Phosphorus thiohalides

Theaction of ammonia on phosphorus halides gives either ammoniates or, by elimination of all hydrogen as ammonium chloride, halonitrides. The amides, which should be formed as intermediate products, seem to be difficult to isolate from the true halides, although the oxylialides (p. 109) and thiohalides (p. 118) readily yield such compounds. Exceptionally, phosphorus diamidotrifluoride, PF3(NH2)2, was prepared as a white mass by the following reaction —... 

The effect of volatile phosphorus-containing compounds in polymer flames has not yet been studied. For gas systems it has been found that the flame retarding effect of the additives depends on the concentration (trimethyl phosphate, phosphorus halides and thiohalides). HPO fragments were detected in the radiation spectrum of a H2/O2 flame, upon the introduction of trimethyl phosphate Pj, PO, POj and HPO, P and PH fragments in low concentrations were discovered in a CH /Oj flame inhibited with triphenylphosphine oxide. As regards the flame retardation effect, phosphorus in triphenylphosphine occupies an intermediate position between Sb and As. Triphenyl phosphate is less effective than SbClj. Most effective are POQ3, PCI3 and PBrj. 

Very little is known about the structures of metal thiohalides although a considerable number have been prepared for the thiohalides of phosphorus see... 

Phosphonyl halides react with SF4 or SbF3 to give tetrafluorophosphoranes (6.506), and phosphorus pentasulphide converts them into the corresponding thiohalides (9.426). Phosphonyl halides form cyelic boron-phosphorus compounds with sodium borohydride (9.35) and phosphonic diamides with amines (7.158). 

The thiohalides of phosphorus, PSX3 (9.364), constitute the simplest and best-known compounds containing P = S linkages. Their molecular configuration has been studied by electron diffraction and spectroscopic techniques, which have confirmed a simple tetrahedral arrangement with C3v symmetry about the P = S linkage. Various mixed halides, PSXX 2 and PSXX X", where X = F, Cl, Br, I are also known. 

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