Paramagnetic relaxation of adamantane radical cation in solution

To measure the rate of spin-lattice relaxation in the Jahn–Teller active adamantane radical cation, the method of time-resolved magnetic effect in recombination fluorescence of spin-correlated radical ion pairs was applied. A very low value of about 6 ± 1 ns was obtained for the relaxation time of the radical cation in magnetic field of 1 T. A rapid spin-lattice relaxation was also found in the cases of 1,3-dimethyladamantane and hexamethylenetetramine radical cations. Similarly to the case of benzene radical anion and cyclohexane radical cation, the relaxation is attributed to the spin–orbital interaction repeatedly arising in electronically degenerate states.