Syntheses, crystal structures and magnetic properties of two 2D copper–nitroxide coordination polymers bridged by flexible aliphatic dicarboxylate ligands

• Two novel two-dimensional copper–nitroxide coordination polymers were characterized.
• Two complexes contain the corrugated 2D sheets bridged by the flexible dicarboxylate anions.
• The corrugated 2D sheets are composed of paddle-wheel binuclear Cu(II) units with radicals.
• The conformations of the dicarboxylate ligands adopt the gauche-forms.
• Complex 1 displays a 2D helical layer rarely found in metal–nitroxide systems.

Two novel two-dimensional copper–nitroxide coordination polymers of formula [Cu2(NIT3Py)2(glu)2]n (1) and {[Cu2(NIT3Py)2(adip)2] · CH3OH · 0.5H2O}n (2) (NIT3Py = 2-(3′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, H2glu = glutaric acid and H2adip = adipic acid), have been synthesized and characterized structurally as well as magnetically. The crystal structures of both polymers contain the paddle-wheel binuclear Cu(II) units axially coordinated by NIT3Py ligands which are bridged by the flexible glutarate or adipate anions into the corrugated 2D sheets. Interestingly, complex 1 displays a 2D helical layer structure rarely found in metal–nitroxide systems. The magnetic measurements show the strong antiferromagnetic interactions in the binuclear Cu(II) units and weak antiferromagnetic interactions between copper ions and nitroxides.

Two novel copper–nitroxide coordination polymers have been synthesized. Two complexes contain the paddle-wheel binuclear Cu(II) units axially coordinated by NIT3Py ligands which are bridged by the flexible dicarboxylate anions into the corrugated 2D sheets. Complex 1 displays a 2D helical layer structure rarely found in metal–nitroxide systems. The magnetism is discussed.Figure optionsDownload as PowerPoint slide