SEARCH Articles Figures Tables 2- pyridine, photoinduced proton transfer 2.3- Dimethyl pyridine, protonated Protonation of pyridine Pyridine ring protonization Pyridine ring protonization temperature Pyridine, protonation Pyridine, protonation Pyridines proton abstraction Pyridines proton exchange Pyridines protonation shifts Pyridines protonation, regioselectivity Pyridines protonic salts