Fig. 2. (A) Optimized structure of transition structure TSia, associated with the isomerisation of imine 2a (M06-2X(PCM)/def2-TZVPP level of theory). Relative Gibbs energies, in kcal mol−1, computed at 195.15 K (A-conditions, see Scheme 3) are also given. Bond distances and angles are in Å and deg., respectively. Numbers in parentheses correspond to the calculated bond orders. (B) Several polar resonance forms corresponding to TSia emphasizing its aza-allenyl structure.
