Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany.
J Am Chem Soc. 2011 Aug 24;133(33):13036-54. doi: 10.1021/ja202485s. Epub 2011 Jul 27.
Aromatic triazoles have been frequently used as π-conjugated linkers in intramolecular electron transfer processes. To gain a deeper understanding of the electron-mediating function of triazoles, we have synthesized a family of new triazole-based electron donor-acceptor conjugates. We have connected zinc(II)porphyrins and fullerenes through a central triazole moiety--(ZnP-Tri-C(60))--each with a single change in their connection through the linker. An extensive photophysical and computational investigation reveals that the electron transfer dynamics--charge separation and charge recombination--in the different ZnP-Tri-C(60) conjugates reflect a significant influence of the connectivity at the triazole linker. Except for the m4m-ZnP-Tri-C(60)17, the conjugates exhibit through-bond photoinduced electron transfer with varying rate constants. Since the through-bond distance is nearly the same for all the synthesized ZnP-Tri-C(60) conjugates, the variation in charge separation and charge recombination dynamics is mainly associated with the electronic properties of the conjugates, including orbital energies, electron affinity, and the energies of the excited states. The changes of the electronic couplings are, in turn, a consequence of the different connectivity patterns at the triazole moieties.
芳基三唑经常被用作分子内电子转移过程中的π共轭连接体。为了更深入地了解三唑的电子中介功能，我们合成了一系列新型的三唑基给体-受体共轭物。我们通过一个中央三唑部分将锌(II)卟啉和富勒烯连接起来——(ZnP-Tri-C(60))——每个连接体都通过一个单键的变化来连接。广泛的光物理和计算研究表明，不同的 ZnP-Tri-C(60) 共轭物中的电子转移动力学——电荷分离和电荷复合——反映了三唑连接体的连接性的显著影响。除了 m4m-ZnP-Tri-C(60)17，所有合成的 ZnP-Tri-C(60) 共轭物都表现出具有不同速率常数的通过键光诱导电子转移。由于所有合成的 ZnP-Tri-C(60) 共轭物的通过键距离几乎相同，因此电荷分离和电荷复合动力学的变化主要与共轭物的电子性质有关，包括轨道能量、电子亲和力和激发态的能量。电子耦合的变化反过来又是三唑部分不同连接模式的结果。
