MULTIPHOTON IONIZATION SPECTROSCOPY OF PCL2 RADICALS - OBSERVATION OF2 NEW RYDBERG STATES

Two new Rydberg states of the PCl2 radical were observed using mass-re solved resonance enhanced multiphoton ionization (REMPI) spectroscopy. The band systems between 440-480 and 380-395 nm are assigned to a (2) A(1)(4s) <--<-- ($) over tilde$$ X(2)B(1) and E(4p) <--<-- ($) over ti lde$$ X(2)B(1) transitions, respectively. These band systems produce s ignal through 2 + 2(($) over tilde D), and 2 + I(($) over tilde E) REM PI processes. Analyses yielded the spectroscopic constants: ($) over t ilde D(2)A(1)(4s) nu(00) = 42 760 +/- 15 cm(-1), nu'(1) = 620 +/- 20 c m(-1), and nu'(2) = 230 +/- 20 cm(-1)); ($) over tilde E(4p) nu(00) = 51320 +/- 10 cm(-1), nu'(1) = 600 +/- 15 cm(-1), and nu'(2) = 240 +/- 15 cm(-1)) and ($) over tilde$$ X(2)B(1) (nu''(1) = 525 +/- 10 cm(-1)) . Previously reported infrared absorptions [J. Phys. Chenz. 1969, 73, 2774] are reassigned as nu''(1) = 525 cm(-1) and nu''(3) = 452 cm(-1). Ab initio calculations yielded the optimized geometries, vibrational frequencies, and ionization potentials of PCl2(($) over tilde$$ X(2)B( 1)), PCl2+(($) over tilde$$ X(1)B(1)), and PCl2+(($) over tilde$$ a(3) B(1)), Ab initio G2 calculations predict the adiabatic ionization pote ntial IPa(PCl2) = 8.51 eV.