多支结构的均三嗪衍生物的合成及双光子吸收性质

合成了3个系列各含有单支、双支和三支结构的9个均三嗪衍生物, 测定了它们的线性吸收和发射性质以及双光子吸收和发射性质. 随着三嗪环上侧链数目的增加, 线性吸收谱(吸收峰位于390～440 nm)、荧光谱(发射峰位于460～580 nm)和双光子荧光谱(激发波长800 nm)都发生红移; 各种光谱的强度逐渐增强; 基态与激发态的偶极矩之差Δμ_eg也逐渐增大. 另外, 从单支到三支结构, 双光子吸收截面σ随侧链数目呈非线性增加. 这表明多支结构的双光子吸收存在显著的增强效应.

Syntheses and Two-photon Absorption Properties of Multi-branched s-Triazine Derivative

Three series of multi-branched s-triazine derivatives with one, two or three branches have been synthesized. For each series, the linear absorption (peak position: 390～440 nm) and emission spectra (peak position: 460～580 nm), along with the two-photon exited fluorescence spectra excited at 800 nm, showed regular red-shifts as the branch number was increased, and their spectral intensities were significantly enlarged from one- to three-branched structures. In addition, the difference of dipole moment (Δμ_eg) between the ground and the excited states became larger as the branch number was increased from 1 to 3. The two-photon absorption cross section σ was non-linearly increased with the increase of the branch number and the reduced σ, indicating a remarkable cooperative enhancement of σ in the multi-branched s-triazine derivatives.