Designing cascades of electron transfer processes in multicomponent graphene conjugate

A novel family of nanocarbon‐based materials were designed, synthesized, and probed within the context of charge‐transfer cascades. In details, we implemented fine‐tuned chains of photo‐ and redox‐active constituents. For the first time, 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. Unique are the linkages between the bridges, on one hand, and the (metallo)porphyrins / GNPs, on the other hand, by means of β ‐linkages and the Prato‐Maggini reaction. With the help of steady‐state absorption, fluorescence, Raman, and XPS measurements we realized the basic physico‐chemical characterization of the photo‐ and redox‐active components, in general, and the multicomponent conjugates, in particular. 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.