Rotational spectroscopy of methyl benzoylformate and methyl mandelate: structure and internal dynamics of a model reactant and product of enantioselective reduction

2015 ◽  
Vol 17 (34) ◽  
pp. 21942-21949 ◽  
Author(s):  
Elijah G. Schnitzler ◽  
Mohammad Reza Poopari ◽  
Yunjie Xu ◽  
Wolfgang Jäger
Keyword(s):  
Minimum Energy ◽  
Rotational Spectroscopy ◽  
Internal Dynamics ◽  
Rotational Spectra ◽  
Enantioselective Reduction ◽  
Methyl Benzoylformate ◽  
Methyl Rotation

Rotational spectra of a prochiral ester, methyl benzoylformate, and the product of its enantioselective reduction, (R)-(–)-methyl mandelate, were measured, and minimum energy conformers and methyl rotation barriers were determined.

Rotational spectroscopy of the atmospheric photo-oxidation product o-toluic acid and its monohydrate

2016 ◽  
Vol 18 (1) ◽  
pp. 448-457 ◽  
Author(s):  
Elijah G. Schnitzler ◽  
Brandi L. M. Zenchyzen ◽  
Wolfgang Jäger
Keyword(s):  
Oxidation Product ◽  
Minimum Energy ◽  
Rotational Spectroscopy ◽  
Rotational Spectra ◽  
Photo Oxidation

Pure rotational spectra of an atmospheric photo-oxidation product, o-toluic acid, and its monohydrate were measured, and the minimum energy conformers of both species were identified.

Internal methyl rotation and molecular structure of trifluorotoluenes: microwave rotational spectra of 2,3,4- and 2,4,5-trifluorotoluene

2020 ◽  
Vol 98 (6) ◽  
pp. 543-550 ◽  
Author(s):  
K.P. Rajappan Nair ◽  
Sven Herbers ◽  
Daniel A. Obenchain ◽  
Jens-Uwe Grabow
Keyword(s):  
Internal Rotation ◽  
Rotation Axis ◽  
Molecular Constants ◽  
Methyl Carbon ◽  
Rotational Spectra ◽  
Pulsed Jet ◽  
Principal Axes ◽  
The Moment ◽  
Centrifugal Distortion Constants ◽  
Methyl Rotation

The microwave rotational spectra of 2,3,4- and 2,4,5-trifluorotoluenes, along with all 13C isotopic species in natural abundance, have been recorded in the frequency range 8–27 GHz employing pulsed-jet Fourier transform microwave spectroscopy. The analysis of the spectra in the lowest torsional state has yielded the rotational constants, centrifugal distortion constants, three-fold barrier to methyl rotation, and the direction of the internal rotation axis in the moment of inertia principal axes systems of these trifluorotoluenes. For both molecules, the molecular constants of their eight isotopologues have been used to obtain the substitution rs structures of the ring and the methyl-carbon. The potential barriers hindering the internal rotation of the methyl top in 2,3,4- and 2,4,5-trifluorotluene are 2.5878(80) and 2.2809(23) kJ/mol, respectively.

Rotational spectra and internal dynamics of Ne—H2S

2002 ◽  
Vol 100 (5) ◽  
pp. 611-622 ◽  
Author(s):  
YAQIAN LIU ◽  
WOLFGANG JÄGER
Keyword(s):  
Internal Dynamics ◽  
Rotational Spectra

scholarly journals Analysis of thyme essential oils using gas-phase broadband rotational spectroscopy

2019 ◽  
Vol 21 (48) ◽  
pp. 26569-26579
Author(s):  
María Mar Quesada-Moreno ◽  
Anna Krin ◽  
Melanie Schnell
Keyword(s):  
Quantitative Analysis ◽  
Essential Oils ◽  
Gas Phase ◽  
Rotational Spectroscopy ◽  
Internal Dynamics

A semi-quantitative analysis as well as determination of the structures and internal dynamics of components of two natural essential oils have been carried out using rotational spectroscopy.

The axial/equatorial conformational landscape and intramolecular dispersion: new insights from the rotational spectra of monoterpenoids

2019 ◽  
Vol 21 (47) ◽  
pp. 26111-26116 ◽  
Author(s):  
Donatella Loru ◽  
Annalisa Vigorito ◽  
Andreia F. M. Santos ◽  
Jackson Tang ◽  
M. Eugenia Sanz
Keyword(s):  
Quantum Chemistry ◽  
Rotational Spectroscopy ◽  
Theoretical Methods ◽  
Rotational Spectra ◽  
Quantum Chemistry Calculations ◽  
Conformational Landscape

Using rotational spectroscopy and quantum chemistry calculations, we show that intramolecular dispersion stabilises the axial conformers of monoterpenoids, and that an accurate account of these interactions is challenging for theoretical methods.

Chalcogen bond and internal dynamics of the 2,2,4,4-tetrafluoro-1,3-dithietane⋯water complex

2019 ◽  
Vol 21 (28) ◽  
pp. 15656-15661 ◽  
Author(s):  
Yan Jin ◽  
Xiaolong Li ◽  
Qian Gou ◽  
Gang Feng ◽  
Jens-Uwe Grabow ◽  
...  
Keyword(s):  
High Resolution ◽  
Rotational Spectroscopy ◽  
Rotational Spectrum ◽  
Internal Dynamics ◽  
Chalcogen Bond ◽  
Water Complex

The rotational spectrum of the 2,2,4,4-tetrafluoro-1,3-dithietane⋯water complex has been investigated by high resolution rotational spectroscopy. Inversion of the water around its C2 axis is hindered by a barrier determined to be 87.4(2) cm−1.

scholarly journals Generation and structural characterization of Ge carbides GeCn (n = 4, 5, 6) by laser ablation, broadband rotational spectroscopy, and quantum chemistry

2019 ◽  
Vol 21 (35) ◽  
pp. 18911-18919
Author(s):  
Kin Long Kelvin Lee ◽  
Sven Thorwirth ◽  
Marie-Aline Martin-Drumel ◽  
Michael C. McCarthy
Keyword(s):  
Fourier Transform ◽  
Laser Ablation ◽  
Structural Characterization ◽  
Quantum Chemical ◽  
Microwave Spectroscopy ◽  
Rotational Spectroscopy ◽  
Chirped Pulse ◽  
Rotational Spectra ◽  
High Level

Rotational spectra of three Ge carbides, linear GeC4, GeC5, and GeC6 have been observed using chirped pulse and cavity Fourier transform microwave spectroscopy via laser ablation, guided by new high-level quantum chemical calculations.

Theoretical Study of Rotational Spectroscopy of Acetonitrile-d3in the Ground and Different Excited Vibrational States

2008 ◽  
Vol 5 (2) ◽  
pp. 201-218
Author(s):  
Motamedi Masoud ◽  
Moradi Parinaz
Keyword(s):  
Least Squares ◽  
Millimeter Wave ◽  
Theoretical Study ◽  
Rotational Spectroscopy ◽  
Accuracy Analysis ◽  
Centrifugal Distortion ◽  
Vibrational States ◽  
Rotational Spectra ◽  
Centrifugal Distortion Constants

The millimeter-wave rotational spectra of the ground and excited vibrational states v8= 1 and v8= 2 of the symmetric top molecule CD3CN have been analyzed again. Thel= ± 1 in v8=1,l= 0 andl= ± 2 series in v8= 2 states have been assigned respectively. The assignment and analysis of the measurements with a least – squares procedure have made it possible to obtain the rotational, quartic and sextic centrifugal distortion constants with more reliable and higher accuracy. Analysis of the v8= 2 state gave the following rotational parameters: Aζ = 62218.96 MHz and xll= 87527.70 MHz. Investigation in v8= 2 state indicates thatl-resonance is observed for this molecule aroundk=xℓℓ+(A−B)−2AζAζ−(A−B)≈4.

scholarly journals Decoding Pure Rotational Molecular Spectra for Asymmetric Molecules

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
S. A. Cooke ◽  
P. Ohring
Keyword(s):  
Rotational Constant ◽  
Rotational Spectroscopy ◽  
Molecular Spectra ◽  
Web Page ◽  
Mobile Web ◽  
Molecular Systems ◽  
Rotational Spectra ◽  
Constant Determination ◽  
Line Positions ◽  
Spectral Assignment

Rotational spectroscopy can provide insights of unparalleled precision with respect to the wavefunctions of molecular systems that have relevance in fields as diverse as astronomy and biology. In this paper, we demonstrate how asymmetric molecular pure rotational spectra may be analyzed “pictorially” and with simple formulae. It is shown that the interpretation of such spectra relies heavily upon pattern recognition. The presentation of some common spectral line positions in near-prolate asymmetric rotational spectra provides a means by which spectral assignment, and approximate rotational constant determination, may be usefully explored. To aid in this endeavor we have created a supporting, free, web page and mobile web page.

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