Designing Cascades of Electron Transfer Processes in Multicomponent Graphene Conjugates. (15th October 2020)

• Record Type: Journal Article
• Authors: Limosani, Francesca; Kaur, Ramandeep; Cataldo, Antonino; Bellucci, Stefano; Micciulla, Federico; Zanoni, Robertino; Lembo, Angelo; Wang, Bingzhe; Pizzoferrato, Roberto; Guldi, Dirk M.; Tagliatesta, Pietro
• Is Part Of: Angewandte Chemie. Volume 132:Number 52(2020)
• Page Start: 23914
• Page End: 23923
• Publication Date: 2020-10-15
• Subjects: graphene nanoplates -- zinc-tetraphenylporphyrin; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202008820
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: 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. Abstract : Nanocarbon‐based charge‐transfer cascades were designed by integrating electron‐donating ferrocenes with light‐harvesting/electron‐donating (metallo)porphyrins and electron‐accepting graphene nanoplates. The building blocks were bridged through oligo‐ p ‐phenyleneethynylenes. Physico‐chemical characterization of the multicomponent conjugates revealed a selective photoexcitation triggered cascade of charge transfer events.