Reaction and relaxation of vibrationally excited formyl radicals
Ground state and vibrationally excited formyl radicals were produced by excimer laser (308 nm) photolysis of formaldehyde and glyoxal at 295 K. The subsequent evolution of the (0,1,0) and (0,0,0) vibrational levels was monitored through time-resolved laser resonance absorption. Rate constants of (6.4 +- 1.0) x 10/sup -12/, (3.0 +- 0.5) x 10/sup -12/, (2.5 +- 0.3) x 10/sup -13/, (2.5 +- 0.8) x 10/sup -13/, (3.4 +- 0.4) x 10/sup -11/, and (9.4 +- 1) x 10/sup -12/ cm/sup 3/ molecule/sup -1/ s/sup -1/ were determined for removal of HCO(0,1,0) by (HCO)/sub 2/, H/sub 2/CO, He, N/sub 2/, NO, and O/sub 2/, respectively. Upper limits of 8.0 x 10/sup -12/ and 4.4 x 10/sup -12/ cm/sup 3/ molecule/sup -1/ s/sup -1/ were established for reactive removal of HCO(0,1,0) by NO and O/sub 2/. The rate constant for relaxation of an unidentified higher vibrational level of HCO to (0,1,0) by (HCO)/sub 2/ was measured to be (2.4 +- 0.4) x 10/sup -11/ cm/sup 3/ molecule/sup -1/ s/sup -1/ and rate constants of (7 +- 2) x 10/sup -13/ and (2.6 +- 0.6) x 10/sup -11/ cm/sup 3/ molecule/sup +1/ s/sup -1/, respectively, were determined for removal of DCO(0,1,0) by D/sub 2/CO and NO. The relaxation and reaction rates with NO and O/sub 2/ are understood in terms of the formation and decomposition of an HCONO and HCOO/sub 2/ collision complex.
- Research Organization:
- Department of Chemistry, University of California, Berkeley, and Materials and Molecular Research Division of the Lawrence Berkeley Laboratory, Berkeley, California 94720
- OSTI ID:
- 6594366
- Journal Information:
- J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 80:9; ISSN JCPSA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ACYL RADICALS
ALDEHYDES
CHALCOGENIDES
CHEMICAL REACTION KINETICS
ELEMENTS
ENERGY LEVELS
EXCITED STATES
FORMALDEHYDE
FORMYL RADICALS
KINETICS
NITRIC OXIDE
NITROGEN
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHOTOCHEMICAL OXIDANTS
RADICALS
REACTION INTERMEDIATES
REACTION KINETICS
RELAXATION
SMOG
VIBRATIONAL STATES