N-15-LABELED CYCLOTRIPHOSPHAZATRIENES (N-15PR2)3 AS EXAMPLES FOR A SIMPLIFIED AA'A''XX'X'' SPIN SYSTEM

Hexasubstituted 15N-labeled cyclotriphosphazatrienes are examples of an AA′A″XX′X″spin system which can be evaluated by using simple procedures. Since the coupling constants 2JNN and 3JPN are very small and therefore can be neglected in the evaluation of the spectra, the shape of the 31P spectrum as well as that of the 15N spectrum depends only on the ratio of the two coupling constants 1JPN and 2JPN. 1JPP is directly taken from the spectra, whereas 2Jpp can be graphically determined through a series of simulated model spectra. This procedure is demonstrated by examples of hexahalocyclotriphosphazatrienes (RF, Cl, Br) and hexaethylthiocyclotriphosphazatriene (R = SEt). © 1979.