Raman spectra and ab initio calculation of a structure of aqueous solutions of methanol
| Autor: | A. Jumabaev, U. N. Tashkenbaev, F. H. Tukhvatullin, H. Hushvaktov, A.A. Absanov, B. Hudoyberdiev, B. Kuyliev |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Aqueous solution
Chemistry Hydrogen bond Organic Chemistry Intermolecular force Ab initio Alcohol 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Analytical Chemistry Inorganic Chemistry chemistry.chemical_compound symbols.namesake symbols Physical chemistry Organic chemistry Methanol Solubility 0210 nano-technology Raman spectroscopy Spectroscopy |
| Zdroj: | Journal of Molecular Structure. 1131:25-29 |
| ISSN: | 0022-2860 |
| DOI: | 10.1016/j.molstruc.2016.10.061 |
| Popis: | Small amount of low molecular weight alcohols leads to appearance of some special properties of alcohol-water solutions. In the literature it is associated with structural changes in solution with changing concentration. However, the problem special properties and structure of solutions at low concentration of alcohol is not very clear. Accordingly, we carried out quantum-chemical calculations and experimental studies of aqueous solutions of methyl alcohol. The calculations performed for ten molecular alcohol-water mixtures showed that with a low concentration of methyl alcohol in water the solubility of alcohol is poor: the alcohol molecules are displaced from the water structure and should form a particular structure. Thus, with low concentration of alcohol in the aqueous solution there are two types of structures: the structure of water and the structure of alcohol that should lead to the presence of specific properties. At high concentration of alcohol the structure of water is destroyed and there is just the structure made of alcohol-water aggregates. This interpretation is consistent with the experimental data of Raman spectroscopy. The band of C O vibrations of alcohol is detected to be of complex character just in the region of the presence of specific properties. Formation of intermolecular H-bonds also complicates the Raman spectra of O H or O-D vibrations of pure alcohol: a non-coincidence of peak frequencies, a shift of the band towards low-frequency region, a strong broadening of the band. |
| Databáze: | OpenAIRE |
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