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.

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.

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.

The Rotational Spectrum and Nuclear Quadrupole Coupling of CH35C1F2

1996 ◽  
Vol 51 (1-2) ◽  
pp. 129-132 ◽  
Author(s):  
Susana Blanco ◽  
Alberto Lesarri ◽  
Juan C. López ◽  
José L. Alonso ◽  
Antonio Guarnieri
Keyword(s):  
Fourier Transform ◽  
Vibrational State ◽  
Frequency Region ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Frequency Range ◽  
Vibrational States ◽  
Ground Vibrational State ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

Abstract The rotational spectrum of CH35CIF2 in the ground vibrational state has been measured in the frequency range 8-18 GHz using a waveguide Fourier transform microwave (FTMW) spectrometer in order to determine accurate nuclear quadrupole coupling constants. The spectra of the excited vibrational states ν5 = 1, ν6 = 1 and ν9 = 1 have been also observed and analyzed in the frequency region 8-250 GHz using FTMW, Stark, and source modulation spectrometers. Quadrupole coupling constants are also reported for these states.

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.

The Hyperfine Structure in the Rotational Spectrum of CuCl

1977 ◽  
Vol 32 (12) ◽  
pp. 1477-1479
Author(s):  
E. Tiemann ◽  
J. Hoeft
Keyword(s):  
Hyperfine Structure ◽  
Vibrational State ◽  
Rotational Transition ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Ground Vibrational State ◽  
Quadrupole Coupling ◽  
Magnetic Spin ◽  
Nuclear Quadrupole ◽  
Rotational Coupling

Abstract The hyperfine structure of the rotational transition J = 1 ← 0 of 63Cu35Cl in the ground vibrational state was observed. The analysis resulted in the following nuclear quadrupole coupling constants: 63Cu: e q0 Q= +16.08(20) MHz; 35Cl: eq0 Q = - 32.25(15) MHz. The influence of the small magnetic spin rotational coupling of both nuclei on the hyperfine spectrum is discussed.

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.

Microwave Spectrum of N-Methyl Morpholine

1974 ◽  
Vol 52 (3) ◽  
pp. 434-439 ◽  
Author(s):  
S. C. Dass ◽  
R. Kewley
Keyword(s):  
Dipole Moment ◽  
Vibrational State ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Vibrational States ◽  
Methyl Group ◽  
Ground Vibrational State ◽  
Chair Form ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

The microwave spectrum of N-methyl morpholine has been investigated within the 8 to 40 GHz region. The observed rotational constants for the ground vibrational state are (in MHz), A = 4821.235(0.077), B = 2342.579(0.004), and C = 1719.452(0.003). The dipole moment components have been determined as (in D), μa = 1.21(0.02), μc = 0.10(0.03), and μ= 1.21(0.02). The values of these parameters show that the observed spectrum is due to the chair form with an equatorial methyl group. The 14N nuclear quadrupole coupling constants have the values (in MHz), χaa = 2.4(0.1), χbb =.6(0.3) and χcc = −5.0(0.2). Sets of rotational transitions due to six excited vibrational states have also been assigned.

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.

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