Main-Group-Based Electro- and Photoactive Chiral Materials

Abstract

This Review discusses the structure−property relationships in chiral molecules, macromolecules (polymers), and supramolecules (crystals, liquid crystals, or thin films) containing main-group elements. Chirality is a major property in our world, having a prominent influence on processes in biology, chemistry, and physics. Its impact in optics due to its interaction with electromagnetic waves gave rise to a multitude of effects, such as the Cotton effect and circularly polarized luminescence, making possible applications such as 3D displays and polarized sunglasses. Herein, a particular emphasis will be given to the influence of chirality on the conducting and optical properties of molecules or materials containing frontier heteroelements, particularly boron, silicon, phosphorus, and sulfur. These synergic materials are expected to become game-changers in the field of materials science by bringing new properties into the realm of reality, such as chirality-induced spin-selectivity, circularly polarized luminescence, and electrical magnetochiral anisotropy. This Review should be of interest for chemists and also physicists working in the fields of molecular and supramolecular chemistry, and molecular materials in the broadest sense.

Simple Perylene Diimide Cyclohexane Derivative With Combined CPL and TPA Properties

“…Organic materials presenting circularly polarized luminescence (CPL) (Riehl and Richardson, 1977;Kumar et al, 2015;Sanchez-Carnerero et al, 2015;Longhi et al, 2016;Tanaka et al, 2018) have recently emerged as promising candidates for advanced optical applications (Zinna et al, 2015;Han et al, 2018;Shi et al, 2018;Zheng et al, 2018;Burrezo et al, 2019;David et al, 2019;Jiménez et al, 2019;Pop et al, 2019;Yang and Zhong, 2019). Thus for example, CPL emitters have been proposed as chiroptical sensors (Staszak et al, 2019), for smart sensing methodologies (Imai et al, 2018;Reine et al, 2018a,b;Zinna et al, 2019), to encode information in light (Andréassons and Pischel, 2018), in patterning processes using security inks (Andres et al, 2014), or constituents of CPL organic lightemitting diodes OLEDs (Brandt et al, 2016;Di Nuzzo et al, 2017).…”

Helicene Bis(pyrazol‐1‐yl)pyridine Ligands for Luminescent Transition‐Metal Complexes

“…It would be therefore interesting to investigate the potential of the herein reported helicenic bpp's in such SCO active complexes. Secondly, the preparation of enantiomerically pure bpp‐[6]helicenes, which should be conformationally stable, holds much promise in order to obtain luminescent chiral complexes possibly showing strong CPL activity ,…”

“…Helicenes have recently attracted a lot of attention in the field of chiral materials . Thanks to their helical π‐conjugated backbone, they present exceptional chiroptical properties such as high optical activity, intense electronic circular dichroism (ECD) and circularly polarized luminescence (CPL) .…”

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

“…[2,3, The relation between current and concentration could also allow for the determination of the enantiomer concentration, and even, in favorable cases, the estimation of the enantiomeric excess directly in solution. In this frame, chirality can be implemented at the interphase either by electrode surface modification with a high variety of selectors, [2][3][4][5] or by choosing a chiral medium or medium component, such as the solvent, the supporting electrolyte, or more effectively, a chiral ionic liquid or even an ionic liquid with chiral additives. [2] In particular, outstanding discrimination ability, in terms of large peak potential differences between chiral probe enantiomers, has been recently observed when "inherently chiral" selectors were adopted for the above task.…”