Control of chiral symmetry breaking: Interplay between achiral reactant concentration and diffusive asymmetries

Area of Science:

• Chemical Physics
• Physical Chemistry
• Theoretical Chemistry

Background:

• Chiral environments can influence enantiomer diffusion, termed chiral diffusive asymmetry (CDA).
• CDA is a potential pathway for chiral symmetry breaking (CSB), crucial for deracemization and homochirality.
• Existing methods for CSB often require initial enantiomeric excess or diffusion asymmetry.

Purpose of the Study:

• To demonstrate that CDA, combined with a nonuniform achiral precursor concentration, can induce CSB.
• To show that precursor distribution can serve as a controllable parameter for emergent chirality.
• To elucidate the mechanism of CSB driven by precursor gradients.

Main Methods:

• Utilized a Kondepudi-type reaction scheme.
• Performed reaction-diffusion simulations.
• Analyzed the influence of spatially nonuniform precursor concentrations on CSB.

Main Results:

• CSB was induced even without an initial enantiomeric excess.
• The spatial distribution of the achiral precursor determined the emergent chirality.
• CSB arises from the nucleation and growth of chiral domains influenced by precursor concentration and gradient.
• A linear relationship was found between CDA and precursor distribution, enabling predictive control.

Conclusions:

• CDA and precursor gradients offer a novel route to induce and control CSB.
• Precursor distribution provides an experimentally accessible control parameter for achieving homochirality.
• The findings enable predictive control over the emergence of chirality in chemical systems.