聚集诱导发光3-溴-5-吡唑甲酰胺类蓝光材料的潜指纹识别应用

Blue emitting 3-bromo-5-pyrazolamide material with aggregation-induced emission for latent fingerprint detection

摘要:

以3-溴- (3-氯吡啶基)吡唑-5-甲酰氯和4-(3,6-二叔丁基咔唑)苯胺为原料，合成了一种D–π–A构型的蓝光N-[4-(3,6-二叔丁基咔唑)苯基]-3-溴-(3-氯-2-吡啶基)-5-吡唑甲酰胺（化合物1），利用紫外可见吸收光谱、荧光发射光谱、动态光散射等对化合物1的聚集诱导发光（AIE）和光物理性质进行测试。结合密度泛函理论计算结果表明，化合物1具有分子内的电荷转移性质，与其溶剂化效应相一致。化合物1的荧光量子产率随着分子的聚集不断增大〔Φ（二氯甲烷）=60.1%；Φ（粉末）=67.5%；Φ（晶体）=70.2%〕。在乙腈和水的混合溶液中，随着水的体积分数的不断增加，化合物1表现出优良的AIE性质。晶体化合物1最大发射波长 (λmax) 为439 nm，处于蓝光发射区域。相比于晶体状态，粉末状态化合物1的λmax发生17 nm红移。此外，化合物1可以对潜指纹进行精准识别包括一级结构，二级结构，甚至三级结构，同时对老化指纹也具有较好的识别效果。

Abstract:

A new blue emitting 3-bromo-(3-chloropyridinyl)-N-[4-(3,6-ditertbutylcarbazolyl)phenyl]- pyrazole-5-carboxamide (compound 1) with D-π-A type was designed and synthesized by using 3-bromo-(3-chloropyridinyl)pyrazole-5-carbonyl chloride and 4-(3,6-ditertbutylcarbazolyl)aniline. Aggregation-induced emission (AIE) and photophysical properties of compound 1 were tested by UV-vis absorption spectrum, fluorescence emission spectra and dynamic light scattering. Based on density-functional theory calculation, compound 1 shows intramolecular charge transfer property, agreeing with its solvent effect. Quantum yield of the compound increased with molecular aggregation 〔Φ(DCM)=60.1%; Φ(powder) = 67.5%; Φ(crystal) = 70.2%〕. Notably, compound 1 exhibited good AIE properties with increasing water fraction in the mixture solution of acetonitrile and water. The maximum emission wavelength (λmax) of crystal compound 1 is 439 nm, which is blue emission. Compared with the crystal state, λmax of compound 1 in powder is redshifted by 17 nm. In addition, compound 1 can accurately detect latent fingerprints including the first level, the second level and even the third level, and also has a good recognition effect on the aged fingerprints.