Magnetic Anisotropy from Easy-Plane to Easy-Axial in Square Pyramidal Cobalt(II) Single-Ion Magnets

• DOI: 10.1021/acs.cgd.2c00160
• Publication Date: 2022-03-29T11:41:56Z
• Authors: Hui-Hui Cui; Hongjuan Xu; Mingxing Zhang; Shuchang Luo; Wei Tong; Miao Wang; Tongming Sun; Lei Chen; Yanfeng Tang
• Keywords: Axial symmetry; Dimethyl formamide; Square (algebra); Realization (probability)

By elaborately employing a rigid tetrazo macrocyclic ligand, both the designed Co(II) complexes [Co(12-TMC)Py](BF4)2 (1) and [Co(12-TMC)DMF](BF4)Cl (2) (12-TMC = 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane; Py pyridine; DMF N,N-dimethylformamide) adopt distorted square pyramidal geometry with identical equatorial site but flexible axial ligand environment. Such molecular design enables realization of field-induced single-ion magnets. Importantly, single-molecule magnets display ligand-mediated magnetic anisotropy. The axially elongated in complex 1 is devoted to stabilizing positive zero-field splitting parameter (D), while an compressed one 2 tends stabilize negative D. understanding was further validated by series same different ligands such as Cl– NCO–. Therefore, this study provides new example delicate modification behavior presents fundamental insights into magneto-structural correlation.