Answers are grounded in this paper and cite their sources.
1 H, 13C, 14N, and 15N NMR data are presented for two amidine derivatives and their complexes with TFA in 1:1 and 1∶2 molar ratios. The protonation site at the N5 atom was established based upon the observed coupling constants, NOE interactions, and chemical shift change. The GIAO-CHF calculations were also performed for the free bases and their N5 cations.
No takes yet. Share an insight, caveat, or question.
Wiench et al. (1999) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: