Proton chemical shift of the aqua-aluminium ion Al(H2O) 3+6

Abstract

The variation of the proton chemical shift of the aqua-aluminium complex Al(H₂O)³⁺₆ has been measured for solutions of Al(ClO₄)₃ in a series of acetone + water mixtures of different compositions from –80 to +32 °C. The variation of chemical shift with temperature depends strongly upon the acetone/water ratio and appears to be small in pure water. Evidence is obtained for ion pairing in the second sphere in the acetone-rich solutions and this is believed to account for the temperature effects observed.