scholarly journals Laboratory spectroscopic study of isotopic thioformaldehyde, H2CS, and determination of its equilibrium structure

2019 ◽  
Vol 621 ◽  
pp. A143 ◽  
Author(s):  
Holger S. P. Müller ◽  
Atsuko Maeda ◽  
Sven Thorwirth ◽  
Frank Lewen ◽  
Stephan Schlemmer ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Laboratory Data ◽  
Abundant Species ◽  
Equilibrium Structure ◽  
Natural Isotopic Composition ◽  
Spectroscopic Parameters ◽  
Rotational Spectra ◽  
Isotopic Species ◽  
Semi Empirical

Context. Thioformaldehyde is an abundant molecule in various regions of the interstellar medium. However, available laboratory data limit the accuracies of calculated transition frequencies in the submillimeter region, in particular for minor isotopic species. Aims. We aim to determine spectroscopic parameters of isotopologs of H2CS that are accurate enough for predictions well into the submillimeter region. Methods. We investigated the laboratory rotational spectra of numerous isotopic species in natural isotopic composition almost continuously between 110 and 377 GHz. Individual lines were studied for most species in two frequency regions between 566 and 930 GHz. Further data were obtained for the three most abundant species in the 1290−1390 GHz region. Results. New or improved spectroscopic parameters were determined for seven isotopic species. Quantum-chemical calculations were carried out to evaluate the differences between ground state and equilibrium rotational parameters to derive semi-empirical equilibrium structural parameters. Conclusions. The spectroscopic parameters are accurate enough for predictions well above 1 THz with the exception of H213C34S where the predictions should be reliable to around 700 GHz.

scholarly journals Laboratory spectroscopic study of the 15N isotopomers of cyanamide, H2NCN, and a search for them toward IRAS 16293−2422 B

2019 ◽  
Vol 623 ◽  
pp. A93 ◽  
Author(s):  
Audrey Coutens ◽  
Olena Zakharenko ◽  
Frank Lewen ◽  
Jes K. Jørgensen ◽  
Stephan Schlemmer ◽  
...  
Keyword(s):  
Laboratory Data ◽  
Natural Isotopic Composition ◽  
Interstellar Molecules ◽  
Spectroscopic Parameters ◽  
Rotational Spectra ◽  
Isotopic Species ◽  
Upper Limits ◽  
Solar Type ◽  
Line Survey

Context. Cyanamide is one of the few interstellar molecules containing two chemically different N atoms. It was detected recently toward the solar-type protostar IRAS 16293−2422 B together with H2N13CN and HDNCN in the course of the Atacama Large Millimeter/submillimeter Array (ALMA) Protostellar Interferometric Line Survey (PILS). The detection of the 15N isotopomers or the determination of upper limits to their column densities was hampered by the lack of accurate laboratory data at the frequencies of the survey. Aims. We wanted to determine spectroscopic parameters of the 15N isotopomers of cyanamide that are accurate enough for predictions well into the submillimeter region and to search for them in the PILS data. Methods. We investigated the laboratory rotational spectra of H215NCN and H2NC15N in the selected region between 192 and 507 GHz employing a cyanamide sample in natural isotopic composition. Additionally, we recorded transitions of H2N13CN. Results. We obtained new or improved spectroscopic parameters for the three isotopic species. Neither of the 15N isotopomers of cyanamide were detected unambiguously in the PILS data. Two relatively clean lines can be tentatively assigned to H215NCN. If confirmed, their column densities would imply a low 14N/15N ratio for cyanamide toward this source. Conclusions. The resulting line lists should be accurate enough for observations up to about 1 THz. More sensitive observations, potentially at different frequencies, may eventually lead to the astronomical detection of these isotopic species.

Rotational spectra of rare isotopic species of bromofluoromethane: Determination of the equilibrium structure from ab initio calculations and microwave spectroscopy

2007 ◽  
Vol 127 (16) ◽  
pp. 164302 ◽  
Author(s):  
Cristina Puzzarini ◽  
Gabriele Cazzoli ◽  
Agostino Baldacci ◽  
Alessandro Baldan ◽  
Christine Michauk ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Equilibrium Structure ◽  
Microwave Spectroscopy ◽  
Rotational Spectra ◽  
Isotopic Species

Rotational spectra of rare isotopic species of fluoroiodomethane: Determination of the equilibrium structure from rotational spectroscopy and quantum-chemical calculations

2012 ◽  
Vol 137 (2) ◽  
pp. 024310 ◽  
Author(s):  
Cristina Puzzarini ◽  
Gabriele Cazzoli ◽  
Juan Carlos López ◽  
José Luis Alonso ◽  
Agostino Baldacci ◽  
...  
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Equilibrium Structure ◽  
Rotational Spectroscopy ◽  
Rotational Spectra ◽  
Isotopic Species

scholarly journals Determination of Rotational Parameters of CH3CN, CD3CN and their Different Isotopic Species in the Ground and v4= 1 States

2009 ◽  
Vol 6 (2) ◽  
pp. 577-593
Author(s):  
Masoud Motamedi ◽  
Parinaz Moradi
Keyword(s):  
Millimeter Wave ◽  
Rotational Spectra ◽  
Isotopic Species ◽  
Symmetric Top Molecules ◽  
First Time

The millimeter-wave rotational spectra of the symmetric top molecules CH3CN,13CH3CN, CH313CN, CH3C15N, CD3CN ,13CD3CN, CD313CN and CD3C15N have been investigated again in their ground and v4= 1 states. The analysis of spectra and fitting the frequencies in these states give rotational parameters with higher accuracy compare with previous works. The parameter HJ= -0.107(96) mHz was determined for CH3C15N for the first time.

Detection of the Millimeter Wave Spectrum of Hydrogen Isocyanide, HNC1,2

1976 ◽  
Vol 31 (3-4) ◽  
pp. 221-224 ◽  
Author(s):  
R. A. Creswell ◽  
E. F. Pearson ◽  
M. Winnewisser ◽  
G. Winnewisser
Keyword(s):  
Millimeter Wave ◽  
Structural Parameters ◽  
Wave Spectrum ◽  
Linear Molecule ◽  
Parent Species ◽  
Molecular Constants ◽  
Rotational Spectra ◽  
Isotopic Species ◽  
Wave Region ◽  
Hydrogen Isocyanide

The rotational spectra of three isotopic species of HNC have been observed in the millimeter wave region. In the case of the parent species, H14N12C, our measurement of the J = 1←0 transition unequivocally confirms the assignment of the U90.7 interstellar line to HNC. For the parent species the molecular constants obtained are B0 = 45332.005(40) MHz and D0 = 0.1019(50) MHz. Structural parameters derived from the ground state rotational constants of this linear molecule are r(H-N) = 0.987 (3) Å and r(N-C) =1.171 (4) Å.

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