Kinetics and mechanism of the oxidation of lower oxyacids of phosphorus by hexamethylenetetramine bromine

✍ Scribed by Satish K. Mehla; Seema Kothari; Kalyan K. Banerji

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 71 KB
• Volume: 32
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/(sici)1097-4601(2000)32:3<165::aid-kin6>3.0.co;2-m

✦ Synopsis

The oxidation of lower oxyacids of phosphorus by hexamethylenetetramine bromine (HABR) in glacial acetic acid resulted in the formation of corresponding oxyacids with phosphorus in a higher oxidation state. The reaction exhibited stoichiometry. The reaction 2 : 1 is first order with respect to HABR. Michaelis-Menten-type kinetics were observed with respect to the acids. The formation constant of the phenylphosphinic acid-HABR complex also has been determined spectrophotometrically. The thermodynamic parameters for the complex formation and the activation parameters for their decomposition were calculated. The reaction showed the presence of a substantial kinetic isotope effect. It is proposed that the HABR itself is the reactive oxidizing species. It has been shown that the pentacoordinated tautomer of the phosphorus oxyacid is the reactive reductant. A suitable mechanism has been proposed.