13C-NMR-Sequenzanalyse, 4. Lösungsmitteleinflüsse auf die Chemische Verschiebung bei Polyamiden und niedermolekularen Carbonsäurederivaten

The ¹³C-chemical shift for the carbonyl carbon in polyamides, ω-aminocarboxylic acids, and N-substituted carboxylic amides is studied at different acid concentrations (D₂SO₄, CF₃COOD, D₂O). It is found, that the spectroscopic behaviour of polyamides resembles more to ω-aminoacids than to monomeric amides. The rule of the observed chemical shift and the resulting consequences for the sequence determination in polyamides are discussed.