XUV-LASER SPECTROSCOPY ON CO - ISOTOPE-SELECTIVE PREDISSOCIATION RATES

The K (4p-sigma) (1)SIGMA+, upsilon = 0 and W (3s-sigma) 1II, upsilon = 2 states in (CO)-C-12-O-16 and (CO)-C-13-O-16 have been studied in high resolution with extreme ultraviolet laser radiation in the wavelength range 94 - 97 nm. Accurate spectroscopic constants for both isotopes and states have been derived from absolute rotational line positions. From linewidths of individual rotational transitions predissociation rates for (CO)-C-12-O-16 and (CO)-C-13-O-16 in the W 1II upsilon = 2 state have been deduced: k(p) (CO)-C-12 = 1.15 (15) x 10(11) s-1 and k(p) (CO)-C-13 = 0.58 (13) x 10(11) s-1. The rate of photodissociation of K (1)SIGMA+, upsilon = 0 was found to be smaller: k(p) = 2.6 (1.3) x 10(10) s-1 for both isotopes.