A series bi-spin transition metal(II) complexes based on triazole nitronyl nitroxide radical

Abstract

Four new transition complexes were obtained by using triazole nitronyl nitroxide radical as ligand. The complexes with formula [Mn(4-Me-3-Nit-trz)(hfac)2] (1) and [M(4-Me-3-Nit-trz)(hfac)2]2 [M=Co(II) 2, Ni(II) 3, Cu(II) 4; 4-Me-3-Nit-trz=2-[3-(4-methyl-l,2,4-triazolyl)]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; hfac=hexafluoroacetylacetone] are characterized structurally and magnetically. The metal ions in the four complexes are all in six-coordinated environment with four oxygen atoms from two hfac− ligands, and one radical oxygen atom and one triazole nitrogen atom from a two teeth 4-Me-3-Nit-trz ligand. The magnetic behaviors for 1–3 indicate that the metal ions and the direct coordinated radicals are antiferromagnetically coupled (JMn-rad=−49.61cm−1, for 1; JCo-rad=−22.36cmcm−1, for 2; JNi-rad=−115.39cm−1, for 3), whereas a ferromagnetic coupling between the Cu(II) ion and the nitroxide group (JCu-rad=3.45cm−1) is observed in 4.