engleski

Concentrational Dependence of the Imino Proton (H-a) in 1H NMR Spectra of Protonated Model Imines

Imine protonation is a very important process that is taking place in the nature (visual cycle, proton pumping etc.) Two model compounds (trans-N-benzylideneaniline, tBA, and trans-N-salicylideneaniline, SAN) were chosen in order to study the protonated form of imines. Trifluoroacetic acid (CF3COOH) was used as protonation agent. Two series of unprotonated and protonated tBA, as well as SAN samples, were prepared (each series was consisted of 10 samples with different concentration). The linear dependence of imino proton chemical shift on concentration of protonated species was observed. There are no concentrational dependence of H-a chemical shift in unprotonated species. The observed concentrational dependence indicate some kind of aggregation in protonated species of chosen model imines.

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nije evidentirano