Field-induced single-ion magnet behavior in a hydrogen-bonded supramolecular cobalt(II) complex

Hydrogen-bonded supramolecular frameworks remain highly interesting for the development of novel porous materials. Herein a hydrogen-bonded supramolecular framework of a cobalt(II) complex, [Co(cpt)2(H2O)2] (Hcpt = 4-(p-carboxyphenyl)-1,2,4-triazole), was synthesized and structurally characterized. A single crystal X-ray diffraction (SC-XRD) study indicates that the monometallic Co2+ ion is located in a distorted octahedral geometry and the complex forms a two-dimensional supramolecular network, stabilized by significant intermolecular N···H interactions. Variable-temperature PXRD and TGA analysis experiments revealed considerable thermal stability of the supramolecular framework of the CoII complex. Magnetic studies showed that the distorted octahedral Co2+ ion exhibits considerable easy-plane magnetic anisotropy with D = 22.3 cm−1, while field-induced single-ion magnet (SIM) behavior was evidenced at low temperature. The forgoing results further highlight that a hydrogen-bonded supramolecular framework can be used as a great platform for the development of molecular nanomagnets.