Product angular anisotropy in CO 2 photodissociation at 157 nm

AbstractThe Photodissociation dynamics of CO 2 has been reinvestigated using the photofragment translational spectroscopictechnique based on direct vacuum ultraviolet (VUV) ionization using synchrotron radiation. The product translationalenergy spectrum as well as the product angular anisotropy have been measured for both the CO and O products. Theexperimental results indicate that the O( 3 P)+CO channel has an anisotropy parameter of 1.25, while that for theO( 1 D)+CO channel depends on the translational energy dependent. 2003 Elsevier B.V. All rights reserved. 1. IntroductionPhotochemistry of CO 2 is an important topic inatmospheric and interstellar chemical processes.The electronically excited states of CO 2 are quitecomplicated. There are two weak bands betweenthe CO 2 ( 1 R þg ) ground state and the group of ex-cited states ( 1 P g , 1 R u , 1 D u and 1 R þg ) that occur inthe range of 120–200 nm, and all of them areelectric dipole forbidden (D 1h symmetry) [1]. Allof these states correlate with the O(