Novel cationic mixed-ligand palladium and platinum complexes based on the chelating ligands 4,7-dimethyl-1,10-phenanthroline and 2,2 0 -bipyridine with a pyridine bearing the nitronylnitroxide radical are reported. The synthesis, X-ray crystal structures and magnetic properties of the two complexes [Pd(4,7-dimethyl-1,10-phenanthroline)(NIT-pPy) 2 ](PF 6) 2 . DMF and [Pt(2,2 0 -bipyridine-N,N 0)(NIT-pPy) 2 ](PF 6) 2 AE 0.25H 2 O, (where NIT-pPy = 2-(p-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) are described. The two metal complexes show a strained square planar geometry. Short intermolecular contacts take place through the nitroxide groups and weak intermolecular antiferromagnetic interactions are dominant at low temperature.