. Author manuscript; available in PMC: 2010 Aug 7.

Published in final edited form as: J Org Chem. 2009 Aug 7;74(15):5369–5380. doi: 10.1021/jo900856x

Table 2.

EPR parameters for the hydroxyl and superoxide radical anion adducts of 4a and 4b in DMSO.

Hydroxyl Adducts (in PBS)

Adducts	g	a_n (G)	a_β-H (G)	Relaxation Coefficients^a
Adducts	g	a_n (G)	a_β-H (G)	α	β	γ
4a-OH^a	2.0054	13.8	12.7	1.82	0.41	0.46
4b-OH	2.0053	13.8	12.5	1.77	0.38	0.38

Superoxide Adducts (in DMSO)^b
	axis	g	a_n(G)	a_β-H (G)	Correlation time (ns)

4a-OO⁻	x	2.0089	2	12	1.74 (4a)
or	y	2.0085	3	10
4b-OO⁻	z	1.992	31	11	1.61 (4b)

$Γ = α + β M_{I} + γ M_{I}^{2}$ , where Γ is the linewidth, α, β, and γ are relaxation coefficients and M_I is the z component secondary quantum number for the nuclear-spin angular momentum for N atom (M_I= 1).

The anisotropic g’s, hfsc’s and correlation times were calculated as follows: From the isotropic signal, the line width variation was interpreted via a relaxation model assuming a rhombic g- and hyperfine tensors, where the anisotropy was partially averaged out by the isotropic rotational tumbling. The spectrum fit was optimized for both the anisotropic tensor elements and the correlation time.