title: Photodissociation of spatially aligned acetaldehyde cations.
abstract: Photofragment translational energy and angular distributions are reported for the photodissociation of acetaldehyde cations in the wavelength range 354-363 nm obtained using the DC slice ion imaging technique. Vibrationally selected parent ions were produced by 2+1 resonance-enhanced multiphoton ionization (REMPI) via the 3s<--n Rydberg transition, with photodissociation resulting from absorption of a fourth additional photon. Three product channels were observed: HCO+, CH3CO+, and CH4+. The angular distributions reveal that all product channels have a predominantly parallel recoil anisotropy although the lower beta2 parameter of CH3CO+ indicates the concomitant presence of a perpendicular component. Furthermore, the distinct angular distribution of the CH3CO+ fragments shows a large value of the higher order Legendre polynomial term, providing evidence that acetaldehyde cations are spatially aligned during the ionization process.
authors: Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
authors: Suk Kyoung
authors: SK
authors: Lee
authors: Ruchira
authors: R
authors: Silva
authors: Myung Hwa
authors: MH
authors: Kim
authors: Lei
authors: L
authors: Shen
authors: Arthur G
authors: AG
authors: Suits