Abstract

Rotational spectra of the gaseous free radical HOCO were first observed at 1.1-mm wavelength in a Faraday rotation absorption spectrometer.¹ These radicals were generated by hydrogen abstraction from formic acid by chlorine atoms produced in a microwave discharge. Further exploration of this radical was done at wavelengths between 0.3 and 0.7 mm in a far-in feared laser magnetic resonance (LMR) spectrometer. The LMR spectra consist of a moderate number of very narrow lines. This suggests that they arise from b-type transitions of the “avoided crossing” type.² In a few cases the spectra consist of a single giant line at low magnetic fields; these fields probably result from a piling up of magnetic components. HOCO is very reactive toward molecular oxygen and forms HO₂ as one of the reaction products.

© 1991 Optical Society of America