Driving forces (ΔG) and kinetic barriers (ΔG*) for the two degradation paths of OTfdU: A (leading to the C–O bond break and dU product) and B (leading to the O–S bond break and OHdU product), calculated at the M06-2X, B3LYP, ωB97XD and MP2 level. All values are given in kcal mol⁻¹.

		M06-2X	B3LYP	ωB97XD	MP2
Path A (C–O bond break)		8.6	5.2	7.0	5.8
	ΔGAN→COM	−17.6	−24.1a	−20.3	−22.2
	ΔGCOM→ISOL	−4.3	−6.3	−4.3	−2.3
Path B (O–S bond break)		1.5	BFb	0.4	0.2
	ΔGAN→COM	−51.4	−62.7a	−55.3	−48.5
	ΔGCOM→ISOL	−2.7	−5.3	−3.1	0.0

^aDue to the barier-free O–S bond break, the value calculated relative to OTfdU˙⁻ anion radical with the freezed O–S bond.

^bBarrier-free O–S bond break.