Enhanced Intersystem Crossing in Gable-Type Copper(II) Porphyrin−Free Base Porphyrin Dimers: Evidence of Through-Bond Exchange Interaction
Enhanced Intersystem Crossing in Gable-Type Copper(II) Porphyrin−Free Base Porphyrin Dimers: Evidence of Through-Bond Exchange Interaction
复制标题
山墙型铜(II)卟啉-游离碱卟啉二聚体中增强的系间穿过：通过键交换相互作用的证据
DOI：
10.1021/jp9941864
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发表时间：
2000
影响因子：
2.9
通讯作者：
Y. Kaizu
中科院分区：
文献类型：
--
作者：
N. Toyama;M. Asano;A. Ichino;Y. Kaizu
研究了一系列铜卟啉-游离碱卟啉二聚体中远距离金属未配对电子对体系间交叉（ISC）的影响。在这些二聚体中，游离碱部分的荧光被经由菲、萘或苯连接的铜对应物显著猝灭。异二聚体中游离碱部分的荧光寿命和量子产率取决于间隔基为游离碱单体的1/10 - 1/35，而在游离碱同二聚体中没有观察到变化。铜（II）−游离碱二聚体的变化归因于游离碱一半中ISC的增强，这是由于与另一半Cu（II）离子中的未配对电子相互作用所致。从实验结果估计ISC率表现出很强的相关性与键的连接，但不与中心到中心的距离的两个一半。推导出了存在未成对电子时ISC速率的表达式。交流互动
Spacer dependence of intersystem crossing (ISC) affected by a remote metal unpaired electron was studied in a series of copper(II) porphyrin−free base porphyrin dimers. In these dimers, fluorescence of the free base moiety is remarkably quenched by the copper counterpart which is linked via a phenanthrene, a naphthalene, or a benzene. Fluorescence lifetimes and quantum yields of the free base moiety in the heterodimers are 1/10−1/35 of the free base monomer depending upon the spacer, whereas no change was observed in the free base homodimers. The changes in the copper(II)−free base dimers are attributed to an enhancement of ISC in the free base half, due to interaction with an unpaired electron in Cu(II) ion of the other half. Estimated ISC rates from the experimental results exhibit a strong correlation with the number of bonds of the linkage but not with the center-to-center distance of the two halves. An expression for the ISC rate in the presence of an unpaired electron is derived. Exchange interactio...