Phosphorus–nitrogen compounds: novel spiro-crypta-phosphazenes. Structure of {pentane-3-oxa-N,N0-bis(1,5-oxybenzyl)-spiro (propane-10,30-diamino)-4,4,6,6-tetrachlorocyclo- 2l5,4l5,6l5-triphosphazatriene}. Part IX

The condensation reactions between hexachlorocyclotriphosphazatriene (1), N3P3Cl6, and dibenzo-diaza crown ethers (2 and 3) afforded two novel spiro-crypta-phosphazene derivatives (4 and 5). Compounds (4 and 5) have been characterized by elemental analyses, FTIR, 1H-, 13C-, 31P NMR, HETCOR and MS. The structure of crypta-phosphazene (5) has been determined crystallographically. Compounds (4 and 5) are the first examples of the crypta-phosphazene derivatives. The 31P NMR spectra of compounds (4 and 5) indicate that both of the compounds have anisochrony, possibly because of the stereogenic nitrogen atoms. In compound (5), the pyramidal geometries of four spirocyclic nitrogen atoms give rise to stereogenic properties. The sum of the bond angles around N4, N4A, N5 and N5A nitrogens are 346.2(4), 348.8(3), 347.1(3) and 345.8(4)8, respectively. Compound (5) crystallizes in the P21 space group with aZ11.831(2), bZ21.108(2), cZ11.936(1) A ° , bZ102.70(1)8, VZ2907.9(6) A ° 3, ZZ2 and DxZ1.442 g cmK3. The absolute structure was determined successfully. There are two molecules in the asymmetric unit. The structure consists of a non-centrosymmetric, non-planar phosphazene ring with a bulky dibenzo-diaza crown ether side group. q 2004 Elsevier B.V. All rights reserved.