The first one-dimensional copper(ii)-radical system with alternating double end-on and end-to-end azido bridges

A novel one-dimensional copper(II)-radical complex [Cu(NITmPy)(N3)2(CH3OH)] [NITmPy = 2-(3′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide] has been synthesized and structurally characterized. The structure consists of neutral chains of copper(II) ions alternatively bridged by double symmetric end-on and asymmetric end-to-end azide groups. The NITmPy radical ligand coordinates to the copper(II) ions through the nitrogen atom of the pyridyl ring. The magnetic properties were investigated in the temperature range 5–300 K. The complex exhibits ferromagnetic interactions between the copper(II) ions through the end-on and end-to-end azido bridging ligands, and between the copper(II) ion and NITmPy radical. The magnetic behavior is discussed with reference to the crystal structure.