Intramolecular Energy Transfer in a Covalently Linked Copper(II) Porphyrin−Free Base Porphyrin Dimer: Novel Spin Polarization in the Energy Acceptor
Intramolecular Energy Transfer in a Covalently Linked Copper(II) Porphyrin−Free Base Porphyrin Dimer: Novel Spin Polarization in the Energy Acceptor
复制标题
共价连接的铜（II）卟啉碱基卟啉二聚体中的分子内能量转移：能量受体中的新型自旋极化
DOI：
10.1021/jp9912096
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发表时间：
1999
影响因子：
2.9
通讯作者：
H. Levanon
中科院分区：
文献类型：
--
作者：
M. Asano;A. Est;U. Krüger;D. Stehlik;and Youkoh Kaizu;H. Levanon
时间分辨EPR的激发波长依赖性被用来证明在共价连接的铜（II）-游离碱卟啉二聚体的分子内能量转移的途径。在50 K和80 K下，给出了铜卟啉供体（540 nm）和游离碱卟啉受体（640 nm）选择性激发的自旋极化光谱。在所有的情况下，所观察到的光谱被分配到三重态的游离碱，这是弱耦合到铜的基态双峰。由选择性激发的自由碱的一半所产生的偏振模式是指示系统间交叉（ISC），而激发的铜（II）的一半给出了eaa/eea偏振模式。后者是合理化的能量转移方面通过最低激发trip-四重态的铜（II）部分，其次是选择性的人口从自旋态的双重字符在弱耦合的自由碱三重态铜双重系统。这导致了一个光谱，其中...
The excitation wavelength dependence of time-resolved EPR is used to demonstrate the pathway of intramolecular energy transfer in a covalently linked copper(II)−free base porphyrin dimer. Spin polarized spectra are presented for selective excitation of both the copper(II) porphyrin donor (at 540 nm) and the free base porphyrin acceptor (at 640 nm) at 50 and 80 K. In all cases the observed spectra are assigned to the triplet state of the free base which is coupled weakly to the copper ground state doublet. The polarization pattern generated by selective excitation of the free base half is indicative of intersystem crossing (ISC), whereas excitation of the copper(II) half gives an eaa/eea polarization pattern. The latter is rationalized in terms of energy transfer via the lowest excited trip−quartet state of the copper(II) moiety, followed by selective depopulation from the spin states with doublet character in the weakly coupled free base triplet-copper doublet system. This leads to a spectrum which resemb...