AbstractTwo reduced Schiff bases, namely 5-[(2-hydroxybenzyl)amino]isophthalic acid (1) and 5-[(pyridin-4-ylmethyl)amino]isophthalic acid (2), were synthesized in two-step method using 5-aminoisophthalic acid as the starting material, and were characterized by single-crystal X-ray diffraction, elemental analysis, infrared, 1H NMR, mass, absorption and fluorescence spectra. Both 1 and 2 crystallize in monoclinic system with space groups P21/c for 1 and P21/n for 2. Photophysical properties of both 1 and 2 are significantly different from those of raw material 5-aminoisophthalic acid due to stronger p → π conjugation when one amino hydrogen atom in 5-aminoisophthalic acid is substituted with electron-donor group. 1 displays a very strong narrow-band blue fluorescence with the maximum peak at 439 nm, a high quantum efficiency up to 64%, and a narrow full width at half maximum of 35 nm, while 2 has a broader and weaker fluorescence with the peak at 418 nm and FHWM of about 50 nm.Graphical AbstractTwo reduced Schiff bases with blue fluorescence were synthesized from 5-aminoisophthalic acid in two-step method including formation of the corresponding Schiff bases and further reduction by NaBH4.

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5-氨基间苯二甲酸衍生的两种还原席夫碱的合成、晶体结构和光物理性质

摘要 使用 5-[(2-羟基苄基)氨基]间苯二甲酸 (1) 和 5-[(吡啶-4-基甲基)氨基]间苯二甲酸(2)，采用两步法合成了两种还原席夫碱。以氨基间苯二甲酸为起始原料，通过单晶X射线衍射、元素分析、红外、1H NMR、质量、吸收和荧光光谱进行表征。1和2都在单斜晶系中结晶，1的空间群为P21/c，2的空间群为P21/n。由于p→π共轭更强，1和2的光物理性质与原料5-氨基间苯二甲酸有显着差异。 5-氨基间苯二甲酸中的一个氨基氢原子被电子给体基团取代。1 显示出非常强的窄带蓝色荧光，最大峰值在 439 nm，量子效率高达 64%，