Ito Soichi, Nagami Takanori, Nakano Masayoshi
Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka 560-8531, Japan.
J Phys Chem A. 2016 Aug 11;120(31):6236-41. doi: 10.1021/acs.jpca.6b07153. Epub 2016 Aug 2.
We theoretically investigate the singlet fission in three types of covalently-linked systems, that is, ortho-, meta- and para-linked pentacene dimers, where these are shown to have significantly different singlet fission rates. Each molecule is composed of two chromophores (pentacenes), which are active sites for singlet fission, and covalent bridges linking them. We clarify the origin of the difference in the electronic couplings in these systems, which are found to well support a recent experimental observation. It is also found that the next-nearest-neighbor interaction is indispensable for intramolecular singlet fission in these systems. On the basis of these results, we present design principles for efficient intramolecular singlet fission in covalently-linked systems and demonstrate the performance by using several novel conjugated linkers.
我们从理论上研究了三种共价连接体系中的单重态裂变，即邻位、间位和对位连接的并五苯二聚体，结果表明这些体系具有显著不同的单重态裂变速率。每个分子由两个发色团（并五苯）组成，发色团是单重态裂变的活性位点，还有连接它们的共价桥。我们阐明了这些体系中电子耦合差异的起源，发现其很好地支持了最近的实验观察结果。还发现，次近邻相互作用对于这些体系中的分子内单重态裂变是必不可少的。基于这些结果，我们提出了共价连接体系中高效分子内单重态裂变的设计原则，并通过使用几种新型共轭连接体展示了其性能。
