Encoding Chiral Molecular Information in Metal Structures

Abstract

The concept of encoding molecular information in bulk metals has been proposed over the past decade. The structure of various types of molecules, including enantiomers, can be imprinted in achiral substrates. Typically, to encode metals with chiral information, several approaches, based on chemical and electrochemical concepts, can be used. In this Minireview, recent achievements with respect to the development of such materials are discussed, including the entrapment of chiral biomolecules in metals, the chiral imprinting of metals, as well as the combination of imprinting with nanostructuring. The features and potential applications of these designer materials, such as chirooptical properties, enantioselective adsorption and separation, as well as their use for asymmetric synthesis will be presented. This will illustrate that the development of molecularly encoded metal structures opens up very interesting perspectives, especially in the frame of chiral technologies.

Widening the Scope of “Inherently Chiral” Electrodes: Enantiodiscrimination of Chiral Electroactive Probes with Planar Stereogenicity

“…While switching to CH 2 Cl 2 as working medium (orange series, in Figure 3) results in a linear fit similar to one for CH 3 CN, but with higher slope, consistently with the lower solvent shielding effect. 6 ] medium, including formal first oxidation potentials (related to the ferrocene site) E°' Fc , first oxidation and reduction peak potentials, E Ia and E Ic respectively, oxidation and reduction peak potentials for the subsequent redox processes, E IIa , IIIa and E IIc,IIIc ). All potentials are referred to the formal potential of the Fc + j Fc couple measured in the same conditions.…”

Chiral Electrochemistry: Anodic Deposition of Enantiopure Helical Molecules

“…As an example, the chiral resolution of penicillamine enantiomers is based on DNA-modified multi-walled CNTs immobilized onto a glassy carbon electrode (GCE) surface. [18] Interesting and recent applications include imprinting chiral molecules into a metal matrix [19] (Figure 2). The procedure is such that a template composed of a liquid crystal with the added target chiral analyte (e. g. mandelic acid) is formed on the conductive surface.…”

“…The reduced metal has a mesoporous character, which facilitates the access and the interaction of the chiral analyte with 'chiral fingerprints' and enables easy implementation of such an electrode material into flow systems and microfluidic techniques. [19] This approach can also be used in the field of asymmetric synthesis. [20]…”

Orientation of 1,1′-Bi-2-naphthol Grafted onto TiO2

“…Modification of oxide surfaces and particles by organic ligands has numerous applications, such as in selective separations, chemical sensing, selective catalysis, and drug delivery. − A common feature of these applications is a dependence on chemical and physical interactions between an analyte and a recognition site, referred to as the “molecular recognition event”. The molecular recognition event is sensitive to the chemical composition, local structure, and, where relevant, chirality of the organic modifier. ,− Therefore, it is of great importance to understand the properties of organic modifiers when immobilized onto surfaces.…”