Hydration number of aluminium(III) in dilute aqueous solution

Abstract

The chemical shifts of hydration and bulk water protons have been measured in concentrated aluminium chloride solutions between –11 and –40 °C. The bound water resonance is 2·36 p.p.m. low-field of the value assumed by Malinowski and Knapp on the basis of their dilute solution measurements. This result is used to recalculate the aluminium hydration number from their data and a value near 6 is found in agreement with n.m.r. area measurements.