A study of the electric quadrupole fundamental band of D2 using an infrared difference frequency laser system

1978 ◽  
Vol 56 (10) ◽  
pp. 1315-1320 ◽  
Author(s):  
A. R. W. McKellar ◽  
T. Oka
Keyword(s):  
Laser System ◽  
Electric Quadrupole ◽  
Difference Frequency ◽  
Ratio Method ◽  
Molecular Constants ◽  
Frequency Tunable ◽  
Vibration Rotation ◽  
Frequency Laser ◽  
Deuterium Molecule ◽  
Rotation Spectrum

Frequency tunable infrared radiation from a difference frequency laser system has been used with a long path cell to study the electric quadrupole vibration–rotation spectrum of the deuterium molecule in the 2.8–3.9 μm region. A ratio method as well as frequency modulation were used to detect the weak absorption. Sub-Doppler linewidths due to collisional narrowing were observed with a D2 pressure of 1 atm. The wavelengths of 11 transitions were measured relative to infrared reference lines, and improved molecular constants for the ν = 0 and 1 states of D2 were determined.

Difference-frequency laser spectroscopy of the ν4 fundamental band of NH3D+

1986 ◽  
Vol 64 (10) ◽  
pp. 1356-1358 ◽  
Author(s):  
T. Nakanaga ◽  
T. Amano
Keyword(s):  
Laser System ◽  
Rotational Constant ◽  
Rotational Transition ◽  
Difference Frequency ◽  
High Resolution Spectrum ◽  
Interstellar Space ◽  
Molecular Constants ◽  
Fundamental Band ◽  
Least Squares Fit ◽  
Frequency Laser

The high-resolution spectrum of the ν4 fundamental band of NH3D+ has been observed in absorption in a hollow-cathode discharge with a difference-frequency laser system. The molecular constants have been determined through a least squares fit of the observed transition wave numbers to an effective Hamiltonian. The equilibrium rotational constant is estimated to be 4.438 ± 0.027 cm−1, from which the equilibrium N—H bond length is calculated to be 1.021 ± 0.003 Å. Some low-lying rotational transition frequencies in the ground state are calculated to assist in the search for pure rotational transitions in the laboratory and in interstellar space.

The Vibration–Rotation Spectrum of Ammonia Gas. II. A Rotational Analysis of the 6450 A Band

1972 ◽  
Vol 50 (2) ◽  
pp. 93-102 ◽  
Author(s):  
J. O. P. McBride ◽  
R. W. Nicholls
Keyword(s):  
Vibrational Level ◽  
Normal Modes ◽  
Rotational Analysis ◽  
Molecular Constants ◽  
Ammonia Gas ◽  
Modes Of Vibration ◽  
Vibrational Energies ◽  
Temperature And Pressure ◽  
Vibration Rotation ◽  
Rotation Spectrum

A rotational analysis of the 5ν1 (6450 A) band in the vibration–rotation spectrum of ammonia is presented here. The QP, QQ, and QR branches of a parallel transition are observed for values of J′ and K′ less than 6. Members of the SQ and OQ branches are observed with very low intensity. The molecular constants of the molecule in the (5, 0, 0, 0) vibrational level were determined; the N–H bond length is 1.015 ± 0.005 A and the bond angle is 112.0 ± 0.8° for this vibrational level. The potential energy to inversion of the molecule by excitation of the ν1 vibration only is 51 800 ± 1200 cm−1. The width of individual rotational lines increases with increase in J′ and K′. This increase in width is characteristic of a tunnelling mechanism. It may be due to the interaction between the normal modes of vibration at large vibrational energies. This analysis should improve the usefulness of the 6450 A band of ammonia for monitoring the temperature and pressure of the Jovian atmosphere.

ChemInform Abstract: DIFFERENCE FREQUENCY LASER SPECTROSCOPY OF THE ν3 BAND OF THE METHYL RADICAL

1983 ◽  
Vol 14 (8) ◽  
Author(s):  
T. AMANO ◽  
P. F. BERNATH ◽  
C. YAMADA ◽  
Y. ENDO ◽  
E. HIROTA
Keyword(s):  
Laser Spectroscopy ◽  
Difference Frequency ◽  
Methyl Radical ◽  
Frequency Laser

scholarly journals Accurateab initiopotential energy curve of F2. III. The vibration rotation spectrum

2007 ◽  
Vol 127 (20) ◽  
pp. 204313 ◽  
Author(s):  
L. Bytautas ◽  
N. Matsunaga ◽  
T. Nagata ◽  
M. S. Gordon ◽  
K. Ruedenberg
Keyword(s):  
Energy Curve ◽  
Vibration Rotation ◽  
Rotation Spectrum

Intensités des raies d'absorption dans la bande chaude ν8 + ν11 − ν11 de l'aliène 12C3H4

1986 ◽  
Vol 64 (3) ◽  
pp. 289-296 ◽  
Author(s):  
M. Dang-Nhu ◽  
A. S. Pine
Keyword(s):  
High Resolution ◽  
Difference Frequency ◽  
Laser Spectrometer ◽  
Intensity Parameters ◽  
Hot Band ◽  
Frequency Laser ◽  
Group D

Strengths of individual lines of the hot band ν8 + ν11 − ν11 of 12C3H4 at 3 μm have been measured with a high-resolution difference-frequency laser spectrometer. Finally, two intensity parameters have been determined using a general formulation written for hot bands E′ × E ← E of group D2d.

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