Table 2.

Second-Order Rate Constants (k₂′) (normalized per reactive C−H bond) for the Reaction of Mn^IV(O-LA)(TBP₈Cz^•+) with H-Atom Donor Substrates (units (k₂′) = M⁻¹ s⁻¹)

Lewis acid (A.N.a)	xanthene	kLA/knone (xanthene)	DHAb	CHDc
none42,43	1.8 ± 0.2 × 10−3		1.8 ± 0.5 × 10−5	3.3 ± 0.1 × 10−5
TFA (40)	9 ± 1 × 10−4	0.5
Zn(OTf)2 (68)	8.1 ± 0.4 × 10−3	4
HBArF (102)	1.9 ± 0.2 × 10−2	10	6.7 ± 0.1 × 10−4	2.0 ± 0.1 × 10−4
B(C6F5)3 (82)	5.5 ± 0.3 × 10−2	28	4.3 ± 0.2 × 10−4	1.3 ± 0.8 × 10−4

^aA.N. = acceptor number.

^bDHA = 9,10-dihydroanthracene.

^cCHD = 1,4-cyclohexadiene.