A family of 2p-3d complexes based on 4,5-dimethyltriazole nitronyl nitroxide radical: synthesis, structure, and magnetic properties

Three 2p-3d complexes were successfully synthesized by using 4,5-dimethyltriazole nitronyl nitroxide radical. All of the complexes with the same formula of [M(hfac)(2)(4,5-di-Me-3-NIT-trz)(2)] [M = Co(II) 1, Ni(II) 2, Cu(II) 3; 4,5-di-Me-3-NIT-trz = 2-[3-(4,5-dimethyl-T2,4-triazolyel-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; hfac = hexafluomacetylacetone] are characterized by X-ray analysis, and their magnetic properties were studied in detail. The metal ions in 1-3 are all in distorted octahedral configuration with four oxygen atoms from two bidentate hfac ligands, and two triazole N atoms from two different 4,5-di-Me-3-NIT-trz ligands. The magnetic behaviors for 1-3 indicate that the metal ions and the radicals are antiferromagnetically coupled (J(Co-rad) = -7.11 cm(-1), for 1; J(Ni-rad) = -1.63 cm(-1), for 2; J(Cu-rad) = -8.71 cm(-1), for 3). In addition, ferromagnetic coupling exists between the uncoordinated NO radicals in complex 1, while the magnetic reactions J(rad-rad) are antiferromagnetic in complexes 2-3.