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

Copper(II) complexes of a racemic mixture of a chiral nitronyl-nitroxide ar e characterised. One, A, is a centro-symmetrical species where two enantiom ers are coordinated to a metal centre. The second, B, is a 1D compound comp rising bridging ligands through the oxyl and pyridyl donor sites. One obser ves that, although the crystals are racemic, within a chain, all ligands an d metal centres have respectively the same chirality. Possibilities of obta ining optically active extended structures through chiral induction from ni troxide ligands to metal ions are discussed in relation with molecular spin transition species. (C) 2001 Academie des sciences / Editions scientifique s et medicales Elsevier SAS.