Composition,structure, and ir spectra of acid trialkylmethylammonium acetates in CCl4+HAc solutions

The composition and structure of neutral and acid trialkyl(C₈-C₁₀)methylammonium acetates in CCl₄+HAc solutions formed by the reaction R₃CH₃N⁺Ac⁻+nHAc⇔R₃CH₃N⁺(Ac·nAc)⁻ are investigated by IR spectroscopy. As the molar ratio HAc/R₃CH₃N⁺Ac⁻ increases in solutions, complex anions Ac·nAc⁻ (I) with n=1, 2, 3, 4 are formed in sequence. The curves of formation of anions with n=0, 1, 2 are plotted. One terminal COO group of anions I is bonded to (“blocked” by) the R₃CH₃N⁺ cation, and another group sequentially adds H-bonded HAc molecules as the concentration of HAc in solutions increases. The sequence of IR spectral changes in the series of anions I with n=0, 1, 2, 3, 4 is discussed. Institute of Catalysis, Siberian Branch, Russian Academy of Sciences. Novosibirsk State University. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 2, pp. 310–318, March–April, 1996. Translated by L. Smolina