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.

scholarly journals Methyl Internal Rotation and 14N Nuclear Quadrupole Coupling from the Rotational Spectra of Ethyl Isocyanide, iso-Propyl Isocyanide and gauche- and trans-n-Propyl Isocyanide

1992 ◽  
Vol 47 (10) ◽  
pp. 1067-1072 ◽  
Author(s):  
Michael Krüger ◽  
Helmut Dreizler
Keyword(s):  
Fourier Transform ◽  
Internal Rotation ◽  
Vibrational State ◽  
Fourier Transform Spectroscopy ◽  
Coupling Constants ◽  
Ground Vibrational State ◽  
Rotational Spectra ◽  
Barrier Heights ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

AbstractThe barrier heights (V3) hindering methyl internal rotation were determined with microwave Fourier transform spectroscopy from the ground vibrational state for the title molecules and found to be V3 = 3.336(52) kcal/mol for ethyl isocyanide, V3 > 3.1 kcal/mol for iso-propyl isocyanide, V3 = 2.894(23) kcal/mol for gauche-n-propyl isocyanide and V3 = 2.954(22) kcal/mol for transn- propyl isocyanide. The quadrupole coupling constants of iso-propyl isocyanide are χaa = 179.3(31) kHz, χbb = -140(15) kHz and χcc - 39(15) kHz; the constants of trans-n-propyl isocyanide were determined to be χaa = 268.1 (71) kHz, χbb = - 108(23) kHz and χcc = - 160(23) kHz.

Nitrogen Quadrupole Coupling in the Rotational Spectrum of l-Isocyanoprop-2-yne, HC ≡ CCH2NC

1990 ◽  
Vol 45 (8) ◽  
pp. 986-988 ◽  
Author(s):  
M. Krüger ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Ground State ◽  
Fourier Transform Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Vibrational Ground State ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Hyperfine Splittings

AbstractThe rotational spectrum of l-isocyanoprop-2-yne, HC≡CCH2NC, has been measured in the vibrational ground state by microwave Fourier transform spectroscopy from 5 to 26.5 GHz. The nuclear quadrupole hyperfine splittings due to 14N have been analysed to obtain the coupling constants χaa = 290.3(78) kHz, χbb = 10.6(80) kHz and χcc= -300.9(80) kHz

scholarly journals Deuterium Quadrupole Coupling Constants of Deuterohalogenoacetylens

1988 ◽  
Vol 43 (8-9) ◽  
pp. 755-757 ◽  
Author(s):  
N. Heineking ◽  
M. Andolfatto ◽  
C. Kruse ◽  
W. Eberstein ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Fourier Transform Spectroscopy ◽  
Spin Rotation ◽  
Coupling Constants ◽  
Centrifugal Distortion ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Rotational Transitions

Abstract Employing the high resolution of microwave Fourier transform spectroscopy, we investigated the lowest rotational transitions of fluoro-, bromo-, and iodoacetylene-d. Along with the rotational, centrifugal distortion, halogen nuclear quadrupole, and halogen spin-rotation coupling constants, we determined the deuterium quadrupole coupling constants of bromo-and iodoacetylene-d. For fluoroacetylene-d, we redetermined the deuterium nuclear quadrupole coupling constants with higher accuracy.

Nuclear Quadrupole Hyperfine Structure in the Rotational Spectrum of 3-Chloropyridine. An Application of Microwave-Microwave Double Resonance Fourier Transform Spectroscopy

1988 ◽  
Vol 43 (7) ◽  
pp. 657-661 ◽  
Author(s):  
N. Heineking ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Double Resonance ◽  
Fourier Transform Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Rotational Constants ◽  
Modulation Technique ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

AbstractWe redetermined the rotational and the chlorine-35 and nitrogen-14 nuclear quadrupole coupling constants of 3-chloropyridine. The values are A = 5839.5330(12) MHz, B = 1604.1875(6) MHz, and C = 1258.3121 (5) MHz for the rotational constants, and χaa(Cl) = - 72.255(19) MHz, χbb(Cl) = + 38.500(13) MHz, χcc(Cl) = + 33.755(23) MHz and χaa(N) = - 0.009(13) MHz, χbb(N) = - 3.473(10) MHz, χCC(N) = + 3.482(16) MHz for the chlorine-35 and nitrogen-14 nuclear quadrupole coupling constants, respectively.Application of double resonance modulation technique is shown to greatly simplify the assign­ment of hyperfine structure components even of weak rotational transitions.

14N Quadrupole Coupling in the Rotational Spectra of Cyclopropylamine and Cyclopropyl Cyanide

1989 ◽  
Vol 44 (7) ◽  
pp. 655-658 ◽  
Author(s):  
Olaf Böttcher ◽  
Nils Heineking ◽  
Dieter Hermann Sutter
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Fourier Transform Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectra ◽  
Quadrupole Coupling

Abstract The 14N hyperfine structure in the rotational spectra of cyclopropylamine and cyclopropyl cyanide has been reinvestigated by microwave Fourier transform spectroscopy. The observed quadrupole coupling constants in units of MHz are: Xaa = 2.3338(18), Xbb = 1.7874(20), Xcc = −4.1209(20) for cyclopropylamine and Xaa = −3.4536(35), Xbb= 1.7468(51), Xcc= 1.7068(51) for cyclopropyl cyanide.

Nuclear Quadrupole Hyperfine Structure and Methyl Torsional Fine Structure in the Rotational Spectra of N,N-Dimethylformamide and N-Nitrosodimethylamine

1993 ◽  
Vol 48 (4) ◽  
pp. 570-576 ◽  
Author(s):  
N. Heineking ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Fine Structure ◽  
Hyperfine Structure ◽  
Internal Rotation ◽  
Amino Nitrogen ◽  
Coupling Constants ◽  
Methyl Group ◽  
Rotational Spectra ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

Abstract The complicated nuclear quadrupole hyperfine structure and methyl torsional fine structure in the rotational spectra of N,N-dimethylformamide and N-nitrosodimethylamine have been studied using microwave Fourier transform spectroscopy. It has been found that both molecules are rather similar in terms of their parameters of methyl group internal rotation as well as in terms of their amino nitrogen quadrupole coupling constants.

Nitrogen and Deuterium Hyperfine Structure in the Rotational Spectrum of Morpholine

1989 ◽  
Vol 44 (9) ◽  
pp. 833-836 ◽  
Author(s):  
J.-U. Grabow ◽  
H. Ehrlichmann ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Fourier Transform Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Rotational Spectra ◽  
Quadrupole Coupling

Abstract We reinvestigated the rotational spectra of morpholine and N-deutero morpholine with the higher precision of microwave Fourier transform spectroscopy. The rotational, centrifugal, and nitrogen quadrupole coupling constants were improved and the deuterium quadrupole coupling constants determined.

Nitrogen and Deuterium Hyperfine Structure in the Rotational Spectrum of Piperidine

1989 ◽  
Vol 44 (9) ◽  
pp. 841-847 ◽  
Author(s):  
H. Ehrlichmann ◽  
J.-U. Grabow ◽  
H. Dreizler ◽  
N. Heineking ◽  
M. Andolfatto
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Fourier Transform Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Rotational Spectra ◽  
Coupling Tensor ◽  
Quadrupole Coupling

Abstract We reinvestigated by microwave Fourier transform spectroscopy the rotational spectra of the axial and equatorial isotopomers of piperidine and N-deutero piperidine. The rotational, centrifugal, and nitrogen quadrupole coupling constants were improved, the deuterium quadrupole coupling constants were determined. The principal coupling tensor elements for nitrogen were estimated.

Contribution of Microwave Fourier Transform Spectroscopy to the Investigation of Nuclear Quadrupole Coupling

1992 ◽  
Vol 47 (1-2) ◽  
pp. 342-352 ◽  
Author(s):  
Helmut Dreizler
Keyword(s):  
Fourier Transform ◽  
Fourier Transform Spectroscopy ◽  
Rotational Spectra ◽  
Quadrupole Coupling ◽  
Fine Structures ◽  
Free Molecules ◽  
Nuclear Quadrupole

AbstractBy simple examples it is shown how fine structures in rotational spectra of free molecules can be used to analyse nuclear quadrupole coupling. It is demonstrated that microwave Fourier transform spectroscopy is an adequate tool for these studies. Examples for different nuclei illustrate the present possibilities

The Rotational Spectra of the 32S-, 33S-, and 34S-Isotopomers of Thiophene

1993 ◽  
Vol 48 (5-6) ◽  
pp. 733-736
Author(s):  
U. Kretschmer ◽  
W. Stahl ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Fourier Transform Spectroscopy ◽  
Coupling Constants ◽  
Centrifugal Distortion ◽  
Rotational Spectra ◽  
Quadrupole Coupling ◽  
Centrifugal Distortion Constants

The rotational spectra of the 32S-, 34S- and 33S-isotopomers of thiophene have been studied in their natural abundances using microwave Fourier transform spectroscopy. For the 32S-isotopomer the rotational and centrifugal distortion constants were found to be A' = 8041.59407(46) MHz, B' = 5418.26219(17) MHz, C' = 3235.78061(16) MHz, D'J = 0.6967(96) kHz, D'JK = 0.530(14) kHz, D'K = 1.789(49) kHz, δ'K = 0.3067(21) kHz, R'6 = - 0.0738(12) kHz. For the 34S-isotopomer A' = 8041.7055(84) MHz, B'= 5274.1837(23) MHz, C' = 3183.8432(23) MHz, and for the 33S-isotopomer A'= 8041.651 (10) MHz, B' = 5344.2988(15) MHz, C' = 3209.25777(66) MHz with almost the same centrifugal distortion constants were obtained. The 33S-quadrupole coupling constants of the 33S-thiophene are χaa = 6.8610(64) MHz and χbb - χcc = -48.766(11) MHz.

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