scholarly journals Rotational spectra and structure of the Ar2–H2S complex: pulsed nozzle Fourier transform microwave spectroscopic and ab initio studies

2005 ◽  
Vol 7 (14) ◽  
pp. 2740 ◽  
Author(s):  
Pankaj K. Mandal ◽  
Dharmender J. Ramdass ◽  
E. Arunan
Keyword(s):  
Fourier Transform ◽  
Ab Initio ◽  
Rotational Spectra ◽  
Pulsed Nozzle

A rotational spectroscopic and ab initio study of cis and trans (-)-carveol: Further insights into conformational dynamics in monoterpenes and monoterpenoids

2021 ◽  
Author(s):  
Arsh Singh Hazrah ◽  
Mohamad al-Jabiri ◽  
Raiden Speelman ◽  
Wolfgang Jaeger
Keyword(s):  
Fourier Transform ◽  
Ab Initio ◽  
Conformational Dynamics ◽  
Ab Initio Study ◽  
Chirped Pulse ◽  
Rotational Spectra ◽  
Microwave Spectrometer ◽  
Cis And Trans

Broadband rotational spectra of cis- and trans- (-) carveol were recorded using a chirped pulse Fourier transform microwave spectrometer in the 2-6 GHz region. To aid in spectroscopic assignments a...

scholarly journals Understanding (coupled) large amplitude motions: the interplay of microwave spectroscopy, spectral modeling, and quantum chemistry

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ha Vinh Lam Nguyen ◽  
Isabelle Kleiner
Keyword(s):  
Fourier Transform ◽  
Quantum Chemistry ◽  
Large Amplitude ◽  
Environmental Chemistry ◽  
Broad Band ◽  
Microwave Spectroscopy ◽  
Rotational Spectrum ◽  
Spectral Modeling ◽  
Rotational Spectra ◽  
Large Amplitude Motions

AbstractA large variety of molecules contain large amplitude motions (LAMs), inter alia internal rotation and inversion tunneling, resulting in tunneling splittings in their rotational spectrum. We will present the modern strategy to study LAMs using a combination of molecular jet Fourier transform microwave spectroscopy, spectral modeling, and quantum chemical calculations to characterize such systems by the analysis of their rotational spectra. This interplay is particularly successful in decoding complex spectra revealing LAMs and providing reference data for fundamental physics, astrochemistry, atmospheric/environmental chemistry and analytics, or fundamental researches in physical chemistry. Addressing experimental key aspects, a brief presentation on the two most popular types of state-of-the-art Fourier transform microwave spectrometer technology, i.e., pulsed supersonic jet expansion–based spectrometers employing narrow-band pulse or broad-band chirp excitation, will be given first. Secondly, the use of quantum chemistry as a supporting tool for rotational spectroscopy will be discussed with emphasis on conformational analysis. Several computer codes for fitting rotational spectra exhibiting fine structure arising from LAMs are discussed with their advantages and drawbacks. Furthermore, a number of examples will provide an overview on the wealth of information that can be drawn from the rotational spectra, leading to new insights into the molecular structure and dynamics. The focus will be on the interpretation of potential barriers and how LAMs can act as sensors within molecules to help us understand the molecular behavior in the laboratory and nature.

scholarly journals Variational analysis of HF dimer tunneling rotational spectra using an ab initio potential energy surface

2021 ◽  
pp. 111481
Author(s):  
Oleg L. Polyansky ◽  
Roman I. Ovsyannikov ◽  
Jonathan Tennyson ◽  
Sergei P. Belov ◽  
Mikhail Yu. Tretyakov ◽  
...  
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Ab Initio ◽  
Variational Analysis ◽  
Energy Surface ◽  
Rotational Spectra

Rotational spectra, conformational structures and dipole moments of 2-(ethylthio)ethanol by jet-cooled FTMW and ab initio calculations

2004 ◽  
Vol 223 (1) ◽  
pp. 9-19 ◽  
Author(s):  
R.D. Suenram ◽  
D.F. Plusquellic ◽  
F.J. Lovas ◽  
A.R. Hight Walker ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Dipole Moments ◽  
Rotational Spectra

scholarly journals HNCO-based synthesis of formamide in planetary atmospheres

2018 ◽  
Vol 616 ◽  
pp. A150 ◽  
Author(s):  
M. Ferus ◽  
V. Laitl ◽  
A. Knizek ◽  
P. Kubelík ◽  
J. Sponer ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Fourier Transform ◽  
Ab Initio ◽  
Molecular Dynamics Simulations ◽  
Emission Spectroscopy ◽  
Planetary Atmospheres ◽  
Infrared Emission ◽  
Ab Initio Molecular Dynamics ◽  
Isocyanic Acid ◽  
Dynamics Simulations

Time-resolved Fourier transform infrared emission spectroscopy, Fourier transform absorption infrared spectroscopy, and high-resolution UV–ViS emission spectroscopy have been used to characterize the chemistry of isocyanic acid (HNCO) under glow discharge conditions in planetary atmospheres. HNCO mixtures (i.e., composed of di-hydrogen or ammonia) have been investigated in order to unveil the possible reaction pathways leading to the synthesis of the key prebiotic molecule formamide (HCONH2), upon planetary atmospheres containing isocyanic acid in presence of di-hydrogen and, separately, of ammonia. In addition, ab initio molecular dynamics simulations coupled with a modern metadynamics technique have been performed in order to identify the most likely chemical pathways connecting HNCO to formamide. It turned out that the direct hydrogenation of HNCO is thermodynamically favored. Incidentally, the experimental results – supplied by a simplified kinetic model – also proved the favorability of the reaction HNCO + H2→ HCONH2which, moreover, spontaneously takes place in unbiased ab initio molecular dynamics simulations carried out under the effect of intense electric fields.

14N-and D-Hyperfine Structure in the Rotational Spectrum of Pyrrolidine

1989 ◽  
Vol 44 (9) ◽  
pp. 837-840
Author(s):  
H. Ehrlichmann ◽  
J.-U. Grabow ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Fourier Transform Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Spectra

Abstract We present an analysis of the rotational spectra of the normal and the N-deuterated pyrrolidine measured by microwave Fourier transform spectroscopy. The quartic centrifugal distortion con­ stants and the 14N coupling constants have been determined with higher accuracy. In addition the D hyperfine structure could be analyzed.

The Rotational Spectra of Fluorinated Acetonitriles; 14N-nuclear Quadrupole Hyperfine Structures Measured with a Microwave Fourier Transform Spectrometer

1983 ◽  
Vol 38 (9) ◽  
pp. 1015-1021
Author(s):  
W. Kasten ◽  
H. Dreizler ◽  
Brian E. Job ◽  
John Sheridan
Keyword(s):  
Fourier Transform ◽  
Nitrogen Atom ◽  
Fourier Transform Spectroscopy ◽  
Coupling Constants ◽  
Fourier Transform Spectrometer ◽  
Rotational Spectra ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Hyperfine Splittings ◽  
Hyperfine Structures

Abstract The microwave spectra of CF3CN, CH2FCN, CHDFCN, CD2FCN and CHF2CN have been measured and analysed. The nuclear quadrupole hyperfine splittings due to 14N have been measured by Microwave Fourier Transform spectroscopy. The nuclear quadrupole coupling constants, transformed to the bonding axis systems of the C-C ≡ N groups, are shown to be in accord with structural predictions of the p-electron populations at the nitrogen atom.

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