Field-induced slow magnetic relaxation in a distorted trigonal prismatic cobalt(II) complex

Abstract

Two mononuclear complexes [M(DQ)(OTf)](OTf)·H2O (M = Co for 1 and Fe for 2, DQ = 6,6′′-di(quinolin-8-yl)-4′-phenyl-2,2′:6′,2′′-terpyridine) with distorted trigonal prismatic geometry have been synthesized and characterized. Crystal structures show that the 3d ions are helically coordinated by a pentadentate DQ and encapsulated by a terminal OTf− anion, resulting in [MN5O] coordination environments. Magnetic measurements and ab initio calculation indicate that complex 1 displays easy axis anisotropy and exhibits field-induced slow magnetic relaxation which is dominated by Raman and direct processes. For 2, no slow magnetic relaxation had been recorded owing to the significant fast quantum tunneling of magnetization.