ISSN:
0894-3230
Keywords:
Organic Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
[2.1.1] Cryptated lithium salts of a wide range of CH-acids were studied spectrophotometrically and conductimetrically in solvents of low polarity. Such salts exist in media of different dielectric constants in the form of cryptand-separated ion pairs which are identical in their spectral and conductance properties with common solvent-separated ion pairs. No formation of higher ionic clusters was observed for the studied ions at concentrations below 10-3 mol-1 even in the benzene. The relative equilibrium acidities in benzene, N-methylmorpholine and tetrahydrofuran for a number of CH-acids are reported. Solvent polarity does not influence the cryptate ion-pair acidity of the investigated compounds. The relative free ion acidities were calculated for some of the studied acids in different solvents by combination of the ion-pair acidity values with the conductimetric data on dissociation constants of the cryptate ion pairs. A linear relationship between the free ion acidity and the reciprocal of the dielectric constant was found. An extrapolation method is suggested for the calculation of gas-phase acidity from the data obtained in solution.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/poc.610070404
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