The ν3 vibration–rotation band of DCP and the equilibrium structure of methinophosphide

1982 ◽  
Vol 60 (3) ◽  
pp. 304-306 ◽  
Author(s):  
Jacques Lavigne ◽  
Aldée Cabana
Keyword(s):  
Force Constant ◽  
Rotational Constant ◽  
Equilibrium Structure ◽  
Moment Of Inertia ◽  
Rotation Band ◽  
A Value ◽  
Internuclear Distances ◽  
Vibration Rotation

The ν3 band of D12CP(C—P stretching) has been recorded at a resolution of about 0.03 cm−1. The band centre, ν0, is found to be at 1231.4025(6) cm−1, whereas a force constant calculation had previously given a value of 1216 cm−1. The rotational constant B3 is determined and this allows the calculation of Be since the constants B1 and B2 are already known. Finally, the equilibrium moment of inertia, Ie, of the D12CP molecule is calculated. Since Ie for the H12CP molecule is also known, the equilibrium internuclear distances of methinophosphide may be calculated. One obtains: re (C—H) 1.0666(2) Å, and re(C≡P) 1.54020(3) Å.

Vibration-rotation bands of methyl fluoride

1954 ◽  
Vol 222 (1151) ◽  
pp. 443-455 ◽  
Keyword(s):  
Ground State ◽  
Rotational Constant ◽  
Microwave Spectrum ◽  
Complete Analysis ◽  
Methyl Fluoride ◽  
A Value ◽  
Infra Red ◽  
Type Band ◽  
Vibration Rotation

The vibration-rotation bands of methyl fluoride between 2⋅5 and 5 μ have been measured with higher resolution than previously. Three parallel bands have been analyzed, providing three independent values for B ", the rotational constant in the ground state. Each of these values is close to that obtained from the microwave spectrum (0⋅8518 cm -1 ), and some earlier values deduced from infra-red bands are shown to be incorrect. A value of 2⋅28 x 10 -6 cm -1 has also been obtained for D J , the centrifugal stretching constant, which is shown to be more satisfactory than that previously deduced from the microwave spectrum. A perpendicular type band has been resolved fairly completely, and it has been possible to measure the P and R lines of the sub-bands in addition to the strong Q branches. An analysis has been made which accounts satisfactorily for most of the lines in the entire band, and this provides the first example of such a complete analysis of a perpendicular band of a symmetrical top molecule.

Vibration-rotation bands and rotational constants of dideuteroacetylene

1955 ◽  
Vol 232 (1190) ◽  
pp. 291-309 ◽  
Keyword(s):  
Resolving Power ◽  
Vibrational States ◽  
Absorption Bands ◽  
Rotational Constants ◽  
Vibrational Assignments ◽  
Vibrational Anharmonicity ◽  
A Value ◽  
Vibrational Levels ◽  
Vibration Rotation ◽  
Very High

Nine vibrational absorption bands of dideutero-acetylene have been examined with very high resolving power. The rotational constants have been determined for the vibrational levels concerned, and the coefficients α i have been determined with more convincing accuracy than previously. In some of the bands the Q branches have been resolved, so that the l -doubling coefficients q i could be derived, and details could be established about the doublet components in some II levels. The results emphasize the need of high resolution if the vibrational assignments are to be unambiguous, and if reliable values of the rotational constants are to be derived. A value of B e has been obtained, and the vibrational anharmonicity coefficients have been considered briefly. Estimates of the centrifugal stretching constants D i in different vibrational states have been made, and one anomalous case has been found.

Infra-red chemiluminescence II. Spectroscopic data

1960 ◽  
Vol 258 (1295) ◽  
pp. 564-575 ◽  
Keyword(s):  
Transition Probabilities ◽  
Molecular Spectroscopy ◽  
Radiative Transition ◽  
Absorption Data ◽  
A Value ◽  
Interaction Factor ◽  
Infra Red ◽  
Rotational Distribution ◽  
Vibration Rotation ◽  
First Time

The technique described in part I has been used to obtain constants of interest in molecular spectroscopy. The vibration-rotation interaction factor, F for HCl has been evaluated from the infra-red emission spectrum. The critical parameter in F is θ = M 0 / M 1 r e , where M 0 and M 1 are the first two coefficients in the electric dipole moment expansion about the equilibrium internuclear distance r e . A value of θ = + 1.12 ± 0.18 has been obtained. It is shown that for molecules with θ = +1 the total band intensity in emission is independent of the rotational distribution in the vibrational state from which the emission occurs. This has been made use of in evaluating radiative transition probabilities. For the HCl v (3-1) transition a value for | R 3 1 | 2 (= 1.60 x 10 -4 debye 2 ) was obtained for the first time. The same method yields a value of | R 2 1 | 2 / | R 2 0 | 2 = 204, in good agreement with an earlier estimate from absorption data.

scholarly journals Bands in the secondary spectrum of hydrogen

1927 ◽  
Vol 114 (767) ◽  
pp. 293-313 ◽  
Keyword(s):  
Quantum Theory ◽  
Static Model ◽  
Moment Of Inertia ◽  
Initial Moment ◽  
A Value ◽  
Starting Point ◽  
Band Spectra ◽  
The University ◽  
Low Pressures ◽  
Complete Account

Fulcher’s discovery of bands in the secondary spectrum of hydrogen at low pressures proved the starting point of a number of investigations, including those, based on the valuable tables of Merton and Barratt, which have been carried out in the University of St. Andrews. The application of the quantum theory to these bands has been discussed by one of us (H. S. A.), by Curtis, and in particular by Richardson who, partly in association with Tanaka, has added greatly to the number of known regularities and done much to bring them into line with the theory of band spectra. Nevertheless, apart from the Fulcher system, of which Richardson has recently given a very complete account, there remains a very large number of lines which have not yet been classified. One of the present writers (I. S.) has been engaged in a study of the secondary spectrum at higher pressures, and among the regularities which have been selected by this method is a band with head at 4582·58 A. U. and shading towards the violet, which has been described in a recent communication. This band yielded an initial moment of inertia agreeing closely with a value deduced from a static model of triatomic hydrogen, H 3 . This band has since been found to be one of a large number of similar bands which it will be the purpose of this paper to describe. We shall refer to it for convenience as “Band II A , a .”

scholarly journals Comparison of HF and HCl Chemical Laser Parameters by using Mathematical Model

2007 ◽  
Vol 4 (1) ◽  
pp. 119-124
Author(s):  
Baghdad Science Journal
Keyword(s):  
Computer Program ◽  
Parametric Analysis ◽  
Rotational Constant ◽  
Published Data ◽  
Vibrational Quantum Number ◽  
Theoretical Comparison ◽  
Fabry Perot ◽  
Vibrational Levels ◽  
Hf Laser ◽  
Vibration Rotation

A simplified theoretical comparison of the hydrogen chloride (HCl) and hydrogen fluoride (HF) chemical lasers is presented by using computer program. The program is able to predict quantitative variations of the laser characteristics as a function of rotational and vibrational quantum number. Lasing is assumed to occur in a Fabry-Perot cavity on vibration-rotation transitions between two vibrational levels of hypothetical diatomic molecule. This study include a comprehensive parametric analysis that indicates that the large rotational constant of HF laser in comparison with HCl laser makes it relatively easy to satisfy the partial inversion criterion. The results of this computer program proved their credibility when compared with the little published data.

Pressure broadening in the 6190 Å vibration-rotation band of methane

1979 ◽  
Vol 65 (2) ◽  
pp. 201-205 ◽  
Author(s):  
Jack Gelfand ◽  
Wahid Hermina ◽  
William Hayden Smith
Keyword(s):  
Pressure Broadening ◽  
Rotation Band ◽  
Vibration Rotation

DERIVATIVES OF MONOGERMANE: PART I. THE VIBRATION–ROTATION SPECTRA OF GERMYL FLUORIDE AND BROMIDE

1962 ◽  
Vol 40 (4) ◽  
pp. 579-589 ◽  
Author(s):  
J. E. Griffiths ◽  
T. N. Srivastava ◽  
M. Onyszchuk
Keyword(s):  
Harmonic Oscillator ◽  
Infrared Absorption ◽  
Thermodynamic Functions ◽  
Low Frequency ◽  
Rotational Constant ◽  
Rigid Rotator ◽  
Harmonic Oscillator Model ◽  
Infrared Absorption Spectra ◽  
Vibration Rotation ◽  
Derivatives Of

The vibration–rotation infrared absorption spectra of germyl fluoride and bromide have been observed. All of the fundamentals in GeH3F were located, and the rotational structure of the E-type bands were resolved and analyzed. The low-frequency band, ν3(a1), in GeH3Br was not observed but an estimate of its position was made from the frequencies of the combination band ν3 + ν6 and of ν6. The rotational constant A″ and the Coriolis constants ζ4, ζ5, and ζ6 were calculated for both molecules, and agreement with microwave A″ values was satisfactory. Thermodynamic functions based upon a rigid-rotator, harmonic-oscillator model have been evaluated for germyl fluoride and bromide.

Diode Laser Spectrum of HCCCN near 5 μm

1980 ◽  
Vol 35 (7) ◽  
pp. 690-693 ◽  
Author(s):  
Koichi Yamada ◽  
R. Schieder ◽  
G. Winnewisser ◽  
A. W. Mantz
Keyword(s):  
Excited State ◽  
Diode Laser ◽  
Rotational Constant ◽  
Doppler Broadening ◽  
Laser Spectrometer ◽  
Laser Spectrum ◽  
Band Center ◽  
Diode Laser Spectrometer ◽  
Vibration Rotation ◽  
Better Than

The ν3 vibration-rotation band of cyanoacetylene, HC3N, has been measured in the wavenumber range 2068 to 2095 cm-1 to an accuracy of better than ± 0.005 cm-1 using a diode laser spectrometer. The width of the observed lines is essentially limited by Doppler-broadening. The band center of the ν3 vibration is determined from the observed P- and R-branch transitions to be at 2079.30500 (58) cm-1. The rotational constant of the excited state is B′= 0.151212 (10) cm-1.

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