Semiempirical Calculation of Force Constants of Stretching Vibrations in Excited States of Retinal and Its Related Compounds

1985 ◽  
Vol 54 (12) ◽  
pp. 4861-4868 ◽  
Author(s):  
Hideo Suzuki ◽  
Etsuro Ito ◽  
Tohru Sugimoto
Keyword(s):  
Excited States ◽  
Semiempirical Calculation ◽  
Force Constants ◽  
Stretching Vibrations ◽  
Related Compounds

scholarly journals Semiempirical Calculation of the Rotational Barrier and Valence Force Constants in Fluorocarbonylsulfenyl Chloride

1983 ◽  
Vol 38 (1) ◽  
pp. 61-63
Author(s):  
A. H. Jubert ◽  
C. O. Della Védova ◽  
E. L. Varetti ◽  
O. E. Piro ◽  
P. J. Aymonino
Keyword(s):  
Semiempirical Calculation ◽  
Rotational Barrier ◽  
Force Constants ◽  
Cndo Method ◽  
Normal Coordinate ◽  
Valence Force ◽  
Related Compounds ◽  
Normal Coordinate Calculation

Abstract The rotational barrier about the C-S bond in fluorocarbonylsulfenyl chloride [FC(O)SCl] is investigated using the CNDO method. The results confirm the existence of planar eis and trans conformers and the higher stability of the latter, as suggested by previous vibrational results. The valence force constants in FC(O)SCl were also calculated and the values obtained compare favourably with results from a previous normal coordinate calculation and with those of related compounds.

Vibrational spectra of aquadioxotetra; peroxodivanadates(V) M2[V2O2(O2)4(H2O)]·xH2O (M = N(CH3)4, Cs)

1990 ◽  
Vol 55 (6) ◽  
pp. 1485-1490 ◽  
Author(s):  
Peter Schwendt ◽  
Milan Sýkora
Keyword(s):  
Raman Spectra ◽  
Vibrational Spectra ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Infrared And Raman Spectra ◽  
Empirical Correlations ◽  
Normal Coordinate ◽  
Bond Lengths ◽  
Stretching Vibrations

The infrared and Raman spectra of M2[V2O2(O2)4(H2O)]·xH2O and M2[V2O2(O2)4(D2O)]·xD2O (M = N(CH3)4, Cs) were measured. In the region of the vanadium-oxygen stretching vibrations, the spectra were interpreted based on normal coordinate analysis, employing empirical correlations between the bond lengths and force constants.

Darstellung und Schwingungsspektren von cis- und trans-[OsXY(acac)2], X ≠ Y = Cl, Br, I sowie Normalkoordinatenanalyse von trans-[OsClBr(acac)2]/Synthesis and Vibrational Spectra of cis- and trans-[OsXY(acac)2], X ≠ Y = Cl, Br, I, and Normal Coordinate Analysis of trans-[OsClBr(acac)2]

1998 ◽  
Vol 53 (2) ◽  
pp. 227-231
Author(s):  
K. Dallmann ◽  
W. Preetz
Keyword(s):  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Vibrational Modes ◽  
Normal Coordinate ◽  
Valence Force ◽  
Valence Force Field ◽  
Stretching Vibrations ◽  
Cis And Trans ◽  
Ir And Raman ◽  
Good Agreement

Abstract In the reaction of K2[OsX3 Y3] with boiling water/acetylacetone (1:1) the six mixed com­plexes cis-and trans-[OsX2 (acac)2] (X ≠ Y = Cl, Br, I) are formed, which have been purified by column chromatography with toluene on silica gel. The IR and Raman spectra (10K) show the intraligand vibrations of the acac groups with nearly constant frequencies and the stretching vibrations of OsO in the range 460-696, of OsCl at 315-345, of OsBr at 210-225, and of Osl at 160-175 cm-1 . A normal coordinate analysis based on a modified valence force field was performed for trans-[OsClBr(acac)2] and the vibrational modes have been assigned. With a set of 32 force constants, taking into account the intraligand vibrations, a good agreement between observed and calculated frequencies has been achieved. The valence force constants are fd (OsCl•) = 1.75, fd(OsBr′) = 1.63 and fd (OsO) = 3.27 mdyn/Å.

Bestimmung der Kraftkonstanten der Hexafluoro-Komplexe des Technetium(IV) und Rhenium(IV) auf der Basis der D4h-Symmetrie

1970 ◽  
Vol 25 (2) ◽  
pp. 206-210 ◽  
Author(s):  
Wolfgang Krasser ◽  
Klaus Schwochau
Keyword(s):  
Force Field ◽  
Infrared Spectra ◽  
Force Constants ◽  
Irreducible Representations ◽  
Octahedral Complex ◽  
Site Symmetry ◽  
Complex Ions ◽  
Linear Combinations ◽  
Valence Force Field ◽  
Stretching Vibrations

Abstract The infrared spectra of potassium and cesium hexafluorotechnetate (IV) and -rhenate(IV) show a D4h-distortion of the octahedral complex ions. The splitting of degeneracies is not due to site symmetry. The linear combinations of the force constants of the irreducible representations A2u and Eu are determined in the valence force field on the basis of D4h-symmetry. As expected the force constants of stretching vibrations of [TcF6]-- are then smaller than those of [ReF6]--.

Mikrowellenspektren schwingungsangeregter Zustände und allgemeines Valenzkraftfeld von 12C32SF35Cl / Microwave Spectra of Some Vibrational Excited States of 12C32SF35Cl

1978 ◽  
Vol 33 (5) ◽  
pp. 571-580 ◽  
Author(s):  
R. Hamm
Keyword(s):  
Force Field ◽  
Excited States ◽  
Internal Force ◽  
Equilibrium Structure ◽  
Vibration Frequencies ◽  
Centrifugal Distortion ◽  
General Internal ◽  
Microwave Spectra ◽  
Stretching Vibrations ◽  
Centrifugal Distortion Constants

The microwave spectra of some vibrational excited states of CSFC1 were measured with a conventional stark modulation spectrometer. As the spectra of the upper two stretching vibrations could not be found for lack of intensity, the equilibrium structure which had been estimated using Kuchitsu's procedure could not yet be determined. Nevertheless a general internal force field of CSFC1 was obtained, using the inertial defects of the measured excited states in the fit program NCA in addition to vibration frequencies and centrifugal distortion constants. Moreover, from the determined anharmonic part of the rotation vibration interaction constants, linear relations between some cubic force constants were established

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