Abstract
In donor–acceptor dyads undergoing photoinduced electron transfer (PET), a direction or pathway for electron movement is usually dictated by the redox properties and the separation distance between the donor and acceptor subunits, while the effect of symmetry is less recognized. We have designed and synthesized two isomeric donor–acceptor assemblies in which electronic coupling between donor and acceptor is altered by the orbital symmetry control with the reorganization energy and charge transfer exothermicity being kept unchanged. Analysis of the optical absorption and luminescence spectra, supported by the DFT and TD-DFT calculations, showed that PET in these assemblies corresponds to the Marcus inverted region (MIR) and has larger rate for isomer with weaker electronic coupling. This surprising observation provides the first experimental evidence for theoretically predicted adiabatic suppression of PET in MIR, which unambiguously controlled solely by symmetry.
| Original language | English |
|---|---|
| Pages (from-to) | 17120-17127 |
| Number of pages | 8 |
| Journal | Chemistry - A European Journal |
| Volume | 26 |
| Issue number | 71 |
| DOIs | |
| State | Published - Dec 18 2020 |
Funding
We thank Dr. P. Schulze, Mrs. I. Erxleben, Dipl.-Ing. J. Stelten (Institute of Organic and Analytical Chemistry, Laboratory Prof. Dr. D. Leibfritz, University of Bremen) for Mass spectrometry and NMR spectroscopy measurements, Dr. H.-M. Schiebel (TU Braunschweig) for interpretation of mass spectra and Dr. V. Azov for supporting manuscript preparation. We are indebted to Mrs. A. Lincke for performing analytical and preparative HPLC separations. This work was supported by Deutsche Forschungsgemeinschaft Mo 274/10 and the Extreme Science and Engineering Discovery Environment (XSEDE) TG-CHE170004. Open access funding enabled and organized by Projekt DEAL. We thank Dr. P. Schulze, Mrs. I. Erxleben, Dipl.‐Ing. J. Stelten (Institute of Organic and Analytical Chemistry, Laboratory Prof. Dr. D. Leibfritz, University of Bremen) for Mass spectrometry and NMR spectroscopy measurements, Dr. H.‐M. Schiebel (TU Braunschweig) for interpretation of mass spectra and Dr. V. Azov for supporting manuscript preparation. We are indebted to Mrs. A. Lincke for performing analytical and preparative HPLC separations. This work was supported by Deutsche Forschungsgemeinschaft Mo 274/10 and the Extreme Science and Engineering Discovery Environment (XSEDE) TG‐CHE170004. Open access funding enabled and organized by Projekt DEAL.
Keywords
- artificial photosynthesis
- chlorin
- electron transfer
- quinone
- symmetry
