We have also evaluated the bond dissociation energy of the O–H bond in NHPI (88.1 kcal mol −1 ) and the absolute rate constants for hydrogen abstraction from NHPI by the peroxyl radical (7.4 × 10 3 M −1 s −1 at rt, the rate being much higher with alkoxy radical for obvious enthalpic reasons) and from the benzylic C–H bond of cumene by the PINO radical (6.1 M −1 s −1 at rt). 4–6 The PINO radical is much more reactive than the TEMPO radical in hydrogen ...
