HYDRATION OF CBr3COOH MOLECULES AND CBr3CO ANIONS IN AQUEOUS SOLUTIONS
E. G. Tarakanova, G. V. Yukhnevich
Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
Keywords: трибромуксусная кислота, трибромацетат натрия, водные растворы, колебательный спектр, расчет методом ТФП, строение гидратов молекул CBrCOOH, строение гидратов анионов CBrCO, tribromoacetic acid, sodium tribromoacetate, aqueous solutions, vibrational spectrum, DFT calculation, structure of hydrates of CBrCOOH molecules, structure of hydrates of CBrCO- anions
Abstract
The optimal structures and the vibrational frequencies of H-bonded complexes formed from one-two CBr3COOH molecules or the CBr3CO anion with water molecules are calculated by density functional theory (B3LYP/6-31++G( d , p )). The comparison of the obtained results with the known Raman spectra of the CBr3COOH-H2O and NaCBr3CO ×H2O solutions (with component molar ratios of £1:16) shows that they include stable hydrates: CBr3COOH×H2O and CBr3CO ×(H2O)6. The first one has a cyclic form, and the second has a cubic globular form. The vibrational band frequencies of the CBr3COOH molecule and the CBr3CO anion in the spectra of both solutions are almost completely determined by the mutual arrangement of units in these hydrates.
|
