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.

Emission Spectrum of the PO Molecule. Part II.2Σ–2Σ Transitions

1971 ◽  
Vol 49 (24) ◽  
pp. 3180-3200 ◽  
Author(s):  
R. D. Verma ◽  
M. N. Dixit ◽  
S. S. Jois ◽  
S. Nagaraj ◽  
S. R. Singhal
Keyword(s):  
Emission Spectrum ◽  
Ionization Potential ◽  
Dissociation Energy ◽  
Ground State ◽  
Rydberg States ◽  
Electronic States ◽  
Electronic Transitions ◽  
A Value ◽  
Upper Limit ◽  
First Ionization Potential

Rotational structure of emission bands of the PO molecule in the region 5300–3800 Å is analyzed. The spectrum is attributed to 5 electronic transitions A2Σ+–B2Σ+, F2Σ+–B2Σ+, G2Σ+–B2Σ+, H2Σ+–B2Σ+, and I2Σ+–B2Σ+, where F, G, H, and I are the new electronic states and A and B are the upper states of the well-known γ and β bands respectively. Practically all the new 2Σ states are found to be perturbed. A qualitative account of these perturbations together with a deperturbation of certain levels is given. A number of cases of predissociation are also observed. This predissociation is attributed to the presence of 4Πi, and A′2Σ+ states, which dissociate to the ground state atomic products. From this an upper limit of the dissociation energy of the ground state of PO is determined to be D0 = 49 536 cm−1. The A, D, E, G, H, and I states of this molecule are assigned as Rydberg states corresponding to the σ4s, π4p, δ3d, σ4p, σ3d, and σ5s orbitals, respectively. From them a value of 67 570 cm−1 is evaluated for the first ionization potential of PO. All the electronic states established for this molecule are described in terms of electron configurations.

Rotational Analysis of the lΠ–XlΣ+ System of C80Se

1974 ◽  
Vol 52 (9) ◽  
pp. 813-820 ◽  
Author(s):  
René Stringat ◽  
Jean-Paul Bacci ◽  
Marie-Hélène Pischedda
Keyword(s):  
Emission Spectrum ◽  
Ground State ◽  
High Frequency ◽  
Rotational Analysis ◽  
Molecular Constants ◽  
High Frequency Discharge ◽  
Perturbed State ◽  
Simple Evaluation ◽  
Π State

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.

THE ABSORPTION SPECTRUM OF BO2

1961 ◽  
Vol 39 (12) ◽  
pp. 1738-1768 ◽  
Author(s):  
J. W. C. Johns
Keyword(s):  
Absorption Spectrum ◽  
Excited State ◽  
Detailed Analysis ◽  
Ground State ◽  
Flash Photolysis ◽  
Electronic Transitions ◽  
Molecular Constants ◽  
Boron Trichloride ◽  
Symmetric Molecule ◽  
First Excited State

The boron flame bands have been observed in absorption during the flash photolysis of mixtures of boron trichloride and oxygen. Detailed analysis of the spectrum has shown that the bands arise from two electronic transitions in the linear symmetric molecule BO2, [Formula: see text] and A2Πu−X2Πg. The main molecular constants, in cm−1 except for r0, are summarized below:[Formula: see text]Both 2Π states show the Renner effect. In the ground state the Renner parameter, εω2, was found to be −92.2, whereas in the first excited state it is much smaller, −13.1 cm−1.

Electronic spectrum of H2O+

1976 ◽  
Vol 54 (20) ◽  
pp. 2028-2049 ◽  
Author(s):  
H. Lew
Keyword(s):  
Emission Spectrum ◽  
Electronic Spectrum ◽  
Ground State ◽  
Energy Levels ◽  
Bond Distance ◽  
Electronic States ◽  
Wavelength Region ◽  
Astrophysical Interest ◽  
Vibrational Levels ◽  
Wave Numbers

Many bands of the [Formula: see text] electronic emission spectrum of H2O+, occurring in the wavelength region 4000–7500 Å, have been analyzed. These include bands that have been observed in the tails of comets. The wavelengths and wave numbers of all assigned lines are tabulated. Accurate rotational constants for the first three bending vibrational levels of the ground state are given, as well as energy levels in the upper and lower electronic states. The O—H bond distance and the H—O—H angle in the [Formula: see text] (0, 0, 0) level are found to be 0.9988 Å and 110.46° respectively. Some predicted microwave and infrared lines that may be of astrophysical interest are included.

The Ground State and A2Π Excited State of Magnesium Deuteride

1975 ◽  
Vol 53 (15) ◽  
pp. 1477-1482 ◽  
Author(s):  
Walter J. Balfour ◽  
Hugh M. Cartwright
Keyword(s):  
Excited State ◽  
High Resolution ◽  
Emission Spectrum ◽  
Isotope Effect ◽  
Ground State ◽  
Visible Emission ◽  
Molecular Constants ◽  
Dissociation Energies ◽  
First Time ◽  
Π State

The visible emission spectrum of MgD has been reexamined at high resolution. Published analyses of the A2Π → X2Σ+ system have been extended and the data have been combined with observations in the B′2Σ+ → X2Σ+ system to provide information on the ground state levels ν = 3, 4, 5, and 6 for the first time. The following molecular constants (in cm−1) have been determined—for the A2Π state: ωc = 1154.75, ωcxc = 16.675, Bc = 3.2190, Dc = 9.64 × 10−5 and for the X2Σ+ state: ωc = 1077.71, ωcxc = 15.92, Bc = 3.0306, and Dc = 9.39 × 10−5. The dissociation energies in the A2Π and X2Σ+ states have been estimated to be ~ 15 500 cm−1 and ~ 11 500 cm−1 respectively. The MgH/MgD isotope effect and the Λ doubling in the A2Π state are discussed.

Rotational Structure in Some Higher Excited States of the GeF Molecule

1974 ◽  
Vol 52 (15) ◽  
pp. 1458-1475 ◽  
Author(s):  
R. W. Martin ◽  
A. J. Merer
Keyword(s):  
Emission Spectrum ◽  
Excited States ◽  
Ground State ◽  
Valence State ◽  
Rydberg States ◽  
The Other ◽  
Electronic Transitions ◽  
Lower State ◽  
High Dispersion ◽  
Higher Excited States

The weaker electronic transitions in the region 2000–9000 Å in the emission spectrum of GeF have been photographed at high dispersion; three new transitions with the A2Σ+ state as lower state have been discovered, and the various systems near 2100 and 8600 Å have been reassigned. The spectra have been explained in terms of six excited states lying between 40 000 and 50 000 cm−1 above the ground state, and representative bands involving all six have been analyzed rotationally. Five of these excited states are Rydberg states (5pσ, 5pπ, 4dπ, 4dδ, and 6sσ), and the other is the σπ22Δ valence state; this latter interacts strongly with the 4dδ 2Δ state.

Emission spectrum of the PO molecule. I. A new B′2Πi–X2Πr transition

1970 ◽  
Vol 48 (20) ◽  
pp. 2391-2398 ◽  
Author(s):  
R. D. Verma
Keyword(s):  
Emission Spectrum ◽  
Ground State ◽  
Rotational Analysis ◽  
Molecular Constants ◽  
New System

A new system of the PO molecule in the region 4800–3800 Å has been obtained. Rotational analysis of its seven bands establishes the transition involved to be B′2Πi–X2Πr, where X2Πr is the known ground state of the molecule. The molecular constants of the lower and upper levels have been evaluated.

Electronic spectrum of the BF molecule

1970 ◽  
Vol 48 (4) ◽  
pp. 432-452 ◽  
Author(s):  
R. B. Caton ◽  
A. E. Douglas
Keyword(s):  
High Resolution ◽  
Emission Spectrum ◽  
Ionization Potential ◽  
Electronic Spectrum ◽  
Excited States ◽  
Electronic Absorption ◽  
Rydberg States ◽  
Electronic States ◽  
Rydberg Series ◽  
Absorption And Emission

The electronic absorption and emission spectrum of BF has been photographed at high resolution from 900 to 11 000 Å. In this work, many new electronic states have been found and corrections have been made to earlier work. The ionization potential has been determined to be between 89 635 and 89 680 cm−1, with the most probable value being 89 650 cm−1. Tables of the vibrational and rotational constants of all the known states of BF are presented. All but two of the excited states of BF have been classified as Rydberg states and have been assigned to Rydberg series. The interactions between the various Rydberg states are discussed.

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.

Rotational Analysis of the A–X System of the SiCl Molecule

1971 ◽  
Vol 49 (4) ◽  
pp. 407-411 ◽  
Author(s):  
S. R. Singhal ◽  
R. D. Verma
Keyword(s):  
Ground State ◽  
Electronic States ◽  
Rotational Structure ◽  
Spin Coupling ◽  
Quartz Tube ◽  
Rotational Analysis ◽  
Coupling Constant ◽  
Spin Coupling Constant ◽  
Molecular Constants ◽  
Vibrational Levels

The A–X system of the SiCl molecule in the region 4500–6400 Å has been excited by an r.f. discharge through a mixture of argon and a trace of SiCl4 vapor, flowing through a quartz tube. Several red degraded and double headed bands with ν′ = 0, 1, 2, and 3 have been observed and the rotational structure of the 0-5, 0-6, 0-7, 0-8, 0-9, 0-10, 1-9, and 1-10 bands has been analyzed. The analysis shows that the bands arise from a 2Σ–2Π transition, 2Π being the ground state of the molecule. The molecular constants have been determined for both the electronic states. The spin coupling constant, Aν, of the X2Π vibrational levels has been found to follow an equation[Formula: see text]

Sign in / Sign up

Export Citation Format

Share Document