Abstract
The use of chemical probes for the characterization of chemical properties was explored for completely non-aqueous aprotic binary solvent mixtures. The Dimroth–Reichardt ET(30) betaine dye, 4-nitrophenol, 4-nitroanisole, 4-nitroaniline and N,N-diethyl-4-nitroaniline were used to study preferential solvation in binary mixtures of a polar aprotic hydrogen bond-acceptor solvent (DMSO, DMF, acetone, butanone and ethyl acetate) with acetonitrile or nitromethane at 25 °C over the whole range of solvent composition. The indicators were employed to determine ET(30), π*, α and β solvatochromic parameters of the mixtures. Each solvent system was analysed according to its deviation from ideal behaviour due to the preferential solvation of the indicators and also from the complicated intermolecular interactions of the mixed solvent. The validity of the concept of an intrinsic, absolute property of a solvent mixture and whether such a property can be defined by means of chemical probes is discussed. These results were related to the solvent effects on some aromatic nucleophilic substitution reactions. The kinetics of the reactions between 1-fluoro-2,4-dinitrobenzene and primary or secondary amines were studied in ethyl acetate– acetonitrile and N,N-dimethylformamide–acetonitrile mixtures, respectively, taken as representatives of two clearly different solvation models. Copyright © 1999 John Wiley & Sons, Ltd.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
