Infrared radiative relaxation of benzene ion. ICR photodissociation study of the deuterium isotope effect

✍ Scribed by M.Saber Ahmed; Hun Young So; Robert C. Dunbar

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 489 KB
• Volume: 151
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(88)80082-4

✦ Synopsis

Using the chopped-laser photodissociation technique to characterize the kinetics oftwo-photon dlssoclation. collisionless coolmg rates of photoexcited &Hz and Ch DC were measured. Colhsionless quenchmg rates of 26 and 13 s-' were determined for benzene ion and perdeuterobenzene ion, respectively, which correspond to first-order energy-removal rate constants of I5 and 7.4 s-'. The factor-of-two deuterium isotope effect on the cooling fate supports the common assumption that the collisionless cooling mechanism involves infrared radiation from excited vibrational states of the ion. The cooling rate is a factor of 10 higher than that calculated using the infrared absorption intensities of the neutral molecules.