ИСТИНА

A large number of cobalt complexes have significantly different magnetic properties. Many of such compounds have the properties of single-ion magnets (SIMs) [1,2]. The present work is devoted to the study of the magnetic properties of two tetrahedral cobalt complexes Co(N)2Br2 with close structures, but only one of them have the properties of SIM [3]. Comparative studies made it possible to identify structural factors that influence on the magnetic properties of such complexes. Low-temperature EPR spectroscopy was used in this work. This experimental technique give us possibilities not only to measure the value of the magnetic anisotropy, but also experimentally determine the sign of zero field splitting (ZFS) due to thermal polarization effect. The conducted quantum-chemical model experiment showed that a small change in the tetrahedral angle can cause a change in the sign of the magnetic anisotropy. These results open new possibilities for the targeted design of such single-molecular magnets.