Slow Magnetic Relaxation in a Mononuclear Ruthenium(III) Complex.

The development of magnetic molecules with long spin reversal/decoherence times highly depends on the understanding of relaxation behavior under different external conditions. Herein, a magnetic study on a Ru complex (1) is presented. Detailed analysis of the relaxation time and the magneto-heat capacity data suggests that the resonant phonon trapping process dominates the magnetic relaxation in the crystalline sample of 1, slowing down the spin relaxation rate, as further confirmed by the measurements on a ground sample and frozen solution. Thus, it provides a rare example showing that 4d metal-centered mononuclear compounds without second-order anisotropy can display slow magnetic relaxation.