Phosphorus-nitrogen compounds: part 16. Synthesis, stereogenism, anisochronism and the relationship between P-31 NMR spectral and crystallographic data of monotopic spiro-crypta phosphazene derivatives

The condensation reactions of N2O3-donor type coronands (1-3) with hexachlorocyclotriphosphazatriene, N3P3Cl6, resulted in the formation of spiro-crypta phosphazene derivatives (4-6). These compounds with excess morpholine and 1,4-dioxa-8-azaspiro[4,5]decane (DASD) afford fully substituted morpholino (7 and 10) and 1,4-dioxa-8-azaspiro[4,5]deca (8)-substituted phosphazene derivatives, respectively. Whilst, in the same conditions, the reactions of 4, 5 and 6 with pyrrolidine, morpholine and DASD also produce partially pyrrolidino-substituted geminal (9 and 11), mono-substituted pyrrolidino (12), morpholino (13) and 1,4-dioxa-8-azaspiro[4,5]deca (14) phosphazenes. It has been clearly observed that the chloride replacement reactions of 4, 5 and 6 with pyrrolidine lead to the geminal products. Compounds 7, 8 and 10 are the first examples of anisochronic tetrakis (amino) phosphazenes according to P-31 NMR data. The structures of 7, 8 and 10-14 have been determined by FTIR, MS, H-1, C-13 and P-31 NMR, DEPT, and HETCOR spectral data. The solid-state structures of 9, 13 and 14 have been examined by X-ray diffraction techniques. The sums of the bond angles around the spiro cyclic nitrogen atoms [344.8(4)A degrees and 347.6(4)A degrees] of 9, indicate that the nitrogen atoms have pyramidal geometries. Thus, the N atoms seem to have stereogenic configurations. Compounds 12-14 also have two stereogenic P-atoms, and they are expected to be in the mixture of enantiomers. The relationships between NPN (alpha and alpha') bond angles and delta P-spiro values and the correlation of Delta(P-N) with delta P-spiro and Delta(delta P) values are presented.