有机分子结构对分子二阶光学极化率的影响

CONTKIBUTION OF THE STRUCTURE OF ORGANICMOLECULAR TO SECOND ORDER HYPERPOLARIZABILITY

文章对具有电子施主和电子受主的π共轭有机分子的分子二阶非线性光学极化率β进行计算，计算中采用ＨＭＯ方法计算分子能级，用多能级模型计算分子二阶非线性光学极化率。从计算结果得到，分子中电子施主和电子受主基团的推拉电子能力越强，对β值的贡献越大；分子中π共扼链长对β的影响比较复杂，随着链长的增加，β值的总趋势是增大，但β值既存在大起伏又存在小起伏．

Second order hyperpolarizability of the molecular that have the donor group,acceptor group and conjugated hydrocarbon is calculated. The level of molecular is gottenwith HMO method and the βis gotten with the level model. The larger the contribtition ofthe donor-acceptorgroups is,the larger the β value is. The relation of length of conjugat-ed hydrocarbon and β value is comples,When length increase,the trend of β value in-crease.The change ofβvalue have the greater undulation and the fewer undulation withlength of hydroccarbon.