title: An 15N NMR study of the protonation of two di-(alpha-pyridyl) compounds in solutions and the solid state.
abstract: 15N NMR data are reported for two Di-(alpha-pyridyl) derivatives in various stages of protonation. A combination of 15N NMR measurements taken, on a number of solutions, and on the solid state provide a quantitative overall view of the progress of protonation of these compounds. 15N shieldings, J(15N-1H) and 2J (15N-1H) interactions all provide information indicative of unsymmetrical monoprotonation in the solid state and producing both the monoprotonated [N-H-N]+ structure and the diprotonated structure in the presence of an excess of TFA.
authors.affiliation: Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Klimkiewicz
authors.forename: L
authors.initials: L
authors.lastname: Stefaniak
authors.forename: E
authors.initials: E
authors.lastname: Grech
authors.forename: G A
authors.initials: GA
authors.lastname: Webb
authors.forename: I
authors.initials: I
authors.lastname: Wawer
mesh_terms: D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009587:Nitrogen Isotopes; D011522:Protons; D011725:Pyridines / Q000737:chemistry*; D011810:Quinoxalines / Q000737:chemistry*; D012996:Solutions
chemical_list: C104773:2,3-dipyridyl-6,7-dimethylquinoxaline; D009587:Nitrogen Isotopes; D011522:Protons; D011725:Pyridines; D011810:Quinoxalines; D012996:Solutions