The influence of the molecular beam temperature on the photodissociation of CF3I at 308 nm

✍ Scribed by Peter Felder

• Book ID: 103031461
• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 742 KB
• Volume: 197
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(92)85795-c

✦ Synopsis

The 308 nm photodissociation of CF,I has been studied by photofragment translational spectroscopy with a polarized photolysis laser. Two overlapping electronic transitions give access to the repulsive states 'Qi and 'QO. The initial excitation of the 'Q, state produces the fragments CF,+I( *P,,*) with a perpendicular recoil anisotropy. In contrast to the "Q, state, the 'Qe state produces photofragments with a parallel recoil. These are CF3 + I* ( 2P,,2), formed in a direct process, and CF, + I (*Pr,r ), formed via a non-adiabatic transition from the 'Qe to the 'Q, state. The photolysis of warmer CF31 molecules was studied by irradiating the early part of the molecular beam pulse. The importance of the 'QetX transition was found to be enhanced due to the absorption from warm molecules. This effect leads to a strong temperature dependence of the 1*/I branching ratio at 308 nm, which was found to increase from 0.27 in the coldest part of the beam pulse to 0.92 in the warmer part.