Microwave Fourier‐transform spectrometer for the entireKband for the investigation of rotational spectra of molecules in the gas phase

1985 ◽  
Vol 56 (9) ◽  
pp. 1759-1762 ◽  
Author(s):  
W. Stahl ◽  
G. Bestmann ◽  
H. Dreizler ◽  
U. Andresen ◽  
R. Schwarz
Keyword(s):  
Fourier Transform ◽  
Gas Phase ◽  
Fourier Transform Spectrometer ◽  
Rotational Spectra

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.

Solvent induced frequency shifts of the C—H stretching bands of n-octane. A Fourier transform infrared study

1981 ◽  
Vol 59 (9) ◽  
pp. 1357-1360 ◽  
Author(s):  
D. G. Cameron ◽  
S. C. Hsi ◽  
J. Umemura ◽  
H. H. Mantsch
Keyword(s):  
Fourier Transform ◽  
Gas Phase ◽  
Carbon Disulfide ◽  
Fourier Transform Infrared ◽  
Dielectric Constants ◽  
Refractive Indices ◽  
Fourier Transform Spectrometer ◽  
Infrared Study ◽  
Frequency Shifts ◽  
Frequency Behavior

Using a Fourier transform spectrometer the frequencies and bandwidths of the infrared active C—H stretching modes of n-octane were determined in a variety of solvents with refractive indices from 1.63 (carbon disulfide) to 1.28 (n-perfluorooctane), and dielectric constants from 37.5 (acetonitrile) to 1.8 (n-perfluorooctane). The frequency shifts were correlated with the refractive indices and dielectric constants of the solvents, and fitted with the equation of David and Hallam (Spectrochim. Acta, Part A, 23, 593 (1967)). Generally, solution results in shifts to frequencies lower than those observed in the gas phase. However, solution in n-perfluorooctane resulted in a shift to a higher frequency, behavior in accord with the above equation but not previously observed.

A Microwave Fourier Transform Spectrometer in the Frequency Band From 26 to 40 GHz

1989 ◽  
Vol 44 (3) ◽  
pp. 215-221 ◽  
Author(s):  
Ch. Keussen ◽  
N. Heineking ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Dipole Moment ◽  
Sulfur Dioxide ◽  
Excited States ◽  
Frequency Band ◽  
Carbonyl Sulfide ◽  
Frequency Region ◽  
Fourier Transform Spectrometer ◽  
Rotational Spectra ◽  
And Performance

We report the design and performance of a microwave Fourier transform spectrometer in the frequency region between 26 and 40 GHz for the investigation of rotational spectra. The performance is illustrated by rotational transitions of allene and allene-d4 molecules with a very small dipole moment in vibrational excited states. The sensivity and Doppler limited linewidth is demonstrated by measurements of transitions of isotopomers of carbonyl sulfide and sulfur dioxide.

Improved Version of a Microwave Fourier Transform Spectrometer in the Frequency Band from 26 to 40 GHz

1990 ◽  
Vol 45 (5) ◽  
pp. 711-714
Author(s):  
Ch. Keussen ◽  
R. Schwarz ◽  
U. Andresen ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Frequency Band ◽  
Carbonyl Sulfide ◽  
High Sensitivity ◽  
Frequency Region ◽  
Natural Abundance ◽  
Fourier Transform Spectrometer ◽  
Rotational Spectra ◽  
Rotational Transitions ◽  
And Performance

Abstract We report the design and performance of an improved version of a microwave Fourier transform spectrometer in the frequency region between 26 and 40 GHz for the investigation of rotational spectra. The performance is illustrated by rotational transitions of allene-d4 and isotopomers of carbonyl sulfide in natural abundance. The high sensitivity of the spectrometer allows the measurement of very weak lines in only a few minutes

Gas-phase hydration of nopinone: the interplay between theoretical methods and experiments unveils the conformational landscape

2021 ◽  
Author(s):  
Elias M. Neeman ◽  
Juan Ramón Avilés Moreno ◽  
Thérèse Huet
Keyword(s):  
Fourier Transform ◽  
Gas Phase ◽  
Supersonic Jet ◽  
Theoretical Methods ◽  
Rotational Spectra ◽  
Supersonic Jet Expansion ◽  
Conformational Landscape

The structure of microsolvated nopinone formed in the supersonic jet expansion is investigated in the gas phase. The rotational spectra of nopinone-(H2O)n (n=1,2,3) were analysed by means of Fourier transform...

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.

Sign in / Sign up

Export Citation Format

Share Document