The carbon monoxide flame bands

Abstract

Abstract The carbon monoxide flame bands have been photographed under high resolution from an afterglow source. Bands in the wavelength range 3100 to 3800 Å show a pattern which has been reproduced by calculations of the energies of high vibrational levels of the ground state of CO2. The structure of this energy level pattern is strongly affected by extensive Fermi resonance in the 1Σ+g state. The spectrum is emitted by excited CO2 molecules which radiate to the ground state from the lowest vibrational level and from the v´2 = 1 level of a B2 state. This excited state lies approximately 46 000 cm-1 above the lowest level of the ground state, an d has an OCO angle of 122 + 2° and a CO bond length of 1*246 ± 0*008 Å. Combination of these results with the work of other authors shows that the excited state is a 1B2 state, and that the carbon monoxide flame bands are associated with the weak absorption system of CO2 at 1475 Å.