EMISSION BAND SPECTRA OF NITROGEN THE LYMAN-BIRGE-HOPFIELD SYSTEM

1956 ◽  
Vol 34 (8) ◽  
pp. 780-789 ◽  
Author(s):  
Alf Lofthus
Keyword(s):  
Raman Spectrum ◽  
High Resolution ◽  
Emission Spectrum ◽  
Ground State ◽  
Emission Band ◽  
Equilibrium Constants ◽  
Rotational Constants ◽  
Near Ultraviolet ◽  
Band Spectra

The near ultraviolet part of the emission spectrum of nitrogen has been photographed under high resolution. Thirteen bands of the [Formula: see text] system (Lyman–Birge–Hopfield) have been analyzed and new vibrational and rotational constants obtained. Combining the observed data with those obtained by Stoicheff from the Raman spectrum of nitrogen, refined equilibrium constants for the ground state were obtained. The predissociation in the α1Πg state was observed.

High Resolution Infrared Spectra of the ν2 and 2ν1 Bands of 14N16O2

1975 ◽  
Vol 53 (19) ◽  
pp. 1902-1926 ◽  
Author(s):  
Aldée Cabana ◽  
Michel Laurin ◽  
Walter J. Lafferty ◽  
Robert L. Sams
Keyword(s):  
High Resolution ◽  
Infrared Spectra ◽  
Ground State ◽  
Equilibrium Structure ◽  
Coriolis Interaction ◽  
Rotational Constants ◽  
Average Structures

The infrared spectra of two B type bands, ν2 and 2ν1, of 14N16O2 have been recorded under high resolution. Ground state combination differences from these bands have been combined with combination differences obtained in previous studies and eight pure rotational microwave transitions to yield improved ground state rotational constants. Upper state constants and band centers for the ν2 and 2ν1 bands are also reported. The 2ν1 band contains internal intensity anomalies believed to arise from a weak Coriolis interaction with the much stronger ν1 + ν3 band. Equilibrium rotational constants have been calculated. The equilibrium structure of the molecule is: rc = 1.1945 ± 0.0005 Å and Θc = 133.85 ± 0.10°. For the sake of comparison, effective, substitution, and average structures are also reported.

THE LYMAN BANDS OF MOLECULAR HYDROGEN

1959 ◽  
Vol 37 (5) ◽  
pp. 636-659 ◽  
Author(s):  
G. Herzberg ◽  
L. L. Howe
Keyword(s):  
High Resolution ◽  
Vibrational Level ◽  
Ground State ◽  
Molecular Hydrogen ◽  
Equilibrium Constants ◽  
Dissociation Limit ◽  
Vibrational Levels ◽  
State Formula ◽  
Single Formula ◽  
Vibrational Constants

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.

HIGH RESOLUTION RAMAN SPECTROSCOPY OF GASES: III. RAMAN SPECTRUM OF NITROGEN

1954 ◽  
Vol 32 (10) ◽  
pp. 630-634 ◽  
Author(s):  
B. P. Stoicheff
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectrum ◽  
High Resolution ◽  
Electronic Spectra ◽  
Second Order ◽  
Published Data ◽  
Rotational Spectrum ◽  
Rotational Constants ◽  
Vibrational Constants

The pure rotational spectrum and the Q branch of the 1–0 band of N2 were photographed in the second order of a 21 ft. grating. An analysis of the rotational spectrum yields the rotational constants[Formula: see text]The value of B0 together with the Bν values obtained from the electronic bands of N2 gives[Formula: see text]Revised values of the vibrational constants have also been calculated using the results of the present work and the published data on the electronic spectra.

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
Keyword(s):  
High Resolution ◽  
Emission Spectrum ◽  
Ground State ◽  
Band System ◽  
Vibrational Analysis ◽  
Quartz Tube ◽  
Rotational Analysis ◽  
Vibrational Constants

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.

High-resolution studies of the near-ultraviolet bands of oxygen: III: the system

1986 ◽  
Vol 64 (6) ◽  
pp. 726-732 ◽  
Author(s):  
B. Coquart ◽  
D. A. Ramsay
Keyword(s):  
High Resolution ◽  
Electron Configuration ◽  
Rotational Analysis ◽  
Molecular Constants ◽  
Rotational Constants ◽  
Near Ultraviolet ◽  
Path Lengths

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.

Two New Band Systems in the Near Ultraviolet Spectrum of N2

1975 ◽  
Vol 53 (19) ◽  
pp. 2198-2209 ◽  
Author(s):  
P. K. Carroll ◽  
K. V. Subbaram
Keyword(s):  
High Resolution ◽  
Emission Spectrum ◽  
Rydberg State ◽  
Molecular Nitrogen ◽  
Ultraviolet Spectrum ◽  
Dissociation Limit ◽  
Ultraviolet Emission ◽  
Weak Band ◽  
Near Ultraviolet ◽  
Unusual Type

Two new weak band systems have been identified under high resolution in the near ultraviolet emission spectrum of molecular nitrogen. They are found to arise from a transition from a hitherto unknown 1Πg state, which it is proposed to call k, to the a′ 1Σu− and w1Δu states. The upper state is interpreted as the 1ΠgRydberg state of configuration … (1πu)4 (3σg) 3dπg. Straightforward treatment of the data by conventional methods gives B0d = 1.906 cm−1, B1d = 1.824 cm−1, T0 = 113 630.87 cm−1, and ΔG1/2 = 2305.92 cm−1. Only the d levels, i.e., the levels corresponding to the 1Πg− component, are observed and the absence of the c levels is attributed to an unusual type of predissociation involving the predicted stable 1Σg+ state which goes to the dissociation limit 2D + 2D (14.522 eV) and the 3Σg− state which arises at the limit 4S + 2P (13.332 eV). A new level at 117 661.11 cm−1 with a Bd value of 1.695 cm−1 is identified as v = 2 of the y1Πg state. A strong homogeneous interaction is found to be occurring between the new k1Πg state and the y1Πg state. A deperturbation calculation is carried out and yields the following deperturbed constants: k1Πg: Be = 1.959 cm−1; αe = 0.031 cm−1; re = 1.109 Å; T0 = 113 723.58 cm−1; ΔG1/2 = 2182.32 cm−1, y1Πg: Be = 1.739 cm−1; αe = 0.017 cm−1; re = 1.177 Å; Te = 114 314.36 cm−1; ωe = 1906.43 cm−1; αexe = 37.51 cm−1.

Rotational Raman spectrum of nitric oxide

1970 ◽  
Vol 48 (5) ◽  
pp. 632-634 ◽  
Author(s):  
K. C. Shotton ◽  
W. Jeremy Jones
Keyword(s):  
Nitric Oxide ◽  
Raman Spectrum ◽  
High Resolution ◽  
Rotational Constants ◽  
Exciting Line ◽  
High Resolution Analysis ◽  
Resolution Analysis ◽  
First Time

The pure rotational Raman spectrum of nitric oxide has been recorded for the first time under high resolution. Analysis of the S-branch transitions yields values of 1.69614 cm−1 and 5.46 × 10−6 cm−1 for the rotational constants B0 and D0, respectively. A series of R-branch lines is observed and is shown to arise from transitions between levels in the 2Π3/2 substate. Some weaker R-branch lines arising from the 2Π1/2 state are also observed. A very weak feature approximately 120 cm−1 from the exciting line is interpreted as the 2Π3/2–2Π1/2 transition.

The electronic emission spectrum of triatomic hydrogen. I. Parallel bands of H3 and D3 near 5600 and 6025 Å

1980 ◽  
Vol 58 (8) ◽  
pp. 1238-1249 ◽  
Author(s):  
I. Dabrowski ◽  
G. Herzberg
Keyword(s):  
Interstellar Medium ◽  
Emission Spectrum ◽  
Detailed Analysis ◽  
Ground State ◽  
Emission Band ◽  
Rydberg States ◽  
Electronic States ◽  
Molecular Constants ◽  
Additional Band ◽  
Rydberg Electron

A spectrum of triatomic hydrogen and deuterium was first discovered by means of an emission band with diffuse rotational structure near 5600 Å. An additional band of similar but much better resolved structure was subsequently observed near 6025 Å. The detailed analysis of these two bands for both H3 and D3 is described in this paper. Both bands are [Formula: see text] bands of a symmetric top; their structure establishes beyond doubt that triatomic hydrogen has a D3h structure in its Rydberg states. The molecular constants in upper and lower states are close to those in the ground state of H3+ (or D3+) in accordance with the assumption that these states are Rydberg states in which a single electron moves around a H3+ or D3+ core. The predicted states of such a Rydberg electron in a field of D3h symmetry account very well for the observed electronic states, both those involved in the [Formula: see text] bands described here and those involved in the [Formula: see text] bands to be discussed in subsequent papers of this series. The lowest state of the Rydberg electron 2p2E′ is unstable and dissociates to H2 + H in their ground states. It is this state that causes predissociation in the two lower states 2s2A1′and 2p2A2″ of the two [Formula: see text] bands here under discussion. The predissociation of 2s2A1′ is vibronically allowed and fairly strong such that all lines have widths of about 7 cm−1 for D3 and 30 cm−1 for H3. The predissociation of the 2p2A2″ state is vibronically forbidden and occurs only on account of ro-vibronic interaction. H3+ ions are assumed to be present in the interstellar medium. When they recombine with electrons they must necessarily emit the spectra described in this series of papers.

The rotational analysis of the A1Π–X1Σ+ system of Si130Te

1992 ◽  
Vol 70 (5) ◽  
pp. 291-294 ◽  
Author(s):  
Sheila Gopal ◽  
M. Singh ◽  
G. Lakshminarayana
Keyword(s):  
High Resolution ◽  
Emission Spectrum ◽  
Microwave Discharge ◽  
Band System ◽  
Rotational Structure ◽  
Quartz Tube ◽  
Rotational Analysis ◽  
Rotational Constants

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.

Vibration-rotation bands of monodeuteroacetylene and the molecular dimensions

1956 ◽  
Vol 234 (1198) ◽  
pp. 306-317 ◽  
Keyword(s):  
High Resolution ◽  
Ground State ◽  
Fermi Resonance ◽  
Rotational Constants ◽  
Bond Lengths ◽  
Vibrational Levels ◽  
Vibration Rotation ◽  
Molecular Dimensions

Some vibration-rotation bands of monodeuteroacetylene have been measured with high resolution. Values have been derived for the coefficients α i relating the rotational constants in different vibrational levels, as follows: α 2 = + 0⋅00439, α 3 = + 0⋅00638, α 4 = — 0⋅0032 2 , α 5 = — 0⋅0011. Using the value B 00000 = 0⋅9910 5 cm -1 , also determined from many bands, a new value, B e = 0⋅9948, has been obtained leading to new estimates for the bond lengths r e CH = 1⋅058 Å, and r e C≡C = 1⋅205 0 . The l -doubling coefficient has been determined in two states, namely, q 00010 = 0⋅0056 and q 00003 = 0⋅0072. In the ground state the results are in accordance with a centrifugal stretching coefficient D = 0⋅7 x 10 -6 , but in some higher levels a markedly different value is derived, which may, however, arise through the effects of Fermi resonance.

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