How do defects in carbon nanostructures regulate the photoinduced electron transfer processes? The case of phenine nanotubes

Abstract

Photoinduced electron transfer is studied in a series of inclusion complexes of structurally modified phenine nanotubes (pNT) with C70 using the TD DFT method. Analysis of electronic properties of the complexes shows that the electron transfer is infeasible in pNT_4d⊃C70 built on the tetrameric array of [6]cyclo-meta-phenylene ([6]CMP) units. However, replacing one or more [6]CMP units with a coronene moiety enables electron transfer from pNT to C70. The generation of the charge separated states from the lowest locally excited states occurs on a sub-nanosecond time scale. Depending on the number of the [6]CMP units, the charge recombination rate changes in the range of five orders of magnitude from 1.8∙107 to 3.1∙102 s-1

We are grateful for financial support from the Spanish MINECO (Network RED2018-102815-T, project CTQ2017‐85341‐P, and Juan de la Cierva contract IJC2019-039846-I to A.J.S. and FJCI‐2017‐32757 to O.A.S.) and the Catalan DIUE (2017SGR39). A.J.S. and M.S. are grateful for the computer resources at LaPalma (IAC) and the technical support provided by Canary Islands Institute of Astrophysics (RES-QSB2020-3-0020)