title: Rational design of three-dimensional (3D) optically active molecule-based magnets: synthesis, structure, optical and magnetic properties of ([Ru(bpy)3](2+), ClO4(-), [Mn(II) Cr(III)(ox)3](-))n and ([Ru(bpy)2ppy](+), [M(II)Cr(III)(ox)3](-))n, with M(II) = Mn(II), Ni(II). X-ray structure of ([deltaRu(bpy)3](2+), ClO4(-), [deltaMn(II)DeltaCr(III)(ox)3](-))n and ([lambdaRu(bpy)2ppy)](+), [lambdaMn(II)lambdaCr(III)(ox)3](-))n.
abstract: To elucidate the relation between structural and magnetic properties, we have synthesized molecular materials having both Cotton effects and a ferromagnetic long range order. Such optically active 3D molecule-based magnets were rationally designed using the enantioselective template effect of optically active cations, namely Delta or Lambda [Ru(bpy)3, ClO4](+) or Delta or Lambda [Ru(bpy)3ppy](+) (bpy = bipyridine; ppy = phenylpyridine). Such cations are able to template the formation of optically active 3D anionic networks in which transition metal ions (Cr-Mn) and (Cr-Ni) are connected by oxalate ligands (ox). Following this strategy, we described the synthesis of ([Ru(bpy)3](2+), ClO4(-), [Mn(II)Cr(III)(ox)3](-))n and ([Ru(bpy)2ppy](+), [M(II)Cr(III)(ox)3](-))n with M(II) = Mn(II), Ni(II) in their optically active forms. In these 3D networks, all of the metallic centers have the same configuration, Delta or Lambda, as the template cation. We have determined the structure of ([DeltaRu(bpy)3][ClO4][DeltaMnDeltaCr(ox)3])n and ([LambdaRu(bpy)2ppy](+), [LambdaMn(II)LambdaCr(III)(ox)3](-))n by X-ray diffraction studies. These optically active networks show the Cotton effect and long-range ferromagnetic order at low temperatures. The magnetic circular dichroism of ([Ru(bpy)3](2+), ClO4(-), [Mn(II)Cr(III)(ox)3](-))n at 2 K is reported.
authors.affiliation: Laboratoire de Chimie Inorganique et Matériaux Moléculaires, CIM(2) Unité CNRS 7071, Université Pierre et Marie Curie, 4 place Jussieu, case 42, 75252 Paris Cedex 05, France.
authors.forename: R
authors.initials: R
authors.lastname: Andrés
authors.forename: M
authors.initials: M
authors.lastname: Brissard
authors.forename: M
authors.initials: M
authors.lastname: Gruselle
authors.forename: C
authors.initials: C
authors.lastname: Train
authors.forename: J
authors.initials: J
authors.lastname: Vaissermann
authors.forename: B
authors.initials: B
authors.lastname: Malézieux
authors.forename: J P
authors.initials: JP
authors.lastname: Jamet
authors.forename: M
authors.initials: M
authors.lastname: Verdaguer