Single-Chain Magnet Based on 1D Polymeric Azido-Bridged Seven-Coordinate Fe(II) Complex with a Pyridine-Based Macrocyclic Ligand

Peculiar magnetic behavior was found for 1D-polymeric seven-coordinate pentagonal bipyramidal Fe­(II) complex {[Fe­(L)­(μ_1,3-N₃)]­(ClO₄)}_n (1) with a pentadentate macrocyclic ligand L (3,12,18-triaza-6,9-dioxabicyclo[12.3.1]­octadeca-1(18),14,16-triene) coordinated in the pentagonal equatorial plane and with end-to-end bridging azido ligands in axial positions. The static and dynamic magnetic data revealed that spin-canting in the 1D-chain of 1 results in the single-chain magnet (SCM) behavior with high spin-reversal energy barrier U_eff (Δ_τ) = 87.5 K, exhibiting magnetic hysteresis below 4 K and coexistence with the metamagnetism altogether resulting in weak 3D-ferromagnetic behavior. This is the first reported example of the exclusively azido-bridged homospin Fe­(II)-based SCM.