Phosphorus-nitrogen compounds: Part 15. Synthesis, anisochronism and the relationship between crystallographic and spectral data of monotopic spiro-crypta phosphazenes

The reactions of hexachlorocyclotriphosphazatriene, N3P3Cl6, with N2O2-donor type coronands, Ph2[OR1O][CH2NHR2NHCH2] [R1 = (CH2)3, R2 = (CH2)3 (1), R1 = (CH2)3, R2 = (CH2)4 (2), R1 = (CH2)4, R2 = (CH2)4 (3)], give monotopic spiro-crypta phosphazene architectures, N3P3Cl4{Ph2 [OR1O][CH2NR2NCH2]} [R1 = (CH2)3, R2 = (CH2)3 (4), R1 = (CH2)3, R2 = (CH2)4 (5) and R1 = (CH2)4, R2 = (CH2)4 (6)], respectively. The reaction of 4 with excess pyrrolidine leads to the formation of geminal N3P3Cl2(C5H5N)2{Ph2[O(CH2)3O] [CH2N(CH2)3NCH2]} (7). The 31P-NMR spectra of 5 and 6 indicate that these compounds have anisochronism. The structures of 5, 6 and 7 were investigated by X-ray crystallography. For 7, the sums of the bond angles around the N atoms were 348.6(2)° and 349.7(2)° indicating that the N atoms have pyramidal configurations and are stereogenic. The relationship between the chemical shift values δP(spiro) and the Δ(P-N) (electron density transfer parameters) of 4, 5, 6, 7 and the analogous compounds as well as the relationship between the Δ(δP) values and the above mentioned Δ(P-N) are presented respectively. In addition, the relationship between the endocyclic NPN bond angles of these compounds and the 31P-NMR chemical shifts of the spiro-phosphorus atoms were investigated. The spectroscopic and structural investigations of the compounds were made by elemental analyses, MS, FTIR, one-dimensional 1H-, 13C-, 31P-NMR, DEPT and two-dimensional COSY, HETCOR, HMBC, homo-and heteronuclear correlation techniques.