A-B2型含二苯甲酮的对硝基二苯乙烯类染料的合成、双光子性质与电化学

报道了3',4'-二(对苯甲酰基苯甲氧)基-4-硝基二苯乙烯(C1)的合成与表征. 研究了在不同溶剂中分子的吸收与荧光发射. 分子在可见光区的吸收可以归于生色团对硝基二苯乙烯部分的贡献, 而其在短波长区的吸收主要由二苯甲酮部分提供. 分子在中等极性溶剂中表现出较强的荧光发射. 系统研究了3',4'-二(对苯甲酰基苯甲氧)基-4-硝基二苯乙烯与2',4'-二(对苯甲酰基苯甲氧)基-4-硝基二苯乙烯(C2)两种A-B2型分子的双光子性质与电化学行为. 结果表明, 在800 nm波长的飞秒激光激发下, 两个分子皆表现出明显的上转换荧光发射, 其双光子吸收横截面的大小与二苯甲酮取代位置表现出一定的相关性. 分子结构优化与电化学的研究表明, 两个分子的电子密度分布与前线轨道能量亦与二苯甲酮取代位置表现出一定的相关性.

Synthesis,Two-Photon Properties and Electrochemistry of A-B2 Type Nitro-stilbene Dyes with Benzophenone Groups

We discuss the synthesis and characterization of 3',4'-bis(p-benzoylphenylmethoxy)yl-4-nitrostilbene (C1). Ultraviolet and fluorescence spectroscopy was used to investigate its behavior in various solvents. Results showed that the visible absorption of C1 could be assigned to the chromophore and that the attached benzophenone made major contribution to the ultraviolet absorption of C1. This compound exhibited strong fluorescence in modest polar solvents.Acomprehensive investigation of the two-photon properties and electrochemistry of C1 and 2',4'-bis(p-benzoylphenylmethoxy)yl-4-nitrostilbene (C2) was undertaken. Results suggested that at 800 nm femtosecond laser excitation, C1 and C2 showed strong two-photon induced upconversion fluorescence. The two-photon absorption cross-section of the compound was shown to be related to the substitution position of benzophenone. Molecular geometry optimization and electrochemistry suggested that the energies of the frontier orbitals and electron densities of C1 and C2 could be correlated to the position of benzophenone substitution as well.