Unusual Magnetic Properties of the Adduct of Copper Chloride with 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-Oxide

Article abstract of DOI:10.1021/ja00282a017

A stable adduct was isolated from copper(II) chloride and the stable free radical 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide.THe stoichiometry of the adduct is 1:2, and a crystal structure analysis has shown the copper ion to be four planar coordinated by two chlorine atoms and two oxygen (nitroxyl) atoms.The nitroxyl ligands are bound with a short Cu-O distance of 1.988 (1) Angstroem.Magnetic measurements show that this material is in a doublet state from 30 to 300 K.At lower temperature a spin pairing process became operative.Crystal data: monoclinic, P2₁/n, a=11.988 (4) Angstroem, b=10.878 (3) Angstroem, c=11.788 (4) Angstroem, β=106.14 (2) grad, Z=2.