苯乙烯基噻吩单体及对应的聚脲烷的合成及其非线性光学性能

一种新型的反式-7-[4-N,N-二(β-羟基乙基胺基苯)]-3,5-二硝基乙烯基-噻吩(HBDT)单体分子及对应的预聚物和聚脲烷被合成和表征.由于噻吩环的电子去局域化能量低于苯环,在受授有机共轭化合物中噻吩环比苯环表现出更有效的共轭和更高的非线性,同时也能使目标分子保持好的光、热稳定性.该单体分子及其对应的聚脲烷在普通有机溶剂中具有良好的可溶性,聚脲烷膜具有好的热稳定性.制备了高质量的聚脲烷膜并进行了电晕极化.单体在甲醇中的紫外可见吸收峰(530nm)与对应未经电晕极化聚脲烷膜的吸收峰基本上没有改变.通过溶剂变色法及简并四波混频(DFWM)法测试了单体的二阶和三阶非线性极化率,其β_μ,χ⁽³⁾和γ值分别为8.443×10^-45esu,1.016×10^-12esu(c=3.96×10^-3mol/L),3.93×10^-32esu.

Synthesis of a Styrylthiophene Monomer and Corresponding Polyurethane and Their Optical Nonlinearity

Anovel trans-7-[4-N,N-di-(β-hydroxy ethylamino-benzene)]-ethenyl-ethenyl-3,5-dinitrothiophene(HBDT) monomer and corresponding prepolymer, polyurethane with the monomer covalently incorporated were synthesized and characterized. The reaction temperature affecting monomers formation were discussed. Since thiophene has a lower delocalization energy than that of benzene, it can offer more effective conjugation and higher nonlinearity than that of benzene in donoracceptor organic compounds, and forms objective molecules with reasonable optical, thermal stability. The monomer and polyurethane exhibited a good solubility in common organic solvents and thermal stability. The high optical quality films of the polyurethane were fabricated and coronapoled. The UVVis absorption peaks (530 nm) of the monomer in methanol and the without poling polyurethane films didnt change basically. The second, thirdorder nonlinear optical susceptibility, (3), of HBDT was measured by solvatochromic method and DFWMmethod, respectively, they were 8.443×10^-45esu,1.016×10^-12esu(c=3.96×10^-3mol/L),3.93×10^-32esu. respec-tively.