Unstable intermediates. Part XCV. Electron spin resonance spectra assigned to the radicals POCl3–, POCl2, PO2Cl2, PCl2, and PCl4 in γ-irradiated POCl3, PCl3, and PCl5

Abstract

After exposure of phosphoryl chloride to 60Co γ-rays at 77 K, three radical species were detected. One, having a large 31P hyperfine coupling of about 1350 G is thought to be POCl3–, having two strongly coupled chlorine atoms (Aiso 66 G) and one weakly coupled chlorine atom (Aisoca. 20 G). The second species, thought to be POCl2 gave an axially symmetric spectrum at 77 K, but this became isotropic on warming the sample to 100 K, when Aiso(31P) was 759 G and Aiso(35Cl) was 18 G.The third major species, thought to be PO2Cl2, had Aiso(31P) 43 G and Aiso(35Cl) 3 G. This species was probably formed from HPO2Cl2 impurity.With similar treatment, phosphorus trichloride gave PCl2 and PCl4 radicals whilst the pentachloride gave PCl4 and an unidentified radical containing two chlorine atoms.