Photochemistry - Techniques and Applications

Magnetic field effects on radical pairs are caused by the photochemistry of the systems under observation

Photochemistry underlies a large amount of the work performed by the Timmel group. Typical experimental techniques include EPR performed on photo-generated radicals, pump-probe transient absorption experiments, lock-in detected continuous wave fluorescence experiments and cavity-enhanced spectroscopic techniques (Cavity Enhanced Absorption Spectroscopy (CEAS) and Cavity Ring-Down Spectroscopy (CRD)).

C-P-F Triad Photoscheme C-P-F Triad Molecular Structure

The C-P-F Triad, and its corresponding photoscheme. Interconversion between the singlet and triplet radical states is field dependent, and leads to an magnetic field effect on the time-resolved radical concentration. The magnitude and sign of this field effect are highly dependent on the rates of the other pathways present in the photoscheme.