-(2-呋喃基)-(4-N-甲基吡啶基)杂芪碘(FPSI)和反式-(2-噻吩基)-(4-N-甲基吡啶基)杂芪碘(TPSI)在15种溶剂中的分子第一超极化率(β_(xxx))与给电子取代基的富电子性间的线性关系,得到了β_(xxx)值与溶剂极性间的线性相关性,从以上两个线性相关中得到了溶剂极性影响类杂芪分子给/吸电子取代基的给/吸电子能力的溶剂系数δ_A和δ_D,以及分子内电荷转移对溶剂极性的敏感因子η.

We have proved that the first - hyperpolarizabilities (βxxx) of the four stilbazolium - like dyes, which are trans - (N - methylpyrrol -2-yl) - 4 - (N - methyl - pyridinio) - stilbazolium iodide ( MPPSI) , trans - (pyrrol -2-yl) - 4 - (N - methyl - pyridinio) - stilbazolium iodide (PPSI) , trans - (furan - 2 -yl) - 4 - (TV - methyl - pyridinio) - stilbazolium iodide (FPSI) and trans - (thiophene -2-yl) - 4- (N -methyl- pyridinio) - stilbazolium iodide (TPSI), can be linearly correlated with the electron excessivities ofdonors in fifteen solvents. Then we obtained the linearity correlation between the βxxx of the dyes and thesolvents polarity [ET(30) ]. From the two linearity correlations we obtain three solvent factors η, δA and δD fordescribing the solvents effects on the βxxx: η describes the sensitivity of the intramolecular electron transfer tothe solvent polarity, δA and δD describe the accepting/donating ability of the acceptor/donor effected by thesolvent polarity respectively. The δA increases linearly, but the δD is decreased linearly with increasing of the ET(30).