(A) Gas-phase free energy
profile for the hydroxylation of toluene
by 2 at the UB3LYP/6-31G*, LANL2DZ (Fe) level of theory.
Violet and black colors represent energy profiles at S = 3/2 and S = 1/2 spin states, respectively. All
of the values are in kcal mol–1. (B) Electronic
energy profile for the rate-determining step of toluene hydroxylation
catalyzed by 2. All of the values correspond to gas-phase
data. Values outside and inside the parentheses correspond to the
ROM062X/6-31G*, LANL2DZ (Fe) and UB3LYP/6-31G*, LANL2DZ (Fe) levels
of theory, respectively. Black, green, and yellow colors represent
the energy profile with zero, one, and two explicitly added water
molecules, respectively. (i, ii, and iii) UB3LYP optimized transition
state structures for the hydrogen atom abstraction rate-determining
step (RDS) with zero, one, and two explicitly added water molecules,
respectively. Hydrogen atoms not involved in the reaction coordinate
are removed for clarity. All of the values are in kcal mol–1. All atom–atom distances are in Å.