title: Radio frequency magnetic field effects on a radical recombination reaction: a diagnostic test for the radical pair mechanism.
abstract: The photoinduced electron-transfer reaction of chrysene with isomers of dicyanobenzene is used to demonstrate the sensitivity of a radical recombination reaction to the orientation and frequency (5-50 MHz) of a approximately 300 muT radio frequency magnetic field in the presence of a 0-4 mT static magnetic field. The recombination yield is detected via the fluorescence of the exciplex formed exclusively from the electronic singlet state of the radical ion pair Chr*+/DCB*-. Magnetic field effects are simulated using a modified version of the gamma-COMPUTE algorithm, devised for the simulation of magic angle spinning NMR spectra of powdered samples. The response of a chemical or biological system to simultaneously applied radio frequency and static or extremely low-frequency magnetic fields could form the basis for a diagnostic test for the operation of the radical pair mechanism that would not require prior knowledge of the nature and properties of the radical reaction.
authors.affiliation: Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, Oxford OX1 3QZ, U.K.
authors.forename: Kevin B
authors.initials: KB
authors.lastname: Henbest
authors.forename: Philipp
authors.initials: P
authors.lastname: Kukura
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Rodgers
authors.forename: P J
authors.initials: PJ
authors.lastname: Hore
authors.forename: Christiane R
authors.initials: CR
authors.lastname: Timmel