Electron Paramagnetic Resonance Study of Ph2P(O)CH2Cl- Trapped in X-ray Irradiated (Chloromethyl)diphenylphosphine Oxide Crystals at 3 K and Ph2P(O)C.H2 at 77 K

Article abstract of DOI:10.1021/j150653a027

The radical Ph2P(O)CH2Cl^- is observed in 3 K X-ray irradiated crystals of (chloromethyl)diphenylphosphine oxide.The X-ray irradiation was carried out in the dark.The hyperfine coupling tensors were found to be A(35Cl) = (40.4, 17.9, 16.1 G), A₁(1H) = ( 24.0, 17.2, 13.1 G), A₂(1H) = (25.0, 16.4, 9.0 G), and A(31P) = (42.1, 33.6, 23.8 G).The g-tensor components are equal to 2.0021, 2.0040, and 2.0046.The maximum 35Cl coupling and the minimum g value are located within 5 deg of the parent C-Cl bond direction.Upon thermal annealing to ca. 170 K, the anion decays and the Ph2P(O)C^.H2 radical appears.UV photolysis of the anion at 3 K results in the disappearance of the anion and the formation of Ph2P(O)C^.H2.Ph2(O)C^.H2 decays above 230 K, giving rise to a room-temperature-stable species.