INIQUI   05448
INSTITUTO DE INVESTIGACIONES PARA LA INDUSTRIA QUIMICA
Unidad Ejecutora - UE
artículos
Título:
A complete assignment of the vibrational spectra of sucrose in aqueous medium based on the SQM methodology and SCRF calculations
Autor/es:
ALICIA BEATRIZ BRIZUELA; MARIA VICTORIA CASTILLO; ANA BEATRIZ RASCHI; LILIAN DAVIES; ELIDA ROMANO; SILVIA ANTONIA BRANDÁN
Revista:
CARBOHYDRATE RESEARCH
Editorial:
ELSEVIER SCI LTD
Referencias:
Lugar: Inglaterra; Año: 2014 vol. 388 p. 112 - 124
ISSN:
0008-6215
Resumen:
In the present study, a complete assignment of the vibrational spectra of sucrose in aqueous medium was performed combining Pulay?s Scaled Quantum Mechanics Force Field (SQMFF) methodology with self-consistent reaction field (SCRF) calculations. Aqueous saturated solutions of sucrose and solutions at different molar concentrations of sucrose in water were completely characterized by infrared, HATR, and Raman spectroscopies. In accordance with reported data of the literature for sucrose, the theoretical structures of sucrose penta and sucrose dihydrate were also optimized in gas and aqueous solution phases by using the density functional theory (DFT) calculations. The solvent effects for the three studied species were analyzed using the solvation PCM/SMD model and, then, their corresponding solvation energies were predicted. The presence of pure water, sucrose penta-hydrate, and sucrose dihydrate was confirmed by using theoretical calculations based on the hybrid B3LYP/6-31G⁄ method and the experimental vibrational spectra. The existence of both sucrose hydrate complexes in aqueous solution is evidenced in the IR and HATR spectra by means of the characteristic bands at 3388, 3337, 3132, 1648, 1375, 1241, 1163, 1141, 1001, 870, 851, 732, and 668 cm1 while in the Raman spectrum, the groups of bands in the regions 3159?3053 cm1 , 2980, 2954, and 1749?1496 cm1 characterize the vibrationmodes of those complexes. The inter and intra-molecular H bond formations in aqueous solution were studied by NaturalBond Orbital (NBO) and Atoms in Molecules theory (AIM) investigation.