The unexpectedly low sensitivity of the nitrogen NMR shieldings of covalent azides to solvent effects

[摘要] The nitrogen shieldings of covalent azides are shown to be essentially independent of molecular interactions in solutions of a large variety of solvents. They present a rare case where substituent effects, exerted by an aryl or alkyl group attached to the azide, clearly swpass the range of solvent induced effects on the nitrogen shieldings. This occurs in spite of the large net change splitting in the electronic structure of the azide group and the presence of lone pair electrons on this group. The observed induced range of solvent effects does not exceed 2 ppm in most cases which is similar to that previously observed for dinitrogen (N2) and an azo bridged structure.

[学科分类] 光谱学