Figure 5.

EPR spectral simulations of transient and persistent radicals in the reaction of l-4-thialysine.

The upper spectrum is of the transient radical (—) and the simulation (- - -). Parameters used in the calculated spectrum: Co²⁺ g-tensor, 2.32, 2.22, 2.00; radical g-tensor, 2.009, 2.003, 2.002; ZFS parameters, D = −75 G, E = 0 G; exchange coupling constant, J = 4 × 10³ G; ⁵⁹Co-hyperfine tensor (G), 10, 7, 112; isotropic ¹⁴N-hyperfine splitting, 19 G. Euler angles relating the interspin vector to the Co²⁺ g-axis: ζ = 43°, η = 0°, and ξ = 78°. A uniform line width of 6 G was used in the calculation. The lower spectrum is of the persistent radical (—) and the simulation (- - -). Parameters used in the calculated spectrum: Co²⁺ g-tensor, 2.32, 2.20, 2.00; radical g-tensor, 2.009, 2.004, 2.002; ZFS parameters, D = −20 G, E = 0 G; exchange coupling constant, J = 525 G; ⁵⁹Co-hyperfine tensor (G), 10, 7, 112; isotropic ¹⁴N-hyperfine splitting, 19 G. Euler angles relating the interspin vector to the Co²⁺ g-axis: ζ = 60°, η = 0°, and ξ = 35°. A uniform line width of 8 G was used in the calculation. In these spectra, g =2.0 corresponds to 3261 G.