Rational Design of Three-Dimensional (3D) Optically Active Molecule-Based Magnets: Synthesis, Structure, Optical and Magnetic Properties of {[Ru(bpy)3]2+, ClO4-, [MnIICrIII(ox)3]-}n and {[Ru(bpy)2ppy]+, [MIICrIII(ox)3]-}n, with MII = MnII, NiII. X-ray Structure of {[ΔRu(bpy)3]2+, ClO4-, [ΔMnIIΔCrIII(ox)3]-}n and {[ΛRu(bpy)2ppy]+, [ΛMnIIΛCrIII(ox)3]-}n

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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 Δ or Λ [Ru(bpy)3, ClO4]+ or Δ or Λ [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-, [MnIICrIII(ox)3]-}n and {[Ru(bpy)2ppy]+, [MIICrIII(ox)3]-}n with MII = MnII, NiII in their optically active forms. In these 3D networks, all of the metallic centers have the same configuration, Δ or Λ, as the template cation. We have determined the structure of {[ΔRu(bpy)3][ClO4][ΔMnΔCr(ox)3]}n and {[ΛRu(bpy)2ppy]+, [ΛMnIIΛCrIII(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-, [MnIICrIII(ox)3]-}n at 2 K is reported.