The Impact of Coordination Distortion on Magnetic Properties of Co (II) Single-Ion Magnets With Trigonal Prism Coordination Geometry

Two Co (II) compounds [Co (abs)₂]·2H₂O (1) and [Co (pabs)₂] (2) (Habs = N-(pyridine-2′-yl methylene)-2-aminobenzene sulfonic acid, Hpabs = N-[(pyridine-2′-yl)(phenyl)methylene]-2-aminobenzene sulfonic acid) were synthesized by the introduction of sulfonate ligands with different substitutions. Both Co (II) ions are located in a trigonal prism coordination environment with different coordination distortions. Static magnetic studies and theoretical calculations found that easy-axis magnetic anisotropy is present in both complexes. The contributions of the negative D values are principally derived from the first quartet excited state. Dynamic magnetic investigations uncovered that both compounds have field-induced single-ion magnet (SIM) behavior and their magnetic relaxations mainly realize through Raman and direct pathways.