Effect of Electronic Coupling on Electron Transfer Rates from Photoexcited Naphthalenediimide Radical Anion to Re(bpy)(CO)3X
[1];
[1];
[2];
[1];
[1]
- Northwestern Univ., Evanston, IL (United States). Center for Light Energy Activated Redox Processes (LEAP), and Inst. for Sustainability and Energy, Dept. of Chemistry
- Yale Univ., New Haven, CT (United States). Center for Light Energy Activated Redox Processes (LEAP), and Energy Sciences Inst., Dept. of Chemistry
- Hamad Bin Khalifa Univ., Doha (Qatar). Qatar Environment and Energy Research Inst.
The electron transfer rate between a donor and an acceptor depends on the free energy change for the reaction as well as differences in structure and electronic coupling between the initial and final states. Selective excitation of a naphthalenediimide radical anion (NDI•–) covalently linked at the 4-, 5-, or 6-positions of the bipyridine (bpy) in the Re(bpy)(CO)3X (X = Cl or pyridine) carbon dioxide reduction catalyst results in electron transfer from 2*NDI•– to Re(bpy)(CO)3X to form Re(bpy•–)(CO)3X, the first intermediate in the photocatalytic reduction of CO2. Femtosecond UV/vis, near-IR, and mid-IR spectroscopy on these constitutional isomers and a set of appropriate reference molecules show that systematically varying the electronic coupling as well as the reaction free energy increases the lifetime of Re(bpy•–)(CO)3X by an order of magnitude when the NDI chromophore is attached to the 6-position of bpy. NMR and X-ray structural studies along with computational modeling are used to identify the conformation of Re(6-NDI-bpy)(CO)3X responsible for these favorable changes. Extending the lifetime of the reduced complex in the covalent photosensitizer–catalyst assembly is a critical requirement for the photocatalytic CO2 reduction and artificial photosynthesis.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Center for Light Energy Activated Redox Processes (LEAP); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- FG02-99ER14999; SC0001059
- OSTI ID:
- 1528916
- Journal Information:
- Journal of Physical Chemistry. C, Vol. 123, Issue 16; ISSN 1932-7447
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Electron transfer reactions in sub-porphyrin–naphthyldiimide dyads
|
journal | January 2019 |
Similar Records
Photoinduced electron transfer from rylenediimide radical anions and dianions to Re(bpy)(CO)3 using red and near-infrared light
Electron Transfer from Photoexcited Naphthalene Diimide Radical Anion to Electrocatalytically Active Re(bpy)(CO)3 Cl in a Molecular Triad