ALKYL PHOSPHAZINES, (C6H5)(3)PNNC(R-1)(R-2) - [I) R-1=CH3 - R-2=I-BU AND II) R-1=R-2=C6H5CH2-] - SYNTHESIS, CONVERSION TO METHYL-IODIDE SALT AND SINGLE-CRYSTAL X-RAY STRUCTURE OF PHOSPHAZINIUM BROMIDE, [(C6H5)(3)P=N(H)N=C(CH3)(I-BU)]BR--)(()

Two new examples of alkyl triphenylphosphazinium bromides have been pr epared and characterised. Contrary to earlier practice, these salts ha ve been effectively dehydrobrominated by the use of triethylamine. Exc ess of methyl iodide in its reaction with phosphazine afford only mono methylation, occurring at phosphinimino nitrogen. P-31 chemical shift s of several phosphazinium bromides measured in this study show a much smaller variation (35-38 delta) compared to their free bases (14-20 d elta). The first single crystal X-ray structure of beta-N (methyl, iso butyl) triphenylphosphazinium bromide (la) reveals the presence of i) nearly unaffected N-N bond distance and ii) hydrogen bonding with the bromide ion.