两个查尔酮衍生物的合成及超快三阶非线性光学响应

Synthesis and Ultrafast Third-order Nonlinear Optical Response of Two Chalcone Derivatives

合成了两个二茂铁基查尔酮衍生物:1-二茂铁基-3-(4,5-苯并噻吩-3-基)丙烯酮(FBTAK)和1-二茂铁基-3-(5-苯基噻吩-2-基)丙烯酮(FPTAK),经核磁共振氢谱、碳谱和高分辨质谱对其结构进行表征。采用Z-扫描技术测定了化合物的三阶非线性光学吸收系数(β)、折射系数(n2)和分子超极化率(γ),采用密度泛函理论方法计算了它们的几何结构、分子轨道电子云图和相关能量,同时也测定了其紫外-可见吸收光谱和DSC曲线。FPTAK的分子超极化率(γ)分别是FBTAK、1-二茂铁基-3-(4-叔丁基苯基)丙烯酮(a)和1-二茂铁基-3-联苯基丙烯酮(b)的6. 04倍、4. 3倍和3. 7倍。从构效关系看,苯联噻吩基比苯并噻吩基和联苯基的贡献大,也就是噻吩环比苯环的贡献大。结果表明,电荷转移可以在分子内发生,表现出超快三阶非线性光学响应。

Two chalcone derivatives,1-ferrocenyl-3-( 4,5-benzothiophen-3-yl) acrylic ketone( FBTAK) and 1-ferrocenyl-3-( 5-phenylthiophen-2-yl) acrylic ketone( FPTAK),were successfully synthesized and characterized by1 H NMR,13 C NMR and HR-MS. The third-order nonlinear optical( NLO) properties of the titled compounds were investigated by using Z-scan technique. Their geometrical structures,molecular orbital electron cloud images and related energies were calculated by density functional theory. Meanwhile,their UV-Vis absorption spectra and DSC curves were also measured. The molecular hyperpolarizability( γ) of FPTAK is 6. 04,4. 3 and 3. 7 times higher than those of FBTAK,1-ferrocenyl-3-( 4-t-butylphenyl) acrylic ketone( a) and 1-ferrocenyl-3-biphenylyl acrylic ketone( b),respectively. As far as the structure-activity relationship is concerned,the contribution of phenylthiophene is greater than that of benzothiophene and biphenyl. That is to say,thiophene ring contributes more than benzene ring.The results indicated that intramolecular electron transfer can occur and two compounds both exhibit an ultrafast third-order NLO response.