Lowest Overtone and Combination Levels of DCCI: The Fermi Resonance v3 = 1/v5 = 2.
The infrared spectrum of deuterated monoiodoacetylene DCCI in the region of 220-550 cm-1 has been studied at a resolution of 0.0020 cm-1. The hot bands nu3 <-- nu15 and 2nu0,25 <-- nu15 have been analyzed by considering especially the Fermi resonance v3 = 1/v5 = 2. In the next layer of the hot bands (nu3 + nu5)1 <-- nu3, (nu3 + nu5)1 <-- 2nu0,25 and 3nu1,35 <-- 2nu25 the same Fermi resonance appears between v3 = v5 = 1 and v5 = 3. In addition, various l resonances at the overtone levels have been considered. As a result, the vibrational and rotational constants for the level systems v3 = 1/v5 = 2 and v3 = v5 = 1/v5 = 3 together with the resonance parameters have been obtained. Copyright 1999 Academic Press.
Molecular structure of iodoacetylene
Abstract The pure rotational spectra of iodoacetylene and its [1-13C]-, [2-13C]-, and [D]-isotopomers have been assigned. From the set of four rotational constants obtained, the r0-structure and the partial rs-structure of the ethynyl moiety have been determined. From the hyperfine structures the nuclear quadrupole and spin-rotation coupling constants of iodine have also been measured.
Experiences with microwave Fourier transform spectroscopy of molecular gases
After an introduction to the interaction of a microwave field and an ensemble of dipolar molecules the experimental conditions for the microwave Fourier transform spectroscopy are given. Specifications are derived for a spectrometer. A typical set up of a spectrometer is presented and discussed. The application to rotational spectroscopy of stable molecules is demonstrated by some examples. Possibilities for extension are mentioned.