Fluorescence of 4-aminophthalimide in supercritical CO 2-ethanol mixtures
Steady-state and time-resolved fluorescence studies of 4-aminophthalimide (AP) in neat supercritical CO 2 and supercritical CO 2-ethanol mixtures at 35 and 45 °C are presented. In neat CO 2, the emission maximum of AP shifts to the red upon density increase because of the increase of average number...
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todo:paper_03010104_v305_n1-3_p27_Wetzler2023-10-03T15:18:14Z Fluorescence of 4-aminophthalimide in supercritical CO 2-ethanol mixtures Wetzler, D.E. Fernández-Prini, R. Aramendía, P.F. 4-Aminophthalimide Carbon dioxide Fluorescence Solvathochromic Solvation Supercritical fluid alcohol amide carbon dioxide article density entropy fluorescence mathematical model molecular interaction molecular probe solvation steady state supercritical fluid temperature dependence Steady-state and time-resolved fluorescence studies of 4-aminophthalimide (AP) in neat supercritical CO 2 and supercritical CO 2-ethanol mixtures at 35 and 45 °C are presented. In neat CO 2, the emission maximum of AP shifts to the red upon density increase because of the increase of average number of solvent molecules interacting with the probe. In CO 2-ethanol mixtures of different ethanol densities (0.025 and 0.125 M) the tendency upon CO 2 density increase is opposite. In mixtures, the CO 2 density increase, also increases the probability of exchange of the ethanol molecules interacting with AP by CO 2 molecules. This causes a blue shift that is bigger than the red shift caused by density increase. In all the cases, emission spectra were time independent in the nanosecond time range. This allowed to take solvation effects into account using a Langmuir adsorption model, under equilibrium conditions. This is the simplest association model that can semiquantitative describe the results and can successfully explain the lack of solvation entropic effects in emission of AP in the mixtures near the critical density of CO 2. © 2004 Elsevier B.V. All rights reserved. Fil:Wetzler, D.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Fernández-Prini, R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Aramendía, P.F. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_03010104_v305_n1-3_p27_Wetzler |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
4-Aminophthalimide Carbon dioxide Fluorescence Solvathochromic Solvation Supercritical fluid alcohol amide carbon dioxide article density entropy fluorescence mathematical model molecular interaction molecular probe solvation steady state supercritical fluid temperature dependence |
| spellingShingle |
4-Aminophthalimide Carbon dioxide Fluorescence Solvathochromic Solvation Supercritical fluid alcohol amide carbon dioxide article density entropy fluorescence mathematical model molecular interaction molecular probe solvation steady state supercritical fluid temperature dependence Wetzler, D.E. Fernández-Prini, R. Aramendía, P.F. Fluorescence of 4-aminophthalimide in supercritical CO 2-ethanol mixtures |
| topic_facet |
4-Aminophthalimide Carbon dioxide Fluorescence Solvathochromic Solvation Supercritical fluid alcohol amide carbon dioxide article density entropy fluorescence mathematical model molecular interaction molecular probe solvation steady state supercritical fluid temperature dependence |
| description |
Steady-state and time-resolved fluorescence studies of 4-aminophthalimide (AP) in neat supercritical CO 2 and supercritical CO 2-ethanol mixtures at 35 and 45 °C are presented. In neat CO 2, the emission maximum of AP shifts to the red upon density increase because of the increase of average number of solvent molecules interacting with the probe. In CO 2-ethanol mixtures of different ethanol densities (0.025 and 0.125 M) the tendency upon CO 2 density increase is opposite. In mixtures, the CO 2 density increase, also increases the probability of exchange of the ethanol molecules interacting with AP by CO 2 molecules. This causes a blue shift that is bigger than the red shift caused by density increase. In all the cases, emission spectra were time independent in the nanosecond time range. This allowed to take solvation effects into account using a Langmuir adsorption model, under equilibrium conditions. This is the simplest association model that can semiquantitative describe the results and can successfully explain the lack of solvation entropic effects in emission of AP in the mixtures near the critical density of CO 2. © 2004 Elsevier B.V. All rights reserved. |
| format |
JOUR |
| author |
Wetzler, D.E. Fernández-Prini, R. Aramendía, P.F. |
| author_facet |
Wetzler, D.E. Fernández-Prini, R. Aramendía, P.F. |
| author_sort |
Wetzler, D.E. |
| title |
Fluorescence of 4-aminophthalimide in supercritical CO 2-ethanol mixtures |
| title_short |
Fluorescence of 4-aminophthalimide in supercritical CO 2-ethanol mixtures |
| title_full |
Fluorescence of 4-aminophthalimide in supercritical CO 2-ethanol mixtures |
| title_fullStr |
Fluorescence of 4-aminophthalimide in supercritical CO 2-ethanol mixtures |
| title_full_unstemmed |
Fluorescence of 4-aminophthalimide in supercritical CO 2-ethanol mixtures |
| title_sort |
fluorescence of 4-aminophthalimide in supercritical co 2-ethanol mixtures |
| url |
http://hdl.handle.net/20.500.12110/paper_03010104_v305_n1-3_p27_Wetzler |
| work_keys_str_mv |
AT wetzlerde fluorescenceof4aminophthalimideinsupercriticalco2ethanolmixtures AT fernandezprinir fluorescenceof4aminophthalimideinsupercriticalco2ethanolmixtures AT aramendiapf fluorescenceof4aminophthalimideinsupercriticalco2ethanolmixtures |
| _version_ |
1782028620135399424 |