有机分子三重激发态的调控与应用

对近期有机分子三重激发态调控的研究进展进行了总结评述。控制分子的三重激发态性质,可以制备多种具有新颖性质的分子,如用于可激活光动力治疗(PDT)的光敏剂、磷光分子探针与生物标识试剂,以及可控的三重态湮灭上转换等。但目前对三重态控制方面的研究相对较少,其中的规律也很不明确。近期有文献陆续报道了使用超分子方法和共价修饰法进行的三重态调控,利用的光物理过程有单重态能量转移、三重态能量转移、电子转移等等。现有研究结果表明,三重态的调控规律与单重态的调控规律有所不同,例如:发色团的单重激发态(荧光)往往可以被光诱导电子转移(PET)所猝灭,但是在多个例子中已发现,相同发色团的三重态并不能被PET所猝灭。本文总结的研究结果及所作的分析,将对该领域的分子结构设计及后续研究起到一定的促进作用。

Controlling and Application of the Triplet Excited State of Organic Chromphores

The recent development of controlling of the triplet excited state of organic chromophores was summarized.Controlling the triplet excited state is very useful,by which various functional organic compounds can be developed.For instance,the activatable PDT photosensitizers,phosphorescent molecular probes,and can be applied in photoswitchable triplet-triplet annihilation (TTA) upconversion.However,by comparison to the controlling of singlet excited state (fluorescence),the study on the controlling of the triplet excited state is rare.Recently there are some reports on triplet state switching by supramolecular or covalent modification methods,based on photophysical processes such as F(o)rster resonance energy transfer (FRET),triplet triplet energy transfer (TTET),photo-induced electron transfer (PET),etc.These reports show that controlling of the triplet excited state is very different from controlling of the singlet excited state.For example,usually the singlet excited state can be quenched by PET effect,but the triplet excited state can not be quenched by PET effect in many cases.This review article summarizes the development of triplet state switching,and will be useful for the molecular design concerning the controlling and application of triplet excited state in functional organic compounds.