Glycine aqueous solutions have been studied as a function of temperature and concentration by means of UV Brillouin and Raman spectroscopes. Brillouin spectra provided information on the average relaxation time τ α related to the mechanisms of hydrogen bonds (HBs) formation and breaking. The concentration-temperature behavior of τ has been compared to the vibrational dephasing lifetime of atoms involved in HBs, as derived by a lineshape analysis of Raman spectra. We point out how it is possible to trace the thermodynamic behavior of a selected HB from Raman data. In particular, our results confirm the predominant role played in the hydration process by the water molecules surrounding the hydrophobic groups and, furthermore, evidence how at low temperature the HB strength between these molecules is greater than those found in bulk water and between glycine and water molecules. © 2013 AIP Publishing LLC.
D'Amico, F., Bencivenga, F., Camisasca, G., Gessini, A., Principi, E., Cucini, R., et al. (2013). Thermodynamic hydration shell behavior of glycine. THE JOURNAL OF CHEMICAL PHYSICS, 139(1), 015101 [10.1063/1.4812283].
Thermodynamic hydration shell behavior of glycine
Camisasca G.;
2013-01-01
Abstract
Glycine aqueous solutions have been studied as a function of temperature and concentration by means of UV Brillouin and Raman spectroscopes. Brillouin spectra provided information on the average relaxation time τ α related to the mechanisms of hydrogen bonds (HBs) formation and breaking. The concentration-temperature behavior of τ has been compared to the vibrational dephasing lifetime of atoms involved in HBs, as derived by a lineshape analysis of Raman spectra. We point out how it is possible to trace the thermodynamic behavior of a selected HB from Raman data. In particular, our results confirm the predominant role played in the hydration process by the water molecules surrounding the hydrophobic groups and, furthermore, evidence how at low temperature the HB strength between these molecules is greater than those found in bulk water and between glycine and water molecules. © 2013 AIP Publishing LLC.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
