Homochirality as a Consequence of Thermodynamic Equilibrium?

• Published in: Chemistry : a European journal Vol. 12; no. 30; pp. 7776 - 7781
• Main Authors: Crusats, Joaquim, Veintemillas-Verdaguer, Sabino, Ribó, Josep M.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 16.10.2006; WILEY‐VCH Verlag
• Subjects: chiral resolution; Chlorates - chemistry; crystal growth; Crystallization; Phase Transition; phase transitions; Stereoisomerism; Thermodynamics
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.200600580

Recent results on the crystallisation/dissolution equilibrium of enantiomorphic crystals of NaClO3 lead to the conclusion that liquid‐phase systems composed of achiral or fast racemising compounds yielding enantiomorphic solid phases (racemic conglomerates) can derive spontaneously to a single homochiral solid phase. This is a thermodynamically driven total resolution, which can only occur when the system is so perturbed that chiral recognition between the species of the system becomes feasible. Resultats recents sobre l'equilibri de cristal.lització/dissolució de cristalls enantiomòrfics de NaClO3 duen a la conclusió següent. El sistemes composats per solucions o fases líquides de compostos aquirals que racemitzen ràpidament i cristal.litzen en fases sòlides enantiomòrfiques (conglomerats racèmics) poden derivar espontàniament cap a l'homoquiralitat. Es tracta d'una ressolució total que ve control.lada termodinàmicament i que només es pot produir quan el sistema és perturbat de manera que faci possible el reconeixement quiral entre les espècies del sistema. Homochirality as the most stable final state: The crystallisation/dissolution final stable states of compounds, achiral in solution, but yielding chiral conglomerate crystals (e.g., NaClO3), according to the phase rule are those containing only homochiral crystals (for immiscible enantiomorphs). A necessary condition for this is a strong perturbation of the system leading to chiral recognition between enantiomorphs that is possible through nonlinear dynamics.