双亲性噻吩羧酸衍生物的制备及潜指纹检测应用

Preparation of amphiphilic thienyl carboxylic acid derivatives and application for latent fingerprint detection

摘要:

5-溴噻吩-2-羧酸和(4-(二苯基氨基)苯基)硼酸通过Suzuki偶联反应，合成双亲性噻吩羧酸衍生物5-(4-(二苯基氨基)苯基)噻吩-2-羧酸及其钾盐（TTC-H和TTC-K）。在结构表征的基础上，利用紫外-可见光吸收光谱，荧光发射光谱系统讨论了目标分子及其聚集态的光物理性质。通过密度泛函理论计算和溶剂化显色效应，进一步验证了分子内存在电荷转移特性。晶体结构解析及Hirshfeld表面分析表明，TTC-H分子间存在C…H (31.6%)和O…H (14.6%)氢键等弱相互作用力。TTC-H与TTC-K均具有聚集诱导发光性质。TTC-K因具有羧酸盐结构，表现出更好的水溶性，将其水溶液通过化学浸渍法和雾化法应用于潜指纹成像，均可精确高效地得到指纹的3级结构。TTC-K水溶液试剂能在低浓度下（1×10-4 mol/L）实现对潜指纹的快速识别（< 5 s），陈化稳定性好，对于陈旧指纹（< 14天）也具有良好的成像效果。

Abstract:

The amphiphilic carboxylic acid derivatives, 5-[(4-(diphenylamino)phenyl)]thiophen-2-carboxylic acid and its potassium salts (TTC-H and TTC-K), were synthesized through a Suzuki coupling reaction involving 5-bromothiophen-2-carboxylic acid and [(4-(diphenylamino)phenyl)]boric acid. The structures of the two compounds were characterized by 1HNMR and 13CNMR. The UV-Vis absorption spectroscopy was used to verify the photophysical properties of TTC-H and TTC-K, while fluorescence emission spectroscopy systematically discussed their aggregated states. Density-functional theory calculations and solvation colorimetric effects confirmed the charge transfer properties within the molecules of TTC-H and TTC-K. Their crystal structures were resolved and analyzed by Hirshfeld surface analysis, and the results showed that there were weak interaction forces between TTC-H molecules, such as C···H (31.6%, accounting for the percentage of the total interaction force, similarly hereinafter), H···H (44.6%) and O···H (14.6%). Both TTC-H and TTC-K possessed the property of aggregation-induced emission (AIE). The aqueous solution of TTC-K was proved effective in revealing the tertiary structure of latent fingerprints through chemical impregnation and atomization methods with a good stability of aging. And even at low concentrations (5×10-5 mol/L), the TTC-K aqueous solution reagent enabled rapid identification of latent fingerprints (≤5 s) by chemical impregnation method. And both old fingerprints (≤14 d) and fingerprints soaked in water (≤7 d) have good imaging effects.