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.

A 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 as PowerPoint slide