Hyperfine coupling, phenoxyl radical

Since the phenoxyls possess an S = ground state, they have been carefully studied by electron paramagnetic spectroscopy (EPR) and related techniques such as electron nuclear double resonance (ENDOR), and electron spin-echo envelope modulation (ESEEM). These powerful and very sensitive techniques are ideally suited to study the occurrence of tyrosyl radicals in a protein matrix (1, 27-30). Careful analysis of the experimental data (hyperfine coupling constants) provides experimental spin densities at a high level of precision and, in addition, the positions of these tyrosyls relative to other neighboring groups in the protein matrix. [Pg.155]

Experimental(40) and calculated(29) isotropic hyperfine coupling constants and calculated spin densities for phenoxyl radical. Calculations were done using the B3LYP/6-3 lG(d) method. [Pg.665]

TABLE 33. Hyperfine coupling constants (G) of phenoxyl radical and phenol radical cation"... [Pg.114]