Pair of chiral 2D silver(i) enantiomers: chiral recognition of l- and d-histidine via differential pulse voltammetry

Self-assembly of AgPF₆ with a pair of chiral tridentate ligands (1S,1′S,1′′S,2R,2′R,2′′R) and (1R,1′R,1′′R,2S,2′S,2′′S)-(benzenetricarbonyltris(azanediyl))tris(2,3-dihydro-1H-indene-2,1-diyl)triisonicotinate (s,r-L) and (r,s-L) in a mixture of methanol and dioxane yields 2D sheets consisting of [Ag(s,r-L)](PF₆)·3C₄H₈O₂·0.5H₂O and [Ag(r,s-L)](PF₆)·3C₄H₈O₂·0.5H₂O, respectively. The differential pulse voltammetric (DPV) technique using the pair of chiral 2D-sheet enantiomers was employed for chiral discrimination of amino acid enantiomers, and was found to be an effective tool for enantio-recognition of l- and d-histidines. Both the size and the binding site of amino acids were strongly dependent on electrochemical enantio-recognition via the chiral 2D sheets.