Limosani Francesca, Kaur Ramandeep, Cataldo Antonino, Bellucci Stefano, Micciulla Federico, Zanoni Robertino, Lembo Angelo, Wang Bingzhe, Pizzoferrato Roberto, Guldi Dirk M, Tagliatesta Pietro
Fusion and Nuclear Department, Photonics Micro and Nanostructures Laboratory, ENEA, Via E. Fermi 45, 00044 Frascati, Rome, Italy.
Department of Chemical Science and Technologies, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133, Rome, Italy.
Angew Chem Int Ed Engl. 2020 Dec 21;59(52):23706-23715. doi: 10.1002/anie.202008820. Epub 2020 Oct 15.
A novel family of nanocarbon-based materials was designed, synthesized, and probed within the context of charge-transfer cascades. We integrated electron-donating ferrocenes with light-harvesting/electron-donating (metallo)porphyrins and electron-accepting graphene nanoplates (GNP) into multicomponent conjugates. To control the rate of charge flow between the individual building blocks, we bridged them via oligo-p-phenyleneethynylenes of variable lengths by β-linkages and the Prato-Maggini reaction. With steady-state absorption, fluorescence, Raman, and XPS measurements we realized the basic physico-chemical characterization of the photo- and redox-active components and the multicomponent conjugates. Going beyond this, we performed transient absorption measurements and corroborated by single wavelength and target analyses that the selective (metallo)porphyrin photoexcitation triggers a cascade of charge transfer events, that is, charge separation, charge shift, and charge recombination, to enable the directed charge flow. The net result is a few nanosecond-lived charge-separated state featuring a GNP-delocalized electron and a one-electron oxidized ferrocenium.
我们设计、合成并研究了一种基于纳米碳材料的新型家族，其处于电荷转移级联的背景下。我们将供电子的二茂铁与光捕获/供电子（金属）卟啉以及电子受体石墨烯纳米片（GNP）整合到多组分共轭物中。为了控制各个结构单元之间的电荷流动速率，我们通过β-键和普拉托-马吉尼反应，用不同长度的寡聚对苯撑乙炔将它们连接起来。通过稳态吸收、荧光、拉曼和XPS测量，我们实现了光活性和氧化还原活性组分以及多组分共轭物的基本物理化学表征。除此之外，我们进行了瞬态吸收测量，并通过单波长和目标分析证实，选择性（金属）卟啉光激发引发了一系列电荷转移事件，即电荷分离、电荷转移和电荷复合，以实现定向电荷流动。最终结果是形成了一种寿命为几纳秒的电荷分离态，其特征是一个GNP离域电子和一个单电子氧化的二茂铁鎓。
