# Phototunable Chiral-Selective Nanoporous Material

## TL;DR

Scientists created a light-sensitive material that can selectively absorb one form of a molecule based on its handedness, with potential uses in drug development.

## Contribution

A phototunable chiral-selective nanoporous material is developed for enantioselective adsorption.

## Key findings

- The material adsorbs one enantiomer of (hexan-2-yl)-4-nitroaniline selectively.
- Pore chirality can be reversed by changing the handedness of circularly polarized light.
- The material forms stable films through photodimerization of coumarin moieties.

## Abstract

Herein, we present the development of tunable chiral
nanoporous
materials capable of enantioselectively adsorbing racemic mixtures.
The materials are based on hydrogen-bonded supramolecular structures
formed from a melamine derivative as the central core and three peripheral
dendrons functionalized with coumarin and azobenzene moieties that
are organized in hexagonal columnar phases. Upon irradiation with
circularly polarized light (CPL), the azobenzene units induce controlled
chirality in the material, which is stabilized by photodimerization
of the coumarin moieties, obtaining mechanically stable films. The
elimination of the melamine template results in nanoporous materials
that retain their homeotropic hexagonal columnar alignment. These
materials show selective adsorption of one particular enantiomer of
racemic mixtures of (hexan-2-yl)-4-nitroaniline. Pore chirality can
be reversed by changing the handedness of the CPL, allowing nanoporous
materials to adsorb predominantly one or the other enantiomer. These
findings offer a versatile strategy for enantioselective separation
with potential applications in pharmaceuticals and materials science.