Acids and bases : solvent effects on acid-base strength / Brian G. Cox.

Format:

Book

Author/Creator:

Cox, Brian G.

Contributor:

George R. Fink Memorial Fund.

Language:

English

Subjects (All):

Acids.

Bases (Chemistry).

Solvents.

Physical Description:

xii, 143 pages : illustrations ; 25 cm

Edition:

First edition.

Place of Publication:

Oxford : Oxford University Press, 2013.

Summary:

Acids and bases are ubiquitous in chemistry. Our understanding of them, however, is dominated by their behaviour in water. Transfer to non-aqueous solvents leads to profound changes in acid-base strengths and to the rates and equilibria of many processes: for example, synthetic reactions involving acids, bases and nucleophiles; isolation of pharmaceutical actives through salt formation; formation of zwitter- ions in amino acids; and chromatographic separation of substrates. This book seeks to enhance our understanding of acids and bases by reviewing and analysing their behaviour in non-aqueous solvents. The behaviour is related where possible to that in water, but correlations and contrasts between solvents are also presented. Fundamental background material is provided in the initial chapters: quantitative aspects of acid-base equilibria, including definitions and relationships between solution pH and species distribution; the influence of molecular structure on acid strengths; and acidity in aqueous solution.

Contents:

Machine generated contents note: 1.Introduction

1.1.Why are non-aqueous solvents important?

1.1.1.Range of accessible pH-values

1.1.2.Reactivity of acids and bases

1.1.3.Ionizable compounds and high-performance liquid chromatography (HPLC)

1.2.Classification of solvents and their properties

1.2.1.Electron donor-acceptor properties of solvents

References

2.Acid-Base Equilibria: Quantitative Treatment

2.1.Definitions

2.2.pH and acid-base ratios

2.3.pH-dependence of species distribution

2.4.Acid strengths and molecular structure: dissociation constants in water

2.4.1.The strength of the X-H bond

2.4.2.Charge dispersion on anions, A-, or cations, BH+

2.4.3.The nature of X in R-X-H

2.5.Carbon acids

2.6.Acid-base equilibria

Appendix 2.1 Species distribution in acid-base systems

3.Solvation and Acid-Base Strength

3.1.Solvation and acid dissociation constants: free energies of transfer

Contents note continued: 3.1.1.Solvent-transfer activity coefficients

3.2.Determination of free energies of transfer

3.2.1.Non-electrolytes

3.2.2.Electrolytes

3.3.Free energies of ion solvation

3.3.1.Hydration of ions

3.3.2.Solvation in pure solvents

3.3.3.Solvation in mixed solvents

3.4.Solvation of non-electrolytes

3.5.Solvation energies and solvent properties

3.6.Solvation and acid strength

3.7.Summary

Appendix 3.1 Composition of mixed solvents

4.Determination of Dissociation Constants

4.1.pH-scales

4.1.1.pH in aqueous media

4.1.2.pH in non-aqueous media

4.2.Influence of solution concentration: activity coefficients

4.3.Ion association

4.4.Homohydrogen-bond formation

4.5.Experimental methods for the determination of dissociation constants

4.5.1.Potentiometric titration using a glass electrode

4.5.2.Acid-base indicators

4.6.Autoionization constants of solvents

Contents note continued: Appendix 4.1 Dissociation of acetic acid in the presence of sodium chloride

Appendix 4.2 Ion-pair formation and pKa-determination

Appendix 4.3 Determination of homohydrogen-bond association constants, KAHA

5.Protic Solvents

5.1.Autoionization constants

5.2.Methanol

5.2.1.Neutral acids: carboxylic acids, phenols

5.2.2.Cationic acids: protonated anilines, amines, N-heterocycles

5.2.3.Summary

5.3.Higher alcohols

5.4.Alcohol-water mixtures

5.5.Salt formation in alcohols and aqueous-alcohol mixtures

5.6.Formamide, acetamide, N-methylpropionamide

5.7.Formic acid

6.High-Basicity Polar Aprotic Solvents

6.1.Dimethylsulphoxide

6.1.1.Neutral acids: carboxylic acids, phenols and thiophenols, water and methanol, anilines and amides, carbon acids

6.1.2.Cationic acids (neutral bases)

6.1.3.Amino acids

6.2.N-methylpyrrolidin-2-one, N, N-dimethylformamide, N, N-dimethylacetamide

Contents note continued: 6.2.1.Neutral acids

6.2.2.Cationic acids (neutral bases)

6.3.Liquid ammonia

6.4.Summary

6.5.Estimation of dissociation constants in basic aprotic solvents

7.Low-Basicity and Low-Polarity Aprotic Solvents

7.1.Acetonitrile

7.1.1.Neutral acids: carboxylic acids and phenols, carbon acids

7.1.2.Cationic acids (neutral bases)

7.2.Propylene carbonate, sulpholane, acetone, methyl iso-butyl ketone, nitrobenzene

7.3.Tetrahydrofuran

8.Acid-Base Equilibria and Salt Formation

8.1.Charge-neutral equilibria

8.2.Charge-forming equilibria

8.2.1.Alcohols and mixed-aqueous solvents

8.2.2.Polar aprotic solvents

8.2.3.Non-polar aprotic solvents

9.Appendices: Dissociation Constants in Methanol and Aprotic Solvents

9.1.Methanol

9.1.1.Carboxylic acids and phenols

9.1.2.Protonated nitrogen bases

9.2.Dimethylsulphoxide

9.2.1.Carboxylic acids, alcohols, phenols

Contents note continued: 9.2.2.Inorganic acids and miscellaneous

9.2.3.Anilines, anilides, amides (N-H-ionization)

9.2.4.Carbon acids: ketones, esters, nitroalkanes

9.2.5.Carbon acids: nitriles, sulphones

9.2.6.Carbon acids: fluorenes

9.2.7.Cationic acids: anilinium, ammonium, pyridinium ions

9.3.N, N-Dimethylformamide

9.3.1.Neutral acids

9.3.2.Cationic acids

9.4.Acetonitrile

9.4.1.Neutral acids

9.4.2.Inorganic acids and miscellaneous

9.4.3.Cationic acids: ammonium, anilinium, pyridinium ions

9.4.4.Phosphazene bases

9.5.Tetrahydrofuran

9.5.1.Neutral acids

9.5.2.Cationic acids.

Notes:

Includes bibliographical references and index.

Local Notes:

Acquired for the Penn Libraries with assistance from the George R. Fink Memorial Fund.

ISBN:

9780199670512

019967051X

9780199670529

0199670528

OCLC:

835079607

Publisher Number:

99953841215