resumo
The complete vibrational spectra assignment of dihydrocoumarin is performed through a combined vibrational spectroscopy and DFT calculations approach. To provide effective information, vibrational analysis was also performed for alpha-pyrone and coumarin related systems. The presence of extra components in the vC=O band profile can only be understood by both Fermi resonance and monomer/dimer equilibrium phenomena, the latter established by C-H center dot center dot center dot O hydrogen bond with Delta H degrees value of -8.4 +/- 0.9 kJmol(-1). The analysis of the vC-H region indicates that both the methylene and aromatic C-H groups have a significant contribution to the formation of C-H center dot center dot center dot O bonded dimers in liquid dihydrocoumarin. (C) 2012 Elsevier B.V. All rights reserved.
palavras-chave
AB-INITIO CALCULATIONS; CRYSTAL-STRUCTURE; SPECTRA; DENSITY; FLAVONOIDS; BEHAVIOR; TANNINS; H...O; ACID; RNA
categoria
Chemistry; Physics
autores
Nolasco, MM; Vaz, PM; Vaz, PD; Ribeiro-Claro, PJA
nossos autores
Mariela Martins Nolasco
Investigador Auxiliar
Patrícia Vaz
Estudante de doutoramento
Paulo Ribeiro-Claro
Professor Associado com Agregação
Pedro Miguel Duarte Vaz
Colaboradoragradecimentos
The authors thank to the Portuguese Foundation for Science and Technology, FCT, for the financial support (PEst-OE/QUI/UI0612/2011, FCT_PTDC/CTMNAN/112168/2009). MN (SFRH/BPD/32103/2006) and PMV (BI/UI89/5377/2011) also acknowledge FCT for a research grant.