Solvent Effects and Molecular Clusters : Especially in Aqueous Organic Solvents

Abstract

Ethanol, acetonitrile, acetone etc. are miscible with water at any mixing ratio; however, the mixtures are not homogeneous in view of the molecular level owing to the hydrogen-bonding interaction between water molecules and the hydrophobic interaction between water and organic solvent molecules. Through these interactions, molecular clusters are easy to be formed in the aqueous organic solvents. The clustering structure of the aqueous organic solvents influences the microscopic environment of substrates in these solvents and controls various chemical reactions such as the hydrolysis of tert-butyl chloride (S_N1 reaction).
This review will focus on the solvent effects studied in terms of the molecular clusters which reflect the microscopic environment around the substrates. Furthermore, it will be described that the fluctuation of solvent molecules in the solvation cluster is another important factor to trigger a chemical reaction.