Volumes of Activation for Dimethylsulfoxide and N,N‐Dimethylformamide Exchange with Hexasolvates of Aluminium (III) and Gallium (III) Ions in Deuterionitromethane Solution

High‐pressure 1H‐NMR. has been used to determine volumes of activation (ΔV#) for solvent exchange with [M(S)6]3+ ion (M = Al(III), Ga(III); S = dimethylsulfoxide (DMSO) and N,N‐dimethylformamide (DMF)) in [2H]3‐nitromethane solution. For Al(III),Δ V# = + 15.6 ± 1.4 (S = DMSO, 358.5 K) and ΔV# = + 13.7 ± 1.2 cm3mol−1 (S = DMF, 354.5 K), whilst for Ga(III), ΔV# = + 13.1 ± 1.0 (S = DMSO, 334.6 K) and ΔV# = +7.9 ± 1.6 cm3mol−1 (S= DMF, 313.8 K). Variable temperature studies over a temperature range of 107.2 K (Al(III)) and 101.1 K (Ga(III)) were carried out for solvent exchange with [M(DMF)6]3+ ions in [2H]3‐nitromethane solution, using stopped‐flow NMR, and conventional linebroadening, and gave ΔH# = 88.3 ± 0.9 and 85.1 ± 0.6 kJ+ mol−1, and ΔS# = 28.4 ± 2.7 and 45.1 ± 1.9 JK−1 mol−1 for Al(III) and Ga(III) ions respectively. All of these results are consistent with dissociative modes of activation.