Tetraphosphonitrilic chloride

While the hydrolysis of triphosphonitrilic chloride furnishes trimetaphosphimic acid, the hydrolysis of tetraphosphonitrilic chloride, P4N4018, furnishes tetrameta-phosphimic acid, P4N4H808, which, by analogy with trimetaphosphic acid, has the ring formula ... 

While the hydrolysis of triphosphonitrilic chloride with sodium acetate furnishes trimetaphosphimic acid and the hydrolysis of tetraphosphonitrilic chloride with water furnishes tetrametaphosphimic acid, the hydrolysis of pentaphosphonitrilic chloride, P5N5C1i0, with sodium hydroxide in ethereal soln. furnishes sodium pentametaphosphimic acid, PsNsHloO10, or rather the alkali pentameta-phosphimate—sufficient alkali must be present to maintain the alkalinity of the soln. The sodium salts are amorphous, and are precipitated in a gelatinous form by the addition of alcohol to the alkaline soln., or to the soln. neutralized with acetic... 

Triphosphonitrilic chloride, (PNCla)3 Tetraphosphonitrilic chloride, (PNC12)4 Pentaphosphonitrilie chloride, (PNC12)6 Hexaphosphonitrilic chloride, (PNClJ, Heptaphosphonitrilie chloride, (PNC12), Polyphosphonitrilic chloride, (PNCla)n 114° 123-5° 40-5° 41° 90° below —18° below 500° 127° 188° 223°-224-3° 261°-263° 289°-294° depolymerizes 256-5° 328-5° polymerizes polymerizes polymerizes on distillation... 

The next member of the series, tetraphosphonitrilic chloride, P4N4GT8, forms colourless prisms with a sp. gr. 2-18. B. Schenck and G. Bomer gave 185° for the b.p. at 10 mm. press., and 123-5° for the m.p., and added that above 255° it behaves like the tri-polymer. H, N. Stokes found that analyses, vapour density determinations in dry hydrogen, and the depression of the f.p. of benzene soln., agree with the formula P4N4C18 and by analogy with triphosphonitrilic chloride, the constitution may be ... 

The kinetics of the polymerization of tri- and tetraphosphonitrilic chlorides in solution and in bulk have been studied by Patat and Kol-linsky (58) and Patat and Frombling (57). Hydrocarbons are unsuitable solvents, since they react to give hydrogen chloride successful results w ere obtained in carbon tetrachloride. The proposed mechanism involves unimolecular initiation, either by oxygen (in solution) or another phosphonitrilic molecule (in bulk). A bimolecular propagation step is followed by unimolecular termination. Traces of water were foimd by Renaud to have a significant effect on the polymerization process (62, 63). 

Fig. 4. The structure of (a) tetraphosphonitrilic chloride and (b) tetraphosphoni-trilic fluoride. The phosphorus atoms are shaded and the halogen atoms dotted.

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