卟啉-蒽醌化合物分子内光诱导电子传递的光谱研究

摘要

合成了以不同长度柔韧碳链相连的三种卟啉(Por)-蒽醌(AQ)二元化合物Por-Cn-AQ (n=1,4,10),主要通过稳态荧光光谱和瞬态荧光光谱研究了它们的分子内光诱导电子传递情况,并结合密度泛函理论(DFT)对分子内电子转移机理进行了初步探讨.结果表明:共价相连的卟啉-蒽醌二元化合物在光激发下能够发生从卟啉组分到蒽醌组分的分子内光诱导电子传递;连接链性质对电子传递速率有直接的影响.实验和理论计算结果表明卟啉-蒽醌之间的分子内电子转移很可能是通过超交换机理进行的.%A series of covalently linked porphyrin (Por)-anthraquinone (AQ) hybrids Por-C-AQ (n=1, 4, 10) with flexible different length carbon chains were synthesized and their intramolecular photoinduced electron transfer (PET) properties were investigated mainly by steady-state fluorescence and decayed luminescence spectra. We studied the PET mechanism using density functional theory (DFT). We found that PET occurs from the porphyrin moiety to the anthraquinone moiety of these dyads and that the PET efficiency is influenced considerably by the length of the linkage between the two moieties in the hybrids. From both the experimental and theoretical results, we can conclude that the PET of these dyads is seemingly most compatible with a "through-bond" (super-exchange) mechanism.