Chiral Sign Induction by Vortices during the Formation of Mesophases in Stirred Solutions

• Published in: Science (American Association for the Advancement of Science) Vol. 292; no. 5524; pp. 2063 - 2066
• Main Authors: Ribó, Josep M., Crusats, Joaquim, Sagués, Francesc, Claret, Josep, Rubires, Raimon
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 15-06-2001; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Absorption spectra; Aggregation; Animal cells; Broken symmetry; Cell division; Chemical reactions; Chemistry; Chirality; Chromophores; Circular Dichroism; Crystallization; Dichroism; Enantiomers; Exact sciences and technology; General and physical chemistry; Hydrogen Bonding; Logical Thinking; Molecular Conformation; Motion; Organic chemistry; Porphyrins; Porphyrins - chemistry; Robustness (Statistics); Solution properties; Solutions; Spectroscopy; Spectrum Analysis; Static Electricity; Statistical Analysis; Statistical Distributions; Stereoisomerism; Aggregation; Chemical solution; Stirred vessel; Porphyrin; Chirality; Supramolecular structure; Molecular association; Mesophase; Aqueous solution
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1060835

Achiral diprotonated porphyrins, forming homoassociates in aqueous solution, lead to spontaneous chiral symmetry breaking. The unexpected result is that the chirality sign of these homoassociates can be selected by vortex motion during the aggregation process. This result is confirmed by means of circular dichroism spectra. These experimental findings are rationalized in terms of the asymmetric influence of macroscopic forces on bifurcation scenarios and by considering the specific binding characteristics of the porphyrin units to form the homoassociates.