Manganese(II) coordination polymer with simultaneous azide, tetrazolate and carboxylate bridges: Synthesis, structure and magnetism

•The Mn(II) chain with mixed (azide)(carboxylate)(tetrazolate) bridges was obtained.•A zwitterionic bifunctional ligand was formed in situ via two organic reactions.•The AF coupling via the triple bridges increases as the Mn–N–Mn angle decreases.

The reaction of a pyridinium-containing ligand precursor with manganese(II) chloride and sodium azide yielded a Mn(II) coordination polymer, [MnLN3]n·1.5nH2O, where L is 1-(tetrazolato-5-methyl)pyridinium-4-carboxylate, a bifunctional zwitterionic ligand generated in situ from a non-coordinative precursor via two organic reactions (cyano-to-azide cycloaddition and ester hydrolysis). In the compound, metal ions are connected into uniform chains by the triple bridges consisting of μ-1,1-azide, μ-2,3-tetrazolate and μ-1,3-carboxylate, and the formally anionic chains are charge compensated and interlinked into 2D layers by the cationic 1-methylenepyridinium backbone of the L ligand. The compound displays typical 1D antiferromagnetism with J = − 2.37 cm− 1 through the triple bridges. Magneto-structural analysis indicates the antiferromagnetic interaction increases as the Mn–N–Mn angle of the azide bridge decreases.

Graphical abstractA 2D coordination polymer containing Mn(II) chains with μ-1,1-azide, μ-2,3-tetrazolate and μ-1,3-carboxylate triple bridges was derived from an in-situ formed bifunctional zwitterionic ligand; the antiferromagnetic interaction via the triple bridges increases as the Mn–N–Mn angle decreases.Figure optionsDownload full-size imageDownload as PowerPoint slide