Thermodynamic analysis of the solvent effect on tautomerization of acetylacetone: An <i>ab initio</i> approach

DOI PDF 5 Citations
  • Tateki Ishida
    Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606, Japan
  • Fumio Hirata
    Institute for Molecular Science, Myodaiji, Okazaki, Aichi 444, Japan
  • Shigeki Kato
    Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606, Japan

Search this article

Description

<jats:p>The keto-enol tautomerism of acetylacetone in solution is studied with the reference interaction site model self-consistent-field (RISM-SCF) method. We choose three solvents, H2O, dimethyl sulfoxide (DMSO), and carbon tetrachloride (CCl4), representing, respectively, protic polar, aprotic polar and nonpolar solvents. The analysis is made taking account of the solute electronic as well as geometrical change of the tautomers due to solvent effect. In addition, the electronic correlation energy of solute molecule and solute vibrational energies are considered. The free energy differences are analyzed by decomposing them into the enthalpy and entropy terms. The theory reproduces the total free energy determined by the experiment fairly well. We also find that, as solvent polarities increase, the keto tautomer shows the drastic geometric change in order to make its dipole moment larger and that the geometric change of the keto tautomer is enthalpically driven in H2O and entropically in DMSO. It is made clear that these depend on the solvent property—protic or aprotic.</jats:p>

Journal

Citations (5)*help

See more

Details 詳細情報について

Report a problem

Back to top