ChemInform Abstract: The Millimeter-Wave Spectra of Furan, Pyrrole, and Pyridine: Experimental and Theoretical Determination of the Quartic Centrifugal Distortion Constants.

ChemInform ◽  
1988 ◽  
Vol 19 (20) ◽  
Author(s):  
G. WLODARCZAK ◽  
L. MARTINACHE ◽  
J. DEMAISON ◽  
B. P. VAN EIJCK
Keyword(s):  
Millimeter Wave ◽  
Wave Spectra ◽  
Centrifugal Distortion ◽  
Theoretical Determination ◽  
Centrifugal Distortion Constants

Sub-millimeter Wave Spectra of Cyanoacetylene and Revised Ground State Constants

1995 ◽  
Vol 50 (12) ◽  
pp. 1179-1181 ◽  
Author(s):  
K. M. T. Yamada ◽  
A. Moravec ◽  
G. Winnewisser
Keyword(s):  
Millimeter Wave ◽  
Ground State ◽  
Vibrational State ◽  
Frequency Region ◽  
Wave Spectra ◽  
Centrifugal Distortion ◽  
Ground Vibrational State ◽  
Wave Data ◽  
Centrifugal Distortion Constants ◽  
Wave Spectrometer

Abstract Sixteen new rotational transitions of cyanoacetylene in the ground vibrational state have been measured in the frequency region from 570 GHz to 710 GHz by the Cologne sub-millimeter wave spectrometer. The observed transition frequencies were analyzed together with unpublished millimeter wave data of our group and with the data available in the literature. Precise rota­ tional constant and the quartic and sextic centrifugal distortion constants have been determined; B = 4549.058224(37) MHz, D = 0.544110(19) kHz, and H = 0.0345(21) mHz.

Millimetre-wave spectrum of HC17O+. Experimental and theoretical determination of the quadrupole coupling constant of the 17O nucleus

2001 ◽  
Vol 79 (2-3) ◽  
pp. 359-366 ◽  
Author(s):  
L Dore ◽  
C Puzzarini ◽  
G Cazzoli
Keyword(s):  
Wave Spectrum ◽  
Quadrupole Coupling Constant ◽  
Basis Sets ◽  
Coupling Constant ◽  
Centrifugal Distortion ◽  
Millimetre Wave ◽  
Quadrupole Coupling ◽  
Self Consistent Field ◽  
Centrifugal Distortion Constants

The millimetre-wave spectrum of HC17O+ has been analyzed up to 348.2 GHz by recording the J = 2 [Formula: see text] 1 and J = 4 [Formula: see text] 3 rotational transitions. Present measurements and the previous detection of the J = 1 [Formula: see text] 0 transition carried out in this laboratory allowed us to determine accurate values of the rotational and centrifugal distortion constants, and of the nuclear quadrupole coupling (χ) and spin-rotation constants. Moreover, χ has been evaluated from the electric field gradient at the oxygen nucleus calculated by using the multiconfiguration self-consistent field approach plus subsequent multireference configuration interaction computation, employing basis sets of quadruple zeta quality. Excellent agreement with experiment has been obtained. In addition, the molecular dipole moment has been calculated at the same level of accuracy. PACS No.: 33.20Bx

Spectroscopic investigations of hydrogen bonding interactions in the gas phase. V.t The identification and determination of the geometry and electric dipole moment of the hydrogen bonded heterodimer formed between oxirane and hydrogen fluoride, (CH 2 ) 2 O • • • HF, by infrared and microwave spectroscopy

1981 ◽  
Vol 373 (1755) ◽  
pp. 511-526 ◽  
Keyword(s):  
Hydrogen Fluoride ◽  
Point Group ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Rotational Spectra ◽  
Hydrogen Bonding Interactions ◽  
Pyramidal Configuration ◽  
Centrifugal Distortion Constants ◽  
Hydrogen Bonded

The hydrogen bonded heterodimer formed between oxirane and hydrogen fluoride has been identified through its infrared and microwave spectra. Rotational constants/MHz and centrifugal distortion constants/kHz for the following isotopic varieties have been derived from an analysis of the rotational spectra in the vibrational ground state: A B A (CH 2 ) 2 160* • -HF 16099 3638.75 3462.31 15.3 25.8 (CH2)2160- • *DF 15984 3605.66 3434.85 14.1 20.9 For the species (CH2)2180 • • • HF only the rotational constants 7059.7 MHz and B — C = 135 MHz could be obtained. It is established from arguments based on Pband A that the dimer has a pyramidal configuration at the oxygen atom and that the molecular point group is (7g. If the justifiable assumption is made that the monomer geometries are unchanged on dimer formation, then the observed rotational constants for (CH 2 )2160* • -H F leadtor0(O* • *F) = 2.627 A ja n d ^ = 71.8°, where ^ is the angle between the plane of the three-membered ring and the H—F direction. Replacement of H by D in the hydrogen bond does not significantly change these values.

Mikrowellenspektrum, Rotationskonstanten, Kernquadrupolkopplungskonstanten und r0-Struktur von Äthylchlorsilan / Microwave Spectrum, Rotational Constants, Nuclear Quadrupol Coupling Constants and ro structure of Ethylchlorosilane

1974 ◽  
Vol 29 (7) ◽  
pp. 1081-1096 ◽  
Author(s):  
V. Typke ◽  
M. Dakkouri ◽  
W. Zeil
Keyword(s):  
Microwave Spectrum ◽  
Coupling Constants ◽  
Centrifugal Distortion ◽  
Trans Form ◽  
Rotational Constants ◽  
Bond Angles ◽  
Centrifugal Distortion Constants

The MW-spectra of trans- and gauche-rotamers of 5 isotopes of ethylchlorosilane have been measured and partially analyzed. From the analysis rotational constants, centrifugal distortion constants and nuclear quadrupol coupling constants have been obtained. The determination of the restructure from 30 rotational constants leads to different bond angles C -C -Si for the two conformers. The optimalization of the quadrupol coupling constants in the bond axis system on the basis of the r0-structure using all information on the 35Cl-species yields the following values: ZZZ = (-35.5±0.8) MHz, η = - 0.25±0.11 for the trans-form and ZZZ= (-36.3±2.7) MHz, η = -0.08±0.10 for the gauche-form.

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