Abstract
The rotationally resolved laser-induced fluorescence spectrum of the HCO B̃ 2 A′-X̃ 2 A′ transition in the 0 0 0 band is observed under thermalized conditions. The formyl radical is produced from acetaldehyde photolyzed at wavelengths 310 or 308 nm. Some spin-splitting s of the spectra are resolved. About 988 transitions to K′ a ≤ 3 and N′ ≤ 24, ~94% of the observed lines, are assigned in this work including weak ΔK a = ±2 transitions that become allowed because of the effects of axis-switching. © 1997 Academic Press.