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Protonierung von Amino‐ und Hydroxypyrimidinen NMR‐Spektren und Strukturen der Mono‐ und Dikationen
Author(s) -
Wagner R.,
Von Philipsborn W.
Publication year - 1970
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19700530210
Subject(s) - protonation , chemistry , proton , chemical shift , proton nmr , coupling constant , stereochemistry , crystallography , computational chemistry , ion , organic chemistry , physics , particle physics , quantum mechanics
Proton‐NMR. spectra of amino‐ and hydroxypyrimidines including biologically important bases have been measured in four solvents: CF 3 COOH, CF 3 COOHSO 2 , FSO 3 H and FSO 3 HSbF 5 –SO 2 at 27° and −55°C. In CF 3 COOH mono‐cations are formed, whereas in FSO 3 H and FSO 3 HSbF 5 –SO 2 double protonation occurs. In each case the structures of the protonated species are derived from the chemical shifts of CH, NH and OH protons and proton‐proton spin coupling constants. A combination of the measurements described leads to a complete assignment of all proton resonances of the protonated pyrimidines. This approach is also recommended for the structural determination of heterocyclic compounds.