Figure : Mechanisms in the hydrolysis of formamide investigated in . (a) Stepwise, one water molecule; (b) Stepwise, two-water catalyzed; (c) Concerted, two-water catalyzed was larger than the difference between using geometries optimized in the liquid-phase, rather than geometries optimized in the gas phase and then modeled with PCM . This study further confirms the usefulness of PCM for deducing both kinetic solvent effects and likely mechanistic pathways; however, care should be taken with the level of theory for quantum chemistry calculations. The O-neophyl rearrangement of two 1,1-diphenylethoxyl radicals, one of which is illustrated in Figure , was investigated with laser flash photolysis in five solvents by Bietti and Salamone . For both radicals, the rate constant decreased with increasing solvent polarity. A linear correlation was found between the logarithm of the rearrangement rate constant and the Dimroth-Reichardt parameter E N T . Because E N T represents the solvent anion's solvating ability, the trend was explained in terms of the "decrease in the extent of negative charge on the oxygen atom on going from the starting radical to the transition state." This experimental study provides another example of solvent effect being deduced from a single solvent parameter.