权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Control of Photodynamics in Supramolecules Containing Metal Complexes by an Unpaired Electron

不成对电子对含金属配合物超分子光动力学的控制

基本信息

批准号：
13640554
负责人：
ASANO Motoko S.
金额：
$ 2.18万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

A paramagnetic centers perturbs reaction dynamics and photophysical properties of molecular system even via a long distance. Thus by utilizing the paramagnetic species attached in a remote site, it will be possible to control the local dynamics of the molecular system with a long-range interaction.Intersystem crossing is one of the simple photophysical processes, and it is suitable to study effect on the photodynamics by the long-range interaction with unpaired electron. In paramagnetic-metalloporphyrin - free base (diamagnetic) porphyin heterodimers such as a copper-free base porphyrin, the free base half undergoes enhanced intersystem crossing by interaction with the unpaired electron in the other half. Recently we have reported that in a series of copper(II)-free base porphyrin dimer linked via an aromatic spacer, the EISC rate exponentially decreases with the number of bonds of the spacer. In addition, the porphyrin HOMO affects EISC rates itself but does not influence the spacer dependence. This feature is in good agreement with an expression for EISC, derived theoretically.In this project, we examined dependence of the EISC on the paramagnetic species in linearly-linked porphyrin dimers. The paramagnetic porphyrin halves we studied are V(IV)O porphyrins and a radical coordinated zinc(II) porphyrins. Difference of the EISC rate of the free base half between different paramagnetic species does not simply depends on the species itself. The EISC rate depends on the interaction between the unpaired electron and pai system, which is directly connected to the paramagnetic species. Long-range interaction with a remote electron is summarized in terms of three different factors, i.e., spacer, terminal HOMO and interaction between the unpaired electron and direct connecting site.

顺磁中心会对分子体系的反应动力学和光物理性质产生远距离的扰动。因此，通过利用附着在远程位点的顺磁性物质，可以通过远程相互作用来控制分子系统的局部动力学。系统间交叉是一种简单的光物理过程，适合研究与未配对电子的远距离相互作用对光动力学的影响。在顺磁性-金属卟啉-无碱（抗磁性）卟啉异源二聚体中，如无铜基卟啉，通过与另一半中的未配对电子相互作用，自由基的一半经历了增强的系统间交叉。最近我们报道了一系列无铜（II）碱卟啉二聚体通过芳香间隔键连接，EISC速率随着间隔键的键数呈指数下降。此外，卟啉HOMO本身影响EISC速率，但不影响间隔剂依赖性。这一特征与理论推导的EISC表达式很好地吻合。在这个项目中，我们研究了线性连接卟啉二聚体中EISC对顺磁性物质的依赖。顺磁性卟啉一半是V(IV)O卟啉和自由基配位锌（II）卟啉。不同顺磁性物质之间自由碱半部分的EISC速率的差异并不仅仅取决于物质本身。EISC速率取决于未配对电子与pai系统之间的相互作用，这与顺磁性直接相关。与远端电子的远程相互作用可归纳为三个不同的因素，即间隔层、末端HOMO和未配对电子与直接连接位点之间的相互作用。