Chiral Recognition of Proline Enantiomers by the Catalytic Oxygen Reduction and Formation of Cu(II)‐Polymer Complex Crystals

Abstract

A Cu(II)‐Poly(terthiophene carboxylic acid) (pTTC)/Nafion modified glassy carbon electrode has been used for the chiral recognition and discrimination of d‐ and l‐prolines by the catalytic oxygen reduction process and the shape of crystals formed on the electrode surface. The cyclic voltammetry with the modified electrode in the presence of oxygen recognized d‐ and l‐form of prolines by exhibiting a difference in the peak potential and the peak current of the oxygen reduction. The effect of pH and proline concentration on the peak current and the peak potential of oxygen have been studied. The SEM studies on the nature of crystals formed on a proline‐Cu(II)pTTC complex. The oxidation state of the copper species present at the electrode surface was characterized by ESCA.

Chiral Cyclodimeric Zinc(II) Complexes: Enantio-recognition via Differential Pulse Voltammetry

“…However, interaction of symmetric chiral molecules with some chiral entities results in an asymmetric environment in which different electrochemical behaviors are exhibited. In recent years, great efforts have been made to construct an effective chiral electrode surface by utilizing various chiral selectors for enantio-recognition of amino acids. − Proline and its derivatives are used in the biosynthesis of proteins and act as asymmetric catalysts in many organic reactions. − In the literature, only limited attention has been devoted to enantioselective recognition of chiral prolines. − Construction of efficient chiral sensors for enantioselective recognition of enantiomeric prolines remains as a necessary and challenging task. Previously, our group achieved enantioselective electrochemical recognition of prolines by an electrode consisting of an M -helical crystal of [CuCl 2 (L)­(Me 2 SO)]·Me 2 SO (L = bis­(4-pyridyl)-methylvinylsilane) .…”