Vibration rotation spectroscopy of excited electronic states Faraday-L.M.R. spectroscopy of CO a³π

Abstract

By employing CO Laser Faraday L.M.R. using a combination of concentration modulation and magnetic field modulation the vib-rot spectrum of the first excited state of CO: a ³π has been observed. Altogether 50 transitions (214 Zeeman components) for v=1←0 to v=3←2 within all fine structure systems of the a ³π state have been assigned. They were fitted to a hamiltonian, where the interaction between the a ³π and the a′ ³Σ state is taken into account only by perturbation theory. Our set of parameters describes the experimental data within 10⁻³ cm⁻¹, which is better than any other I.R.-data available so far.