一种以环戊并双噻吩作为π电子桥的新型发色团的合成和电光性质的表征

Synthesis and Electro-optical Properties of a Novel Nonlinear Optical Chromophore Containing 4,4-dihexyl-4H-cyclopenta[2,1-b:3,4-b′]dithiophene asπBridge

本文以4,4-二己基-4H-环戊并[2,1-b:3,4-b′]二噻吩为π电子桥,合成了一种新型非线性光学发色团,并通过紫外-可见吸收光谱、热重分析以及密度泛函理论计算等对其物理和化学性质系统地进行了表征。结果表明,4,4-二己基-4H-环戊并[2,1-b:3,4-b′]二噻吩作为π电子桥能有效地提高分子内的电荷转移速率和分子的一阶超极化率。同时,侧链二己基的空间位阻效应能很好地削弱分子间静电相互作用。最后,将发色团掺杂到主体聚合物聚碳酸酯中,测试得到发色团浓度为20%的极化聚合物薄膜的电光系数r33为85pm/V。

A novel second-order nonlinear optical chromophores containing 4, 4-dihexyl-4H-cyclopenta[2,1-b. 3, 4-b＇]dithiophene （CPDT） as π-electron bridges was prepared, and its chemical and physical properties were systematically evaluated. UV-Vis spectra, thermal stability and density functional thoery （DFT） calculations revealed that CPDT as π-spacer can dramatically enhance intramolecular charge transfer （ICT） properties and narrow the energy gaps. And due to the hindrance of dihexyl, the chromophore showed weak dipole-dipole aggregation. As expected, the poled polymer film which was prepared by doping chromophore A into amorphous polycarbonate（APC） with 20% （mass fraction） doping density, exhibited 85 pm/V in electro-optical （EO） coefficient test.