PMR study of ligand exchange rates in aluminium perchlorate solutions in methanol and ethanol

Abstract

The kinetics of exchange of the whole molecule between solvation sphere of Al³⁺ and bulk at Al(ClO₄)₃ in CH₃0D, CH₃CD₂0D and CD₃CH₂0D has been studied by means of line-shape analysis of PMR spectra of methyl and methylene groups. The activation enthalpy Δ H^≠ of 65 kJ/mol for methanol and 52 kJ/mol for ethanol were found. The exchange at 25°C is about 70 times faster for ethanol than for methanol.