Supramolecular electron transfer by anion binding
- 25 May 2012
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Chemical Communications
- Vol. 48 (79), 9801-9815
- https://doi.org/10.1039/c2cc32848h
Abstract
Anion binding has emerged as an attractive strategy to construct supramolecular electron donor–acceptor complexes. In recent years, the level of sophistication in the design of these systems has advanced to the point where it is possible to create ensembles that mimic key aspects of the photoinduced electron-transfer events operative in the photosynthetic reaction centre. Although anion binding is a reversible process, kinetic studies on anion binding and dissociation processes, as well as photoinduced electron-transfer and back electron-transfer reactions in supramolecular electron donor–acceptor complexes formed by anion binding, have revealed that photoinduced electron transfer and back electron transfer occur at time scales much faster than those associated with anion binding and dissociation. This difference in rates ensures that the linkage between electron donor and acceptor moieties is maintained over the course of most forward and back electron-transfer processes. A particular example of this principle is illustrated by electron-transfer ensembles based on tetrathiafulvalene calix[4]pyrroles (TTF-C4Ps). In these ensembles, the TTF-C4Ps act as donors, transferring electrons to various electron acceptors after anion binding. Competition with non-redox active substrates is also observed. Anion binding to the pyrrole amine groups of an oxoporphyrinogen unit within various supramolecular complexes formed with fullerenes also results in acceleration of the photoinduced electron-transfer process but deceleration of the back electron transfer; again, this is ascribed to favourable structural and electronic changes. Anion binding also plays a role in stabilizing supramolecular complexes between sulphonated tetraphenylporphyrin anions ([MTPPS]4−: M = H2 and Zn) and a lithium ion encapsulated C60 (Li+@C60); the resulting ensemble produces long-lived charge-separated states upon photoexcitation of the porphyrins.Keywords
This publication has 139 references indexed in Scilit:
- Determination of the Structural Features of a Long-Lived Electron-Transfer State of 9-Mesityl-10-methylacridinium IonJournal of the American Chemical Society, 2012
- Conformationally Constrained Macrocyclic Diporphyrin−Fullerene Artificial Photosynthetic Reaction CenterJournal of the American Chemical Society, 2011
- Stopped-Flow Kinetic Analysis of the Interaction of Cyclo[8]pyrrole with AnionsJournal of the American Chemical Society, 2010
- Anion binding behavior of heterocycle-strapped calix[4]pyrrolesJournal of inclusion phenomena and molecular recognition in chemistry, 2009
- Benzene‐, Pyrrole‐, and Furan‐Containing Diametrically Strapped Calix[4]pyrroles—An Experimental and Theoretical Study of Hydrogen‐Bonding Effects in Chloride Anion RecognitionAngewandte Chemie-International Edition, 2008
- Do Sitting-Atop Metalloporphyrin Complexes Exist? Observation of N−H- - -π Bonding in Arene Solvates of a Diprotonated Porphyrin DicationInorganic Chemistry, 2007
- Energy Gap and Temperature Dependence of Photoinduced Electron Transfer in Porphyrin-Quinone CyclophanesThe Journal of Physical Chemistry, 1994
- Electroreduction of Buckminsterfullerene, C60, in aprotic solvents. Solvent, supporting electrolyte, and temperature effectsThe Journal of Physical Chemistry, 1992
- Geometry dependence of intramolecular photoinduced electron transfer in synthetic zinc-ferric hybrid diporphyrinsJournal of the American Chemical Society, 1990
- A Spectrophotometric Investigation of the Interaction of Iodine with Aromatic HydrocarbonsJournal of the American Chemical Society, 1949