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

Abstract

The condensation reactions between hexachlorocyclotriphosphazatriene ( 1), N 3P 3Cl 6, 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 spiro-cyclic 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)°, respectively. Compound ( 5) crystallizes in the P2 1 space group with a=11.831(2), b=21.108(2), c=11.936(1) Å, β=102.70(1)°, V=2907.9(6) Å 3, Z=2 and D x =1.442 g cm −3. 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.