Synthesis, coordination and magnetic properties of a novel family of stable chelate based biradicals: molecular structure of a 2,2′-bipyridine N-oxide N-oxyl biradical and its copper(II) complex
Abstract
Multiple (aldehyde + hydroxylamine) condensation followed by mild oxidation gives the chelating N-oxide N-oxyl biradicals 3 and 6; both ligands gave mononuclear copper(II) and nickel(II) complexes which coordinatae the two radicals and display strong antiferromagnetic coupling ant low temperature.