Mixed-bridging manganese(II) and copper(II) complexes with azide and pyridylbenzoate N-oxide: Structures and magnetic properties

Two Mn(II) and Cu(II) coordination polymers with azide and 4-(3-pyridyl)benzoic acid N-oxide (4,3-Hopybz) were synthesized and structurally and magnetically characterized. They are formulated as [M(4,3-opybz)(μ-N3)]n (M = Mn, 1 and Cu, 2). Compound 1 consists of 2D coordination layers in which 1D coordination chains with uniform [(μ-EO-N3)(μ-COO)(μ-O)] (EO = end-on, μ-O from N-oxide group) triple bridges are interlinked by the 4,3-opybz spacers. Compound 2 also presents a 2D coordination layers in which the Cu(II) ions are triply bridged in a fashion similar to 1, while the azide ions reside at different positions around the metal ions. Magnetic studies demonstrated that the magnetic coupling through the mixed triple bridge is antiferromagnetic in the Mn(II) compound (1) but ferromagnetic in the Cu(II) species (2).

A 4-(3-pyridyl)benzoate N-oxide as coligand led to two 2D coordination compounds with similar azide, carboxylate, and N-oxide mixed triple bridges. The Mn(II) compound behaves as a antiferromagnetic, while the Cu(II) compound behaves as a ferromagnet.Figure optionsDownload as PowerPoint slideHighlights
► We have described two Cu(II) and Mn(II) coordination polymers.
► They both consist of 2D coordination layers.
► The structural difference is mainly due to the cis or trans coordination geometry.
► The magnetic coupling is antiferromagnetic in the Mn(II) compound but ferromagnetic in the Cu(II) species.