Laser induced fluorescence spectroscopy of ZrN: rotational structure in the A2Π-X2Σ(2,2) band

The A2Π-X2Σ (2,2) band of ZrN between 5661 and 5891 Å has been studied using laser induced fluorescence and wavelength resolved fluorescence spectroscopy. All the 12 branches expected from a 2Π-2Σ transition have been observed and assigned. Three strong perturbations at J = 16.5, 23.5 and 36.5 of the 2Π32 substate ν = 2 level have been found. Since both e and f Λ-doubling components of the 2Π32 state are perturbed to nearly the same extent, which is consistent with the perturbing state being degenerate. Magnetic hyperfine splitting of the 91ZrN molecule with ν = 2 has been identified and analyzed.