Bastiansen-Morino Shrinkage Effects Research Articles

Mean amplitude of vibration and Bastiansen–Morino shrinkage effect of some linear XF 2 species

Mean amplitudes of vibration of the linear XF 2 − difluorohalogenate ( I) anions were calculated, using a recently reported set of consistent vibrational–spectroscopic data, in the temperature range between 0 and 1000 K. The study was complemented with similar calculations for KrF 2 and XeF 2 and with comparisons with other related species. Values of the Bastiansen–Morino shrinkage effect for these species were also estimated.

Mean amplitudes of vibration and Bastiansen-Morino shrinkage effect of chromium tetrafluoride

The Bastiansen-Morino shrinkage effect and the mean amplitudes of vibration of gaseous CrF 4 were calculated from vibrational spectroscopic data, using the L-matrix method of A. Müller. Mean amplitude values were also obtained with the “Method of the Characteristic Vibrations”. The resultant values compared well with the experimental data derived from electron diffraction experiences. Some comparisons with related molecules were also made.

General Valence Force Field and Molecular Dynamic Parameters for Cubic Lanthanide Hexachloro-Elpasolite Crystals

Abstract A normal coordinate analysis has been carried out for the series Cs2NaLnCl6 where Ln represent a trivalent lan thanide cation such as Pr+3, Sm+3, Eu+3, Tb+3, HO+3 and Tm+3 by using a general valence force field (GVFF). A convenient parametrization has been developed to obtain symmetrized F-matrix elements which are able to reproduce both the experimental frequencies and the expected potential energy distribution for these systems, It is shown that these force fields may be of great interest to calculate vibronic intensities for these complex ions, when a molecular model is adopted, The force fields developed throughout this work have been used to calculate mean amplitudes of vibrations, mean square perpendicular amplitudes and Bastiansen-Morino shrinkage effects at 0 and 298 K.

Molecular Vibrations of Aluminum Trichloride Monomer with Application of the Keating Bendings

The vibrational spectra and previous normal coordinate analyses of AICI3 are reviewed. The valence force field (VFF), central force field (CFF) and Keating force field (KFF) are tested. KFF is found to be the best one of these approximations with regard to the agreement with an observed isotopic frequency. A final force field is taken from a very recent work. It confirms that KFF is superior to both CFF and KFF. The data of a Coriolis constant, mean amplitudes of vibration and the Bastiansen-Morino shrinkage effect are calculated and discussed.

Molecular vibrations of sulphur trioxide: Application of the Keating bendings

A new type of internal coordinates referred to as Keating's bending is defined. A generalized bending is also introduced and includes the ordinary (Decius') bending, Keating's bending and the nonbond interatomic distance deviation as special cases. The theory is applied to the planar symmetrical XY 3 molecular model, for which the mean-square amplitude quantities are treated in particular. The Keating Force Field (KFF) is defined in analogy with the well-known VFF (Valence Force Field) and CFF (Central Force Field). Numerical computations are performed for SO 3. From the calculated Coriolis constants it is deduced that the KFF is much superior to both of the other approximations. An “exact” force field is produced by means of an experimental Coriolis constant as additional data. The force field is presented in terms of the valence, central and Keating coordinates. The analysis confirms that the Keating coordinates (which involve Keating's bendings) in this case of SO 3 are best suited as the basis of a force field approximation. Calculated mean amplitudes of vibration and the Bastiansen—Morino shrinkage effect are reported.

Planar Symmetrical XY3and Boron Trihalides: Mean-Square Amplitudes and Keating Coordinates

Abstract The E' block of the mean-square amplitude matrix (Σ) for the planar symmetrical XY3 molecular model is treated theoretically in terms of the Keating coordinates. A numerical example for 11BF3 is given. Also the mean amplitudes of vibration (ι) and Bastiansen-Morino shrinkage effect (Δ) are considered. New relations which connect the mean-square amplitudes and force constants are given. Previous works on mean amplitudes and related quantities for boron trihalides from vibrational spectroscopy and gas electron diffraction are reviewed, and some new calculations are reported.

Molecular Vibration Analysis of Tetracyanomethane

Abstract The experimental vibrational frequencies for C(CN)4 from literature were re-assigned with the aid of approximate force field calculations. Refined force fields were deduced on the basis of (I) the original experimental assignment and (II) the present re-assignment. Calculated mean amplitudes of vibration and Bastiansen-Morino shrinkage effects strongly support the re-assignment (II) when comparing with gas electron diffraction results.

ChemInform Abstract: MOLECULAR CONSTANTS OF SOME XY4 TETRAHEDRAL IONS

The kinetic constants method developed in relation to tetrahedral XY4 molecules(1, 2) resulted in fresh results with respect to force constants and mean amplitudes of vibration of some molecules. Extending this procedure to eighteen ions in this paper, it is found that the kinetic constants method leads to interesting results in these oases as well. The generalized mean square amplitudes and the Bastiansen-Morino shrinkage effects are also reported in the present investigation.

ChemInform Abstract: VIBRATIONAL FREQUENCIES, FORCE CONSTANTS, MEAN AMPLITUDES, SHRINKAGE EFFECTS AND THERMODYNAMIC FUNCTIONS FOR MONOHALOACETYLENES

Abstract Harmonic force fields are developed for the monohaloacetylenes on the basis of recent vibrational spectra of H-CC-I and previously published spectra of H-CC-X (X = F, Cl, Br). Mean amplitudes of vibration and Bastiansen-Morino shrinkage effects are reported for monohaloacetylenes and their deuterated derivatives. Thermodynamic functions are listed for monoiodoacetylene.

Vibrational frequencies, force constants, mean amplitudes, shrinkage effects and thermodynamic functions for monohaloacetylenes

Harmonic force fields are developed for the monohaloacetylenes on the basis of recent vibrational spectra of H-CC-I and previously published spectra of H-CC-X (X = F, Cl, Br). Mean amplitudes of vibration and Bastiansen-Morino shrinkage effects are reported for monohaloacetylenes and their deuterated derivatives. Thermodynamic functions are listed for monoiodoacetylene.

Harmonic Force Fields and Mean Amplitudes for Aluminum Trifluoride Monomer and Dimber

Abstract A harmonic force field is developed for AlF3, and used to re-calculate the mean amplitudes of vibration and the Bastiansen-Morino shrinkage effect. A vibrational re-assignment of observed frequencies from literature is proposed for Al2F6. Harmonic force constants and mean amplitudes are reported also for this molecule.

Vibrational frequencies, force constants, mean amplitudes, shrinkage effects, and Coriolis constants for CF3C≡CX (where X = Cl, Br, and I)

Harmonic force fields are developed for 1-chloro-, 1-bromo-, and 1- iodo-3,3,3-trifluoropropyne on the basis of recent infrared and Raman data. Calculated mean amplitudes of vibration, Bastiansen-Morino shrinkage effects, and Coriolis coupling constants are reported.

Molecular Constants of GeCl4 and SnCl4 from Coriolis Coupling Constants and an Appraisal of the Accuracy of the Method in Determining Force Fields, Mean Amplitudes and Shrinkage

The Coriolis Coupling constants of GeCl4 and SnCl4 are obtained from the contours of the ν4 bands and used to determine the force fields. From consideration of these and that previously reported for SiCl4 it is shown that even relatively inaccurate Coriolis constants can yield better force fields and Bastiansen-Morino shrinkage effects than experimental mean amplitudes of vibration; but that for SnCl4 , because of significant differences between usually valid approximate force fields and the Coriolis constant fixed one, a wrong value of the constant may have been obtained. It is also shown that the force field obtained from Vol’kenshtein’s theory of absolute Raman intensities is not very good for GeCl4 and wildly inaccurate for SnCl4 .

Infra-red spectra, vibrational assignments, and force constants of some monohalogeno diacetylenes, including force constants of some halogeno cyanoacetylenes

The infra-red spectra of the monohalogeno diacetylenes HCCCCX (X = Cl, Br and I) have been recorded in the gaseous phase and in solution in the region 4000-280 cm −1. These spectra can be interpreted in terms of a linear structure. The spectra show a striking similarity and the assignments have been supported by the band contours. Force constant calculations have been made for the monohalogeno diacetylenes as well as for the corresponding halogeno cyanoacetylenes. The force constants are adjusted to fit accurately the fundamental frequencies. Finally, the mean amplitudes of vibration and the Bastiansen—Morino shrinkage effect for these molecules are reported.

Spectroscopic Studies of Molecular Constants in some Polyatomic Molecules

Force constants have been evaluated by the WILSON group theoretical method for various ij3 molecules possessing a planar trigonal symmetry. Mean-square amplitude quantities and mean amplitudes of vibration for the bonded as well as nonbonded atom pairs have been computed at the temperatures T=0 and T=298 °K for C3 , Si3 , and XeF2 by the CYVIN method. The molar thermodynamic functions from spectroscopic data have been calculated for Si3 and XeF2 on the basis of a rigid rotator, harmonic oscillator model. BASTIANSEN-MORINO shrinkage effects have been calculated for various linear asymmetrical ijk, linear symmetrical ij2 and tetrahedral ij4 molecules at the temperatures T=0 and T=298 °K.

Mean Amplitudes of Vibration, Bastiansen-Morino Shrinkage Effect, Thermodynamic Functions, and Molecular Polarizability of Sulfur Trioxide1

Mean Amplitudes of Vibration, Bastiansen-Morino Shrinkage Effect, Thermodynamic Functions, and Molecular Polarizability of Sulfur Trioxide¹

Mean amplitudes of vibration, shrinkage effect and thermodynamic properties : linear XYZ molecules and ions

The theory of mean square amplitude matrices is applied to linear XYZ molecules and ions and the principal mean amplitude quantities are given for 0° and 300° K. The Bastiansen-Morino Shrinkage effects in these molecules have been reported. The thermodynamic properties of these molecules are calculated for the ideal gaseous state at one atmosphere pressure for eleven temperatures from 100° K to 1000° K.

Mean amplitudes of vibration and Bastiansen-Morino shrinkage effect in some linear symmetrical metal dihalides

The transferability of vibrational frequencies among related molecules is discussed, and the vibrational data available for metal dihalides possessing a linear symmetrical structure are briefly surveyed. The mean amplitudes of vibration for the dihalides of thirteen metals, namely, the dihalides of beryllium, magnesium, zinc, cadmium, mercury, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, and copper have been evaluated for the temperatures T = 1000°K, T = 1250°K, and T = 1500°K by the method of Cyvin. The Bastiansen-Morino shrinkage effects for the metal dihalides studied have been computed at these temperatures after derivation of the necessary formulas. A brief discussion of the results follows.

Mean Amplitudes of Vibration and Bastiansen-Morino Shrinkage Effects in Some Octahedral XY6 Molecules.

Mean Amplitudes of Vibration and Bastiansen-Morino Shrinkage Effects in Some Octahedral XY6 Molecules.

Vibrational mean-square amplitude matrices: Part XVIII. The Bastiansen-Morino shrinkage effect of symmetrical XY3 and XY4 molecules

The nonlinear Bastiansen-Morino shrinkage effects are studied for (a) planar symmetrical XY 3, and (b) tetrahedral XY 4 molecular models. In both of these cases the so-called anharmonicity terms vanish. The shrinkage effects are expressed algebraically in terms of the mean-square amplitude matrix elements. Numerical values are given for the trihalides of boron, and germanium tetrachloride. In the case of GeCl 4 the result is compared with that from electron-diffraction data. Finally, the electron-diffraction r g values for this molecule are refined to fit accurately the presently calculated shrinkage effect.