Publication
A diffuse reflectance comparative study of benzil inclusion within microcrystalline cellulose and beta-cyclodextrin
| dc.contributor.author | Ferreira, Luís F. Vieira | |
| dc.contributor.author | Machado, Isabel Ferreira | |
| dc.contributor.author | Silva, José P. da | |
| dc.contributor.author | Oliveira, A. S. | |
| dc.date.accessioned | 2015-06-22T14:13:52Z | |
| dc.date.available | 2015-06-22T14:13:52Z | |
| dc.date.issued | 2004 | |
| dc.description.abstract | Diffuse reflectance and laser-induced techniques were used to study photochemical and photophysical processes of benzil adsorbed on two solid powdered supports, microcrystalline cellulose and beta-cyclodextrin. In both substrates, a distribution of ground-state benzil conformers exists, largely dominated by skew conformations where the carbonyl groups are twisted one to the other. Room temperature phosphorescence was observed in air-equilibrated samples in both cases. The decay times vary greatly and the largest lifetime was obtained for benzil/beta-cyclodextrin, showing that this host's cavity accommodates benzil well, enhancing its room temperature phosphorescence. Triplet - triplet absorption of benzil entrapped in cellulose was detected and benzil ketyl radical formation also occurred. With benzil included into beta-cyclodextrin, and following laser excitation, benzoyl radicals were detected on the millisecond timescale. Product analysis and identification of laser-irradiated benzil samples in the two hosts clearly showed that the main degradation photoproducts were benzoic acid and benzaldehyde. The main differences were a larger benzoic acid/benzaldehyde ratio in the case of cellulose and the formation of benzyl alcohol in this support. | |
| dc.identifier.doi | https://dx.doi.org/10.1039/b307956b | |
| dc.identifier.issn | 1474-905X | |
| dc.identifier.uri | http://hdl.handle.net/10400.1/6577 | |
| dc.language.iso | eng | |
| dc.peerreviewed | yes | |
| dc.publisher | Royal Society of Chemistry | |
| dc.relation.isbasedon | P-000-DCC | |
| dc.title | A diffuse reflectance comparative study of benzil inclusion within microcrystalline cellulose and beta-cyclodextrin | |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| oaire.citation.endPage | 181 | |
| oaire.citation.issue | 2 | |
| oaire.citation.startPage | 174 | |
| oaire.citation.title | Photochemical & Photobiological Sciences | |
| oaire.citation.volume | 3 | |
| person.familyName | Silva | |
| person.givenName | José Paulo da | |
| person.identifier.ciencia-id | 3413-C4F4-73F7 | |
| person.identifier.orcid | 0000-0002-6458-7328 | |
| person.identifier.rid | A-4606-2008 | |
| person.identifier.scopus-author-id | 7201733236 | |
| rcaap.rights | openAccess | |
| rcaap.type | article | |
| relation.isAuthorOfPublication | e2004fa2-a47d-44b0-b11c-fc95fe51cbf9 | |
| relation.isAuthorOfPublication.latestForDiscovery | e2004fa2-a47d-44b0-b11c-fc95fe51cbf9 |
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