Fig. 2. M06-2X/6-31+G(d,p):AM1/MM free energy profiles for covalent complex formation with SARS-CoV-2 Mpro and: N3 (red line); compound B1 (blue line); and compound B2 (green line). Panel (a) shows the formation of the ion pair E(+/−):I; and the full inhibition reaction is shown in panel (b). Energies are in kcal·mol−1.
