中心金属Ga原子对Corrole三重态动力学及单线态氧产生的影响

The influence of central metal Ga atom on triplet-state dynamics and singlet oxygen generation of Corrole

采用激光闪光光解技术测量了5,15-二(五氟苯基),10-苯基Corrole,5,10,15-三(五氟苯基)Corrole及其相应Ga配合物的三重态瞬态吸收光谱和动力学弛豫过程.测量结果表明,四种Corrole样品在440-540 nm波长范围内具有三重态吸收信号且吸收峰位于450 nm.无氧条件下,金属Ga Corrole的三重态寿命比对应的自由Corrole三重态寿命短;有氧条件下,则反之.由此推测,金属Ga原子的插入减缓了氧对Corrole分子三重态的猝灭速率.利用稳态红外发光法测量了四种Corrole样品的单线态氧稳态发光光谱.计算结果显示,金属Ga原子的插入使得Corrole的单线态氧量子产率有所下降.结果表明,金属Ga原子产生的重原子效应对Corrole三重态动力学和单线态氧的产生有一定的影响.

In this paper, the triplet-state transient absorption spectra and the dynamic processes of 5, 15-bis （pentafluorophenyl）-10-（phenyl） corrole, 5, 10, 15-tris （pentafluorophenyl） corrole and their corresponding free-base corroles are measured by the laser flash photolysis technique. The measurement results show that the wavelength region of triplet-state absorption of these corroles ranges from 440 nm to 540 nrn and the absorption peak wavelength of each sample is 450 nm. The insertion of metal Ga atom into corrole ring shortens the triplet lifetime of corrole under anaerobic condition and makes triplet lifetime longer under aerobic condition, which reduces oxygen quenching rate. The steady-state emissions of singlet oxygen of these corroles are also measured by the infrared luminescence method. The results show that the insertion of metal Ga atom makes singlet oxygen quantum yield of corroles slightly decrease. The results indicate that the heavy atom effect generated from metal Ga atom influences the triplet-state dynamics and singlet oxygen generation of corrole.