Initiating Electron Transfer in Doubly Curved Nanographene Upon Supramolecular Complexation of C60

Angew Chem Int Ed Engl. 2022 Feb 7;61(7):e202112834. doi: 10.1002/anie.202112834. Epub 2021 Dec 29.

Abstract

The formation of supramolecular complexes between C60 and a molecular nanographene endowed with both positive and negative curvatures is described. The presence of a corannulene moiety and the saddle shape of the molecular nanographene allows the formation of complexes with 1:1, 1:2, and 2:1 stoichiometries. The association constants for the three possible supramolecular complexes were determined by 1 H NMR titration. Furthermore, the stability of the three complexes was calculated by theoretical methods that also predict the photoinduced electron transfer from the curved nanographene to the electron acceptor C60 . Time-resolved transient absorption measurements on the ns-time scale showed that the addition of C60 to NG-1 solutions and photo-exciting them at 460 nm leads to the solvent-dependent formation of new species, in particular the formation of the one-electron reduced form of C60 in benzonitrile was observed.

Keywords: DFT; curved nanographenes; electron transfer; fullerene; supramolecular complexation.