The Cl-nuclear quadrupole coupling tensors and the internal rotation barrier of 1,1-dichloroethane by Fourier transform microwave spectroscopy

1999 ◽  
Vol 248 (2-3) ◽  
pp. 247-261 ◽  
Author(s):  
Ana de Luis ◽  
Juan Carlos López ◽  
José Luis Alonso
Keyword(s):  
Fourier Transform ◽  
Internal Rotation ◽  
Microwave Spectroscopy ◽  
Rotation Barrier ◽  
Quadrupole Coupling ◽  
Internal Rotation Barrier ◽  
Nuclear Quadrupole ◽  
Fourier Transform Microwave Spectroscopy

The Microwave Spectra of m-Xylene and m-Xylene-d10. Determination of the Low Methyl Internal Rotation Barrier

2001 ◽  
Vol 56 (9-10) ◽  
pp. 635-640 ◽  
Author(s):  
C. Thomsen ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Internal Rotation ◽  
Microwave Spectroscopy ◽  
Methyl Groups ◽  
Rotation Barrier ◽  
Rotational Constants ◽  
Moments Of Inertia ◽  
Rotational Spectra ◽  
Internal Rotation Barrier

Abstract The rotational spectra of m-xylene, (CH3)2C6H4 and of m-xylene-d10, (CD3)2C6D4 have been recorded between 6 and 26.5 GHz using pulsed beam Fourier transform microwave spectroscopy. The clue for the assignment of the internal rotation multiplets was the inertial defect derived from the A1A1 species transitions. The rotational constants for m-xylene and m-xylene-d10 are A = 3572.1117(1) MHz / 2896.1195(17) MHz, B = 1761.8621(1) MHz / 1446.0236(15) MHz, C =1197.3943(2) MHz / 988.2357(7) MHz, the barrier to internal rotation of the two methyl groups are V3 = 53.7(16) J/mol / 39.8(5) J/mol, their moments of inertia were assumed to be I∞= 3.14 uÅ2 / 6.28 uÅ2.

Rotational spectrum and properties of the hydrogen-bonded heterodimer H 2 O· · · HCN from pulsed-nozzle, Fourier-transform microwave spectroscopy

1984 ◽  
Vol 396 (1811) ◽  
pp. 405-423 ◽  
Keyword(s):  
Fourier Transform ◽  
Microwave Spectroscopy ◽  
Coupling Constants ◽  
Spectroscopic Constants ◽  
Rotational Spectrum ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Fourier Transform Microwave Spectroscopy ◽  
Pulsed Nozzle ◽  
Hydrogen Bonded

The ground state rotational spectrum of a hydrogen-bonded heterodimer formed from water and hydrogen cyanide has been detected and measured by using the technique of pulsed-nozzle, Fourier-transform microwave spectroscopy. Rotational constants ( B 0 , C 0 ) centrifugal distortion constants ( ∆ J , ∆ JK ) and, where appropriate, 14 N-, D- or 17 O-nuclear quadrupole coupling constants have been determined for the following isotopic species; H 2 16 O· · · HC 14 N, H 2 18 O· · · HC 14 N, H 2 16 O· · · HC 15 N, HD 16 O· · · HC 15 N, D 2 16 O· · · HC 15 N, H 2 16 O· · · DC 15 N, HD 16 O· · · DC 15 N and H 2 17 O· · · HC 15 N. An analysis of these spectroscopic constants indicates that the heterodimer is effectively planar, with a pair of equivalent protons and the arrangement H 2 O· · · HCN. The intermolecular interaction is through a hydrogen bond between HCN and H 2 O and the distance between the O and C nuclei r (O· · · C) is 3.157 Å (1Å = 10 -10 m). An interpretation of the nuclear quadrupole coupling constants leads to the conclusion that arccos <cos 2 Φ > ½ ≈ 51°, where Φ is the angle between the local C 2 axis of H 2 O and the a -axis of the complex; and that arccos <cos 2 θ > ½ ≈ 10°, where θ is the angle between the HCN axis and the a -axis. The intermolecular stretching force constant k σ = 11 Nm -1 has been determined from ∆ J .

33S Nuclear Hyperfine Structure in the Rotational Spectrum of Thiazole

1993 ◽  
Vol 48 (12) ◽  
pp. 1219-1222 ◽  
Author(s):  
U. Kretschmer ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Molecular Beam ◽  
Microwave Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants

Abstract We investigated the 33S nuclear quadrupole coupling of thiazole- 33S in natural abundance by molecular beam Fourier transform microwave spectroscopy. In addition the 14N nuclear quadrupole coupling could be analyzed with high precision. We derived the rotational constants A = 8529.29268 (70) MHz, B = 5427.47098 MHz, and C = 3315.21676 (26) MHz, quartic centrifugal distortion constants and the quadrupole coupling constants of 33S χaa = 7.1708 (61) MHz and χbb= -26.1749 (69) MHz and of 14N χ aa = -2.7411 (61) MHz and χbb = 0.0767 (69) MHz.

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.

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.

scholarly journals 14N Nuclear Quadrupole Coupling and Methyl Internal Rotation in N-tert-Butylacetamide As Observed by Microwave Spectroscopy

2016 ◽  
Vol 120 (23) ◽  
pp. 3992-3997 ◽  
Author(s):  
Raphaela Kannengießer ◽  
Wolfgang Stahl ◽  
Ha Vinh Lam Nguyen ◽  
Isabelle Kleiner
Keyword(s):  
Internal Rotation ◽  
Microwave Spectroscopy ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole
Sign in / Sign up

Export Citation Format

Share Document