A Single-Chain Magnet Based on {CoII4} Complexes and Azido/Picolinate Ligands

A new homonuclear single-chain magnet self-assembles as a one-dimensional coordination network of defective dicubane {CoII4} complexes linked by single CoII ions with the assistance of azido and picolinate ligands. Dominating intrachain ferromagnetic interactions, intrinsic Ising-like CoII anisotropy, and negligible interchain magnetic interactions lead to a thermally activated relaxation time of the magnetization below 8 K. Two thermally activated regimes above and below 3.5 K are observed with the following energy barriers: Δτ1/kB = 66 K (τ0 = 3.7 × 10–11 s) and Δτ2/kB = 51 K (τ0 = 2.3 × 10–9 s), respectively. The difference between the two energy barriers of the relaxation time, 15 K, agrees well with the experimental energy, Δξ, to create a domain wall along the chain.