TheÅ ngström (B1Σ+→ A1Π) Band System of13C16O: New Observations and Analyses

The emission spectrum of the Angstrom system (B 1 Σ + → A 1 Π) of 1 3 C 1 6 O was recorded and analysed by classical photographical spectroscopy. Under high resolution and with a precision estimated to be 0.010-0.020 cm - 1 the bands 1-2, 1-7, and 0-6 were recorded for the first time and the 0-1, 0-2, 1-1, and 1-5 bands were rephotographed and reexaminated. After the rotational analysis of the bands the following constants were calculated: (1) the rotational constants Β v , D v for the B 1 Σ + and A 1 Π states; (2) the equilibrium constants B e , α e , D e , and β e for the B 1 Σ + state; (3) the v 0 band origins. A combined analysis of the currently observed Angstrom bands and the previously observed Herzberg (C 1 Σ + → A 1 II) and the (E 1 Π → A 1 Π) bands made it possible to perform a precise relative characteristic of the B 1 Σ + (v = 0 and 1), C 1 Σ + (v = 0) and E 1 Π(v = 0) rydberg levels in 1 3 C 1 6 O. Numerous rotational perturbations observed in the A 1 Π state were confronted with the perturbations predicted from the theoretical calculations.