Keto-enol tautomerization rates of acetylacetone in water-acetonitrile and water-dimethyl sulfoxide mixtures: Rate-partition relationship |
| |
| Affiliation: | 1. State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China;2. School of Materials Science Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 637371, Singapore;3. Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore;1. Department of Physics, University of the Free State (Qwaqwa), Private Bag x13, Phuthaditjhaba 9866, South Africa;2. Department of Physics, University of the Free State, P. O. Box 339, Bloemfontein 9300, South Africa;1. N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russian Federation;2. I. Ya. Postovsky Institute of Organic Synthesis, Ural Branch of the Russian Academy of Sciences, 620990 Ekaterinburg, Russian Federation;3. Institute of Chemical Engineering, Ural Federal University, 620002 Ekaterinburg, Russian Federation;1. Fluoroorganics Division, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500607, India;2. Centre for X-ray Crystallography, CSIR-IICT, Hyderabad, 500607, India |
| |
| Abstract: | The rate of the keto-enol tautomerization of acetylacetone was studied in water-acetonitrile (AN) and water-dimethyl sulfoxide (DMSO) mixtures. The apparent partition coefficients of acetylacetone between n-heptane and these mixed solvents were measured to estimate the free energies of transfer of each tautomer from water to the mixed solvents. The rate constants of enolization and ketonization depended remarkably on the composition of the mixed solvents, and a maximum in the enolization reaction was observed at about 20 mol% DMSO in water-DMSO mixtures. These kinetic solvent effects were analyzed with “rate-partition relationship” (RPR) derived on the basis of the transfer free energy concept, and the unusual kinetic solvent effect observed in water-DMSO mixtures was interpreted in terms of the destabilization of the keto form in the mixed solvents. An applicability of the RPR to other reactions was suggested. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
