Synthesis, crystal structures and magnetic properties of copper(II) complexes with nitronyl nitroxide

摘要

Two novel adducts of formula [Cu(pfpr)_2(NITmNO_2)]_2 (I) and Cu(pfpr)_2(NITmNO_2) (II), where pfpr = pentafluoropropionate, hfac = hexafluoroacetylacetonate and NITmNO_2 = 2-(3-nitrophenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, have been synthesized. Compound (I) is the first example of copper (II)-nitroxide complexes bridged by pfpr. Its structure consists of binuclear units with the tetrakis(pentafluoropropionate) bridging two copper ions. Each copper ion has a distorted trigonal-bipyramidal coordination. Compound (II) is a mononuclear complex with a five-coordinated distorted square-pyramidal environment. The variable temperature magnetic susceptibilities show that there are antiferromagnetic interactions between copper ions and radicals for compound (I), and compound (II) is diamagnetic.