Millimeter‐Wave and Vibrational State Assignments for the Rotational Spectrum of Glycolaldehyde

2005 ◽  
Vol 158 (2) ◽  
pp. 188-192 ◽  
Author(s):  
Susanna L. Widicus Weaver ◽  
Rebecca A. H. Butler ◽  
Brian J. Drouin ◽  
Douglas T. Petkie ◽  
Kathryn A. Dyl ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Vibrational State ◽  
Rotational Spectrum

The Rotational Spectrum of Monothioformic Acid IV. cis- and trans-H13C(:O)SH and HC(:18O)SH

1977 ◽  
Vol 32 (10) ◽  
pp. 1108-1118 ◽  
Author(s):  
William H. Hocking ◽  
Gisbert Winnewisser
Keyword(s):  
Millimeter Wave ◽  
Vibrational State ◽  
Wave Spectra ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Ground Vibrational State ◽  
Bond Angles ◽  
Isotopic Species ◽  
Cis And Trans ◽  
Trans Structure

The microwave and millimeter wave spectra of two isotopically substituted species of monothioformic acid, H13COSH and HC18OSH. have been investigated. Over 60 rotational transitions in the ground vibrational state have been assigned and measured for both the eis and trans thiol rotamers. HC(:O)SH. of each isotopic species. Rotational constants and quartic centrifugal distortion comstants of H13COSH and HC18OSH have been determined from the observed spectra. These data have been combined with previously published results on HCOSH, DCOSH. HCOSD and HCO34SH to obtain complete substitutions structures for the planar eis and trans rotamers of HC(:O)SH. All of the in-plane bond angles as well as the SH distance are significantly different for the two rotamers. For the eis rotamer the HSC and HCS angles increase by more than 2°, the OCS angle decreases by more than 3°, and the SH bond shortens compared to the trans rotamer geometry. The eis structure is: r(C-H) = 1.104 ± 0.003 Å, r(C = O) 1.203 ± 0.003 Å. r(C-S) = 1.771 ± 0.003 Å, r(S-H) = 1.335 ± 0.002 Å, ∢(OCS) = 122.5° ± 0.3°, ∢(HSC) = 94.9° ± 0.2° and ∢(HCS) = 114.4° ± 0.2°; whereas the trans structure is: r(C-S) = 1.104 ± 0.003 Å. r(C = O) = 1.205 ± 0.003 Å, r(C-S) = 1.768 ± 0.003 Å, r(S-H) = 1.354 ± 0.002 Å. ∢(OCS) = 125.9° ± 0.3°, (HSC) = 92.5° ± 0.2° and ∢(HCS) = 111.0° ± 0.2°

Millimeter‐Wave Rotational Spectrum of HSSH and DSSD. I. Q Branches

1968 ◽  
Vol 49 (8) ◽  
pp. 3465-3478 ◽  
Author(s):  
Gisbert Winnewisser ◽  
Manfred Winnewisser ◽  
Walter Gordy
Keyword(s):  
Millimeter Wave ◽  
Rotational Spectrum

scholarly journals Millimeter-wave spectroscopy and modeling of 1,2-butanediol

2018 ◽  
Vol 619 ◽  
pp. A140 ◽  
Author(s):  
A. Vigorito ◽  
C. Calabrese ◽  
S. Melandri ◽  
A. Caracciolo ◽  
S. Mariotti ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Conformational Space ◽  
Rotational Spectrum ◽  
Free Jet ◽  
Enhanced Sensitivity ◽  
Millimeter Wavelengths ◽  
Global Minimum Search ◽  
Centrifugal Distortion Constants ◽  
Telescope Arrays ◽  
Complex Organic

Context. The continuously enhanced sensitivity of radioastronomical observations allows the detection of increasingly complex organic molecules. These systems often exist in a large number of isomers leading to very congested spectra. Aims. We explore the conformational space of 1,2-butanediol and provide sets of spectroscopic parameters to facilitate searches for this molecule at millimeter wavelengths. Methods. We recorded the rotational spectrum of 1,2-butanediol in the 59.6–103.6 GHz frequency region (5.03–2.89 mm) using a free-jet millimeter-wave absorption spectrometer, and we analyzed the properties of 24 isomers with quantum chemical calculations. Selected measured transition lines were then searched on publicly available ALMA Band 3 data on IRAS 16293-2422 B. Results. We assigned the spectra of six conformers, namely aG′Ag, gG′Aa, g′G′Ag, aG′G′g, aG′Gg, and g′GAa, to yield the rotational constants and centrifugal distortion constants up to the fourth or sixth order. The most intense signal belong to the aG′Ag species, that is the global minimum. Search for the corresponding 30x,30 − 29x,29 transition lines toward IRAS 16293-2422 B was unsuccessful. Conclusions. Our present data will be helpful for identifying 1,2-butanediol at millimeter wavelengths with radio telescope arrays. Among all possible conformers, first searches should be focused on the aG′Ag conformers in the 400–800 GHz frequency spectral range.

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