Electron spin resonance studies of P\u3csub\u3e2\u3c/sub\u3eH\u3csup\u3e+\u3c/sup\u3e\u3csub\u3e6\u3c/sub\u3eand PH\u3csup\u3e+\u3c/sup\u3e\u3csub\u3e3\u3c/sub\u3e radical cations in rare gas matrices at 4 K. Comparison with theoretical calculations

Detailed experimental and theoreticalelectron spin resonance(ESR) studies of the cation radicals, PH+ 3 and P2H+ 6, isolated in neon and argon matrices are reported. These cations were generated by photoionization (17 eV) and x-irradiation (80 keV) methods. The observed nuclear hyperfine interactions (Atensors) showed reasonable agreement with A iso and A dipolar values calculated at the ab initioconfiguration interaction (CI) level. These ESR results for PH+ 3 clearly indicate its nonplanarity; for P2H+ 6, an earlier theoretical prediction of a C 2h distortion from C 3v was confirmed by these new experimental results which reveal two different H atom environments. The neon magnetic parameters for PH+ 3 are g ∥=2.002(1), g ⊥=2.007(1), A ⊥=920(3), and A ∥=1638(15) MHz for 31P and A(H)≤6 MHz. The neon parameters for P2H+ 6 are g ∥=2.001(1), g ⊥=2.003(1), A ⊥=1527(2), and A ∥=1909(4) MHz for 31P and A(2H)=182(2) and A(4H)=±22(2) MHz