Weak ferromagnetism derived from spin canting in an amido-bridged homochiral Mn(iii) 1-D coordination polymer

A homochiral one-dimensional (1D) Mn(iii) coordination polymer [MnL]_n (1) was synthesised employing the N₃O-donor tetradentate ligand (L = 2-hydroxy-N-[2-[[(2-aminophenyl)methylene]amino]-2-methylpropyl]-benzamide). The X-ray structure of 1 and its magnetic properties were investigated in detail. The crystal structure of 1 shows a homochiral helical arrangement in which spontaneous resolution has occurred, despite the ligand being achiral. Magnetic characterization revealed an antiferromagnetic interaction between manganese(iii) ions (J = -2.48 cm^-1, g = 1.96) that leads to an antiferromagnetic spin-ordering phase transition at T_N ≈ 7 K. Noteworthily, 1 exhibits weak ferromagnetism with a relatively large coercive field of 3.0 kOe based on the spin canting, indicating the formation of a homochiral weak ferromagnet.