Radical-dependent magnetic interactions in two 1-D copper(II) complexes with nitronyl nitroxide and imino nitroxide radicals bridged by iminodiacetate anion

Two novel one-dimensional (1-D) chain complexes [Cu(NIT3Py)(ida)]n (1) and [Cu(IM4Py)(ida)]n (2) (NIT3Py = 2-(3′-pyridinyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, IM4Py = 2-(4′-pyridinyl)-4,4,5,5-tetramethylimidazoline-1-oxyl and ida = iminodiacetate anion), were synthesized and characterized structurally and magnetically. The two complexes crystallize in neutral 1-D chains, where Cu(II)–nitroxide cationic units are linked by iminodiacetate anion ligands. The magnetic measurements show that complex 1 exhibits ferromagnetic coupling, while complex 2 exhibits antiferromagnetic interactions between the Cu(II) ion and the nitroxide radical.