Jump to ContentJump to Main Navigation
Acids and BasesSolvent Effects on Acid-Base Strength$
Users without a subscription are not able to see the full content.

Brian G. Cox

Print publication date: 2013

Print ISBN-13: 9780199670512

Published to Oxford Scholarship Online: May 2013

DOI: 10.1093/acprof:oso/9780199670512.001.0001

Show Summary Details
Page of

PRINTED FROM OXFORD SCHOLARSHIP ONLINE (oxford.universitypressscholarship.com). (c) Copyright Oxford University Press, 2021. All Rights Reserved. An individual user may print out a PDF of a single chapter of a monograph in OSO for personal use. date: 09 March 2021

Low-Basicity and Low-Polarity Aprotic Solvents

Low-Basicity and Low-Polarity Aprotic Solvents

(p.99) 7 Low-Basicity and Low-Polarity Aprotic Solvents
Acids and Bases

Brian G. Cox

Oxford University Press

Low-basicity and low-polarity aprotic solvents, including importantly acetonitrile and tetrahydrofuran, are poor at solvating both anions and cations. Dissociation constants are consequently very low, especially for neutral acids, typically 10–12 orders of magnitude lower than in basic aprotic solvents, such as dimethylsulphoxide, and up to 18 log units lower compared with water. Homohydrogen-bond formation involving carboxylic acids, phenols, and amines, and intramolecular hydrogen bonding in mono-anions of suitable dicarboxylic acids, is extensive. Ion-pair formation is modest except in the low-dielectric solvent tetrahydrofuran. In tetrahydrofuran, acid–base equilibria are dominated by ion association formation, even at concentrations as low as 10‐5 M. In consequence, ion-pair acidity scales, based on solvent-separated lithium ion-pairs or contact caesium ion-pairs have been developed. For carbon acids, the ion-pair acidities correlate well with absolute pKa-values in dimethylsulphoxide.

Keywords:   acetonitrile, tetrahydrofuran, propylene carbonate, acetone, carboxylic acids, phenols, amines, carbon acids, ion-association, hydrogen-bonding, ion-pair acidity

Oxford Scholarship Online requires a subscription or purchase to access the full text of books within the service. Public users can however freely search the site and view the abstracts and keywords for each book and chapter.

Please, subscribe or login to access full text content.

If you think you should have access to this title, please contact your librarian.

To troubleshoot, please check our FAQs , and if you can't find the answer there, please contact us .