First Analysis of the 1–v″ Progression of the Ångström (B¹Σ⁺–A¹Π) Band System in the Rare ¹³C¹⁷O Isotopologue

Abstract

The 1-v″ progression of the Ångström band system, so far unobserved in the rare (13)C(17)O isotopologue, was obtained under high resolution as an emission spectrum using a high accuracy dispersive optical spectroscopy. In the studied region 22,700-24,500 cm(-1), 146 spectral lines were observed, among which 118 were interpreted as belonging to the 1-0 and 1-1 bands of B-A system, and the next 28 were interpreted as extra lines belonging to the 1-1 band of B(1)Σ(+)-e(3)Σ(-) intercombination system, also unobserved in the (13)C(17)O molecule so far. All those lines were precisely measured with an estimated accuracy better than 0.0025 cm(-1), and rotationally analyzed. As a result the following in the (13)C(17)O molecule were calculated for the first time: the merged rotational constants B1 = 1.790227(23) cm(-1), D1 = 6.233(47) × 10(-6) cm(-1), and ΔG1/2 = 2010.9622 (69) cm(-1) and the equilibrium constants, ωe = 2076.04(57) cm(-1), ωexe = 32.54(28) cm(-1), Be = 1.824678(15) cm(-1), αe = 2.2967(24) × 10(-2) cm(-1), De = 5.226(25) × 10(-6) cm(-1), and βe = 6.71(48) × 10(-7) cm(-1) for the B(1)Σ(+) Rydberg state, as well as the individual rotational constant B0 = 1.50485(78) cm(-1), and the equilibrium constants ωe = 1463.340(21) cm(-1), Be = 1.49902(12) cm(-1), αe = 1.7782(49) × 10(-2) cm(-1), De = 7.36(56) × 10(-6) cm(-1) for the A(1)Π state, and σe = 21,854.015(51) cm(-1), RKR turning points, Franck-Condon factors (FCF), relative intensities, and r centroids for the Ångström band system. With the help of the strong and vast A(1)Π (v = 0) ∼ e(3)Σ(-) (v = 1) interaction, the experimental parameters of the e(3)Σ(-) (v = 1) perturbing state were established in the (13)C(17)O molecule for the first time.

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

“…Results on dynamic polarisabilities may provide information on the structure and internal dynamics in molecules, but will not be discussed further in this paper, which focuses on high resolution spectra and perturbations in the excited state. [37,38]. A higher temperature dc-plasma (up to 900 K) was obtained at the centre of the cathode and allowed for observations of B−A(0, 0) rotational transitions with J as high as 40.…”

Fourier-transform spectroscopy of 13C17O and deperturbation analysis of the A1Π (υ=0–3) levels

“…This work focuses on a comprehensive deperturbation analysis of the A 1 Π (υ = 0, 1, 2, and 3) rovibrational levels in the 13 C 17 O isotopologue. In order to perform this analysis, information on the following bands is included: the 13 C 17 O B 1 Σ + → A 1 Π (0, 0), (0, 3), B 1 Σ + ← X 1 Σ + (0, 0), (1, 0), and C 1 Σ + ← X 1 Σ + (0, 0) [58], as well as previously published studies of the B 1 Σ + → A 1 Π (0, 1), (0, 2), (1, 0), (1, 1) [33,34] and C 1 Σ + → A 1 Π (0, 1), (0, 2), and (0, 3) [35]. The B 1 Σ + ← X 1 Σ + , and C 1 Σ + ← X 1 Σ + systems are included in the study in order to determine level energies of A 1 Π in relation to the X 1 Σ + (υ = 0, J = 0) ground state of 13 C 17 O, to search for an occurrence of possible perturbations in the B 1 Σ + (υ = 0) level and to introduce an independent set of improved constants for the B 1 Σ + (υ = 0, 1) and C 1 Σ + (υ = 0) levels.…”

“…The anodes were operated at 2 × 650 V and 2 × 50 mA dc in the conditions of a static gas pressure of 2 Torr inside the lamp. During the discharge process, the 17 O 2 molecules react with the 13 C-carbon atoms ejected from the cathode, thus forming the 13 C 17 O molecules in the gas phase [34,35]. The temperature of the dc-plasma formed at the center of the cathode was about 650 K.…”

Precision spectroscopy and comprehensive analysis of perturbations in the A1∏(v= 0) state of13C18O

“…g On the basis of the isotopically recalculated values given by Refs. [16,29] for the B 1 Σ + as well as using constants determined by Ref. [43] for the X 1 Σ + state.…”