Chiral induction from ligands to metal centres. A copper(II)–nitroxide complex

Copper(II) complexes of a racemic mixture of a chiral nitronyl-nitroxide are characterised. One, A, is a centro-symmetrical species where two enantiomers are coordinated to a metal centre. The second, B, is a 1D compound comprising bridging ligands through the oxyl and pyridyl donor sites. One observes that, although the crystals are racemic, within a chain, all ligands and metal centres have respectively the same chirality. Possibilities of obtaining optically active extended structures through chiral induction from nitroxide ligands to metal ions are discussed in relation with molecular spin transition species.