Phosphorus–nitrogen compounds. Part 59. Aromatic carbon‐13 NMR spectra of phenyl‐substituted cyclotriphosphazatrienes. Second‐order effects with phosphorus‐31 nuclei

Abstract

AbstractThe 13C NMR spectra were obtained for the geminal series N3P3Cl6−nPhn (n = 2, 4, 6) and for the mono spiro series N3P3Ph2[X(CH2)n Y]Cl2 (X = Y = O, n = 2, 3, 4; X = Y = NH, n = 2, 3, 4; X = Y = NMe, n = 2, 3; X = O, Y = NH, n = 3, 4; X = NH, Y = NMe, n = 2, 3; X = O, Y = NMe, n = 2). Multiplet structures were observed in the 13C NMR spectra of N3P3Ph2[HN(CH2)3NH]Cl2 at 0°C. The complexity of these resonances could be altered by a change in temperature. These observations have been rationalized in terms of second‐order interactions with remote phosphorus nuclei, which can be systematically altered with temperature. Inductive and resonance substituent coefficients have been calculated using the dual substituent parameter method from the relative shelding of the meta (C‐3) and para (C‐4) nuclei in the phenyl ring.