THE 4TH POSITIVE (A(1)PI-X(1)SIGMA(-C-12-O-18 AND (CO)-C-13-O-18 - PERTURBATIONS IN THE A(1)PI STATE()) SYSTEM OF (CO))

The fourth positive (A(1)II-X(1) Sigma(+)) system of the carbon monoxi deisotopomers (CO)-C-12-O-18 and (CO)-C-13-O-18 excited in the anode c olumn of a hollow-cathode discharge tube was recorded in the spectral region 1710-1935 Angstrom on a 10.6-m vacuum grating spectrograph. Of the eight bands of the eight bands of (CO)-C-12-O-18 observed with v = 0 to 2 and v = 2 to 6, and three bands of (CO)-C-13-O-18 with v = 0 a nd 1 and v = 4 and 5, the rotational structure of five bands of the fo rmer and two bands of the latter was analyzed. Several perturbations w ere observed in the A(1)II state of both isotopomers. These include, f or (CO)-C-12-O-18, strong perturbations on the order of 2 cm(-1) in A, v = 1 caused by a'(3) Sigma(+), v = 10 and weak perturbations in A, v = 1 by D-1 Delta, v = 1 and d(3) Delta, v - 5, and in A, v - 2 by I-1 Sigma(-), v = 3, e(3) Sigma(-), v = 4, and d(3) Delta v = 7, and for (CO)-C-13-O-18, weak perturbations in A, v = 1 by a'(3) Sigma(+), v = 10 and d(3) Delta, v = 5. The observed perturbations are in good agree ment with those estimated by theoretical calculation. The deperturbed molecular constants were obtained for the A(1)II state of both isotopo mers. Perturbation parameters and mixing coefficients which characteri ze each perturbation were also derived. (C) 1994 Academic Press, Inc.