Spectroscopy and reaction kinetics of HCO

Technical Report · Sun Jan 01 04:00:00 EST 1989

DOI:https://doi.org/10.2172/6416970· OSTI ID:6416970

Guo, Yili

The high-resolution infrared spectrum of the C-H stretching fundamental of HCO has been studied by means of infrared flash kinetic spectroscopy. HCO was generated by flash photolysis of acetaldehyde or formaldehyde using a 308 nm (XeCl) excimer laser. The transient absorption was probed with an infrared difference frequency laser system. The high resolution spectra obtained were assigned and fitted with rotational, spin-rotational, and centrifugal distortion constants. The ..nu../sub 1/ band origin is 2434.48 cm/sup /minus/1/. New ground state constants have been derived from a least-squares fit combining the ..nu../sub 1/ data with previous microwave and FIR LMR measurements. A new set of spectroscopic constants for the (1, 0, 0) state, the equilibrium rotational constants, and the orientation of the transition dipole moment are also reported. The kinetics and product branching ratios of the HCO + NO/sub 2/ reaction have been studied using visible and infrared laser flash kinetic spectroscopy. The rate constant for the disappearance of HCO radical at 296 K is (5.7 +- 0.9) /times/ 10/sup /minus/11/ cm/sup 3/ molec/sup /minus/1/ sec/sup /minus/1/, and it is independent of the pressure of SF/sub 6/ buffer gas up to 700 torr. Less than 10% of the reaction goes through the most exothermic product channel, HNO + CO/sub 2/. The product channel, H + CO/sub 2/ + NO, is responsible for 52% of the reaction. HONO has been observed, though not quantitatively, as a reaction product corresponding to the HONO + CO channel. 51 refs., 21 figs., 8 tabs.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6416970
• Report Number(s): LBL-26690; ON: DE89008487
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
640302 -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
BRANCHING RATIO
CHEMICAL REACTION KINETICS
ENERGY LEVELS
EXCIMER LASERS
EXCITED STATES
GAS LASERS
GROUND STATES
HYDROCARBONS
KINETICS
LASER SPECTROSCOPY
LASERS
ORGANIC COMPOUNDS
REACTION KINETICS
ROTATIONAL STATES
SPECTROSCOPY
VIBRATIONAL STATES