咪唑环取代的BODIPY/BOPHY黄色荧光染料的合成及在白光LED灯的应用研究

In this project, a series of dicarbonitrile imidazole substituted BODIPY/BOPHY dyes were configured for the fabrication of white light LED with a blue light chip built in. The emission maximum of BODIPY/BOPHY dyes could be modulated by the substitution of dicarbonitrile imidazole unit and expansion of conjugated system, which benefit to the enhancement of quantum yield and stability. The synthetic strategy of proposed yellow-emissive BODIPY/BOPHY dyes includes four steps: 1) configuring highly fluorescent molecules by attaching dicarbonitrile imidazole to BODIPY/BOPHY framework; 2) shifting the dye emission to yellow region by π expansion; 3) enhancing solubility of fluorescent dyes by alkyl attachment; 4) introducing blue-absorption unit to the dye molecules and matching the blue LED chip; realizing yellow-emission by blue-excitation with stability enhancement and driving by FRET or TBET mechanism. Quantum calculation for the dye molecules were carried out and the relationship between structure and properties was investigated. Blue chip was encapsulated by BODIPY/BOPHY dyes doping in resins for white light emission. Based on the experimental data, the white LED lighting could be increased to a new level by exploring the parameters in encapsulation established including the influence toward the white light.

本项目旨在合成并优选能与蓝光LED芯片相匹配的BODIPY/BOPHY黄色荧光染料，用来拟和白光LED灯。在BODIPY/BOPHY分子的β-位引入芳炔和二氰基咪唑基团调节发射波长、提高量子效率、强化稳定性。BODIPY/BOPHY荧光染料的分子设计分四个阶段：1)在BODIPY/BOPHY分子中引入二氰基咪唑基团，构建高效荧光母体；2)扩展共轭体系，调节发射至黄光区域；3)引入长烷基链，改善溶解性；4)引入蓝光吸收基团以匹配蓝光LED芯片，通过高效的能量转移(FRET/TBET)实现蓝光激发黄光发射和染料的稳定性强化。结合量子计算，揭示分子结构与物理性质之间的关系。以BODIPY/BOPHY染料封装拟和白光LED，探索封装条件对白光参数的影响。把白光LED照明提高到一个新层次。

有机荧光染料功能的迅速发展使得其在生物和高等功能材料领域的应用也越来越广泛和深入。香豆素与氟硼荧光染料是两大类具有较高光化学稳定性与荧光量子效率的蓝绿荧光染料。本项目通过多种化学手段完成构建香豆素与BODIPY或萘酰亚胺整合的系列单分子双发射团荧光染料及其结构表征。通过化学修饰来调控染料分子的发射波长，研究染料的双荧光发射与分子结的关系。调节双发射峰分别至蓝光与黄光区，以拟合出纯白色荧光。项目设计主要包含以下几方面的研究工作：1) BODIPY的第一b位引入二氰基咪唑基团，构建高量子效率的BOIDPY染料。通过BODIPY第二b位以Sonogashira偶联反应扩展共轭体系以调控其荧光发射波长至黄光区域，构建高量子效率的黄色荧光染料；２) 蓝光的香豆素基团以单键引入BODIPY的meso位，构建高效率有机双发射团荧光染料，并通过二氰基咪唑基团提高其绝对荧光量子效率，红移发射波长至黄光区域；3) 以长链烷基连接高量子效率香豆素与BODIPY，调控染料的双荧光发射性质；4) 香豆素与萘酰亚胺缩合构建双发射荧光染料。-NHN=为有效的隔离基团，能有效的阻止分子内能量转移而导致双荧光发射。探索化合物结构与双发射光谱之间的规律性，并优化分子结构，筛选出具备黄光与蓝光双荧光峰的染料。确定合适的激发波长窗口使染料的蓝光发射与黄光发射近似相等，以拟合出纯白色荧光。通过项目的研究，建立起一套简便合成有机单分子白色荧光染料的策略，发展高效率纯有机单分子白光染料体系。