Please use this identifier to cite or link to this item:
https://hdl.handle.net/10316/17883
DC Field | Value | Language |
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dc.contributor.author | Lopes, S. | - |
dc.contributor.author | Gómez-Zavaglia, A. | - |
dc.contributor.author | Lapinski, L. | - |
dc.contributor.author | Chattopadhyay, N. | - |
dc.contributor.author | Fausto, R. | - |
dc.date.accessioned | 2011-12-13T12:48:55Z | - |
dc.date.available | 2011-12-13T12:48:55Z | - |
dc.date.issued | 2004-09 | - |
dc.identifier.uri | https://hdl.handle.net/10316/17883 | - |
dc.description.abstract | The infrared spectrum and conformational flexibility of benzil, (C6H5CO)2, are studied by matrix-isolation FTIR spectroscopy, supported by DFT calculations. It is shown that the low-frequency (ca. 25 cm-1), large-amplitude torsion around the C−C central bond strongly affects the structural and spectroscopic properties exhibited by the compound. The equilibrium conformational distribution of molecules with different OC−CO dihedral angles, existing at room temperature in the gas phase, and trapped in a low-temperature (T = 9 K) inert matrix can be changed either by in situ irradiation with UV light (λ > 235 nm) or by annealing the matrix to higher temperatures (T ≈ 34 K). In the first case, the increase of the average OC−CO angle results from conformational relaxation in the excited electronic states (S1 and T1), whose lowest-energy conformations correspond, for both S1 and T1 states, to a nearly planar configuration with the OC−CO dihedral angle equal to 180°. In the second case, the decrease of the average value of the OC−CO dihedral angle is a consequence of the change in the So C−C torsional potential, resulting from interactions with the matrix media, which favors the stability of the more polar structures with smaller OC−CO dihedral angles. | por |
dc.language.iso | eng | por |
dc.publisher | American Chemical Society | por |
dc.rights | openAccess | por |
dc.title | Matrix-Isolation FTIR Spectroscopy of Benzil: Probing the Flexibility of the C−C Torsional Coordinate | por |
dc.type | article | por |
degois.publication.firstPage | 8256 | por |
degois.publication.lastPage | 8263 | por |
degois.publication.title | J. Phys. Chem. A | por |
dc.peerreviewed | Yes | por |
dc.identifier.doi | 10.1021/jp047116s | - |
degois.publication.volume | 108 | por |
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.researchunit | CQC - Coimbra Chemistry Centre | - |
crisitem.author.parentresearchunit | Faculty of Sciences and Technology | - |
crisitem.author.orcid | 0000-0002-8705-0160 | - |
crisitem.author.orcid | 0000-0003-2896-4007 | - |
crisitem.author.orcid | 0000-0002-8264-6854 | - |
Appears in Collections: | FCTUC Química - Artigos em Revistas Internacionais |
Files in This Item:
File | Description | Size | Format | |
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J.Physical Chemistry A, 108 (2004) 8256.pdf | 353.95 kB | Adobe PDF | View/Open |
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