Dipartimento di Chimica, Università degli Studi di Milano , via Golgi 19, Milan 20133, Italy.
IFMRI, National Institute of Advanced Industrial Science and Technology (AIST) , 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan.
J Am Chem Soc. 2017 Oct 11;139(40):14017-14020. doi: 10.1021/jacs.7b08287. Epub 2017 Sep 27.
In this proof of concept study, we show that intramolecular singlet fission (iSF) can be initiated from a singlet excited state accessed by two-photon absorption, rather than through a traditional route of direct one-photon excitation (OPE). Thus, iSF in pentacene dimers 2 and 3 is enabled through NIR irradiation at 775 nm, a wavelength where neither dimer exhibits linear absorption of light. The adamantyl and meta-phenylene spacers 2 and 3, respectively, are designed to feature superimposable geometries, which establishes that the electronic coupling between the two pentacenes is the significant structural feature that dictates iSF efficiency.
在这项概念验证研究中，我们展示了可以从双光子吸收所达到的单重激发态引发分子内单态裂变（iSF），而不是通过传统的单光子激发（OPE）途径。因此，通过在 775nm 的近红外光照射，能够实现二聚体 2 和 3 中的 iSF，而在该波长处，这两个二聚体都没有表现出光的线性吸收。金刚烷基和间亚苯基间隔基 2 和 3 的设计分别具有可叠加的几何形状，这表明两个苝之间的电子耦合是决定 iSF 效率的重要结构特征。
