title: Achiral-to-chiral transition in benzil solidification: analogies with racemic conglomerates systems showing deracemization.
abstract: Experimental results show that benzil (1,2-diphenyl-1,2-ethanedione), an achiral compound that crystallizes as a racemic conglomerate, yields by solidification polycrystalline scalemic mixtures of high enantiomeric excesses. These results are related to those previously reported in this type of compounds on deracemizations of racemic mixtures of crystal enantiomorphs obtained by wet grinding. However, the present results strongly suggest that these experiments cannot be explained without taking into account chiral recognition interactions at the level of precritical clusters. The conditions that would define a general thermodynamic scenario for such deracemizations are discussed.
authors.affiliation: Departament de Química Orgànica, Universitat de Barcelona (IEEC-UB), Barcelona, Catalonia, Spain.
authors.forename: Zoubir
authors.initials: Z
authors.lastname: El-Hachemi
authors.forename: Oriol
authors.initials: O
authors.lastname: Arteaga
authors.forename: Adolf
authors.initials: A
authors.lastname: Canillas
authors.forename: Joaquim
authors.initials: J
authors.lastname: Crusats
authors.forename: Alessandro
authors.initials: A
authors.lastname: Sorrenti
authors.forename: Sabino
authors.initials: S
authors.lastname: Veintemillas-Verdaguer
authors.forename: Josep M
authors.initials: JM
authors.lastname: Ribo
keywords: asymmetric amplification; chirality; circular dichroism; phase transition; racemic conglomerates