High resolution emission spectra of the 0–0, 0–1 and 0–2 bands ofE 1 Π-A 1 Π andB 1 Σ +-A 2 Π transitions in12C18O molecule

In the emission spectrum of the12C18O isotopic molecule the 0–0, 0–1 and 0–2 bands of twoE 1 Π-A 1 Π andB 1 Σ + transitions have been photographed at high resolution. After a rotational analysis of bands the following molecular constants have been calculated: (1) the rotational constantsB o andD o for the upperE 1 Π andB 1 Σ + states andB v ,D v for theA 1 Π state, (2) the reduced band originsc ov , for both transitions, (3) the Λ-doubling constants for theE 1 Π state, (4) the distances betweenv=0 levels in theE 1 Π,C 1 Σ + andA 1 Π states. Some molecular constants have been derived from the combinational analysis of bands which belong to theE 1 Π-A 1 Π andB 1 Σ +-A 1 Π and alsoE 1 Π-A 1 Π andC 1 Σ +-A 1 Π transitions. Strong perturbation of theA 1 Π state bye 3 Σ − nearby electronic state, observed in the 0–0 band ofB + Σ +-A 1 Π system has also been analysed.