Phosphorus-nitrogen compounds: New spiro-cyclic phosphazene derivatives. Structure of 40,40,60,60-tetrachloro-3,4-dihydro-3-(3-methylpyridin-2-yl)- spiro-[1,3,2-benzoxazaphosphinine-2,20- (2l5,4l5,6l5-cyclotriphosphazene)]. Part XII

The condensation reactions of {N-[(2-hydroxyphenylmethyl)amino]-methylpyridines (5–8) with trimer, N3P3Cl6, have been afforded partially substituted novel spiro-cyclic phosphazene derivatives (9–12) (Scheme 1). Compounds (9–12) have been characterized by elemental analyses, FTIR, 1H–, 13C–, 31P-NMR, HETCOR, and MS. The structure of the spiro-cyclic phosphazene (9) has been examined crystallographically. It crystallizes in the P21/n space group with aZ10.7906(10) A ° , bZ8.5625(17) A ° , cZ21.187(5) A ° , bZ91.298(12)8, VZ 1957.1(6) A ° 3, ZZ4 and DxZ1.660 g cmK3. The structure consists of a non-planar phosphazene ring with a bulky methylpyridinyl and a benzo-fused spiro-cyclic side group. The six-membered spiro-cyclic ring has a twist-boat conformation. q 2005 Elsevier B.V. All rights reserved.