Tunable diode laser probe of chlorine atoms produced from the photodissociation of a number of molecular precursors

✍ Scribed by Jeunghee Park; Yongsik Lee; George W. Flynn

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 885 KB
• Volume: 186
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(91)90206-o

✦ Synopsis

Time-resolved diode laser absorption spectroscopy is used to probe Cl atoms produced from the photolysis of a number of molecular precursors at excimer laser wavelengths 193,248 and 308 nm. The diode laser was tuned to the Cl atom tine structure transition, 2PJ,2+2P,,2. For 248 and 193 nm photolysis of SsCls, the translational energy of nascent Cl atoms is measured to be 7 f 1 and 10 zk 3 kcal/mol, respectively, from the Doppler lineshape of the diode laser absorption. Only I7 f 2% and 15 + 4%, respectively, of the available energy appear as translational recoil energy of the photofragments produced at 248 and 193 nm. This result is generally consistent with a statistical model, suggesting a long-lived transition state complex. The relative yield, pa= [Cl('P,,,)]/{[Cl('P,,2)1 t [Cl('Ps,,)]}, for producing Cl('Pi,s) is 0.21 kO.03 at 248 nm, 0.2OrtO.03 at 193 nm, and 0.48 ? 0.06 at 308 nm, respectively. The relative yield for producing Cl(2P,,2) has also been measured for the photodissociation of various Cl precursors such as Cli, HCI, ICI, NOCl, SCCls, PC&, and Ccl.,.