Paramagnetic relaxation of cyclohexane radical cation in solution as measured by the method of time-resolved magnetic field effect

The method of time-resolved magnetic field effect was applied to measure the spin-lattice relaxation time T-1 for radical cations of a number of cycloalkanes in n-hexane solution at room temperature. The T-1 value for the Jahn-Teller active cyclohexane radical cation was found to be approximately 9 ns which was substantially shorter than typical values for organic radical ions. Based upon the similarity of effects that various factors had on the spin-lattice relaxation rate of the cyclohexane radical cation and the benzene radical anion it was proposed that the spin-orbital interaction made the predominant contribution to the relaxation of both radicals.