التفاصيل البيبلوغرافية
| العنوان: |
CrystalStructure, Matrix-Isolation FTIR, and UV-InducedConformational Isomerization of 3-Quinolinecarboxaldehyde. |
| المؤلفون: |
Kuş, Nihal1, Henriques, Marta Sofia1, Paixão, José António1, Lapinski, Leszek1, Fausto, Rui1 |
| المصدر: |
Journal of Physical Chemistry A. Sep2014, Vol. 118 Issue 38, p8708-8716. 9p. |
| مصطلحات موضوعية: |
*CRYSTAL structure, *FOURIER transform infrared spectroscopy, *ISOMERIZATION, *ULTRAVIOLET radiation, *QUINOLINE, *ALDEHYDES |
| مستخلص: |
The crystal structure of 3-quinolinecarboxaldehyde(3QC) has beensolved, and the compound has been shown to crystallize in the spacegroup P21/c(monoclinic)with a= 6.306(4), b= 18.551(11), c= 6.999(4) Å, β = 106.111(13)°, and Z= 4. The crystals were found to exhibit pseudomerohedraltwinning with a twin law corresponding to a two-fold rotation aroundthe monoclinic (100) reciprocal lattice axis (or [4 0 1] in directspace). Individual molecules adopt the syn conformation in the crystal,with the oxygen atom of the aldehyde substituent directed toward thesame side of the ring nitrogen atom. In the gas phase, the compoundexists in two nearly isoenergetic conformers (syn and anti), whichcould be successfully trapped in solid argon at 10 K, and their infraredspectra are registered and interpreted. Upon in situ irradiation ofmatrix-isolated 3QC with UV light (λ > 315 nm), significantreduction of the population of the less stable anti conformer wasobserved, while that of the conformational ground state (syn conformer)increased, indicating occurrence of the anti → syn isomerization.Upon irradiation at higher energy (λ > 235 nm), the syn →anti reverse photoreaction was observed. Interpretation of the structural,spectroscopic, and photochemical experimental data received supportfrom quantum chemical theoretical results obtained at both DFT/B3LYP(including TD-DFT investigation of excited states) and MP2 levels,using the 6-311++G(d,p) basis set. [ABSTRACT FROM AUTHOR] |
| قاعدة البيانات: |
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