Study of isotopic 13C2 bands of the Deslandres-D'Azambuja system

Antic‐Jovanović, A.; Bojović, V.; Pešić, D. S.; Vujisić, B.R.; Rakotoarijimy, D.

doi:10.1016/0022-2852(85)90214-0

Cited by 6 publications

(5 citation statements)

References 3 publications

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“…We hope that our work will create a new framework for discussions of the electronic structure of C 2 . Our model for the 1 Π g states is motivated by observations of unusual energy level patterns in the C 1 Π g state, which is the upper state of the Deslandres–d’Azambuja band system ( C 1 Π g – A 1 Π u ). − A diabatic fit model for the C state allows us to account for these strange level patterns as well as to conclusively invalidate the existence of the Messerle–Krauss band system ( C ′1 Π g – A 1 Π u ) . By treating the configuration mixing as a result of diabatic interactions, the usefulness of simple concepts of bond order and correlation diagrams is restored.…”

Section: Introductionmentioning

confidence: 99%

Diabatic Valence-Hole States in the C₂ Molecule: “Putting Humpty Dumpty Together Again”

Jiang

Nauta

et al. 2022

J. Phys. Chem. A

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Despite the long history of spectroscopic studies of the C2 molecule, fundamental questions about its chemical bonding are still being hotly debated. The complex electronic structure of C2 is a consequence of its dense manifold of near-degenerate, low-lying electronic states. A global multi-state diabatic model is proposed here to disentangle the numerous configuration interactions that occur within four symmetry manifolds of excited states of C2 (1Πg, 3Πg, 1Σ u + , and 3Σ u + ). The key concept of our model is the existence of two “valence-hole” configurations, for 1,3Π g states and for 1,3Σ u + states, that are derived from 3σ g ← 2σ u electron promotion. The lowest-energy state from each of the four C2 symmetry species is dominated by this type of valence-hole configuration at its equilibrium internuclear separation. As a result of their large binding energy (nominal bond order of 3) and correlation with the 2s22p2 + 2s2p3 separated-atom configurations, the presence of these valence-hole configurations has a profound impact on the global electronic structure and unimolecular dynamics of C2.

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Section: Introductionmentioning

confidence: 99%

Diabatic Valence-Hole States in the C₂ Molecule: “Putting Humpty Dumpty Together Again”

Jiang

Nauta

et al. 2022

J. Phys. Chem. A

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“…Of particular note is the Deslandres-d'Azambuja band system which has been seen in flames (Hornbeck & Herman 1949), plasma plumes (Camacho et al 2008), laser ablation of graphite (Acquaviva & De Giorgi 2002) and astrophysics (Gredel et al 1989;Berdyugina et al 2007). Yet remarkably the only modern, high resolution study of these band was made of 13 C 2 (Antić-Jovanović et al 1985). A high resolution study of the Deslandres-d'Azambuja bands for 12 C 2 is overdue.…”

Section: Discussionmentioning

confidence: 99%

An update to the MARVEL data set and ExoMol line list for 12C2

McKemmish

Syme

Borsovszky

et al. 2020

Monthly Notices of the Royal Astronomical Society

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The spectrum of dicarbon (C2) is important in astrophysics and for spectroscopic studies of plasmas and flames. The C2 spectrum is characterized by many band systems with new ones still being actively identified; astronomical observations involve eight of these bands. Recently, Furtenbacher et al. (2016, Astrophys. J. Suppl., 224, 44) presented a set of 5699 empirical energy levels for 12C2, distributed among 11 electronic states and 98 vibronic bands, derived from 42 experimental studies and obtained using the Marvel (Measured Active Rotational-Vibrational Energy Levels) procedure. Here, we add data from 13 new sources and update data from 5 sources. Many of these data sources characterize high-lying electronic states, including the newly detected 3 3Πg state. Older studies have been included following improvements in the Marvel procedure which allow their uncertainties to be estimated. These older works in particular determine levels in the C 1Πg state, the upper state of the insufficiently characterized Deslandres–d’Azambuja (C 1Πg–A 1Πu) band. The new compilation considers a total of 31 323 transitions and derives 7047 empirical (Marvel) energy levels spanning 20 electronic and 142 vibronic states. These new empirical energy levels are used here to update the 8states C2 ExoMol line list. This updated line list is highly suitable for high-resolution cross-correlation studies in astronomical spectroscopy of, for example, exoplanets, as 99.4% of the transitions with intensities over 10−18 cm molecule−1 at 1000 K have frequencies determined by empirical energy levels.

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“…While there are many spectroscopic studies available, in fact 42 were analyzed to yield the transitions analyzed, and there has been significant recent activity including the identification of several new band systems, there are also surprising gaps. For example, there is a detailed, fully rovibronically-resolved study of the Deslandres-d'Azambuja (C 1 Π g − A 1 Π u ) band system for 13 C 2 (Antić-Jovanović et al 1985), but even a century after the original observation of this band (Deslandres & d'Azambuja 1905) there is no available high-resolution study for 12 C 2 .…”

Section: Discussionmentioning

confidence: 99%

“…The band was originally observed more than a century ago (Deslandres & d'Azambuja 1905) and, as discussed in the Introduction, has been observed in a number of astronomical objects. However, while a high-resolution line list is available for 13 C 2 (Antić-Jovanović et al 1985) and there are a number of papers reporting laboratory observation of the band for 12 C 2 (Herzberg & Sutton 1940;Hornbeck & Herman 1949;Cisak et al 1969;Urdahl et al 1988;Sorkhabi et al 1997), there are no high resolution line data for the band. A high resolution re-measurement of the band for 12 C 2 would appear to be welcome.…”

Section: Comments On the Data Sourcesmentioning

confidence: 99%

“…Upper states lie at too high energy for data to be validated. (3j) 85AnBoPe (Antić-Jovanović et al 1985) Report of extensive data for 13 C 2 but with no dataset for 12 C 2 . (3k) 87VaHe (van de Burgt & Heaven 1987) Report of a "new" C 2 band: 25 transitions from one (unknown) band were recorded with an uncertainty of 0.2 cm −1 and assigned J quantum numbers; these were supplied by Heaven (private communication, 2015).…”

Section: Comments On the Data Sourcesmentioning

confidence: 99%

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Experimental energy levels and partition function of the $^{12}$C$_2$ molecule

Furtenbacher,

Szabo,

Csaszar

et al. 2016

Preprint

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The carbon dimer, the 12 C 2 molecule, is ubiquitous in astronomical environments. Experimental-quality rovibronic energy levels are reported for 12 C 2 , based on rovibronic transitions measured for and among its singlet, triplet, and quintet electronic states, reported in 42 publications. The determination utilizes the Measured Active Rotational-Vibrational Energy Levels (MARVEL) technique. The 23,343 transitions measured experimentally and validated within this study determine 5,699 rovibronic energy levels, 1,325, 4,309, and 65 levels for the singlet, triplet, and quintet states investigated, respectively. The MARVEL analysis provides rovibronic energies for six singlet, six triplet, and two quintet electronic states. For example, the lowest measurable energy level of the a 3 Π u state, corresponding to the J = 2 total angular momentum quantum number and the F 1 spin-multiplet component, is 603.817(5) cm −1 . This well-determined energy difference should facilitate observations of singlet-triplet intercombination lines which are thought to occur in the interstellar medium and comets. The large

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Study of isotopic 13C2 bands of the Deslandres-D'Azambuja system

Cited by 6 publications

References 3 publications

Diabatic Valence-Hole States in the C₂ Molecule: “Putting Humpty Dumpty Together Again”

Diabatic Valence-Hole States in the C₂ Molecule: “Putting Humpty Dumpty Together Again”

An update to the MARVEL data set and ExoMol line list for 12C2

Experimental energy levels and partition function of the $^{12}$C$_2$ molecule

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Study of isotopic 13C2 bands of the Deslandres-D'Azambuja system

Cited by 6 publications

References 3 publications

Diabatic Valence-Hole States in the C2 Molecule: “Putting Humpty Dumpty Together Again”

Diabatic Valence-Hole States in the C2 Molecule: “Putting Humpty Dumpty Together Again”

An update to the MARVEL data set and ExoMol line list for 12C2

Experimental energy levels and partition function of the $^{12}$C$_2$ molecule

Contact Info

Product

Resources

About

Diabatic Valence-Hole States in the C₂ Molecule: “Putting Humpty Dumpty Together Again”

Diabatic Valence-Hole States in the C₂ Molecule: “Putting Humpty Dumpty Together Again”