Vibrationally resolved photoelectron spectroscopy of PO−3 and the electronic structure of PO3

A vibrationally resolved photoelectron spectrum has been obtained for PO−3 at 193 nm in the gas phase. Transitions to the ground (X2A2′) and first excited state (A2E″) of PO3 were observed. The current spectrum represents the first observation of the 2E″ state, which splits into two states, 2B1 and 2A2, due to the Jahn–Teller effect. The 2A2′ ground state shows a vibrational progression in the ν1 symmetric stretching mode with a frequency of 1000 (100) cm−1. The adiabatic electron affinity of PO3 was measured to be very high, 4.95 (0.06) eV. The 2B1 and 2A2 states of PO3 show very broad features due to the large geometry changes between these states and the anion ground state.