OSU Navigation Bar

The Ohio State University University Libraries Knowledge Bank

The Knowledge Bank is scheduled for regular maintenance on Sunday, April 20th, 8:00 am to 12:00 pm EDT. During this time users will not be able to register, login, or submit content.

FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN

Please use this identifier to cite or link to this item: http://hdl.handle.net/1811/33614

Show full item record

Files Size Format View
abstract.gif 27.84Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
tanaka Ohio4.ppt 2.059Mb Microsoft PowerPoint View/Open
Slide1.GIF 6.603Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide2.GIF 44.02Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide3.GIF 23.10Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide4.GIF 48.50Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide5.GIF 21.08Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide6.GIF 12.12Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide7.GIF 14.64Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide8.GIF 24.55Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide9.GIF 11.70Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide10.GIF 36.89Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide11.GIF 98.83Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide12.GIF 24.90Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide13.GIF 25.34Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide14.GIF 30.09Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide15.GIF 29.30Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide16.GIF 30.37Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide17.GIF 1.023Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide18.GIF 10.15Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide19.GIF 34.10Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide20.GIF 36.27Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide21.GIF 7.580Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Slide22.GIF 24.02Kb GIF image Thumbnail of FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN

Title: FOURIER TRANSFORM MICROWAVE SPECTRA OF ISOBUTYL MERCAPTAN
Creators: Tanaka, Yugo; Sato, Akinori; Kawashima, Yoshiyuki; Hirota, Eizi
Issue Date: 2008
Abstract: In order to obtain information on stable conformers and internal motions of isobutyl mercaptan (2-methyl-1-propanethiol), we have analyzed its rotational spectra observed by Fourier transform microwave spectroscopy. We may expect that isobutyl mercaptan exists in five stable rotational isomers, that is, there are two configurations around the CH(CH${_3}$)${_2}$ - CH${_2}$SH bond referred to as $gauche$ and $trans$ and more than two minima on the internal rotation of the SH group. We scanned the frequency region from 3.7 to 25 GHz using a sample of isobutyl mercaptan diluted in Ar to 0.5${\%}$. We assigned the observed spectra to two $gauche$ forms, $G$${_1}$ and $G$${_2}$, and one $trans$ form $T$${_1}$: 36 $a$-type, 28 $b$-type, and 25 $c$-type transitions for the $G$${_1}$ and 36 $a$-type and 25 $c$-type transitions for the $G$${_2}$, whereas no $b$-type transitions were observed for $G$${_2}$. The $G$${_1}$ spectra were found stronger than those of $G$${_2}$. These observations could be explained by the S-H and C-S bond moments. On the other hand, 25 $a$-type, 25 $b$-type, and 16 $c$-type transitions were assigned for $T$${_1}$, of which all $b$-type lines appeared as doublets with the spacing of about 13 MHz. This splitting was ascribed to the tunneling of the SH group through a potential barrier on the $a$-$c$ plane between two equivalent minima. $Ab$ $initio$ calculations at the MP2/6-311++G($d$, $p$) level demonstrate that there are two minima for the $gauche$ form at the CCSH dihedral angle of 72.2$^irc$ and 298.1$^irc$, which correspond to $G$${_1}$ and $G$${_2}$, as observed, whereas two minima at the CCSH dihedral angles of 73.8$^irc$ and 286.2$^irc$ are equivalent for the $trans$ form. These $ab$ $initio$ results are in good accord with the experimental observations. The rotational spectra of the ${^{34}}$S species were assigned for all the three rotational isomers and the four ${^{13}}$C species for the two $gauche$ forms, all existing in natural abundance. These observations on isotopic species give further support to the above results on the stable rotational isomers.
URI: http://hdl.handle.net/1811/33614
Other Identifiers: 2008-TA-10
Bookmark and Share