The collisional behaviour of ground state atomic carbon, C(2p 2( 3P j) with ethylene and acetylene investigated by time-resolved atomic resonance absorption spectroscopy in the vacuum ultraviolet

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 1993-02, Vol.70 (2), p.119-124
• Main Authors: Nazre, Haider, David, Husain
• Format: Article
• Language: English
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/1010-6030(93)85031-3

We present a kinetic study of the collisional behaviour of ground state atomic carbon, C(2p 2( 3P J ) with the molecules C 3O 2, C 2H 4 and C 2H 2. Atomic carbon was generated by the repetitive pulsed irradiation (λ> ca. 160 nm of C 3O 2 in a slow flow system and then monitored photoelectrically by time-resolved atomic resonance absorption in vacuum ultraviolet (λ= 166 nm, 3 3P J ←2 3P J ) with direct computer interfacing for data capture and analysis. The following absolute second-order rate constants for the reactions of C(2 3P J ) with the molecules C 3O 2, C 2H 4 and C 2H 2 were obtained: k R/cm 3 molecule −1 s −1(300 K); C 3O 2 (1.8 ±0.1) x 10 −10, C 2H 4(2.0±0.1) x 10 −10 and C 2H 4(2.1±0.1) x 10 −10. The result for C 3O 2 is in accord with earlier measurements. Those for C 2H 4 and C 2H 2 yield values at least six orders of magnitude faster than initial estimates from earlier indirect measurements on a flow system.