Spectrum of AsS. I. Analysis of the A′2Π3/2–X2Π3/2 Band System

1971 ◽  
Vol 49 (10) ◽  
pp. 1249-1254 ◽  
Author(s):  
Midori Shimauchi

The emission spectrum of the AsS radical, excited in a quartz tube by a 2450 MHz oscillator, was photographed on a high resolution spectrograph from 2450 to 6900 Å. Seven bands around 6000 Å showing clear rotational structures were chosen for the first rotational analysis of the AsS spectrum. The bands were found to arise from a 2Π3/2–2Π3/2 transition. The rotational and vibrational constants of the two states derived from the present work are consistent with the previous vibrational analysis of the A′2Π3/2–X2Π3/2 system. The constants of the upper doublet component of the ground state, X2Π3/2, are ωe = 562.40 cm−1, ωexe = 2.02 cm−1, re = 2.0216 Å; the constants of the A′2Π3/2 state are ΔG′(1/2) = 403.37 cm−1, ν0,0 = 18 621.21 cm−1, re = 2.2500 Å.

1992 ◽  
Vol 70 (5) ◽  
pp. 291-294 ◽  
Author(s):  
Sheila Gopal ◽  
M. Singh ◽  
G. Lakshminarayana

The emission spectrum of Si130Te was excited by microwave discharge (2450 MHz) in a sealed quartz tube. The A1Π–X1Σ+ band system (3100–3900 Å) (1 Å = 10−10 m) photographed under high resolution on a 10.6 m Ebert grating spectrograph. The rotational analysis of 32 bands was carried out, which led to the determination of the accurate vibrational and rotational constants. The rotational structure belonging to ν′ > 9 levels appear to be perturbed.


1972 ◽  
Vol 50 (12) ◽  
pp. 1402-1408 ◽  
Author(s):  
S. M. Japar

The 2800 Å band system of p-dibromobenzene has been photographed under high resolution and an extended vibrational analysis has been carried out. The analysis is not inconsistent with the assignment of the system to a 1B2u ← 1Ag transition, by analogy with other p-dihalogenated benzenes. The observed spectrum can be explained in terms of a number of strong type-B vibronic bands and a considerably smaller number of type-A vibronic bands. The extensive sequence structure is adequately accounted for, and can be related to observations on other halogenated benzene molecules. Thirteen ground state and nine excited state fundamental vibrational frequencies have been assigned.


1966 ◽  
Vol 44 (2) ◽  
pp. 337-352 ◽  
Author(s):  
R. A. Durie

Observation by the author (Durie 1951) of a well-developed band system in the emission from an iodine–fluorine flame provided the first evidence for the existence of iodine monofluoride (IF), the last of the six possible diatomic inter-halogen compounds to be detected. The spectrum, which lies in the region 4 300 to 7 600 Å, has since been photographed under high resolution using a 21-ft concave grating spectrograph. The rotational structure of the bands is shown to be consistent with an A3Π0+ → X1Σ transition in the IF molecule. A rotational and vibrational analysis of the bands has been carried out and the molecular constants evaluated for IF. The results are as follows:[Formula: see text]The present evidence relating to the value of the dissociation energy of IF is discussed.


1988 ◽  
Vol 66 (11) ◽  
pp. 1012-1024 ◽  
Author(s):  
R. Kępa

Seven bands ((0–0) – (0–6)) belonging to the Herzberg system of 13C18O have been recorded in emission using conventional photographic spectroscopy. For the first time, lines of this system have been recorded at high resolution and identified. After the rotational analysis of bands, the rotational constants of the C1Σ+ (ν = 0) and A1Π (ν = 0–6) states, as well as the vibrational constants of the A1Π state, have been determined. A combined analysis of the bands of the Herzberg and Ångström systems have made it possible to determine the constants of the B1Σ+ state more precisely. Numerous rotational perturbations observed in the A1Π state in this isotopic molecule have been analyzed.


1957 ◽  
Vol 35 (10) ◽  
pp. 1242-1249 ◽  
Author(s):  
N. A. Narasimham

Two band systems attributed to the P2+ molecule have been excited in a hollow cathode discharge tube. The first of these is a 2Π—2Π band system lying in the region 3400–3850 Å. The lower state of this system probably is the ground state of the P2+ molecule. The second system is a 2Σ—2Σ system lying in the region 3900–4400 Å. High resolution spectra of both the band systems have been analyzed and the rotational and vibrational constants determined.


1959 ◽  
Vol 37 (2) ◽  
pp. 136-143 ◽  
Author(s):  
Nand Lal Singh

The fine structures of three of the β bands of PO which occur near 3200 Å have been analyzed. The analysis shows that the upper state of this band system is a 2Σ and not a 2Π state as previously believed. The rotational constants of both electronic states have been determined and it is found that the ground state constants, previously determined from the γ bands, are incorrect.


1976 ◽  
Vol 54 (24) ◽  
pp. 2429-2434 ◽  
Author(s):  
B. R. Yadav ◽  
S. B. Rai ◽  
D. K. Rai

The visible emission spectrum of the GdO molecule has been produced in a DC arc source and has been photographed in the first order of a 10.6 m grating spectrograph. Bands are shown to have a six-headed structure and improved vibrational constants have been obtained in this study. Isotopic shifts have been calculated for the various isotopic molecules. Tentative suggestions regarding the nature of the transition have been made.


1974 ◽  
Vol 52 (9) ◽  
pp. 813-820 ◽  
Author(s):  
René Stringat ◽  
Jean-Paul Bacci ◽  
Marie-Hélène Pischedda

The strongly perturbed 1Π–X1Σ+ system of C80Se has been observed in the emission spectrum of a high frequency discharge through selenium and carbon traces in a neon atmosphere. The analysis of five bands yields, for the molecular constants of the ground state, the values Be″ = 0.5750 cm−1, [Formula: see text], αe″ = 0.00379 cm−1, re″ = 1.676 Å, ΔG″(1/2) = 1025.64 cm−1, and ΔG″(3/2) = 1015.92 cm−1. The numerous perturbations in the 1Π state prohibit the simple evaluation of the constants of the perturbed state and of the perturbing ones.


1959 ◽  
Vol 37 (5) ◽  
pp. 636-659 ◽  
Author(s):  
G. Herzberg ◽  
L. L. Howe

The Lyman bands of H2 have been investigated under high resolution with a view to improving the rotational and vibrational constants of H2 in its ground state. Precise Bv and ΔG values have been obtained for all vibrational levels of the ground state. One or two of the highest rotational levels of the last vibrational level (v = 14) lie above the dissociation limit. Both the [Formula: see text] and ΔG″ curves have a point of inflection at about v″ = 3. This makes it difficult to represent the whole course of each of these curves by a single formula and therefore makes the resulting equilibrium constants somewhat uncertain. This uncertainty is not very great for the rotational constants for which we find[Formula: see text]but is considerable for the vibrational constants ωe and ωexe for which three-, four-, five-, and six-term formulae give results diverging by ± 1 cm−1. The rotational and vibrational constants for the upper state [Formula: see text] of the Lyman bands are also determined. An appreciable correction to the position of the upper state is found.


1966 ◽  
Vol 44 (10) ◽  
pp. 2251-2258 ◽  
Author(s):  
A. E. Douglas ◽  
W. E. Jones

If argon mixed with a small amount of NF3 is pumped rapidly through a mild discharge, a green glow is observed downstream from the discharge. This emission has been photographed with a high dispersion spectrograph and found to consist of a strong band with a head at 5 288 Å and a number of weaker bands. A rotational analysis of the bands has shown that they are the b1Σ+–X3Σ− bands of the NF molecule. The constants of the two states have been determined and it is found that for the ground state, ωe = 1 141.37 cm−1 and re = 1.317 3 Å.


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