Photodetachment imaging study of the vinoxide anion

A photodetachment imaging study of the photoelectron angular distributions produced by the 354.8-nm photodetachment of the vinoxide anion, H2C=CHO-, is reported. The photoelectron angular distributions for both the (X) over tilde (2)A" ground state and (A) over tilde (2)A' excited state of the neutral vinoxy radicals were measured. Energy-dependent photoelectron anisotropy parameters are reported for both electronic states. Photodetachment from the HOMO of the anion (the CCO nonbonding pi(a") orbital) yields ground-state vinoxy radicals and exhibits a sin(2) theta angular dependence (beta((X) over tilde (2)A") = -0.7 +/- 0.1) relative to the electric vector of the laser. Photodetachment from the HOMO-1 of the anion (the oxygen sigma(2px)(a') orbital) yields excited-state (A) over tilde (2)A' radicals and exhibits a cos(2) theta angular dependence (beta ((A) over tilde (2)A') = 0.6 +/- 0.1) of the photoelectrons. These results are qualitatively interpreted in terms of the electronic structure of the anion-neutral system.