A PROTON MAGNETIC RESONANCE SOLVATION STUDY OF ALUMINUM PERCHLORATE IN AQUEOUS MIXTURES OF DIMETHYL SULFOXIDE DIMETHYL SULFONE DIMETHYL SULFATE TETRAMETHYLENE SULFOXIDE TETRAMETHYLENE SULFONE ACETONE AND TETRAHYDROFURAN

A proton magnetic resonance solvation study of Al(III) in aqueous mixtures of dimethyl sulfoxide (DMSO), dimethyl sulfope (DMSO2), dimethyl sulfate (DMS4), tetramethylene sulfoxide (TMSO), tetramethylene sulfone (TMSO2), acetone, and tetrahydrofuran (THF) has been completed. At low temperatures, proton exchange is slowed to such an extent in these systems that separate resonance signals are observed for bulk water and water molecules in the Al(III) solvation shell. Coordination numbers were measured by direct integration of the two water signals. Of the five sulfur-containing solvents, only DMSO and TMSO can effectively compete with water for Al(III), the remaining three being very inactive in this regard. This conclusion was reached by the observation and integration of separate resonance signals for bulk and complexed molecules of the sulfoxides. These results indicate a correlation of solvating ability with the basicity of the solvents in this series. Although acetone and THF also are inactive when there is enough water to saturate the Al(III) solvation shell, at low water concentration they can solvate this ion. Spectra of aqueous solutions of AICCICDs in acetone, THF, and acetone- THF revealed separate resonance signals for bulk and complexed molecules of the nonaqueous components. These spectra also revealed evidence for contact ion pairing and possibly a steric hindrance to solvation. © 1969, American Chemical Society. All rights reserved.