Amines α et β acétyléniques. Couplages J(15N?H), J(15N?13C) et hybridation de l'azote

¹H and ¹³C NMR spectra of ¹⁵N-methylaniline, ¹⁵N-methylphenylpropargylamine and ¹⁵N-methylphenylpropynylamine have been studied. The s character of nitrogen, deduced from ¹J(¹⁵N? ¹³C) and ¹J(¹⁵N? ¹³C), indicates that nitrogen hybridisation is intermediate between sp³ and sp² in ¹⁵N-methylaniline and ¹⁵N-methylphenylpropargylamine, while nitrogen is sp² in the α-acetylenic amine. The ¹J(¹⁵N? ¹³C_sp)cou pling constant calculated with the help of Binsch's relation does not agree with the experimental value, suggesting that orbital and dipolar mechanisms make substantial contributions to this coupling constant.