Dynamics and vibrational coupling of methyl acetate dissolved in ethanol

Autor: P. Mpourazanis, G. Stogiannidis, S. Kaziannis, Soghomon Boghosian, Angelos G. Kalampounias, S. Tsigoias
Rok vydání: 2019
Předmět:
Zdroj: Chemical Physics. 522:1-9
ISSN: 0301-0104
Popis: The structure and vibrational dynamics of methyl acetate (MA) molecules solvated in ethanol have been investigated by means of Raman and IR spectroscopies. Two distinct vibrational bands have been resolved and assigned to two different types of MA molecules, namely the “free” molecules that exist in bulk material and the “solution” molecules which interact with ethanol molecules. All the measured physical properties exhibit a characteristic change near a specific volume fraction (∼0.6) of MA. This behavior is associated to the existence of the two kinds of methyl acetate groups coexisting in the solutions. The micro-viscosity model provides reasonable agreement with the experimental vibrational relaxation times up to a characteristic volume fraction ∼0.6, but fails for higher values since it takes into account solvent instead of solute characteristics. Finally, the so-called non-coincidence effect (NCE) has been observed due to repulsive interactions and is of key importance for the vibrational relaxation process.
Databáze: OpenAIRE