Experimental and theoretical insights into magnetic exchange and anisotropy in multinuclear cobalt complexes displaying slow relaxation

centers in complex 1 show a predominant axial anisotropy. A mixed anisotropic behavior is observed in complex 2, in which the orthogonal arrangement of dominant single-ion easy axes results in a net negative axial anisotropy. Furthermore, all three complexes exhibit slow relaxation of magnetization in zero external magnetic field, primarily in the high-frequency region, with complex 2 showing the most well-resolved temperature-dependent AC signals. Overall, this study emphasizes the role of counter anions in tuning the structural and geometrical features, magnetic exchange pathways, and anisotropy in multinuclear cobalt complexes exhibiting slow magnetic relaxation.