Reversible Mechanical Induction of Optical Activity in Solutions of Soft‐Matter Nanophases |
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| Authors: | Oriol Arteaga Carlos Escudero Dr. Gerard Oncins Dr. Zoubir El‐Hachemi Dr. Joan Llorens Dr. Joaquim Crusats Dr. Adolf Canillas Dr. Josep M. Ribó Prof. |
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| Affiliation: | 1. Department of Applied Physics and Optics Science, and Institut de Nanociència i Nanotecnologia (IN2UB), University of Barcelona, Martí i Franquès 1, 08028‐Barcelona, Catalonia (Spain);2. Department of Organic Chemistry and Institute of Cosmos Science (ICC), University of Barcelona, Martí i Franquès 1, 08028‐Barcelona, Catalonia (Spain), Fax: (+34)?934021251;3. Scientific Services and Institute for Bioengineering of Catalonia (IBEC), University of Barcelona, Martí i Franquès 1, 08028‐Barcelona, Catalonia (Spain);4. Centro de Astrobiología, CSIC‐INTA, Ctra. Ajalvir Km. 4, 28850‐Torrejón de Ardoz, Madrid (Spain);5. Department of Chemical Engineering, University of Barcelona, Martí i Franquès 1, 08028‐Barcelona, Catalonia (Spain) |
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| Abstract: | 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. |
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| Keywords: | chirality circular dichroism nanoparticles self‐assembly supramolecular chemistry |
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