Desolvation-induced magnetic switching from single-ion magnetism to spin-crossover in a halogen-functionalized cobalt(II) complex

Solvation/desolvation induced reversible distortion change and switching between spin crossover and single molecular magnet behaviour in a cobalt(ii) complex

“…Conversely, applying a DC bias field facilitated QTM suppression for various cobalt(II) SMMs. [15][16][17][18][37][38][39][40][68][69][70][71] The frequency dependence of the AC sus-ceptibility was observed in the presence of an applied field, indicating the occurrence of slow magnetic relaxation. A peak indicating a relaxation pathway was observed between 500 and 1500 Oe in the frequency range of 60-400 Hz in the out-ofphase (χ″ m ) component vs. frequency plots.…”

“…Several approaches have been adapted to overcome this issue, including designing complexes with unconventional higher distortion coordination structures [34][35][36] or the usage of light or solvent triggered reverse SCO that stabilizes the HS state at low temperatures. [21][22][23][24][37][38][39][40] As mentioned before, Co(II) complexes are one of the promising targets for pursuing the coexistence of SCO and SMM behaviours, indeed, Shao et al have reported a Co(II) mononuclear complex exhibiting a switching between SCO and SMM phenomena mediated by hydration and dehydration. 37 It is believed that dehydration cancels the hydrogen bonding network, allowing for the rotation of benzene rings and loosening of the packaging of complexes, hence stabilizing the HS state of Co(II) with a distorted octahedral coordination sphere.…”

Cobalt(ii) coordination polymers with single-ion magnet property

“…16 Subsequently, there has been a significant shift towards designing and constructing mononuclear SMMs, termed as single-ion magnets (SIMs), as they are liable to design and synthesize compared to their polynuclear counterparts, while also exhibiting larger magnetic anisotropy. 17–20 Over the past decade, a variety of 3d SIMs, including Cr 2+ , Fe 1+/2+/3+ , Co 1+/2+ , Ni 1+/2+ , Mn 3+ , Cu 2+ , and Re 3+/4+ ions, have been reported, 21–50 with Co( ii ) SIMs being particularly common and prominent in this group due to high air stability and significant magnetic anisotropy resulting from both orbital and spin contributions to the magnetic moment. 51 To date, numerous two- to eight-coordinated Co( ii ) SIMs with diverse structures, including linear, tetrahedral, square antiprism, pyramidal, square pyramidal, trigonal prismatic, octahedral, pentagonal bipyramidal geometries, have been successfully synthesized and characterized.…”