Structural and magnetic properties of iron(ii) complexes with 1,4,5,8,9,12-hexaazatriphenylene (HAT)

Abstract

Reactions of Fe(II) salts with the ligand 1,4,5,8,9,12-hexaazatriphenylene (HAT) led to the isolation and characterization of four new compounds: [Fe₃(HAT)(H₂O)₁₂](SO₄)₃·3.3H₂O (1), [Fe₂(HAT)(SO₄)(H₂O)₅](SO₄)·2H₂O·CH₃OH (2), [Fe₂(HAT)(SO₄)(H₂O)₅](SO₄)·3H₂O (3), and [Fe₃Cl₅(HAT)(CH₃OH)₄(H₂O)]Cl (4). Compound 1 crystallizes as a trinuclear cluster in which HAT acts as a tris-chelating ligand. Compounds 2 and 3 are two polymorphs of an infinite one-dimensional structure in which the Fe atoms are coordinated to HAT and then connected into the chain through bridging sulfate anions. Compound 4 exhibits a similar chain structure, but with bridging chloride ligands. The magnetic behavior of the new compounds is indicative of weak antiferromagnetic coupling between the Fe(II) centers through the HAT ligand.