Cavity enhanced detection methods for probing the dynamics of spin correlated radical pairs in solution

Simon Neil (1) , Kiminori Maeda (1) , Kevin Henbest (1) , Martin Goez (2) , Robert Hemmens (1) , Christiane R Timmel (1) , Stuart Mackenzie (3)

1 Chemistry
2 MLU - Martin-Luther-Universität Halle Wittenberg
3 Physical and Theoretical Chemistry Laboratory

Cavity enhanced absorption spectroscopy (CEAS) combined with phase-sensitive detection is employed to study the effects of static magnetic fields on radical recombination reactions. The chemical system comprises the photochemically generated thionine semiquinone radical and a 1,4-diazabicyclo[2.2.2]octane (DABCO) cationic radical in a micellar solution of sodium dodecyl sulphate. Data obtained using the modulated CEAS technique, describing the magnetic field effect (MFE) on reaction yields, are shown to be superior to those obtained using conventional transient absorption (TA) flash photolysis methods typically employed for these measurements. The high sensitivity afforded by modulated CEAS detection is discussed in terms of the new possibilities it offers such as the measurement of magnetic field effects in real biological systems which have hitherto been largely beyond the detection capabilities of existing techniques.

Mots clés: Physical Sciences

Simon Neil, Kiminori Maeda, Kevin Henbest, Martin Goez, Robert Hemmens, et al.. Cavity enhanced detection methods for probing the dynamics of spin correlated radical pairs in solution. Molecular Physics, 2010, 108 (07-09), pp.993-1003. ⟨10.1080/00268971003614368⟩. ⟨hal-00596280⟩