Two azido-bridged [2×2] cobalt(ii) grids featuring single-molecule magnet behaviour

Abstract

The self-assembly of Co(II) salts, pyridazine derivatives and azides afforded two azido-bridged [2×2] grid-type complexes {[(L)₄Co^II₄(N₃)₄][BPh₄]₄}·sol (1, L = 3,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)pyridazine (pzdz) and sol = 4CH₃CN·3CHCl₃·2CH₃OH and 2, L = 3,6-di(pyridin-2-yl)pyridazine (pydz) and sol = 4CH₃CN). Upon comparison with other related grid-like complexes, the incorporation of end-on azido-bridges resulted in overall intramolecular ferromagnetic couplings, and thus endowed complexes 1 and 2 single molecule magnet behaviour with field-induced slow magnetic relaxation.