Effect of water on the ionic-molecular interaction in the acetone-phenol-H2SO4 system

Complexation in the acetone-phenol system and the effect of water on the ionic-molecular interaction in the acetone-phenol-H₂SO₄ system at 30C were investigated by MFTIR (multifrustrated total internal reflection) IR spectroscopy. Acetone and phenol form a 11 complex (PAC-l). In an excess of acetone, all of the phenol is bound with this complex, and a 21 complex (PAC-2) is formed in an excess of phenol. Relatively small amounts of H₂O virtually do not decompose PAC-1. A broad continuous absorption band due to the formation of complexes with a strong quasisymmetric H bond is observed in the IR spectra of solutions with H₂SO₄. Quasi-ion pairs HOSO₂O...H...OC-(CH₃)₂, are formed in an anhydrous system. The acid-solvent complexes decompose and (H₂O...H...OH₂)⁺ ions are formed on addition of water. The continuous absorption coefficients, ₂₀₀₀, of (H₂O...H...OH₂)⁺ ions and quasi-ion pairs were determined.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1001–1006, May, 1991.