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http://hdl.handle.net/10773/19355
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DC Field | Value | Language |
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dc.contributor.author | Talhi, Oualid | pt |
dc.contributor.author | Lopes, Guido R. | pt |
dc.contributor.author | Santos, Sergio M. | pt |
dc.contributor.author | Pinto, Diana C. G. A. | pt |
dc.contributor.author | Silva, Artur M. S. | pt |
dc.date.accessioned | 2017-12-07T19:09:54Z | - |
dc.date.issued | 2014 | pt |
dc.identifier.issn | 0894-3230 | pt |
dc.identifier.uri | http://hdl.handle.net/10773/19355 | - |
dc.description.abstract | The diastereoselective photodependent isomerization equilibrium of E/Z-1,3-ditolyl-5-[3-oxobenzofuran-2(3H)-ylidene] imidazolidine-2,4-dione (5) is reported. Both diastereomers E-5 and Z-5 are stereochemically stable in solid state but show significant photosensibility in solutions of halogenated solvent. The photoisomerization equilibrium of E/Z-5 is therefore deduced from the H-1 NMR profile after visible-light irradiation of both E-5 and Z-5 samples. The results of the kinetic study, monitored by UV-HPLC, reveal that the E/Z equilibrium is diastereoselective and photodependent, being the transformation E -> Z proceeding faster than that of Z -> E, and the E/Z ratio at the equilibrium depends on the used solvent, light source, and temperature. Both diastereomers are visible-light photosensitive tending to coexist together in equilibrium solutions at a determined ratio, which is always in favor of the Z-product assuming a minimum thermodynamic energy and an increased entropy of the system. Time-dependent density functional theory calculations suggest that the photoisomerization mechanism proceeds via a conical intersection involving the first-excited state: Upon irradiation, the E-5 isomer is excited to the S1 potential energy surface, where it relaxes through rotation of the C=C bond and reaches a conical intersection with the ground-state potential energy surface, thus yielding the Z-5 isomer. Copyright (C) 2014 John Wiley \& Sons, Ltd. | pt |
dc.language.iso | eng | pt |
dc.publisher | WILEY-BLACKWELL | pt |
dc.relation | info:eu-repo/grantAgreement/FCT/COMPETE/132997/PT | pt |
dc.relation | info:eu-repo/grantAgreement/EC/FP7/215009/EU | pt |
dc.relation | info:eu-repo/grantAgreement/FCT/COMPETE/132936/PT | pt |
dc.rights | restrictedAccess | por |
dc.subject | ISOMERIZATION | pt |
dc.subject | DERIVATIVES | pt |
dc.subject | STILBENE | pt |
dc.subject | PROTEIN | pt |
dc.title | Visible light-induced diastereoselective E/Z-photoisomerization equilibrium of the C=C benzofuran-3-one-hydantoin dyad | pt |
dc.type | article | pt |
dc.peerreviewed | yes | pt |
ua.distribution | international | pt |
degois.publication.firstPage | 756 | pt |
degois.publication.issue | 9 | pt |
degois.publication.lastPage | 763 | pt |
degois.publication.title | JOURNAL OF PHYSICAL ORGANIC CHEMISTRY | pt |
degois.publication.volume | 27 | pt |
dc.date.embargo | 10000-01-01 | - |
dc.relation.publisherversion | 10.1002/poc.3335 | pt |
dc.identifier.doi | 10.1002/poc.3335 | pt |
Appears in Collections: | CICECO - Artigos |
Files in This Item:
File | Description | Size | Format | |
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Visible light-induced diastereoselective EZ-photoisomerization equilibrium of the C=C benzofuran-3-one-hydantoin dyad_10.1002poc.3335.pdf | 457.59 kB | Adobe PDF |
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