Le spectre electronique de la molécule LuD

1974 ◽  
Vol 52 (6) ◽  
pp. 523-535 ◽  
Author(s):  
Christiane Effantin ◽  
Jean D'Incan
Keyword(s):  
Electronic Spectrum ◽  
Hollow Cathode ◽  
Isotope Shift ◽  
Visible Region ◽  
Mutual Interaction ◽  
Electronic Transitions ◽  
Molecular Constants ◽  
Fundamental State ◽  
Symmetry Properties ◽  
Vibrational Levels

The electronic spectrum of LuD has been excited in a Lu2O3–Th–Cu hollow cathode filled with argon and traces of deuterium. All the recorded bands, lying in the visible region, belong to six electronic transitions towards the X1Σ+ fundamental state of the molecule. Molecular constants and symmetry properties of these states have been deduced from the vibrational and rotational analyses. The electronic isotope shift has been obtained from data of the H → X system. Finally, the anomalous intensities observed in the Δν = 2 sequences of the E → X and G → X systems are explained in terms of a mutual interaction between pairs of vibrational levels belonging to the E and G states.

Rotational analysis of selected bands from the electronic spectrum of the LuF molecule

1976 ◽  
Vol 54 (3) ◽  
pp. 279-294 ◽  
Author(s):  
C. Effantin ◽  
G. Wannous ◽  
J. d'Incan ◽  
C. Athenour
Keyword(s):  
Electronic Spectrum ◽  
Excited States ◽  
Direct Approach ◽  
Rotational Analysis ◽  
Molecular Constants ◽  
Fundamental State

Rotational analysis of 20 selected bands from the electronic spectrum of the LuF molecule has been carried out. No perturbation was detected; the molecular constants deduced from a 'direct approach' including all the bands are given for the fundamental state X1Σ (ωe = 611.79, Be = 0.26764) and the excited states A1Σ (ωe = 587.95, Be = 0.26356), B1Π (ωe = 581.3, Be = 0.2632), E1Π (ωe = 543.42, Be = 0.25647), and F1Σ (ωe = 560.8, Be = 0.25815).

THE SPECTRUM OF CN IN THE VACUUM ULTRAVIOLET

1956 ◽  
Vol 34 (1) ◽  
pp. 83-95 ◽  
Author(s):  
P. K. Carroll
Keyword(s):  
Dissociation Energy ◽  
Fourth Order ◽  
Hollow Cathode ◽  
Vacuum Ultraviolet ◽  
Hollow Cathode Discharge ◽  
Molecular Constants

The spectrum of the CN radical has been investigated in the Schumann region using a three-meter vacuum spectrograph in the fourth order. A hollow cathode discharge through streaming helium, to which a trace of cyanogen was added, was used as source. Three new systems of bands were found in the region 1650–2100 Å. These involve two hitherto unknown states: a 2Σ state designated by E, which gives rise to the transitions E2Σ → X2Σ and E2Σ → A2Π, and an inverted 2Δ state designated by J, which gives rise to the transition J2Δ → A2Π. Rotational analyses of the bands have been made and the molecular constants evaluated. The new data, although not decisive, support the higher value (8.2 ev.) for the dissociation energy of CN.

The spectroscopy of jet-cooled porphyrins: an insight into the vibronic structure of the Q band

2010 ◽  
Vol 14 (04) ◽  
pp. 314-323 ◽  
Author(s):  
Joseph M. Beames ◽  
Timothy D. Vaden ◽  
Andrew J. Hudson
Keyword(s):  
Laser Desorption ◽  
Electronic Transitions ◽  
Quantum Mechanical ◽  
Supersonic Expansion ◽  
Two Photon ◽  
Vibrational Levels ◽  
Inert Carrier ◽  
Mechanical Interpretation ◽  
Photon Ionization ◽  
Insight Into

We will present resonant two-photon ionization spectra for meso-tetraphenylporphyrin, H 2 TPP , measured under isolated conditions. The polycrystalline compound was vaporized, in vacuo, using both thermal and laser desorption, and seeded into a supersonic expansion of an inert-carrier gas. The molecules remain largely intact in the gaseous phase. However, the two techniques for vaporizing H 2 TPP give different internal temperatures for the isolated substrate, with greater vibrational cooling achieved using laser desorption. A comparison of the peak positions and intensities in the resonant two-photon ionization spectra of thermal- and laser-desorbed molecules provides an insight into the vibrational structure of the Q band. In particular, the greater contribution made by electronic transitions originating from higher vibrational levels in the ground state of H 2 TPP is emphasized. We conclude that vibronic coupling in the ground electronic state plays an important role in a quantum-mechanical interpretation of the Q band.

Rotational Analysis of the A2Π–X2Σ+ Band System of the BeBr Molecule

1975 ◽  
Vol 53 (14) ◽  
pp. 1321-1326 ◽  
Author(s):  
M. Carleer ◽  
M. Herman ◽  
R. Colin
Keyword(s):  
High Resolution ◽  
Hollow Cathode ◽  
Band System ◽  
Rotational Analysis ◽  
Molecular Constants ◽  
Bromine Vapor

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]

BAND SPECTRUM AND STRUCTURE OF THE CH+ MOLECULE; IDENTIFICATION OF THREE INTERSTELLAR LINES

1942 ◽  
Vol 20a (6) ◽  
pp. 71-82 ◽  
Author(s):  
A. E. Douglas ◽  
G. Herzberg
Keyword(s):  
Ground State ◽  
Band System ◽  
Lower State ◽  
Band Spectrum ◽  
Interstellar Space ◽  
Molecular Constants ◽  
Vibrational Levels ◽  
State Formula ◽  
Heat Of Dissociation ◽  
Π State

In a discharge through helium, to which a small trace of benzene vapour is added, a new band system of the type 1Π – 1Σ is found which is shown to be due to the CH+ molecule. The R(0) lines of the 0–0, 1–0, and 2–0 bands of the new system agree exactly with the hitherto unidentified interstellar lines 4232.58, 3957.72, 3745.33 Å, thus proving that CH+ is present in interstellar space. At the same time this observation of the band system in absorption shows that the lower state 1Σ is the ground state of the CH+ molecule. The new bands are closely analogous to the 1II – 1Σ+ BH bands. The analysis of the bands leads to the following vibrational and rotational constants of CH+ in its ground state: [Formula: see text], Be″ = 14.1767, αe″ = 0.4898 cm.−1. The internuclear distance is re″ = 1.1310∙10−8 cm. (for further molecular constants see Table V). From the vibrational levels of the upper 1Π state the heat of dissociation of CH+ can be obtained within fairly narrow limits: D0(CH+) = 3.61 ± 0.22 e.v. From this value the ionization potential of CH is derived to be I(CH) = 11.13 ± 0.22 e.v. The bearing of this value on recent work on ionization and dissociation of polyatomic molecules by electron impacts is briefly discussed.

Etats Rydberg de NS. Etude du domaine spectral 2400–1750 Å

1976 ◽  
Vol 54 (18) ◽  
pp. 1909-1923 ◽  
Author(s):  
Michel Vervloet ◽  
Alain Jenouvrier
Keyword(s):  
Energy Level ◽  
Relative Position ◽  
Rydberg States ◽  
Energy Level Diagram ◽  
Electronic Transitions ◽  
Complete Analysis ◽  
Molecular Constants ◽  
Π State ◽  
Potential Curves

Five electronic transitions, C2Σ+–X2Π, I2Σ+–X2Π, E2Π–X2Π, J2Σ+–X2Π, and F2Δ–X2Π of NS have been observed in the region 1750–2400 Å. The complete analysis of these transitions has been carried out. The molecular constants of the C2Σ+, E2Π, J2Σ+, and F2Δ Rydberg states are given. Many perturbations in the rotational structures (ν = 1 and 2 of C2Σ+, ν = 0 of E2Π) and predissociations in the levels ν = 0 J2Σ+ and F2Δ are observed. The perturbation in the level ν = 0 of the E2Π state is described, the perturbing level being ν = 11 of the H2Π valence state.The most important results are given in the tables of constants. An energy level diagram and potential curves show the relative position of the different states. All the observed states of NS are finally compared with those of PO.

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.

Emission spectra of group IV monohalide ions: , 3Π1–X1Σ+ emissions of SiBr+

1984 ◽  
Vol 62 (4) ◽  
pp. 353-360 ◽  
Author(s):  
M. Tsuji ◽  
K. Shinohara ◽  
S. Nishitani ◽  
T. Mizuguchi ◽  
Y. Nishimura
Keyword(s):  
Thermal Energy ◽  
Vibrational Temperature ◽  
Vibrational Analysis ◽  
Emission Spectra ◽  
Ionic Species ◽  
Group Iv ◽  
Rare Gas ◽  
Molecular Constants ◽  
Vibrational Levels ◽  
Effective Vibrational Temperature

Emission spectra of SiBr4 in the rare gas flowing afterglows have been measured to detect and identify SiBr+ emissions. Two systems of SiBr+ emissions were detected in the He, Ne, and Ar afterglows in the region from 335 to 380 nm. By analogy with the emission spectrum of SiCl+, they were ascribed to the [Formula: see text]–X1Σ+ and a3Π1–X1Σ+ subsystems of SiBr+. The vibrational analysis of the latter system gave the following molecular constants for the a3Π1 state: T0 = 29 140 ± 5 cm−1 and ΔG(1/2) = 392.0 ± 3.7 cm−1. The SiBr+ emissions disappeared when ionic species were removed from the afterglows, indicating that the emitting SiBr+ states were produced through thermal-energy reactions of rare gas ions with SiBr4. In the He and Ne afterglows, the [Formula: see text] ions were produced in higher vibrational levels than in the Ar afterglow. The relative vibrational populations in the He and Ne afterglows were nearly exponential with an effective vibrational temperature of 460 ± 30 K.

Vibration-rotation bands of trideuteromethyl iodide

1965 ◽  
Vol 288 (1412) ◽  
pp. 39-49 ◽  
Keyword(s):  
Fine Structure ◽  
Coupling Constants ◽  
Coriolis Coupling ◽  
Molecular Constants ◽  
Rotational Constants ◽  
Vibrational Levels ◽  
Theoretical Predictions ◽  
Vibration Rotation ◽  
Combination Bands

The rotational fine structure of six parallel and nine perpendicular vibration bands of tri­deuteromethyl iodide has been analysed, and molecular constants have been derived. These include the band origins, the rotational constants in different vibrational levels, the α A i and α B i values, and the Coriolis coupling constants ς i for the fundamental degenerate vibrations. The ς values for overtone and combination bands have been compared with values calculated from the ς i values of the fundamentals, and agree closely with previous theoretical predictions.

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.

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