ASSIGNMENT OF $GG$, $GG'$, $TT$ and $TG$ CONFORMERS IN THE $FASSST$ ROTATIONAL SPECTRUM OF $N$-PROPANOL
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Date
2006
Journal Title
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Publisher
Ohio State University
Abstract
Recent broadband measurements of the rotational spectrum of $n$-propanol up to 375 GHz resulted in determination of precise spectroscopic constants for the $Gt$ conformer of this molecule.}, 428 (2006)} This is most likely the most stable conformer, although four other conformers are predicted to be very similar in energy. Assignment of some of these in cm-wave rotational spectra has previously been reported, but it was not possible to extend that work directly to mm-wave spectra. \vspace{0.2cm} Application of graphical Loomis-Wood techniques built into AABS}, 231 (2005)} and CAAARS}, 229 (2005)} spectral analysis packages eventually allowed successful assignment of the remaining four conformers: $Gg$, $Gg'$, $Tt$, and $Tg$ $n$-propanol. It was realised that rotational energies in ($Gg$, $Gg'$) and ($Tt$, $Tg$) pairs of conformers are highly coupled, but also amenable to description in terms of the Coriolis interaction mechanism. This allowed very precise determination of some energy level differences, such as $\Delta E(Gg'-Gg)=3.035046(7)$ cm$^{-1}$. The assignment was checked against $ab initio$ calculations, and is supported by new, precise determinations of dipole moments of some conformers, which were carried out using supersonic expansion cavity-FTMW spectroscopy.
Description
Author Institution: Institute of Physics, Polish Academy of Sciences, Al. Lotnikow; 32/46, 02-668 Warszawa, Poland; Department of Physics, The Ohio State University, Columbus,; OH 43210