An Anionic {[MnCo(ox)3]-}n Network with Appropriate Cavities for the Enantioselective Recognition and Resolution of the Hexacoordinated Monocation [Ru(bpy)2(ppy)]+ (bpy = bipyridine, ppy = phenylpyridine)

Abstract

Partial resolution of the rac-[Ru(bpy)2(ppy)]+ monocation into [Δ-Ru(bpy)2(ppy)]PF6 (1Δ) (ee = 44%) and [Λ-Ru(bpy)2(ppy)]PF6 (1Λ) (ee = 50%) enantiomers was achieved by an unprecedented resolving process which involves the diastereoselective preparation of optically active networks of the type {[Λ-Ru(bpy)2(ppy)][Mn-Λ-Co(ox)3]}n (2Λ) and {[Δ-Ru(bpy)2(ppy)][Mn-Δ-Co(ox)3]}n (2Δ). In these optically active inorganic polymers, the counter-monocation [Ru(bpy)2(ppy)]+ of appropriate configuration occupies the cavities while the excess [Ru(bpy)2(ppy)]+, of opposite configuration, remains in solution and is thus recovered. Anion metathesis of the optically active [Ru(bpy)2(ppy)]PF6 (1Δ) (ee = 44%) and (1Λ) (ee = 50%) with [l-cinchonidinium][Δ-trisphat] [trisphat = tris(tetrachlorobenzenediolato)phosphate(V)] provides the related diastereomers [Δ-Ru(bpy)2(ppy)][Δ-trisphat] (3Δ) (de = 44%) and [Λ-Ru(bpy)2(ppy)][Δ-trisphat] (3Λ) (de = 50%) in 60% yield. Their diastereomeric excesses were assessed by 1H NMR analysis. All products were fully characterized and the absolute configuration was determined by circular dichroism techniques in solution or in the solid state. Additionally the X-ray structure of [Ru(bpy)2(ppy)]PF6 (1) was determined.