Zango Germán, Zirzlmeier Johannes, Claessens Christian G, Clark Timothy, Martínez-Díaz M Victoria, Guldi Dirk M, Torres Tomás
Departamento de Química Orgánica , Universidad Autónoma de Madrid , Cantoblanco , 28049 Madrid , Spain . Email:
Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universitaet Erlangen-Nuernberg , Egerlandstraße 3 , 91058 Erlangen , Germany . Email:
Chem Sci. 2015 Oct 1;6(10):5571-5577. doi: 10.1039/c5sc01709b. Epub 2015 Jun 17.
Unsymmetrical subphthalocyanine fused dimers have been prepared from appropriate -dinitrile SubPc precursors. In particular, either electron-donating or electron-accepting substituents have been introduced on each SubPc constituent unit, resulting in unprecedented push-pull π-extended curved aromatic macrocycles. From fluorescence experiments in solvents of different polarity we conclude a dual fluorescence, namely a delocalized singlet excited state (1.73 eV) and a polarized charge transfer state (<1.7 eV). Pump probe experiments corroborate the dual nature of the fluorescence. On one hand, the delocalized singlet excited state gives rise to a several nanosecond lasting intersystem crossing yielding the corresponding triplet excited state. On the other hand, the polarized charge transfer state deactivates within a few picosesonds. Visualization of the charge transfer state was accomplished by means of molecular modeling with a slight polarization of the HOMO towards the electron donor and of the LUMO towards the electron acceptor.
不对称亚酞菁稠合二聚体是由合适的二腈亚酞菁前体制备而成。具体而言，在每个亚酞菁组成单元上引入了供电子或吸电子取代基，从而形成了前所未有的推-拉π-扩展弯曲芳香大环。通过在不同极性溶剂中的荧光实验，我们得出存在双重荧光，即离域单重激发态（1.73电子伏特）和极化电荷转移态（<1.7电子伏特）。泵浦-探测实验证实了荧光的双重性质。一方面，离域单重激发态引发了持续数纳秒的系间窜越，产生相应的三重激发态。另一方面，极化电荷转移态在几皮秒内失活。通过分子建模实现了电荷转移态的可视化，其中最高占据分子轨道（HOMO）向电子供体略有极化，最低未占据分子轨道（LUMO）向电子受体略有极化。
