Spontaneous Chiral Symmetry Breaking for Finite Systems

• Published in: Chemphyschem 2015-12, Vol.16 (17), p.3728-3735
• Main Authors: Boscheto, Emerson, López-Castillo, Alejandro
• Format: Article
• Language: English
• Subjects: asymmetric catalysis; chiral symmetry; kinetics; Life; Models, Chemical; nonequilibrium processes; spontaneous symmetry breaking; Thermodynamics
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.201500635

Theoretical clues are desirable to help uncover the origin of bio‐homochirality in life, as well as the mechanisms for the asymmetric production of functional chiral substances. Here, an open‐to‐matter reaction network based on a model proposed by Plasson et al. is studied. In the extended model, the statistical fluctuations lead the system to break chiral symmetry autonomously, that is, without any initial enantiomeric excess or external influence. In the stability diagrams, we observe regions of parameter space that correspond to racemic, homochiral, chiral oscillatory, and, to our knowledge, for the first time in a chiral model, chaotic regimes. The dependencies of the final concentrations of chiral substances on the parameters are determined analytically and discussed for both the racemic and homochiral regimes. Model results: A reaction network containing two families of enantiomers is studied, taking into account the inherent statistical fluctuations that lead the system to spontaneously break the chiral symmetry. Racemic, homochiral, chiral oscillatory, and chaotic (white region, see figure) regimes are seen in the stability diagram, which is characterized in the parameter space of the rate constants ω and α.