This talk will review the time-resolved electron paramagnetic resonance experiment as applied to the study of weakly coupled biradicals and spin correlated radical pairs, such as those found in micelles, reverse micelles, and nanocrystals.  Both rigid and flexible biradical systems will be considered.  The appearance of the TREPR spectrum will be explained when the electron exchange interaction dominates and will be contrasted to situations when the dipolar coupling dominates.  Several models for the simulation of the spectra and extraction of coupling parameters will be presented anddiscussed.  Particular attention will be paid to the role of molecular motion in the spectral shape, and different regions of motional dynamics will be explained. The origin of the chemically induced electron spin polarization (CIDEP) in these systems will also be discussed.   The mechanism of the exchange coupling in flexible systems will be presented as a function of solvent polarity, solvent viscosity, temperature, and molecular structure.

Weakly coupled biradicals and radical pairs: Insight into mechanism from time–resolved EPR spectroscopy

241st National Meeting (2011)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.