ELECTRON SPIN RESONANCE STUDIES OF THE RADICALS OF (Ar′O)₂P(S)Cl AND (Ar″O)₃P=S INDUCED BY GAMMA IRRADIATION (Ar′=2,6-DIMETHYLPHENYL AND 2-TERT-BUTYLPHENYL Ar″=2-ISO-PROPYL-5-METHYLPHENYL)

Abstract

A newly synthesized and dedected stable thiophosphorylradicals, bis(2,6-dimethylphenoxy)thiophosphoryl and bis(2-tert-butylphenoxy)thiophosphosphoryl and alkyl radical have been observed in gamma irradiated bis(2,6-dimethylphenyl)chlorothiophosphate and bis(2-tert- butylphenyl)chlorothiophosphate and tris(2-iso-propyl-5-ethylphenyl)thiophosphate single crystals respectively. The characteristic feature is that the phosphorus hyperfine splitting are 26.76 G and 26.65 G respectively for two compounds, but the g values are very unisotropic varying between 1.9996 and 2.054. Tris(2-iso-propyl-5-methylphenyl)thiophosphate does not give phosphoryl radical on gamma irradiation. The radical observed is carbon-centered (alkyl) and forms after 1,6-hydrogen shift on isopropyl group towards sulphur atom giving methyl proton splitting with 15.86 G and a proton siplitting in the neighborhood with 5.5 G. The g value is measured to be 2.0025 for this radical.

Key Words:

• Thioarylphosphates
• phosphate esters
• esr spectroscopy
• phosphoryl radicals
• carbon-centered radicals