三腈基呋喃推拉型电荷转移分子的双光子吸收

Two-photon Absorption of a Push-pull Type Intramolecular Charge Transfer Molecule Including Tricyanofuran

根据双光子吸收效应与分子之间"构效"关系,设计四种D-π-A推拉偶极型电荷转移分子,采用AM1方法计算出分子三阶极化率,筛选出具有潜在三阶非线性光学活性分子2-(3-腈基-(3-(4-(二甲胺基)苯乙烯基)-5,5-二甲环己基-2-烯)甲基)-5,5-二甲基呋喃-2-烯)丙二腈(CFM).首次在温和条件下使酮羰基与TCF(2-(3-腈基-4,5,5-三甲基呋喃-2-烯)丙二腈)的活泼甲基通过Knoevenagel反应合成出目标分子.通过非线性透过率法研究了CFM的双光子吸收性质,采用Ti:Sapphire激光器在800 nm,150 fs激光激发下测得了CFM的双光子吸收截面σ2,在DMF溶剂中达到104.29 GM,在CH2Cl2溶剂中达到78.22 GM.CFM具有较强的双光子吸收特性和光限幅效应.

Four D-π-A push-pull type charge transfer molecules were designed basing on the relationship between two-photon absorption and the structure.AM1 method was used to calculate the three-order po-larizabilities of the four molecules and the molecule CFM（2-（3-cyano-（3-（4-（dimethyl-amino）styryl）-5,5-dimethylcyclohex-2-enylidene）methyl）-5,5-dimethylfuran-2-ylidene）malononitrile） was selected out.TCF（2-（3-cyano-4,5,5-trimethylfuran-2-ylidene）malononitrile） used as electronic accepter,N,N-dimethyl-aniline moiety was used as electronic donor,isophorone（3,5,5-trimethylcyclohex-2-enone） as conjugate bridge.CFM was synthesized by Knoevenagel reaction under mild conditions between lively methylene of TCF and ketone.The three-order nonlinear optical property of CFM was got with experiment methods.Us-ing a 800 nm 150 femtosecond Ti：sapphire laser,the CFM＇s two-photon absorption（2PA） cross-sections reach 104.29 GM（GM=10-50 cm4·s·photon-1） in DMF and 78.22 GM in CH2Cl2 which obtained by nonlinear transmission method.The CFM has the property of two-photon absorption and optical power lim-iting.