Structures and magnetic properties of ruthenium(II,III) pivalate cation dimers axially coordinated by pyridyl nitronyl nitroxide radicals through their pyridyl nitrogen atoms

Adduct complexes of ruthenium(II,III) pivalate dimer with pyridyl nitronyl nitroxide radicals, [Ru-2 (O2CCMe3)(4)(L)(2)]-X (L = 2-(3-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl 3-N-oxide (m-nitpy) and 2-(4-pyridyl)-4,4, 5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl 3-N-oxide (p-nitpy); X = BF4 and BPh4), have been prepared and characterized. The dimeric cores, which are axially coordinated by the pyridyl nitrogen atoms of the radical ligands, not by the nitroxide oxygen atoms, have been crystallographically confirmed for complexes with m-nitpy (X = BF4) and p-nitpy (X = BPh4) using an X-ray diffraction method. The magnetic interactions between the radical and Pu(II,III) dimer through the pyridyl group and the radicals of the neighboring cation units through the space are weak.