Inequivalent proton hyperfine couplings of CrO 3−4 in LiNH 4SO 4 and LiKSO 4 crystals: An EPR study

Abstract

The CrO 3− 4 radicals produced by λ-irradiation in LiNH 4SO 4 and LiKSO 4 crystals exhibit hyperfine splittings due to two magnetically inequivalent protons. This is in contrast to the magnetic equivalence of the proton hyperfine splittings observed for the NH + 3 radicals simultaneously produced in these same host lattices. The proton hyperfine splittings of the CrO 3− 4 radicals also exhibit much more significant anisotropies than those exhibited by the protons of the NH + 3 radicals. These imply a slowing-down of dynamics of the ammonium protons adjacent to the CrO 3− 4 radical.