Über Phosphazene XXXV, 31P-NMR-Untersuchungen VIII

Abstract

All accessible NMR shifts δ31P of phosphorus surrounded by four nitrogen atoms are compiled systematically. They cover the relatively wide range from -40 to +50 ppm. All shift differences observed correlate well with changes in nitrogen hybridization: in the order p3 → sp3 → sp2 → sp for nitrogen δ31P (N4) is shifted to a higher field. In particular, δ31P (N4) is a linear function of the degree of substitution, when phosphazeno groups are substituted by amino groups in open chain or cyclic systems. This is also true of δ31P (04) in alkoxy or phenoxy/phosphoroxy substitution series