The 4875 Å Band System of cis Glyoxal

1971 ◽  
Vol 49 (3) ◽  
pp. 317-322 ◽  
Author(s):  
G. N. Currie ◽  
D. A. Ramsay

The 4875 Å band of glyoxal has been photographed in absorption under high resolution and a rotational analysis carried out. The band is of type C and the principal molecular constants are: A′ = 0.9069 cm−1, B′ = 0.1983 cm−1, C′ = 0.1627 cm−1, A″ = 0.8910 cm−1, B″ = 0.2066 cm−1, C″ = 0.1681 cm−1, v0 = 20 507.57 cm−1. The A-rotational constants are smaller by a factor of ~2 than the constants found earlier for trans glyoxal. The new results are consistent with the assignment of the band to an allowed 1B1–1A1 (π*–n) transition of cis glyoxal. Temperature studies indicate that the cis isomer lies 1125 ± 100 cm−1 above the trans isomer. This is the first time that cis glyoxal has been detected experimentally.

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.


1975 ◽  
Vol 53 (14) ◽  
pp. 1321-1326 ◽  
Author(s):  
M. Carleer ◽  
M. Herman ◽  
R. Colin

A rotational analysis has been performed on the 0–0 band of the A2Π–X2Σ+ transition of the BeBr molecule photographed at high resolution in emission from a beryllium hollow cathode in the presence of bromine vapor. The following principal molecular constants have been determined:[Formula: see text]


1967 ◽  
Vol 45 (8) ◽  
pp. 2805-2807 ◽  
Author(s):  
P. Ramakoteswara Rao ◽  
K. V. S. R. Apparao

The C band system of 63Cu81Br, lying in the region 3 900–4 600 Å, has been photographed in emission under high resolution and rotational analysis of the (2–0), (1–0), (0–0), (0–1), (0–2), and (1–3) bands carried out. The system is shown to involve a 1Σ(C1Σ)–1Σ(X1Σ) transition. The molecular constants of 63Cu81Br obtained from this fine-structure analysis are as follows:[Formula: see text]


1986 ◽  
Vol 64 (6) ◽  
pp. 726-732 ◽  
Author(s):  
B. Coquart ◽  
D. A. Ramsay

Ten bands of the [Formula: see text] system of oxygen have been observed in absorption using longer path lengths than in the earlier work of Herzberg (1953). Rotational analysis of the bands confirms that the A′ 3Δu state is an inverted state as expected from electron-configuration arguments. Rotational assignments are given for the [Formula: see text] and [Formula: see text] sub-bands with ν′ = 2–11; weaker [Formula: see text] sub-bands are identified for ν′ = 5–11. Sub-band origins and rotational constants are given for all the bands. The following derived molecular constants are obtained:[Formula: see text]A comparison of the frequencies of the diffuse bands of oxygen with the sub-band origins of the [Formula: see text] bands shows convincingly that the diffuse bands can be assigned to a weak (O2)2 complex in which one of the O2 molecules is excited to the A′ 3Δu state.


1979 ◽  
Vol 57 (7) ◽  
pp. 1051-1058 ◽  
Author(s):  
R. Colin

Six bands of the b1Σ+–X3Σ− transition of the PBr molecule have been observed in a microwave discharge of PBr3 + He. High resolution spectra have allowed the rotational analysis of the 0–0 and 1–1 bands. The principal molecular constants obtained are:X3Σ−: P79Br; ωe = 458.35 cm−1, Be = 0.16067 cm−1; P81Br; ωe = 457.78 cm−1, Be = 0.15958 cm−1; re = 2.1714 Å.B1Σ+: P79Br; ωe = 485.47 cm−1, Be = 0.16509 cm−1; P81Br; ωe = 483.84 cm−1, Be = 0.16399 cm−1; re = 2.1421 Å and Te = 11779.75 cm−1.


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.


1987 ◽  
Vol 65 (1) ◽  
pp. 94-100 ◽  
Author(s):  
Z. Jakubek ◽  
R. Kepa ◽  
A. Para ◽  
M. Rytel

The three bands (0–0, 1–0, 0–1) of the B2Σ+ – A2Πi system of the 12C16O+ molecule have been photographed at high resolution. In total, 824 lines were measured, from which 608 were fitted by a nonlinear least squares method to determine 33 molecular constants. The band-by-band results were merged to obtain 23 molecular constants for the B2Σ+, ν = 0 and 1, and A2Πi, ν = 0 and 1, states. The Λ-doubling constants and spin-orbit constants in the A2Πi, ν = 1 state and spin-rotation constants in the B2Σ+, ν = 0 and 1 states were obtained for the first time, and other constants were defined more precisely.


1969 ◽  
Vol 47 (9) ◽  
pp. 979-994 ◽  
Author(s):  
R. Colin

The absorption spectrum of SO radicals produced by flash photolysis of a mixture of COS + O2 + Ar is investigated. A partial rotational analysis of the previously known bands of the B3Σ−–X3Σ− transition which lie in the region of 1900 to 2400 Å is presented, and the predissociations and perturbations of the B3Σ−state are discussed. A complex red-degraded band system near 2500 Å, previously observed in emission and attributed to SO2, is shown to be due to a 3Π–X3Σ− transition of the SO molecule. Effective rotational constants of the 3Π state are derived from the analysis of these bands photographed at high resolution. In order to obtain the vibrational numbering of the 3Π–X3Σ− bands, these were also photographed in emission from a microwave discharge through a mixture of S18O2 + S16O2. A general discussion of the currently known states of the SO molecule is given.


1972 ◽  
Vol 50 (2) ◽  
pp. 171-184 ◽  
Author(s):  
R. Colin ◽  
M. Carleer ◽  
F. Prevot

A rotational analysis has been performed on the 0–0, 1–1, 1–0, and 2–1 bands of the A2Π–X2Σ+ band system of the BeCl molecule photographed at high resolution in emission from a microwave discharge. The following principal molecular constants have been obtained.[Formula: see text]Inspection of the low J value lines shows that the A2Π state is a regular state derived from the electronic configuration σ2σ2π4π although the Λ-doubling constants p and q are of opposite sign.


1962 ◽  
Vol 40 (4) ◽  
pp. 412-422 ◽  
Author(s):  
P. Ramakoteswara Rao ◽  
R. K. Asundi ◽  
J. K. Brody

The F–X band system of Cu65Cl35 extending from 3700 to 4200 Å has been photographed in emission under high resolution. Rotational analysis of the (3,0), (2,0), (1,0), (0,0), (0,1), and (0,2) bands of the system has been made. The electronic transition involved is found to be 1Π–1Σ. The Λ-type doubling in the 1Π state is negligible. The principal molecular constants obtained are as follows (cm−1 units)[Formula: see text]


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