Supramolecular interactions between chiral ions: Synthesis and characterization of [MII(bpy)3][VO(O2)(ox)(bpy)]⋅7H2O (M = Fe and Ni)

Two new compounds containing chiral cations and anions, [M(bpy)3][VO(O2)(ox)(bpy)]2⋅7H2O (M = Fe, Ni; bpy = 2,2′-bipyridine; ox = oxalato(2–)) have been prepared and characterized by elemental analysis, vibrational spectra in the solid state, and by 51V NMR and electronic spectroscopy in solution. The compounds are isostructural and racemic. The crystal structure contains two kinds of alternating (homochiral) triple layers: (i) the layer formed by Δ-[M(bpy)3]2+ cations intercalated between two layers of A-[VO(O2)(ox)(bpy)]−, and (ii) the layer formed by Λ-[M(bpy)3]2+ cations intercalated between two layers of B-[VO(O2)(ox)(bpy)]− (A- and B-denote different enantiomers of anions).

► Racemic compounds with chiral cations as well as anions were prepared.
► Stereochemical discrimination of chiral [VO(O2)(ox)(bpy)]− anions was made.
► Stereospecific recognition was observed between chiral cations and anions.
► Two types of π–π interactions were observed.