The millimeter wave rotational spectrum of pyruvic acid

Abstract

The rotational spectrum of pyruvic acid has been investigated for the first time in the millimeter-wave region, at 160-314 GHz, and also in supersonic expansion, at 10-17.4 GHz. The analysis of the broadband spectra recorded in this work was carried out with the newly developed AABS software package for Assignment and Analysis of Broadband Spectra, and precise spectroscopic constants are reported for the ground state, the first excited state of the low-frequency skeletal torsional mode m 24 , and the first excited state of the methyl torsional mode m 23 . Limited results have also been obtained for several higher excited states. The dataset for the ground state currently exceeds 1500 lines and for both the A and E internal rotor sublevels spans the complete range of values of K a at the mid values of J for the measured transitions. The results were analysed with three freely available computer programs employing different strategies for dealing with internal rotation and a comparative discussion of their merits is made.

Analysis of the rotational spectrum of pyruvonitrile up to 324 GHz

“…Pyruvonitrile is a sufficiently small molecule that it has already been included in studies of potential carriers of astrophysical ir transitions [9]. Pyruvonitrile is also known to be hydrolysed to pyruvic acid in an acidic or alkaline aqueous environment, and pyruvic acid itself has been identified to be an important prebiotic molecule, as discussed in [10,11]. The present work provides sufficiently precise laboratory information for a radioastronomical search for pyruvonitrile.…”

Comprehensive analysis of the FASSST rotational spectrum of S(CN)2

“…Thus, the analysis of other types of broadband high-resolution spectra, such as rotationally resolved vibrational or electronic spectra should be possible without modification. The AABS package has already been applied in several other investigations of broadband mm-wave spectra, including recent studies of Coriolis perturbation in ClONO 2 [18] and of internal rotation in pyruvic acid [26].…”

“…26.5 g of silver cyanide, AgCN, were dispersed by vigorous stirring in 200 ml of carbon disulphide, CS 2 , in a three neck flask kept at a temperature of 30°C. Over a period of 30 min 10 ml of sulphur dichloride, SCl 2 , were added using a disposable syringe.…”

Strong Coriolis coupling between and states of studied by millimeter-wave spectroscopy

“…Loomis-Wood type display options allow graphical assignment of the spectra. Detailed documentation and the package itself are freely available on the PROSPE website [10], and recent examples of the use of the AABS package can be found in [11][12][13].…”