Reversible Mechanical Induction of Optical Activity in Solutions of Soft-Matter Nanophases
| Autor: | Adolf Canillas, Joan Llorens, Joaquim Crusats, Carlos Escudero, Zoubir El-Hachemi, Josep M. Ribó, Oriol Arteaga, Gerard Oncins |
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| Rok vydání: | 2009 |
| Předmět: |
Supramolecular chirality
Porphyrins Optical Rotation Nanoparticle Microscopy Atomic Force Biochemistry Ellipsometry Porfirines Soft matter Chirality Mechanical Phenomena Physics::Biological Physics Acicular Chemistry Circular Dichroism Organic Chemistry Water General Chemistry Nanostructures Vortex Solutions Condensed Matter::Soft Condensed Matter Crystallography Chemical physics Quiralitat Absorption (chemistry) Shear flow |
| Zdroj: | Dipòsit Digital de la UB Universidad de Barcelona |
| ISSN: | 1861-471X 1861-4728 |
| DOI: | 10.1002/asia.200900254 |
| Popis: | Nanophases of J-aggregates of several achiral amphiphilic porphyrins, which have thin long acicular shapes (nanoribbons), show the immediate and reversible formation of a stationary mechano-chiral state in the solution by vortex stirring, as detected by their circular dichroic signals measured by 2-modulator generallized ellipsometry. The results suggest that when a macroscopic chiral force creates supramolecular chirality, it also creates an enantiomeric excess of screw distortions, which may be detected by their excitonic absorption. An explanation on the effect of the shear flow gradients is proposed on the basis of the orientation of the rotating particles in the vortex and the size, shape, and mechanical properties of the nanoparticles. |
| Databáze: | OpenAIRE |
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