# Browse Abstracts & Presentations - 2021 International Symposium on Molecular Spectroscopy by Subject "Mini-symposium: Large Amplitude Motions"

• (International Symposium on Molecular Spectroscopy, 2021-06-22)
In simple cases of methyl group internal rotation, the barrier to internal rotation is equal to the $V_{3}$ coefficient in the standard equation of the potential function. In the past few years, methyl internal rotation ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-22)
The molecular planarity of molecules that contain an alkyl group attached to a system with conjugated double bonds has posed a great challenge for both experiments and theory for a long time. This also holds true for the ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-22)
The presently available tools of rotational spectroscopy do not provide a meaningful way to treat small organic radicals with methyl groups. This in turn prevents astrochemical detection of these species as it is not ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-22)
We used our hybrid program\footnote{I. Kleiner and J. T. Hougen, J. Mol. Spectrosc., 368, 111255 (2020)} to fit an extended dataset consisting of almost 30000 rotational-torsionial-wagging transitions in the MW and FIR ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-22)
As a large amplitude motion, the internal rotation of a methyl group, methyl torsion, is traditionally treated as being separate from the remaining small amplitude vibrations.[1] However, recent studies have shown that ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Methods applicable to the spectroscopic study of non-rigid organic molecular species with various large amplitude motions (torsions and inversions), are shown. Recent studies of ethylene glycol, \chem{C_3O_6H_6} isomers, ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Trifluoroacetic acid (TFA, \chem{CF_3C(O)OH}) is the final degradation product of many hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), and hydrofluoroolifines (HFOs) in the troposphere. While a recent assessment ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-22)
The rotational constants and quartic centrifugal distortion coefficients of hexafluoro-o-xylene and all singly 13C isotopologues were precisely determined from the 8 to 18GHz gas phase microwave spectrum. A preliminary r0 ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
The conformational analysis represents the first step toward a detailed characterization and understanding of the structure-function relationships of molecular systems. In this respect spectroscopic experiments on isolated ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-22)
Silicon chemistry is an extensive research topic due to its importance for industry and technology, and because of its natural abundance on earth. Silicon is a versatile element, its applications range from pure silicon ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Quadrupole coupling of an iodine nucleus with its coupling constants in the GHz order has always been a challenge in microwave spectroscopy. Methyl internal rotations with very low torsional barriers also often complicate ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Organic hydroperoxides and their radical products are important contributors to atmospheric chemistry, especially in atmospheric oxidation processes. Through understanding the vibrational spectroscopy of these compounds, ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Rotational transitions belonging to the three lowest torsional states of dimethylether (DME), \chem{(CH_3)_2O}, have been analyzed using the recently developed model for molecules with two equivalent methyl rotors and ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Pyruvic acid (C$_{3}$H$_{4}$O$_{3}$, or HOOCOCCH$_{3}$) is one of the main reactants in the Krebs Cycle of biological systems where sugar is metabolized and glucose is converted to lactic acid. Its presence in carbonaceous ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
The known interstellar molecule, methyl formate (HCOOCH$_3$) has been studied by microwave spectroscopy since 1959 \footnote{R. F. Curl, \textit{J. Chem. Phys.} \underline{\textbf{30}}, 1529 (1959).}. The laboratory ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-22)
Doubly deuterated methanol CD$_2$HOH is a non-rigid molecule displaying internal rotation of its asymmetrical CD$_2$H methyl group. Like the isotopic species of methanol with a symmetrical CH$_3$ or CD$_3$ group, it ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Water clusters provide an opportunity to explore the effects of nuclear quantum effects on the stability of hydrogen-bonded networks. Because of their well-defined size, such studies provide an opportunity to make ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
\par Diffusion Monte Carlo (DMC) is a technique that can be used to obtain the ground state energy and ground state wave function given a potential energy surface (PES) that fully describes the system of interest. However, ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-24)
One of the main objectives in the study of weakly bound complexes is to provide a quantitative description of the (ro)vibrational dynamics which can be dominated by nuclear quantum effects. For example, water and carbon ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-24)
1,2-Benzenediol, commonly known as catechol, was investigated, an ortho substituted aromatic volatile organic compound (VOC) with two hydroxyl groups which, due to tunneling between two symmetrically equivalent structures, ...

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