0000000000073989
AUTHOR
H. Bürger
Vibrational spectra and force constants of symmetric tops
The infrared spectrum of H3SiI in the 800–1050 cm-1 region has been recorded with a resolution of 0·04 cm-1 and rotationally analysed. Features related to the Fermi resonance between v 5 and v 3 + v 6 and to the Coriolis x, y resonance between v 2 and v 5 have been explained, and a set of vibration-rotation parameters for the three bands has been determined by least-squares calculations, σ(J, K) = 9·4 × 10-3 cm-1. The Fermi resonance matrix element |W 356| is found to be 3·7859(7) cm-1 and the vibrational frequencies are v 2 0 = 904·551(1), v 5 0 = 941·0746(8) and (v 3 + v 6)0 = 953·688(3) cm-1. The anharmonicity constant, x 36 = -1·745(9) cm-1, has been determined. Comparison is made with …
Ab Initio Calculations and High-Resolution Spectroscopy of the Bending Pentad of SiH2D2 in the 10–16 um Region
International audience; The SiH2D2 asymmetric top has nine vibrational modes, five of them forming a pentad strongly perturbed by Coriolis interactions. High-level ab initio calculations of SiH2D2 have been performed which yield numerous spectroscopic parameters related to the harmonic and anharmonic force fields. The bending pentad comprising v4(A1), v7(B1), v5(A2), v9(B2), and v3(A1) has been studied by high-resolution Fourier transform spectroscopy; the region 600 –1050 cm-1 has been investigated with a resolution of ca. 4 x 10-3 cm-1. Raman BOXCARS spectroscopy has been used for the infrared inactive v5 band. The Raman apparatus function was 0.0054 cm-1. Assignments of about 4000 transi…
Analysis of the infrared Fourier transform spectrum of the Dyad of 116SnH4
Abstract The FTIR spectrum of monoisotopic 116SnH4 has been recorded with the Bruker 120 HR interferometer at Giessen, West Germany, in the ν 2 ν 4 range extending from 600 to 850 cm−1. The resolution (FWHM) was 2.1 × 10−3 cm−1. The Dyad ν 2 ν 4 (0100, 0001) was analyzed using a sixth-order Hamiltonian. The analysis of infrared transitions enabled us to determine 10 ground state parameters, 9 ν2 parameters, 17 ν4 parameters, and 18 interaction parameters. Of 3800 calculated transitions assigned to observed lines, 1183 unblended lines have been selected for the data refinement. For J ≤ 19, the value of the standard deviation is of the order of magnitude of the estimated experimental accuracy…
New measurements and global analysis of chloromethane in the region from 0 to 1800cm−1
Abstract New high resolution Fourier transform spectra of pure 12CH335Cl and 12CH337Cl isotopomers of chloromethane have been recorded in Wuppertal covering the region from 600 to 3800 cm−1. New rotational transitions within the v2=1, v5=1, and v3=2 states have been measured at Lille. A first global analysis of the lower four band systems of the molecule (700–1800 cm−1) is reported. The model was based on an effective Hamiltonian and dipole moment expressed in terms of irreducible tensor operators. A common set of 125 effective hamiltonian parameters (sixth order) has been adjusted to fit simultaneously some 11 000 IR data for each of the isotopomers including 153 mm wave data for 12 CH3 35…
Global analysis of 12CH335Cl and 12CH337Cl: simultaneous fit of the lower five polyads (0–2600cm−1)
Abstract The global analysis of the infrared spectrum of chloromethane involving the ground state and the 13 vibrational states lying up to 2600 cm −1 is reported. This work incorporates and extends to the fifth polyad, the preliminary study of the lower four polyads published by [J. Mol. Spectrosc. 221 (2003) 199]. More than 20 000 transitions (including numerous hot bands) for each isotopomer 12 CH 3 35 Cl and 12 CH 3 37 Cl have been assigned and fitted with a standard deviation of about 3 × 10 −4 cm −1 close to the experimental precision. A common set of 288 (resp. 303) effective parameters was determined for each isotopomer. Our global model allowed us to reproduce simultaneously and a…
High-Resolution Spectroscopy and Analysis of the ν3 and ν4 Fundamentals of Monoisotopic 70GeF4
The first high-resolution study on germanium tetrafluoride is reported. We used a monoisotopic sample of (70)GeF(4). The FTIR spectra of the two infrared active fundamentals, namely the nu(4) (bending) and nu(3) (stretching) modes, were recorded at a temperature of ca. 210 K and a resolution (1/maximum optical path difference) of 0.0031 and 0.0023 cm(-1), respectively. These spectra were analyzed using the STDS software developed in Dijon. In both cases, we obtained a fit with a root mean square better than 1x10(-3) cm(-1). Both bands show very regular structures with no detectable perturbation. Copyright 2001 Academic Press.