Synthesis and crystal structures of two metal-nitroxide complexes including a phenanthroline-substituted nitroxide radical

Two metal-nitroxide complexes, [Cu(IMPhenCOO)(CH3OH)]2  · (NO3)2 (1) and [Co(NIT2Py)(H-2,5-PDA)2]  · 0.5CH3OH  · 2H2O (2) (IMPhenCOOH  = 2-carboxyl-9-(4,4,5,5-tetramethylimidazoline-1-oxyl-2-yl)-1,10-phenanthroline, NIT2Py  = 2-(2′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and H2-2,5-PDA  = pyridine-2,5-dicarboxylic acid), have been synthesized and structurally characterized by X-ray diffraction. Complex 1 exists as discrete binuclear molecules and each copper(II) is five-coordinate with one tridentate radical ligand (IMPhenCOOH), the other radical ligand through one carboxyl oxygen and one methanol molecule. Complex 1 is the first structurally characterized complex containing the phenanthroline-substituted nitroxide radical. In 2, the Co(II) is six-coordinate with one radical ligand (NIT2Py) and two bidentate pyridine-2,5-dicarboxylate anions.