Mirror symmetry breaking with limited enantioselective autocatalysis and temperature gradients: a stability survey

TL;DR

This paper investigates how mirror symmetry breaking and chirality emergence can occur in autocatalytic chemical systems under temperature gradients and localized catalysis, relevant to origins of biological homochirality.

Contribution

It demonstrates that mirror symmetry breaking is possible with localized autocatalysis in temperature gradients, expanding understanding of conditions for chiral symmetry breaking.

Findings

Mirror symmetry breaking requires localization of catalysis in temperature regions.

Racemic state becomes unstable and bifurcates to chiral solutions under certain parameters.

Temperature gradients alone do not break symmetry without localization.

Abstract

We analyze limited enantioselective (LES) autocatalysis in a temperature gradient and with internal flow/recycling of hot and cold material. Microreversibility forbids broken mirror symmetry for LES in the presence of a temperature gradient alone. This symmetry can be broken however when the auto-catalysis and limited enantioselective catalysis are each localized within the regions of low and high temperature, respectively. This scheme has been recently proposed as a plausible model for spontaneous emergence of chirality in abyssal hydrothermal vents. Regions in chemical parameter space are mapped out in which the racemic state is unstable and bifurcates to chiral solutions.