Pyrolysis of tetraphenyl imidodiphosphate

• Published in: Journal of analytical and applied pyrolysis 1992-09, Vol.23 (3), p.217-227
• Main Authors: Shimasaki, Choichiro, Muto, Yoshinori, Takashima, Nobuchika, Tsukurimichi, Eiichi, Yoshimura, Toshiaki, Hasegawa, Kiyoshi
• Format: Article
• Language: English
• Subjects: Chemistry; Exact sciences and technology; Imidophosphate; mass spectrometry; Organic chemistry; Organometalloidal and organometallic compounds; P derivatives; Preparations and properties; pyrolysis; thermal decomposition
• ISSN: 0165-2370; 1873-250X
• DOI: 10.1016/0165-2370(92)80018-H

The pyrolysis of tetraphenyl imidophosphate ( 1) was investigated by DTA—TG, IR, 1H- and 31P-NMR, mass spectroscopy, and TG—GC/MS. The DTA—TG/DTG curve showed that the pyrolysis of 1 occurred in one stage. Compound 1 melted at about 110°C and pyrolyzed to polyphosphates accompanied by a weight loss of about 70% in the temperature region from 250 to 450°C. The results of IR, 1H and 31P NMR and TG—GC/MS confirmed that this weight loss could be attributed to the cleavage of the PN bond accompanying the formation of diphenyl phosphoramidate ( 2) and to the liberation of pyrolysis intermediate substances such as phenol, triphenyl phosphate ( 3), triphenyl N-(diphenoxyphosphoryl)imidophosphate ( 4), hexaphenoxycyclotriphosphazene ( 5), diphenyl hydrogen phosphate ( 6), and 2. Cleavage of PO(Ph) or (P)OPh bonds is characteristic of fragmentation in the high mass spectrum of 1. Subsequently, the fission species transform to other species forming new compounds. The activation energy of the pyrolysis of 1 was estimated to be 111 kJ mol −1, and that for 2 and 3 to be 151 and 220 kJ mol −1, respectively.