Molecular Vibration Analysis of the TeCl4 Tetramer and Monomer and the SeCl4 Tetramer

1978 ◽  
Vol 33 (6) ◽  
pp. 714-721 ◽  
Author(s):  
S. J. Cyvin ◽  
B. N. Cyvin ◽  
W. Brockner ◽  
A. F. Demiray
Keyword(s):  
Potential Energy ◽  
Vibration Analysis ◽  
Force Fields ◽  
Molecular Vibration ◽  
Potential Energy Distribution ◽  
Monomeric Form ◽  
Frequency Shifts ◽  
Mean Amplitudes Of Vibration ◽  
Symmetry Coordinates ◽  
Tetrahedral Complexes

Abstract The molecular vibrations of (TeCl4)4 and (SeCl4)4 are studied on the basis of a cubane-like Td model. Symmetry coordinates are produced by using the theory developed for tetrahedral complexes with trigonal ligands. Approximate vibrational frequencies are calculated from very simple four-parameter force fields and used as an aid in tentative assignments of observed frequencies from literature. Next the force fields are refined by adjustments to the observed frequencies assigned as fundamentals. Potential energy distribution terms and mean amplitudes of vibration are calculated. Finally the monomeric form of TeCl4 is analysed, mainly in order to show the frequency shifts on passing from the monomer to tetramer.

Schwingungsberechnungen der Species Ti2Cl102− , Ti2Cl9− und TiCl5− / Molecular Vibration Analysis of Ti2Cl102− , Ti2Cl9− and TiCl5−

1979 ◽  
Vol 34 (3) ◽  
pp. 362-368 ◽  
Author(s):  
A. F. Demiray ◽  
W. Brockner ◽  
B. N. Cyvin ◽  
S. J. Cyvin
Keyword(s):  
Potential Energy ◽  
Matrix Method ◽  
Vibration Analysis ◽  
Molecular Model ◽  
Molecular Vibration ◽  
Normal Coordinate ◽  
Energy Distributions ◽  
Mean Amplitudes Of Vibration ◽  
Symmetry Coordinates ◽  
The Mean

AbstractNormal coordinate analyses of the chlorotitanate ions Ti2Cl102−Ti2Cl9− - and TiCl5− have been carried out following Wilson's FG matrix method. The final force constants are given in terms of symmetry coordinates, which are thoroughly specified for a Ti2Cl9− molecular model. Assignments of the vibrational frequencies of the title compounds are proposed, and the corresponding potential energy distributions are given. The final force fields were used to calculate the mean amplitudes of vibration, of which those of TiCl5− and selected values of Ti2Cl102− andTi2Cl9− are reported.

IV. 1,3,5,7-Cyclooctatetraene

1970 ◽  
Vol 25 (2) ◽  
pp. 134-138 ◽  
Author(s):  
M. Traetteberg ◽  
G. Hagen ◽  
S. J. Cyvin
Keyword(s):  
Vibration Analysis ◽  
Force Fields ◽  
Force Constants ◽  
Harmonic Vibration ◽  
Interatomic Distances ◽  
Mean Amplitudes Of Vibration ◽  
Amplitude Correction ◽  
Symmetry Coordinates

A harmonic-vibration analysis for the vibrations of 1,3,5,7-cyclooctatetraene was performed. A suitable set of symmetry coordinates is specified, and the corresponding symmetry force constants for C8H8 are given. The developed force fields were used to calculate mean amplitudes of vibration for C8H8 and C8D8. Calculated perpendicular amplitude correction coefficients for the various interatomic distances are also reported.

Schwingungsberechnungen des Hexathiometadiphosphatanions P2S62-

1988 ◽  
Vol 43 (5) ◽  
pp. 494-496 ◽  
Author(s):  
Lothar Ohse ◽  
Wolfgang Brockner
Keyword(s):  
Potential Energy ◽  
Energy Distribution ◽  
Force Field ◽  
Field Potential ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Potential Energy Distribution ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration ◽  
Initial Force

A normal coordinate analysis for the Hexathiometadiphosphate anion P2S62- was performed, based on a simple initial force field. The force field was refined by adjusting the symmetry force constants to approximate the observed frequencies. The final force field, potential energy distribution (PED) and mean amplitudes of vibration are also given. Based on the normal coordinate analysis a new assignment of the P2S62- frequencies is proposed.

Vibrations of a Cage-like Molecule, P4S3: Some Theoretical Aspects

1981 ◽  
Vol 36 (7) ◽  
pp. 774-777 ◽  
Author(s):  
S. J. Cyvin ◽  
B. N. Cyvin ◽  
M. Somer ◽  
W. Brockner
Keyword(s):  
Potential Energy ◽  
Energy Distribution ◽  
Force Field ◽  
Normal Modes ◽  
Potential Energy Distribution ◽  
Symmetry Coordinates ◽  
Method Of Fragments ◽  
Compliance Matrices

Abstract Two independent symmetry coordinate sets for P4S3 are developed, starting from the "method of fragments". A simple, approximate force field is expressed in terms of the two sets of symmetry coordinates, and the corresponding compliance matrices are given. The invariance of compliants is demonstrated. The potential energy distribution (PED) is discussed. An example is shown where the PED terms are clearly inadequate for the description of normal modes. A general warning against the interpretation of the PED in terms of such descriptions for cage-like structures seems to be warranted. V ib r a tio n s o f a C a g e -lik e M o le c u le , P 4S3 : S o m e T h e o r e tic a l A sp e c ts

Normal coordinate analysis of diacetylene and dicyanoacetylene

1969 ◽  
Vol 22 (6) ◽  
pp. 1123 ◽  
Author(s):  
K Ramaswamy ◽  
K Spinivasan
Keyword(s):  
Potential Energy ◽  
Interaction Force ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Characteristic Set ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration ◽  
Symmetry Coordinates ◽  
The Mean ◽  
Energy Constants

The potential energy constants of diacetylene and dicyanoacetylene were obtained by the method of ?characteristic set of valence coordinates? of Herranz and Castano. The values of the various interaction force constants were determined without any assumptions regarding force fields. The mean amplitudes of vibration for the various characteristic bonds were calculated by Cyvin's method. It is shown that the conventional set of symmetry coordinates, usually characterized by individual chromophores, leads to abnormally large values for the force constants in the case of dicyanoacetylene. Hence a different set of symmetry coordinates taking into account the whole unit of CC bonds has to be chosen to get a reasonable set of force constants.

Schwingungsspektren und Normalkoordinatenanalyse des P2Se64–-Anions in den konformeren staggered- und eclipsed-Anordnungen in TL4P2Se6und Na4P2Se6

1986 ◽  
Vol 41 (10) ◽  
pp. 1233-1237 ◽  
Author(s):  
M. Parensen ◽  
W. Brockner
Keyword(s):  
Potential Energy ◽  
Energy Distribution ◽  
Force Field ◽  
Vibrational Spectroscopy ◽  
Field Potential ◽  
Coupling Constants ◽  
Potential Energy Distribution ◽  
Coriolis Coupling ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration

Na4P2Se6 has been prepared by elemental synthesis at high temperatures and characterized by vibrational spectroscopy. The vibrational frequencies of Na4P2Se6 are assigned on the basis of eclipsed P2Se64- conformers with D3h symmetry, those of Tl4P2Se6 on the basis of staggered P2Se64- units with D3d symmetry. A normal coordinate analysis has been performed for both conformers. The refined force field, potential energy distribution (PED), mean amplitudes of vibration an Coriolis coupling constants are given.

Normal Coordinate Analysis and Mean Amplitudes of Vibration of Spiropentane

1974 ◽  
Vol 29 (12) ◽  
pp. 1898-1901 ◽  
Author(s):  
B. N. Cyvin ◽  
O. Gebhardt
Keyword(s):  
Electron Diffraction ◽  
Potential Energy ◽  
Spectroscopic Data ◽  
Field Potential ◽  
Normal Coordinate Analysis ◽  
Potential Energy Distribution ◽  
Structure Parameters ◽  
Harmonic Force ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration

Using spectroscopic data and structure parameters observed by electron diffraction, a normal coordinate analysis was performed for spiropentane. Harmonic force field, potential energy distribution and calculated mean amplitudes of vibration are reported. A very satisfactory agreement is found between observed and calculated mean amplitudes of vibration.

Normalkoordinatenanalyse und mittlere Schwingungsamplituden für Cl5SbOPCl3 , Cl5NbOPCl3 und Cl5TaOPCl3

1978 ◽  
Vol 33 (6) ◽  
pp. 709-713 ◽  
Author(s):  
Wolfgang Brockner ◽  
Bjørg N. Cyvin ◽  
Sven J. Cyvin
Keyword(s):  
Potential Energy ◽  
Energy Distribution ◽  
Force Field ◽  
Vibrational Frequencies ◽  
Normal Coordinate Analysis ◽  
Potential Energy Distribution ◽  
Normal Coordinate ◽  
Symmetry Coordinates ◽  
Initial Force

Abstract A normal coordinate analysis was performed for some Cl5MOPCl3 molecules (M = Sb, Nb, Ta). The final force field in terms of a described set of symmetry coordinates is reported for Cl5SbOPCl3. The initial force field for Cl5SbOPCl3 was applied to calculate the vibrational frequencies of the Cl5NbOPCl3 and Cl5TaOPCl3 adducts. An assignment of the vibrational frequencies of the title compounds and the corresponding potential energy distribution terms are given for Cl5SbOPCl3 . For the Cl5SbOPCl3

Normal coordinate analysis of cyanoacetylene

1968 ◽  
Vol 21 (3) ◽  
pp. 575 ◽  
Author(s):  
K Ramaswamy ◽  
K Srinivasan
Keyword(s):  
Potential Energy ◽  
Force Fields ◽  
Pair Bond ◽  
Normal Coordinate Analysis ◽  
Characteristic Set ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration ◽  
Bond Pair ◽  
The Mean ◽  
Energy Constants

The potential energy constants of cyanoacetylene were obtained by the method of characteristic set. The values of the various bond pair-bond pair interactions were determined without any assumptions regarding force fields. The mean amplitudes of vibration for the various characteristic bonds were calculated by Cyvin's method. The results are explained on the basis of the presence of conjugated structures for cyanocetylene.

Schwingungsberechnungen der käfigstrukturierten Moleküle α–P4S4, As4S4 und As4Se4

1988 ◽  
Vol 43 (4) ◽  
pp. 326-330
Author(s):  
L. Ohse ◽  
M. Somer ◽  
W. Brockner
Keyword(s):  
Potential Energy ◽  
Energy Distribution ◽  
Force Field ◽  
Spectroscopic Data ◽  
Field Potential ◽  
Potential Energy Distribution ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration ◽  
Standard Thermodynamic Functions ◽  
Initial Force

Abstract A normal coordinate analysis for the cage-like molecules α-P4S4, As4S4 and As4Se4 is performed, based on a simple initial force field with three numerical parameters and valence coordinates including redundancies. The force field is refined by adjusting the symmetry force constants to fit the observed frequencies. The final force field, potential energy distribution (PED), mean amplitudes of vibration and the standard thermodynamic functions from spectroscopic data are also given for the title compounds.

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