“…[11][12][13][14] Glauber predicted the slow magnetic relaxation in an anisotropic Ising system in 1963, but it was not until 2001 that the first experimental evidence of single-chain magnets was reported by Caneschi et al 15,16 Since then, many efforts have been devoted to synthesizing new single-chain magnets that can exhibit higher spin reversal energy barriers and blocking temperatures. [17][18][19][20] The recent breakthrough has been achieved in two cobalt-radical chain compounds reported by Shi and co-workers, Co(hfac) 2 (R-NapNIT) (hfac = hexafluoroacetylacetonate, R-NapNIT = 2-(2′-(R-)naphthyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, R = MeO or EtO), which showed an ultra-large coercive field above 6 T. 21 Besides pursuing the high-performance single-chain magnets, the switching manipulation of their dynamic relaxation properties has also attracted considerable attention because it provides an alternative in reading and writing information at the molecular level. Several stimuli-responsive units, such as photochromic components and reversible coordinated molecules, have been utilized to modify the local coordination sphere of spin carriers to tune the magnetic relaxation behaviors.…”