Da. Shultz et al., SYNTHESIS AND CHARACTERIZATION OF PHENYLNITROXIDE-SUBSTITUTED ZINC(II) PORPHYRINS, Journal of organic chemistry, 63(3), 1998, pp. 769-774
The syntheses and fluid-solution EPR spectra of nitroxide-substituted
porphyrins 1-3 are described. The phenylnitroxide is attached to the m
eso-position of three porphyrins: (a) directly through a single bond (
1); (b) through an ethenyl group (2); and (c) through an ethynyl group
(3). The spin distribution in each of the three radicals is discussed
and compared to model compounds 4-9. It is suggested that delocalizati
on increases in the order 2, 1, 3.