Figure 2.

Linear free energy relationships between calculated logarithmic rate constants (logk¹ and logk²) and experimental pK_as of leaving groups (top) and between calculated logarithmic equilibrium constants (logK_eq) and experimental pK s of leaving 1 a groups (bottom). k and k² are calculated rate constants for early and late transition states (TS1 and TS2), respectively. Rate constants are obtained from density-functional calculations with PCM solvation model and UFF (left) and UAKS (right) radii. Red down triangle, blue up triangle, yellow square, purple round and green diamond symbols correspond to alkyl, hetero-alkyl, thio, phenyl and acid leaving groups, respectively. Filled and empty symbols stand for TS1 and TS2, respectively. Regression parameters for logk¹, logk² and logK_eq are given as well as linear correlation coefficient for r.