Four heterometallic coordination polymers of a macrocyclic oxamide with aromatic multicarboxylate ligands: Syntheses, crystal structures and magnetic properties

Four new coordination polymers, [Mn(CuL)(aipt)] (1), [Ni(CuL)(aipt)(H2O)]·H2O (2), [Mn(NiL)(tpt)]·1/4H2O (3) and [Mn(NiL)(atpt)] (4) (ML, H2L = 2, 3-dioxo-5, 6, 14, 15-dibenzo-1, 4, 8, 12-tetraazacyclo-pentadeca-7, 13-dien; H2aipt = 5-aminoisophthalic acid; H2tpt = terephthalic acid; H2aipt = 2-aminoterephthalic acid), have been synthesized by a solvothermal method and their structures are characterized by single-crystal X-ray diffraction. Complex 1 exhibits a 1D chain structure formed by Cu2Mn2 units connected via oxamide and 5-aminoisophthalate bridges, while complexes 2, 3 and 4 exhibit different 2D layered structures formed by Cu2Ni2 (2) and Mn2Ni2 (3–4) units, connected via oxamide and diverse carboxylate bridges. Magnetic studies demonstrate that antiferromagnetic interactions exist between the neighboring metal ions through the oxamide and/or carboxyl bridges in complexes 1–4.