(A) EPR spectrum observed during 1min irradiation of RB (20 μM), TBBPA (1 mM), and DMPO (100 mM) in phosphate buffer (pH 7). The spectrum contains a triplet 2,6-dibromo-p-semiquinone radical (x, a2H = 2.4 G, 38%) and a contribution from DMPO/.OH (*, aN = 15.0 G, aH = 14.4 G, 19%). The DMPO adduct of an unknown carbon-centered radical is marked with an open circle (○, aN = 16.0 G, aH = 22.9 G, 43%). (B) Computer simulated spectrum of A.
(A) EPR spectrum observed during 1min irradiation of RB (20 μM), TBBPA (1 mM), and DMPO (100 mM) in phosphate buffer (pH 7). The spectrum contains a triplet 2,6-dibromo-p-semiquinone radical (x, a2H = 2.4 G, 27%) and a contribution from DMPO/.OH (*, aN = 15.0 G, aH = 14.4 G, 15%). The DMPO adduct of an unknown carbon-centered radical is marked with an open circle (○, aN = 15.9 G, aH = 22.9 G, 58%). (B) Computer simulated spectrum of A).