The rotational spectrum, chlorine nuclear quadrupole coupling constants, and molecular geometry of a hydrogen-bonded dimer of cyclopropane and hydrogen chloride

1982 ◽  
Vol 104 (6) ◽  
pp. 1486-1490 ◽  
Author(s):  
A. C. Legon ◽  
P. D. Aldrich ◽  
W. H. Flygare

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 .



1993 ◽  
Vol 48 (12) ◽  
pp. 1219-1222 ◽  
Author(s):  
U. Kretschmer ◽  
H. Dreizler

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.



1996 ◽  
Vol 51 (10-11) ◽  
pp. 1110-1112 ◽  
Author(s):  
Jens-Uwe Grabow ◽  
Masao Onda ◽  
Helmut Dreizler

Abstract The rotational spectrum of 33S 2,2-dimethylthiirane with its 33S nuclear quadrupole coupling hyperfine structure in the range 8.9 to 20.0 GHz and its analysis is reported. The rotational constants are A = 5507.4663(3), B = 3440.58395(18), and C = 2978.5723(3) MHz. The 33 S quadrupole coupling constants are χaa = -22.6390(23), χbb = 47.1830(50), and χcc = -24.5440(50) MHz.



1988 ◽  
Vol 43 (7) ◽  
pp. 657-661 ◽  
Author(s):  
N. Heineking ◽  
H. Dreizler

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.



1991 ◽  
Vol 46 (9) ◽  
pp. 770-776 ◽  
Author(s):  
Kirsten Vormann ◽  
Helmut Dreizler ◽  
Jens Doose ◽  
Antonio Guarnieri

AbstractThe boron and nitrogen hyperfine structure in the rotational spectra of two aminoborane isotopomers, 11 BH2NH2 and 10BH2NH2, has been investigated and the quadrupole coupling constants of boron 10B, 11B and nitrogen 14N have been determined. We get the following results for the nuclear quadrupole coupling constants: χaa(11B) = -1.684 (14) MHz, χbb(11B) = -2.212 (11) MHz, χcc(11B) = 3.896(11) MHz, χaa(10B) = -3.481 (11) MHz, χbb(10B) = -4.623 (14) MHz, χCC(10B) = 8.104 (14) MHz and xaa(14N) = 0.095 (9) MHz, χbb(14N) = 2.091 (8) MHz, χcf4 (14N)=-2.186 (8) MHz. These nitrogen quadrupole coupling constants are those of the 11BH2 NH2 isotopomer. Additionally we were able to determine two out of the three spin rotation coupling constants caa, cbb, and ccc of boron, caa(11 B = 55.2 (26) kHz, cbb(11B) = 6.62 (36) kHz, caa (10B) = 15.26 (69) kHz and cbb(10B) = 4.94 (70) kHz. The spin rotation coupling constants ccc had to be fixed to zero in both cases. Furthermore we measured the rotational spectra in the mm-wave region to determine all quartic and several sextic centrifugal distortion constants according to Watson's A and S reduction



1997 ◽  
Vol 52 (4) ◽  
pp. 297-305 ◽  
Author(s):  
Barbara Kirchner ◽  
Hanspeter Huber ◽  
Gerold Steinebrunner ◽  
Helmut Dreizler ◽  
Jens-Uwe Grabow ◽  
...  

Abstract We present quantum chemical calculations on the MP4(SDQ) level with basis sets of high local quality to determine the nuclear quadrupole coupling tensor of 33S in a series of molecules, which were investigated up to now by microwave spectroscopy. The analysis of the nuclear quadrupole coupling in the rotational spectra provided experimental information on the tensors. As an example for such an analysis, improved values for thiirane, C2H433S, are given: χaa = - 32.9425(78) MHz, χbb = -16.402(14) MHz, χcc = 49.345(14) MHz.



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