Ultrasonic detection of hydrophobic interactions: a quantitative approach |
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| Authors: | Ants Tuulmets Jaak Järv Siim Salmar Giancarlo Cravotto |
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| Institution: | 1. Institute of Chemistry, University of Tartu, Jakobi 2, 51014 Tartu, Estonia;2. Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Via P. Giuria 9, I‐10125 Torino, Italy |
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| Abstract: | Kinetic effects of sonication on ester hydrolysis and tert‐butyl chloride solvolysis, studied in ethanol–water binary solvent, are discussed in terms of quantitative relationships between their magnitude and the hydrophobicity of reagents. A number of conclusions were drawn from the observed linear free‐energy (LFE) relationships. Independent of reaction mechanism, the decrease in reaction rates with increasing ethanol content in the solvent is mainly due to hydrophobic stabilization of the ground state. While hydrophobic species can be hidden in the ethanol clusters present in the region XEtOH > 0.15, at lower ethanol contents hydrophobic reagents are weakly solvated and the hydrophobic stabilization can be easily overcome by sonication. Copyright © 2008 John Wiley & Sons, Ltd. |
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| Keywords: | ester hydrolysis hydrophobic interactions organic– aqueous solutions sonication effects solvolysis reactions |
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