Study of the High-Resolution Fourier Spectrum of the ν9 and ν2 + ν7 + ν8 Bands of the С2D4 Molecule

Russian Physics Journal - Fourier spectra of the C2D4 molecule in the region 2250–3040 cm–1, in which the fundamental ν9 band and the combinational ν2 + ν7 + ν8 band...     

Analysis of the High-Resolution Infrared Spectrum of the PHD2 Molecule: ν1 and 2ν1 Bands

The results of investigation into the infrared spectra of the PHD₂ molecule including the ₁ fundamental band centered at 2324.005 cm^–1 (with a resolution of 4.2·10^–3 cm^–1) and the first 2₁ valence overtone centered at 4563.634 cm^–1 (with a resolution of 8.8·10^–3 cm^–1) are given in the present paper. Based on an analysis of the results obtained, 1340 and 1020 lines are referred to the ₁ and 2₁ bands, respectively. This data are used to calculate 316 and 248 vibrational-rotational energies of the (100000) and (200000) excited vibrational states, respectively. Since both bands can be considered as isolated, we take advantage of the Watson Hamiltonian (the reduction A in the I ^r representation) to describe their rotational structure. The calculated spectroscopic parameters of the examined states of the PHD₂ molecule correlate well with each other and with the corresponding parameters of the ground vibrational state.     

Study of a High-Resolution Spectrum of the 5ν2 Band of the H2S Molecule

Russian Physics Journal -     

Analysis of the Ro-Vibrational Structure of the Fundamental Band ν6 of 13CHF3 Molecule

Optics and Spectroscopy - The high-resolution IR spectrum of the fundamental band ν6 of 13CHF3 molecule, located in the region of 450–750 cm–1, has been investigated. The spectrum...     

Study of the ν2 + ν10 Hybrid Band of the Trans-C2H2D2 Molecule

Russian Physics Journal - The ν2 + ν10 (Bu) hybrid band of the trans-C2H2D2 molecule in the region 2100–2300 cm–1 is studied for the first time. The spectrum has been analyzed...     

A High-Resolution Analysis of the ν3 Absorption Band of Trifluoromethane

A high-resolution (up to 0.0018 cm⁻¹ unapodized) room temperature mid-infrared (650 to 750 cm⁻¹, 13.3 to 15.4 μm) absorption measurement of the ν₃ vibrational band of trifluoromethane (fluoroform, CHF₃, HFC-23) vapor was made with a Fourier transform spectrometer. A rovibrational analysis of over 1400 infrared transitions of the ν₃ band has yielded rotational constants, including sextic centrifugal distortion constants. The results are compared with two previous analyses of microwave and infrared spectra. The line positions of the lower J parts of the ν₃+ν₆−ν₆ and 2ν₃−ν₃ hot bands have been identified and constants obtained for the 2ν₃ state. The central Q branch and a few unblended transitions of the ν₃ band of ¹³CF₃H have been identified and the band origin has been determined. The relative intensities of the ν₃ band together with the 2ν₃−ν₃ hot band and ν₃ band of ¹³CF₃H have been calculated using the constants derived from this work.     

Analysis of the High-Resolution Rovibrational Spectrum of the C2H2D2-cis Molecule in the Region 1620–1780 cm–1

Russian Physics Journal - The spectrum of the cis-ethylene-d2 molecule (C2H2D2-cis) has been recorded with a Bruker IFS 120 HR Fourier spectrometer in the wavelength region 1100–2000...     

Study of the Rotational Structure of the Forbidden ν8 Band of the C2H2D2-CIS Molecule

Russian Physics Journal - The spectrum of the cis-ethylene-d2 (C2H2D2-cis) molecule is recorded with a Bruker IFS 120 HR Fourier spectrometer in the region of 600–1200 cm–1 with...     

High-Resolution Infrared Study of the ν11 Band of Allene

The high-resolution infrared spectrum of allene has been observed in the 280-380 cm⁻¹ region at a nominal resolution of 0.00125 cm⁻¹ using the IR beamline at the MAX-I electron storage ring in Lund. The spectrum shows the bending fundamental of the ν₁₁ band from which spectroscopic constants for the ν₁₁ level have been obtained. The accompanying hot band component 2ν₁₁²-ν₁₁¹ has also been assigned and analyzed.     

Analysis of the Coriolis interaction between ν6 and ν4 bands of ethylene-cis-d2(cis-C2H2D2) by high-resolution FTIR spectroscopy

The Fourier transform infrared (FTIR) spectrum of the ν₆ band of ethylene-cis-d₂(cis-C₂H₂D₂) was recorded with a unapodized resolution of 0.0063 cm^?1 in the 990–1100 cm^?1 region. A total of 609 transitions were assigned to this band centred at 1039.7682 ± 0.0003 cm^?1. The ν₆ band was found to be coupled to the ν₄ band by a-type Coriolis resonance. Both perturbed and unperturbed transitions were assigned and fitted to give eight rovibrational constants with high accuracy for the v₆ = 1 state with a standard deviation of 0.00097 cm^?1 using a Watson’s A-reduced Hamiltonian in the I^r representation. From a rovibrational analysis of the Coriolis interaction between the ν₆ band and non-infrared active ν₄ band of cis-C₂H₂D₂, the band centre of ν₄ at 984.9 ± 0.2 cm^?1 was derived. Furthermore, the second-order a-type Coriolis coupling constant between the two bands was obtained for the first time.     

First High-Resolution Raman Spectrum and Analysis of the ν5 Bending Fundamental of SF6

The high-resolution Raman spectrum of the Q, R, and S branches of the ν₅ bending fundamental of SF₆ has been recorded at a temperature of 195 K (dry ice) and a pressure of 39 mbar. This is the first study ever performed of a ν₅ band of an XY₆ molecule. It has been analyzed thanks to the HTDS software (http://www.u-bourgogne.fr/LPUB/shTDS.html) developed in Dijon. This contribution should be of help in understanding the role hot bands in the strong absorbing ν₃ region.     

Analysis of the ν6 band of carbonyl fluoride

The vibration-rotation spectrum of the ν₆ fundamental band of carbonyl fluoride (COF₂) has been recorded at room temperature and 0.005 cm⁻¹ resolution, using a Fourier transform spectrometer. Although the strong Q branch at 774 cm⁻¹ is only partially resolved in the spectrum, most of the K structure of various J subgroups in the P and R branches has been fully resolved. More than 1500 transitions belonging to J values up to 40 have been assigned and simultaneously fitted with the microwave frequencies reported by J. H. Carpenter [J. Mol. Spectrosc. 50, 182–201 (1974)] with a standard deviation of 0.0006 cm⁻¹. By incorporating quartic and sextic centrifugal distortion coefficients in Watson's reduced Hamiltonian in the I^r representation, upper state rotational constants A, B, and C have been determined to an accuracy better than 10⁻⁵ cm⁻¹. Ground state rotational and fourth order centrifugal distortion constants were constrained in the analysis to the values reported by W. Lewis-Bevan et al. [J. Mol. Spectrosc. 113, 458–471 (1985)].     

First Investigation of the Inversion Rovibrational Spectrum of the 15NHD2 Molecule in the Region from 1100 to 1350 cm–1: the Fundamental ν5 Band

Russian Physics Journal - The high-resolution spectrum of the 15NHD2 molecule recorded in the Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), Paris Diderot University,...     

Diode Laser Spectrum of the ν1 Fundamental Band of PNO

The diode laser spectrum of the ν₁ fundamental band of the short-lived molecule PNO has been detected with 59 R- and P-branch lines accurately measured. The lines were unambiguously assigned using the rotational and distortion constants for the ground and (100) vibrational levels found previously by microwave spectroscopy. The band origin was determined to be 860.301 228(31) cm⁻¹ from a one parameter fit. The gas phase band origin is red-shifted by approximately 4 cm⁻¹ from the matrix value.     

Analysis of the Vibrational-Rotational Structure of 2ν1, ν1 + ν3, and 2ν3 Bands of the D2Se Molecule

The absorption spectrum of the D₂Se molecule in the region of 2₁, ₁ + ₃, and 2₃ absorption bands is registered with a high-resolution Fourier spectrometer and is studied theoretically for a Hamiltonian model with allowance for resonant interactions among (200), (101), and (002) vibrational states.     

Analysis of the High-Resolution Spectrum of Molecules in Doublet Electronic States: Fundamental ν3 Band of Chlorine Dioxide (16O35Cl16O) in the Ground Electronic State X 2B1

Optics and Spectroscopy - Using a Bruker IFS 125 HR Fourier spectrometer, the vibrational–rotational structure of the ClO2 molecule band $${{\nu }_{3}}$$ has been recorded with a resolution...     

Study of the Quantitative Absorption Characteristics in the υ2 Band of the 34SO2 Molecule

Russian Physics Journal - High-resolution infrared spectrum of the 34SO2 molecule is recorded with a Bruker IFS-120 HR Fourier spectrometer. More than 3000 transitions (with Jmax = 60 and $$...     

Pressure-Broadened Linewidth Measurements in the ν2Band of the CH3Radical

Pressure broadening coefficients for an infrared transition of the methyl radical have been measured for the first time. CH₃radicals, generated by pyrolyzing di-tert-butyl peroxide in a flow of either N₂or Ar, were probed using a tunable diode laser and a multipass absorption cell. The Lorentz half-width of theQ(6,6) line of the ν₂band of CH₃at 607.024 cm⁻¹was measured as a function of pressure at 295 K. The broadening coefficients (HWHM) areb(Ar) = 0.0310 ± 0.0012 cm⁻¹atm⁻¹andb(N₂) = 0.0390 ± 0.0020 cm⁻¹atm⁻¹. These coefficients are lower than those for CH₄–Ar, N₂broadening. This may be due to a lower polarizability or smaller effective hard collision diameter for CH₃relative to CH₄.     

High-Resolution Analysis of the ν6, ν17, and ν21 Bands of Dimethyl Ether

The ν₆, ν₁₇, and ν₂₁ fundamental bands of dimethyl ether have been assigned and rotationally analyzed. The spectra used were recorded at 0.005 cm⁻¹ spectral resolution with a Fourier-transform spectrometer coupled to a supersonic molecular beam leading to a rotational temperature of about 70 K. The ν₆ and ν₂₁ bands do not seem to be perturbed and the analysis of the rotational structure leads to band centers located at 933.906 6(9) and 1 103.951(1) cm⁻¹, respectively, and to accurate rotational and centrifugal distortion constants. For the ν₁₇ band at 2817.385(2) cm⁻¹, only the P and R branches could be assigned.