光照活化的磷光三重态及其应用

This proposal aims to a systematic investigation on Photo-activated Phosphorescence (PAP), its mechanism and applications for triplet-triplet annihilation photon upconversion (TTA-UC) under air and photo-patterning of gel surfaces. Long-lived phosphorescent triplet excited states are quenched by molecular oxygen in aerated solutions and highly oxidative singlet oxygen is concurrently sensitized. In this context, strictly deoxygenation is highly demanded for measurements on phosphorescent properties and high-efficiency TTA-UC processes. We propose that photochemically deoxygenating solvents and polymers could be used for protecting the long-lived phosphorescent triplet excited states from oxygen-quenching. Upon a clear understanding of the mechanism of PAP, the chemical identities of photochemically deoxygenating solvents and polymers could be screened out. The generality and practicality of PAP in photochemical deoxygenating media could be demonstrated. The successful commission of this proposal will finally (1) Provide a novel mechanism for the photochemical behavior of phosphorescent materials in solutions; (2) Provide a novel approach to deprival of the trace oxygen from fluid solutions; (3) Realize high-efficiency TTA-UC in fluid solutions under air; (4) Provide at least one photochemically deoxygenating polymer and pave the way for the practice application of PAP for advanced phosphorescent materials.

此项目旨在系统研究光照活化磷光的机理和在三重态湮灭光子上转换及凝胶表面磷光图案化方面的应用。长寿命的磷光三重态在有氧溶液中被分子氧猝灭，高氧化性的单重态氧被敏化产生，所以磷光性质测试和高效率三重态湮灭光子上转换一般都要求严格除氧。本项目提出具有光化学除氧性质的溶剂可以用于空气氛下保护长寿命磷光三重态。在谱学和化学分离检测手段厘清光照活化磷光这一特性的基础上，本项目借用这一特性筛选光化学除氧溶剂品种和聚合物品种。期望有目的性地证明光化学除氧介质中的光照活化磷光具有普适性和实用的简便性。通过此项目的实施，（1）从源头上为磷光化合物与溶剂的光化学行为提供新的机制；（2）提供一种方便快捷的除去溶液中痕量分子氧的方法；（3）高效率的三重态湮灭上光子上转换可以在空气氛下实现；（4）提供光化学除氧聚合物品种，为光照活化磷光和长寿命磷光化合物的实用化打下基础。

此项目研究并光照活化磷光及光化学除氧的机理及其应用。在谱学和化学分离检测手段厘清光照活化磷光这一特性的基础上，证明光化学除氧介质中的光照活化磷光具有普适性和实用的简便性，进一步借用这一特性筛选光化学除氧溶剂品种和聚合物品种用于空气氛下保护长寿命磷光三重态。（1）从源头上为磷光化合物与溶剂的光化学行为提供新的机制；（2）提供一种方便快捷的除去溶液中痕量分子氧的方法；（3）高效率的三重态湮灭上光子上转换可以在空气氛下实现；（4）实现了高分子凝胶表面可擦除可重写的光图案化；（5）实现了程控化光照活化磷光在立体三维显示技术中的应用。这一新机制已经基本厘清的情况下，更为重要的一点是需要实现金属化合物敏化剂的吸收光谱和发射光谱的双重控制。因此进一步构建并发展了两类新型磷光发光化合物：高量子产率的Pd（II）化合物和近红外发光的Cr（III）化合物，为光照活化磷光这一机制的应用拓展提供了物质基础。