scholarly journals Determination of stretching force constants of weakly bound dimers from centrifugal distortion constants

1985 ◽  
Vol 63 (7) ◽  
pp. 1477-1479 ◽  
Author(s):  
D. J. Millen
Keyword(s):  
Force Constants ◽  
Centrifugal Distortion ◽  
Weakly Bound ◽  
Rotational Constants ◽  
Weak Bond ◽  
Centrifugal Distortion Constants

Expressions are derived from which stretching force constants for the weak bond in weakly bound dimers may be evaluated directly from observed rotational constants and centrifugal stretching distortion constants.

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.

Study of the C-D Stretching Vibration Bands v1 of DCCF and DCCBr

1974 ◽  
Vol 29 (5) ◽  
pp. 698-701 ◽  
Author(s):  
Mikko Huhanantti
Keyword(s):  
Ground State ◽  
Force Constants ◽  
Centrifugal Distortion ◽  
Vibrational States ◽  
Rotational Constants ◽  
Stretching Vibration ◽  
Geometrical Data ◽  
Experimental Values ◽  
Centrifugal Distortion Constants

Abstract The rotational structures of the ν1 bands of the deuterated monohaloacetylenes DCCF and DCCBr were investigated. The rotational constants B in the ground state and in the vibrational states involved were obtained. The centrifugal distortion constants D were calculated from the force constants and the geometrical data, too. The results D = 8.7 x 10-8 cm-1 for DCCF and D = 1.9 x 10-8 cm-1 for DCCBr are compatible with the experimental values (12 ± 4) x 10-8 cm-1 and(2±2) x 10-8 cm-1, respectively.

Microwave spectrum and molecular structure of the HS2 radical

1994 ◽  
Vol 72 (11-12) ◽  
pp. 954-962 ◽  
Author(s):  
Satoshi Yamamoto ◽  
Shuji Saito
Keyword(s):  
Zero Point ◽  
Force Constants ◽  
Spectral Lines ◽  
Centrifugal Distortion ◽  
Harmonic Force ◽  
Rotational Constants ◽  
Anharmonic Constants ◽  
Microwave Spectrometer ◽  
Centrifugal Distortion Constants ◽  
Space Cell

Rotational spectral lines of the HS2 and DS2 radicals in the 2A″ ground electronic state are detected by a source-modulation microwave spectrometer combined with a free-space cell. The HS2 radical is produced in the cell by discharging a pure H2S gas. The spectrum of DS2 is observed by using a mixture of H2S and D2. The rotational constants, the centrifugal distortion constants, the spin-rotation interaction constants with their centrifugal distortion corrections, and the hyperfine interaction constants for the hydrogen nucleus are determined by least-squares analyses. The harmonic force constants are evaluated from the observed centrifugal distortion constants in combination with the vibrational frequencies reported previously. The zero-point average structure of HS2 is determined from the observed rotational constants of HS2 and DS2 with the aid of the harmonic force constants: rz(S—S) = 1.9650 (7) Å, rz (S—H) = 1.362 (3) Å, and αz (HSS) = 101/7 (4)° (1 Å = 10−10 m). The equilibrium distances for the S—S and S—H bonds are derived to be 1.9606 (7) Å and 1.352 (3) Å, respectively, by assuming the anharmonic constants of the corresponding diatomic molecules.

scholarly journals The Rotational Spectrum of (17O)Ketene

2001 ◽  
Vol 56 (6-7) ◽  
pp. 440-446 ◽  
Author(s):  
A. Guarnieri ◽  
A. Huckauf
Keyword(s):  
Molecular Beam ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Coupling Structure ◽  
Quadrupole Coupling ◽  
Quadrupole Constant ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants

Abstract The rotational spectrum of H2CC17O in the ground vibrational state has been investigated between 20 and 330 GHz. From 82 R-branch transitions a set of rotational constants and several centrifugal distortion constants could be derived, employing the Watson 5-reduction formalism. The obtained rotational constants in MHz are: A = 282071.6(223), B = 10013.4764(28), C = 9655.9118(24). The nuclear quadrupole coupling structure of the J'Ka'Kc' <- JKaKc = 101 O00 line has been recorded by means of molecular beam Fourier transform microwave spectroscopy allowing the determination of the nuclear quadrupole constant Xaa. = -1.534(54) MHz (without considering the spin-rotation interaction). A recalculation of the rs-structure has also been carried out, using the constants of the new isotopomer. The result agrees with the values reported by East et al. in 1995. This is, to our knowledge, the first reported investigation of the H2CC17O rotational spectrum.

The Microwave Spectrum and Dipole Moment of Hexafluoropropanone

1991 ◽  
Vol 46 (3) ◽  
pp. 229-232 ◽  
Author(s):  
J.-U. Grabow ◽  
N. Heineking ◽  
W. Stahl
Keyword(s):  
Fourier Transform ◽  
Dipole Moment ◽  
Molecular Beam ◽  
Stark Effect ◽  
Microwave Spectrum ◽  
Fourier Transform Spectrometer ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Centrifugal Distortion Constants

AbstractWe recorded the microwave spectrum of hexafluoropropanone between 7 and 15 GHz using a pulsed molecular beam microwave Fourier transform spectrometer. The rotational constants were determined to be A = 2181.71980(14) MHz, B= 1037.22930(7) MHz, C = 934.89233(8) MHz, the quartic centrifugal distortion constants are D'J= 0.07378 (39) kHz, D'JK = 0.10002(75) kHz, D'K = -0.07269(266) kHz, δ'J = 0.00623(29) kHz and R' 6= 0.00755(12) kHz. Stark effect measurements yielded a dipole moment μ = μb= 0.3949 (18) D

The Centrifugally Induced Pure Rotational Spectrum and the Structure of Sulfur Trioxide. A Microwave Fourier Transform Study of a Nonpolar Molecule

1991 ◽  
Vol 46 (8) ◽  
pp. 710-714 ◽  
Author(s):  
Volker Meyer ◽  
Dieter Hermann Sutter ◽  
Helmut Dreizler
Keyword(s):  
Fourier Transform ◽  
Sulfur Trioxide ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Nonpolar Molecule ◽  
Centrifugal Distortion Constants ◽  
First Time

AbstractThe pure rotational spectrum of sulfur trioxide has been observed for the first time. A total of 25 high-J transitions could be assigned. The rotational constants, two quartic centrifugal distortion constants, and three sextic centrifugal distortion constants were determined as: B= 10 449.0667(23) MHz, C = 5216.0330(12) MHz, DJ = 9.2651 (18) kHz, DJK = -16.3922(18) kHz, HJ, = -8.8(34) • 10-3 Hz, HJK= -15.8(73) • 10-3 Hz, and HKJ = 34.2(73) • 10-3 Hz. An r0- and an re -structure are presented: r0= 1.4198(7) Å (calculated from B), r0 = 1.4210(7) Å (calculated from C), and re = 1.4175 Å

Mikrowellenspektrum von 12C34SF37Cl

1976 ◽  
Vol 31 (6) ◽  
pp. 594-601 ◽  
Author(s):  
R. Hamm ◽  
H. J. Kohrmann ◽  
H. Günther ◽  
W. Zeil
Keyword(s):  
Equilibrium Structure ◽  
Microwave Spectrum ◽  
Natural Abundance ◽  
Least Square ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Isotopic Species ◽  
Planar Molecule ◽  
Least Square Fit ◽  
Centrifugal Distortion Constants

The microwave spectrum of the isotopic species 12C34SF37Cl has been measured in natural abundance. The three rotational constants and five quartic centrifugal distortion constants have been determined by a least square fit. In comparison with our former calculations, the five structural r0-parameters of the planar molecule have now been determined from eight rotational constants instead of six, thus yielding remarkably smaller confidence intervalls. Furthermore an re-structure has been calculated and an equilibrium-structure has been estimated

Vibration–rotation interaction constants and the cubic potential function of the NO2 molecule in the small-amplitude approximation

1984 ◽  
Vol 62 (12) ◽  
pp. 1315-1322 ◽  
Author(s):  
Yonezo Morino ◽  
Mitsutoshi Tanimoto
Keyword(s):  
Potential Function ◽  
Small Amplitude ◽  
Microwave Measurement ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Triatomic Molecules ◽  
Standard Deviations ◽  
Vibration Rotation ◽  
Centrifugal Distortion Constants ◽  
Infrared Data

Vibration–rotation interaction constants and cubic potential constants were calculated in the small-amplitude approximation. The standard deviations of the rotational constants previously obtained by the microwave measurement were critically examined and found to depend strongly on the centrifugal distortion constants of the infrared data. Although the Coriolis interactions were all neglected, the α and γ constants thus obtained, together with the cubic potential constants, indicate no abnormal feature, in comparison with those of the ordinary triatomic molecules already studied.

Sign in / Sign up

Export Citation Format

Share Document