Spectroscopy and perturbation analysis of the CO A¹Π −X¹Σ⁺(2,0), (3,0) and (4,0) bands

Abstract

The (2,0) (3,0) and (4,0) bands of the A 1 Π−X 1 Σ + system of 12 C 16 O have been reinvestigated by high-resolution vacuum ultraviolet absorption spectroscopy. A VUV Fouriertransform spectrometer, illuminated by synchrotron radiation, was applied to record a jetcooled spectrum, a room temperature static gas spectrum and a high temperature (900 K) quasi-static gas spectrum, resulting in absolute accuracies of 0.01−0.02 cm −1 for the rotational line frequencies. Precise laser-based data were included in the analysis allowing for a highly accurate determination of band origins. Rotational levels up to J = 52 were observed. The data were used to perform an improved analysis of the perturbations in the A 1 Π, v = 2, v = 3, and v = 4 levels by vibrational levels of the D 1 ∆, I 1 Σ − , e 3 Σ − , d 3 ∆, and a ′3 Σ + states.

Perturbations in the A1Π,v= 0 state of12C18O investigated via complementary spectroscopic techniques

“…16 O main isotopologue [24][25][26][27], and in the 13 state and determine whether it shows anomalous behaviour in common with observations of the a 3 state [31,32]. The new spectroscopic measurements of A 1 (v = 0) state presented here are necessary to obtain the precision required to probe this effect.…”

Spectroscopy and perturbation analysis of the A1π (v=0) state of 13 C16 O

“…A similar methodology as in previous works [19,20] is used in the present analysis of the perturbations affecting the A 1 (0) state of 13 C 16 O. Using the Pgopher software [47], we simulate all measured transition frequencies with the same effective Hamiltonian model previously adopted in Ref.…”

“…Further experimental and analytical details of the VUV-FT spectra are provided in Refs. [18][19][20].…”

“…The operation of this device and its use for molecular spectroscopy have been well described [20,33]. All measurements were performed under steady-state gas conditions, whereby gas is continuously introduced to the interaction region and flows out of a windowless cell.…”

“…[14][15][16][17]). Recently, the spectrum of A 1 −X 1 + in 12 C 16 O was reinvestigated by Doppler-free laser methods [18] and vacuum-ultraviolet Fourier-transform (VUV-FT) spectroscopy [19,20], both at high resolution. The A 1 −X 1 + system of the 13 C 16 O isotopologue was investigated in detail by Haridass and Huber [14], after the observation of unresolved band heads by Tilford and Simmons [9].…”