The k3Π Valence State of CO

Accidental predissociation phenomena in the E 1Π, v=0 and v=1 states of 12C16O and 13C16O

“…By making use of multiple boxcar integrators spectra of different isotopic species could be recorded selectively and simultaneously. The high sensitivity of this setup allows to record spectra of 12 17 O from a natural sample of CO. The 13 C enriched sample of CO, that was used for the 2ϩ1 REMPI experiments and available only in limited quantities, was not sufficient to sustain a molecular beam expansion for the vuv experiment.…”

“…11 Second, in a vuv spectrographical study a vibrational progression k 3 ⌸, vϭ2, 3 and 5 was observed in excitation from the ground state. 17 This allowed reassignment of the vibrational progression observed by Wan and Langhoff 18 in CO excited by electron bombardment. Vibrational levels vϭ1 and 2 of k 3 ⌸ were observed in doubleresonance excitation by Mellinger and Vidal, 19 who also deduced limiting values for their lifetimes.…”

“…First a transition to the perturber state, known as the k 3 ⌸ 0 , vϭ5, J e ϭ7 level, 17 was observed as a very weak extra line at 95 104.24 cm Ϫ1 with an intensity of 2.5% of that of the R(6) line of the E -X ͑1,0͒ band. Moreover, for the first time predissociation-induced line broadening could be observed for these lines.…”

“…Later more accurate information on the k 3 ⌸ state became available through the recording of k 3 ⌸ -X 1 ⌺ ϩ (v,0) absorption bands for vϭ2, 3, and 5 17 and more recently for vϭ0. 20 18 who have pointed out that a perturbation exist at vϭ1, which pushes down the level by 9 cm Ϫ1 .…”

“…In two recent publications by Baker et al 11,17 the issue of the accidental predissociations in the E 1 ⌸ state was addressed. First, two-photon laser excitation revealed the predissociation behavior of both e and f levels for E 1 ⌸, vϭ1 in several isotopes including 12 C 18 O, 13 C 16 O, and 13 C 18 O.…”