Field-induced single-ion magnet based on a quasi-octahedral Co(ii) complex with mixed sulfur–oxygen coordination environment†
Abstract
Synthesis and characterization of structure and magnetic properties of the quasi-octahedral complex (pipH2)[Co(TDA)2] 2H2O (I), (pipH22+ = piperazine dication, TDA2− = thiodiacetic anion) are described. X-ray diffraction studies reveal the first coordination sphere of the Co(II) ion, consisting of two chelating tridentate TDA ligands with a mixed sulfur–oxygen strongly elongated octahedral coordination environment. SQUID magnetometry, frequency-domain Fourier-transform (FD-FT) THz-EPR spectroscopy, and high-level ab initio SA-CASSCF/NEVPT2 quantum chemical calculations reveal a strong “easy-plane” type magnetic anisotropy (D ≈ +54 cm−1) of complex I. The complex shows field-induced slow relaxation of magnetization at an applied DC field of 1000 Oe.