DFT calculations were also undertaken on the mechanism of the reaction of CH3CN with 1b. The computed pathway supports a stepwise double deprotonation of CH3CN by 1b (Figure ). Initial, endergonic (ΔG = 6.5 kcal mol -1 ) coordination of CH3CN to one molecule of 1b yields an unstable intermediate INT-1. INT-1 can undergo an intramolecular deprotonation through TS-1. In this transition state the substrate adopts a bent conformation. TS-1 leads directly to an Al ketene imide complex 3b