Étude De La Liaison Hydrogène Dans Les Complexes Amine‐Alcool Par Résonance Magnétique Nucléaire II. Complexes Entre Les Diéthylamine et Triéthylamine et les Butanols Normal et Secondaire

We have studied the proton magnetic resonance of solutions of butanol N and diethylamine, butanol N and triethylamine and butanol 2 and triethylamine, and their dilutions in benzene. The own shift of the bonded proton in the complex R3N…HOR lies at about 0,5 p.p.m. from the H2O peak. The dependance of the OH shift on the amine and alcohol concentrations indicates that an association of the amine with the polymolecules of alcohol also occurs. Both the protons of the amino-group of the diethylamine and the hydroxylic group of the alcohol show a common peak, due to a rapid exchange between the two protons. One can deduct from the conductivity data that the passage to the ionic form R2 NH+2 is too slow to explain the rapidity of this exchange; one concludes that an important part of the exchange takes place directly in the complex by mean of a double non linear hydrogen bond of the type: The own shift of these protons lying at about 1,75 p.p.m. is intermediate between that of the primary amine complex and that of the tertiary amine complex. This position fit well with the hypothesis of double hydrogen bonds.