Please use this identifier to cite or link to this item:
https://hdl.handle.net/10316/10640
DC Field | Value | Language |
---|---|---|
dc.contributor.author | Barroso, Mónica | - |
dc.contributor.author | Chattopadhyay, Nitin | - |
dc.contributor.author | Klymchenko, Andrey S. | - |
dc.contributor.author | Demchenko, Alexander P. | - |
dc.contributor.author | Arnaut, Luís G. | - |
dc.contributor.author | Formosinho, Sebastião J. | - |
dc.date.accessioned | 2009-07-13T07:46:23Z | - |
dc.date.available | 2009-07-13T07:46:23Z | - |
dc.date.issued | 2006-12-21 | - |
dc.identifier.citation | The Journal of Physical Chemistry A. 110:50 (2006) 13419-13424 | en_US |
dc.identifier.issn | 1089-5639 | - |
dc.identifier.uri | https://hdl.handle.net/10316/10640 | - |
dc.description.abstract | Steady-state fluorescence of 4‘-dimethylamino-3-hydroxyflavone (DMA3HF) was observed in supercritical carbon dioxide (scCO2). Excited-state intramolecular proton transfer (ESIPT) occurs resulting in two well-separated emission bands corresponding to the normal and tautomer forms. As the scCO2 density exceeds 0.7 g/mL, the relative intensity of the two bands tends to a constant value, comparable to that observed for organic solvents with ET(30) = 33.0 ± 0.5 kcal/mol, such as toluene and di-n-butyl ether. At lower densities, the substantial decrease of the total fluorescence intensity (a 600-fold decrease as the pressure decreases from 100 to 80 bar) is accompanied by an even more accentuated decrease of the tautomer fluorescence. This can be explained by a shift in the equilibrium between normal and tautomer forms, concomitant with a more efficient quenching of the less solvated fluorophore, that may change the thermodynamic control of the relative population of the two emissive species to a kinetic control. | en_US |
dc.language.iso | eng | en_US |
dc.publisher | American Chemical Society | en_US |
dc.rights | openAccess | eng |
dc.title | Dramatic Pressure-Dependent Quenching Effects in Supercritical CO2 Assessed by the Fluorescence of 4‘-Dimethylamino-3-hydroxyflavone. Thermodynamic versus Kinetics Control of Excited-State Intramolecular Proton Transfer | en_US |
dc.type | article | en_US |
dc.identifier.doi | 10.1021/jp0643606 | - |
uc.controloAutoridade | Sim | - |
item.fulltext | Com Texto completo | - |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.grantfulltext | open | - |
item.languageiso639-1 | en | - |
item.openairetype | article | - |
item.cerifentitytype | Publications | - |
crisitem.author.dept | Faculty of Sciences and Technology | - |
crisitem.author.parentdept | University of Coimbra | - |
crisitem.author.researchunit | CQC - Coimbra Chemistry Centre | - |
crisitem.author.researchunit | CQC - Coimbra Chemistry Centre | - |
crisitem.author.parentresearchunit | Faculty of Sciences and Technology | - |
crisitem.author.parentresearchunit | Faculty of Sciences and Technology | - |
crisitem.author.orcid | 0000-0002-3223-4819 | - |
crisitem.author.orcid | 0000-0001-6607-0026 | - |
Appears in Collections: | FCTUC Química - Artigos em Revistas Internacionais |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
Dramatic Pressure-Dependent Quenching Effects in Supercritical.pdf | 99.5 kB | Adobe PDF | View/Open |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.