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Vasquez G, Huq A, Latturner SE. In Situ Neutron Diffraction Studies of the Metal Flux Growth of Ba/Yb/Mg/Si Intermetallics. Inorg Chem 2019; 58:8111-8119. [DOI: 10.1021/acs.inorgchem.9b00857] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Guillermo Vasquez
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Ashfia Huq
- Neutron Scattering Division, Spallation Neutron Source, Oak Ridge, Tennessee 37831, United States
| | - Susan E. Latturner
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
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Gomes R, Parola AJ, Laia CAT, Pina F. Promoting Photochromism on Flavylium Derived 2-Hydroxychalcones in Aqueous Solutions by Addition of CTAB Micelles. J Phys Chem B 2007; 111:12059-65. [PMID: 17914794 DOI: 10.1021/jp073859c] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A strategy to obtain photochromism from the network of chemical reactions originated by flavylium compounds in solution is described. This strategy is particularly useful for flavylium salts bearing amino groups which give rise to a variety of beautiful colors but lack photochemistry in water. The trans-chalcone of 7-(N,N-diethylamino)-4'-hydroxyflavylium interacts strongly with CTAB micelles defining a yellow dark state. Upon irradiation, the system switches to a pink-red state emerging from the flavylium cation that is formed inside the micelle and ejected to the bulk aqueous phase. The photochemical product reverts back to the trans-chalcone adduct with the micelle in the dark. The thermodynamics as well as the kinetics of the photochromic system were studied in detail. The best color contrast is obtained at pH = 4.25 with Phi = 0.001 and a recovery lifetime of approximately 3 h. This photochromic system works with no need of changing the pH, which constitutes an important improvement over previously described systems dependent on pH jumps.
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Affiliation(s)
- Raquel Gomes
- REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
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Giestas L, Yihwa C, Lima JC, Vautier-Giongo C, Lopes A, Maçanita AL, Quina FH. The Dynamics of Ultrafast Excited State Proton Transfer in Anionic Micelles. J Phys Chem A 2003. [DOI: 10.1021/jp0265900] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Letícia Giestas
- Instituto de Tecnologia Química e Biológica, ITQB/UNL, Oeiras Portugal, Chemical Systems Engineering Group, Instituto de Química, Universidade de São Paulo, CP 26077, São Paulo 05513-970, Brazil, and Departamento de Química, IST/UTL, Lisbon, Portugal
| | - Chang Yihwa
- Instituto de Tecnologia Química e Biológica, ITQB/UNL, Oeiras Portugal, Chemical Systems Engineering Group, Instituto de Química, Universidade de São Paulo, CP 26077, São Paulo 05513-970, Brazil, and Departamento de Química, IST/UTL, Lisbon, Portugal
| | - João C. Lima
- Instituto de Tecnologia Química e Biológica, ITQB/UNL, Oeiras Portugal, Chemical Systems Engineering Group, Instituto de Química, Universidade de São Paulo, CP 26077, São Paulo 05513-970, Brazil, and Departamento de Química, IST/UTL, Lisbon, Portugal
| | - Carolina Vautier-Giongo
- Instituto de Tecnologia Química e Biológica, ITQB/UNL, Oeiras Portugal, Chemical Systems Engineering Group, Instituto de Química, Universidade de São Paulo, CP 26077, São Paulo 05513-970, Brazil, and Departamento de Química, IST/UTL, Lisbon, Portugal
| | - António Lopes
- Instituto de Tecnologia Química e Biológica, ITQB/UNL, Oeiras Portugal, Chemical Systems Engineering Group, Instituto de Química, Universidade de São Paulo, CP 26077, São Paulo 05513-970, Brazil, and Departamento de Química, IST/UTL, Lisbon, Portugal
| | - Antonio L. Maçanita
- Instituto de Tecnologia Química e Biológica, ITQB/UNL, Oeiras Portugal, Chemical Systems Engineering Group, Instituto de Química, Universidade de São Paulo, CP 26077, São Paulo 05513-970, Brazil, and Departamento de Química, IST/UTL, Lisbon, Portugal
| | - Frank H. Quina
- Instituto de Tecnologia Química e Biológica, ITQB/UNL, Oeiras Portugal, Chemical Systems Engineering Group, Instituto de Química, Universidade de São Paulo, CP 26077, São Paulo 05513-970, Brazil, and Departamento de Química, IST/UTL, Lisbon, Portugal
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