Synthesis, Structures, and Magnetism of Three 1D MnIIIChains with Oxazoline-Based Ligands

Three novel Mn(III) polymers, [Mn(phox)(2)(N(3))](n) (1), [Mn(Etphox)(2)(N(3))](n) (2), and [Mn(Etphox)(2)(C(2)N(3))](n) (3), using achiral ligand Hphox (Hphox = 2-(4,5-dihydrooxazol-2-yl)phenol) and chiral ligand HEtphox (HEtphox = 2-(4-ethyl-4,5-dihydrooxazol-2-yl)phenol) were synthesized and structurally and magnetically characterized. All complexes are of 1D chain structures and form 2D frameworks by weak interactions. The adjacent 1D chains of complex 1 are connected by face-to-face pi-pi interactions, C-H...pi interactions, and hydrogen bonding, which leads to the formation of a supramolecular 2D sheet structure. The three compounds show antiferromagnetic coupling between Mn(III) ions. And compound 2 is a spin-canted weak ferromagnet with T(N) = 5.6 K, showing metamagnetic behavior with a two-step magnetic phase transition.