| Abstract: | Proton magnetic resonance chemical shifts and coupling constants for a series of 2-substituted-5-nitropyridines and 2-substituted-3-nitropyridines, both in the free base and protonated forms, are reported. The substituents were chloro, bromo, iodo, and hydroxyl. The effect of the substituents on the chemical shifts are substantial but not unusual. The coupling constants are less sensitive to the nature of the substituent and are perturbed only slightly when the ring nitrogen is protonated. This latter observation is consistent with the results of LCAO-MO calculations. |
