Structures of the nearest surroundings of the K+, Rb+, and Cs+ ions in aqueous solutions of their salts

Abstract

Published data on structural characteristics of hydration of K + , Rb + , and Cs + ions in aqueous solutions of their salts under standard conditions, including authors’ X-ray diffraction data, are summarized and correlated. The structural parameters of the nearest surrounding of the K + , Rb + , and Cs + ions, such as the coordination numbers, interparticle distances, and types of ionic association, are discussed. It is noted that, because of weak tendency of these cations to hydration, the parameters of their coordination spheres strongly depend on the concentration and chemical nature of counterions.