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.

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.

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.

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.

Normal Coordinate Analysis of Some Nitrogen-Halogen Compounds

1970 ◽  
Vol 25 (2) ◽  
pp. 169-173 ◽  
Author(s):  
K. Ramaswamy ◽  
N. Mohan
Keyword(s):  
Potential Energy ◽  
Linear Relationship ◽  
Force Constant ◽  
Bond Order ◽  
Normal Coordinate Analysis ◽  
Normal Coordinate ◽  
Molecular Constants ◽  
Halogen Compounds ◽  
Bond Stretching ◽  
Energy Constants

The approximate force fields for a group of nitrogen halogen compounds like ONF3, NF3, NF2Cl, NFCl2, NF2D and NCl3 were studied using the kinematic methods of Herranz and Torkington. It was found that the application of Torkington's method yields a reliable set of potential energy constants consistent with other molecular constants. A linear relationship between the N -F bond stretching force constants and the bond order was found to exist. It was also found that the value of the N-F bond stretching force constant is proportional to the number of fluorine atoms substituted.

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.

Force Field and Mean Amplitudes of Vibration of (NH2)2CX Compounds ( X = O, S, Se)

1982 ◽  
Vol 37 (11) ◽  
pp. 1289-1291
Author(s):  
Marcelo Campos ◽  
Guillermo Díaz
Keyword(s):  
Force Field ◽  
Matrix Method ◽  
Force Fields ◽  
Normal Coordinate Analysis ◽  
Vibrational Assignment ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration ◽  
Valence Force ◽  
Valence Force Field

Normal coordinate analysis of urea, thiourea and selenourea was performed on the basis of the general valence force field; Wilson’s FG matrix method has been used. The final force fields were obtained through an iterative selfconsistent method. The vibrational assignment for these molecules is discussed. Calculated mean amplitudes of vibration for the urea series and their deuterated derivatives are reported.

SUBSTITUTED METHANES: PART XXXVI. CALCULATED WAVE NUMBERS, ASSIGNMENTS, AND THERMODYNAMIC PROPERTIES FOR CH2DI AND CD2HI, AND CALCULATED ROTATIONAL DISTORTION CONSTANTS AND MEAN AMPLITUDES FOR CH3I AND CD3I

1964 ◽  
Vol 42 (12) ◽  
pp. 2841-2846 ◽  
Author(s):  
Earle F. Ditzel ◽  
Arnold G. Meister ◽  
Edward A. Piotrowski ◽  
Forrest F. Cleveland ◽  
Y. Anantarama Sarma ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Potential Energy ◽  
Fundamental Wave ◽  
Mean Amplitudes Of Vibration ◽  
Gaseous State ◽  
Rotational Distortion ◽  
Wave Numbers ◽  
Complete Assignment ◽  
The Mean ◽  
Energy Constants

A set of potential energy constants has been obtained for CH3I and CD3I from their vibrational spectral data. From these constants, the rotational distortion constants and the mean amplitudes have been calculated for these two molecules. The rotational distortion constants DJ, DJK, and DK were, respectively, CH3I, 6.34, 59.36, and 3 542.30; CD3I, 3.90, 33.08, and 866.43 kc/s. The principal mean amplitudes of vibration in pm (pm = picometer = 10−12 meter = 10−2 Å) at 298.16°K are CH3I, 5.25 (C—I), 7.71 (C—H), 12.37 [Formula: see text], and 12.00 [Formula: see text]; CD3I, 5.14 (C—I), 6.63 (C—D), 10.85 [Formula: see text], and 10.65 [Formula: see text]. The potential energy constants were used to obtain the wave numbers of CH2DI and CD2HI. A complete assignment of the observed wave numbers for the molecules CH2DI and CD2HI has been made. The fundamental wave numbers for the gaseous state of CH2DI are a′, 2 980, 2 235, 1 418, 1 170, 723, and 519; a″, 3 091, 1 266, and 871 cycles/cm. For CD2HI, the corresponding values are a′, 3 017, 2 174, 1 185, 1 009, 757, and 508; a″, 2 273, 1 279, and 676. With these wave numbers, the thermodynamic functions have been calculated for the two molecules for 12 temperatures from 100 to 1 000°K for 1 atm pressure. The values of (H0−E00)/T, −(F0−E00)/T, S0, and Cp0 at 298.16°K are, respectively, CH2DI, 8.82, 54.66, 63.48, and 10.98; CD2HI, 9.00, 55.20, 64.19, and 11.53 cal deg−1 mole−1.

Condensed Aromatics. Part V

1979 ◽  
Vol 34 (12) ◽  
pp. 1512-1517 ◽  
Author(s):  
S. J. Cyvin ◽  
J. Brunvoll ◽  
B. N. Cyvin ◽  
V. S. Mastryukov
Keyword(s):  
Vibrational Frequencies ◽  
Normal Coordinate Analysis ◽  
Molecular Vibrations ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration ◽  
Characteristic Values ◽  
The Mean ◽  
Parameter Approximation

Abstract The five-parameter approximation is applied to a normal coordinate analysis of the in-plane molecular vibrations of naphthacene. Vibrational frequencies and mean amplitudes of vibration are reported. The mean amplitudes of vibration for the nonbonded CC distances are studied in particular on the basis of data for benzene, naphthalene, anthracene, pyrene, coronene and naphthacene. The distance types are classified, and characteristic values for the mean amplitudes of the corresponding distances in different molecules are detected.

Molecular Vibrations of Gallium Trichloride Monomer with Application of the Keating Bending

1985 ◽  
Vol 40 (7) ◽  
pp. 714-718 ◽  
Author(s):  
B. N. Cyvin ◽  
S. J. Cyvin ◽  
G. Diaz ◽  
T. Mogstad ◽  
E. Rytter
Keyword(s):  
Force Field ◽  
Field Approximation ◽  
Normal Coordinate ◽  
Frequency Shifts ◽  
Mean Amplitudes Of Vibration ◽  
Central Force Field ◽  
Valence Force Field ◽  
New Type ◽  
The Mean ◽  
Gallium Trichloride

The vibrational spectra and previous normal coordinate analyses of GaCl3 are reviewed. The valence force field (VFF), Keating force field (KFF) and central force field (CFF) are investigated, taking into account isotopic frequency shifts and the mass influence on Coriolis constants. It seems that KFF is an appropriate force field approximation. In its definition a new type of internal coordinates, the Keating's bending, is invoked. A final force Field is tentatively determined and used to calculate the mean amplitudes of vibration.

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