Phosphorus–nitrogen compounds. Part XIX. The 1H nuclear magnetic resonance spectra of some geminal ethoxycyclotriphosphazatrienes: virtual coupling with two and three phosphorus atoms

Abstract

The ¹H n.m.r. spectra of 2,2-diethoxy-4,4,6,6-tetraphenyl-, 2,2,4,4-tetraethoxy-6,6-diphenyl-, and hexaethoxycyclotriphosphazatriene have been measured at 60 and 100 Mc./sec. The methylene-proton signals of these compounds on decoupling of the methyl protons provide evidence for virtual long-range coupling with the remote phosphorus nuclei, and hence strong phosphorus–phosphorus spin–spin coupling between chemically equivalent phosphorus nuclei, in these systems. The first example of virtual coupling to three phosphorus nuclei is reported.