Figure 5.

(a) ¹H NMR spectra of 10 (in D₂O) recorded at solution pH levels 10.0, 5.3, and 2.0 with signal attribution as indicated in the structure; (b) Titration curves obtained from signals b (□) and c,c’ (■, ●) (see signal attribution) with a fit, and the values of pK_a for pyridine and amidine functions; (c) Kinetics of homolysis of alkoxyamine 10 (0.02 M solution) at 368 K as determined by ¹H NMR in the presence of 40 eq. of ascorbic acid or ascorbate at different pH levels. Adapted with permission from Ref. [30]. Copyright 2011 American Chemical Society.