Cox B.G. Acids and Bases: Solvent Effects on Acid-Base Strength

Oxford University Press, 2013. — 156 p. — ISBN: 978–0–19–967051–2.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. Solvent properties are reviewed, along with the magnitude of the interaction energies of solvent molecules with (especially) ions; the ability of solvents to participate in hydrogen bonding and to accept or donate electron pairs is seen to be crucial. Experimental methods for determining dissociation constants are described in detail.Acid–Base Equilibria: Quantitative Treatment
Solvation and Acid–Base Strength
Determination of Dissociation Constants
Protic Solvents
High-Basicity Polar Aprotic Solvents
Low-Basicity and Low-Polarity Aprotic Solvents
Acid–Base Equilibria and Salt Formation
Appendices. Dissociation Constants in Methanol and Aprotic Solvents