Infrared Studies on Rotational Isomerism. VI. Normal-Coordinate Analysis of 2-Chloro-, 2-Bromo-, and 2-Cyanoethanol

1972 ◽  
Vol 50 (2) ◽  
pp. 152-161 ◽  
Author(s):  
Paul A. Giguère ◽  
Michel Schneider
Keyword(s):  
Rotational Isomerism ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Potential Energy Distribution ◽  
Normal Coordinate ◽  
Bending Vibrations ◽  
Fundamental Frequencies ◽  
Infrared Studies ◽  
Fortran Language ◽  
Bond Strengths

A normal-coordinate analysis of three substituted ethanol molecules X—CH2—CH2—OH (where X = Cl, Br, or CN) was carried out using the simple valence force field model, and a computer program of Schachtschneider translated into Fortran language by Brooks. The effect of internal hydrogen bonding was studied by adding one extra symmetry coordinate, H … X (two, H … C and H … N, in the case of 2-cyanoethanol). The corresponding force constants show a good correlation with the hydrogen bond strengths. Most of the other force constants maintain the same value in the gauche and the trans rotamers. In general the calculated fundamental frequencies agree closely with the observed ones. The potential energy distribution confirms the extensive coupling between certain vibrations; particularly the skeleton stretching and the CH2 twisting and rocking. Only the C—X stretching and the skeleton bending vibrations are strongly affected by rotational isomerism.

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.

Darstellung, Schwingungsspektren und Normalkoordinatenanalyse der 10B-und 11B-Isotopomeren von [B2(NCS)6]2- sowie Kristallstruktur von (Ph3P=N=PPh3)2[B2(NCS)6] / Preparation, Vibrational Spectra and Normal Coordinate Analysis of the 10B and 11B Isotopomers of [B2(NCS)6]2- and Crystal Structure of (Ph3P=N=PPh3)2[B2(NCS)6]

1996 ◽  
Vol 51 (4) ◽  
pp. 551-556 ◽  
Author(s):  
W. Preetz ◽  
B. Steuer
Keyword(s):  
Crystal Structure ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Potential Energy Distribution ◽  
X Ray Diffraction ◽  
Normal Coordinate ◽  
Triclinic Space Group ◽  
X Ray ◽  
Fractionated Crystallization ◽  
Good Agreement

Abstract By reaction of [B6H6]2- with a solution of (SCN)2 in dichloromethane in the presence of solid KOH the hexaisothiocyanatodiborate anion [B2(NCS)6]2- is formed and can be isolated by fractionated crystallization. The crystal structure of (PNP)2[B2(NCS)6] has been determined by single crystal X-ray diffraction analysis; triclinic space group P1̄ with a=12,282(5), b=12,416(5), c=14,155(5)Å, a=68,36(5), β=70,59(5), γ=80,93(5)°.The [B2(NCS)6]2- anion reveals a staggered conformation with nearly local D3d symmetry and a B-B bond length of 1,73(2) Å. Using the crystallographic data a normal coordinate analysis has been performed. With a set of 12 force constants (e.g. fd(BB)=3,62, fd(BN)=4,21 mdyn/Å) a good agreement between observed and calculated frequencies for the 10B and 11B isotopomers has been achieved. The potential energy distribution on the force constants reveals strong vibrational couplings within the B2N6 framework.

Bond properties of anionic mixed halogeno-complexes InX3Y- (X ≠ Y = Cl, Br, I)

1985 ◽  
Vol 50 (2) ◽  
pp. 329-335 ◽  
Author(s):  
D. R. Singh ◽  
U. P. Verma ◽  
A. N. P. Pandey ◽  
Bohuslav Strauch
Keyword(s):  
Bond Order ◽  
Reliable Data ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Bond Properties ◽  
Normal Coordinate ◽  
Fundamental Frequencies ◽  
Bond Polarizability ◽  
The Mean

The normal coordinate analysis has been performed for the anionic mixed halogeno-complexes InX3Y- (X ≠ Y = Cl, Br, I). The trends among the force constants are discussed and the assignments of the observed fundamental frequencies are examined thoroughly. It has been found that the present analysis provides reliable data to introduce a light into the bond properties of InX3Y- ions. In addition to this the mean amplitudes of vibrations, bond order and bond polarizability derivatives have been studied for the systems under investigation and a comparison of bond parameters among the halides of indium are made.

Darstellung, Schwingungsspektren und Normalkoordinationsanalyse der D- und 13C-Isotopomeren des Methylpentahydro-closo-hexaborats [B6H5(CH3)]2- sowie Kristallstruktur von [P(C6H5)4][B6H6(CH3)] / Preparation, Vibrational Spectra and Normal Coordinate Analysis of the D and 13C Isotopomeres of the Methylpentahydro-closo-hexaborate [B6H5(CH3)]2- and the Crystal Structure of [P(C6H5)4][B6H6(CH3)]

1995 ◽  
Vol 50 (4) ◽  
pp. 623-629 ◽  
Author(s):  
J. Baurmeister ◽  
A. Franken ◽  
W. Preetz
Keyword(s):  
Crystal Structure ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Potential Energy Distribution ◽  
X Ray Diffraction ◽  
Normal Coordinate ◽  
Triclinic Space Group ◽  
Stretching Vibration ◽  
Ir And Raman ◽  
Good Agreement

The crystal structure of [P(C6H5)4][B6H6(CH3)] has been determined by single crystal X-ray diffraction analysis; triclinic space group P 1̄ with a = 7.408(2), b = 11.887(3), c = 14.4486(9) Å , α = 80.013(12), β = 79.421(10), γ = 88.85(2)°. The additional H atom could be refined with B - H distances between 1.21 and 1.31 Å above one of the facettes of the B6 octahedron adjacent to the methyl group. The IR and Raman spectra of the ueprotonated Cs salts of the six isotopomers [B6H5(CH3)]2-, [B6H5(CD3)]2-, [B6H5(13CH3)]2-, [B6D5(CH3)]2-, [B6D5(CD3)]2- and [B6D5(13CH3)]2- exhibit characteristic shifts of their vibration bands. Using the crystallographic data a normal coordinate analysis has been performed, based on a general valence force field. With a set of 14 force constants (e.g. fd(BB ) = 1.80, fd(BC ) = 3.70, fd(BH ) = 3.17, fd(CH ) = 4.62 mdyn/Å) good agreement between observed and calculated frequencies o f all D and 13C isotopically labeled derivatives has been achieved. The potential energy distribution on the force constants reveals strong vibrational couplings of the boron cage with the substituents. The B - C stretching vibration o f the CH3 group is observed in the region 1142-1153 cm-1, for the CD3 substituent at higher frequencies of 1168-1179 cm-1.

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.

The Vibrational Spectrum and Urey-Bradley Force Constants of the Trifluoromethyltrifluoroborate(1-) Anion

1973 ◽  
Vol 27 (3) ◽  
pp. 209-213 ◽  
Author(s):  
John F. Jackovitz ◽  
Charles E. Falletta ◽  
James C. Carter
Keyword(s):  
Potential Energy ◽  
Vibrational Spectrum ◽  
Energy Distribution ◽  
Force Field ◽  
Raman Spectra ◽  
Normal Modes ◽  
Force Constants ◽  
Potential Energy Distribution ◽  
Infrared And Raman Spectra ◽  
Normal Coordinate

Infrared and Raman spectra for (K+) (CF3BF3−) have been obtained from 4000 to 50 cm−1. Spectral assignments were made on the basis of C3v symmetry using both 10B and 11B compounds. In addition, a normal coordinate analysis was performed to obtain the potential energy distribution of the normal modes. A Urey-Bradley type force field was used, and force constants obtained for the CF3 and BF3 groupings were compared to those in C2F6 and BF4−.

Vibrational Spectra of Triphenyl Compounds of Group VA Elements

1969 ◽  
Vol 23 (1) ◽  
pp. 12-16 ◽  
Author(s):  
Kosuke Shobatake ◽  
Clarence Postmus ◽  
John R. Ferraro ◽  
Kazuo Nakomoto
Keyword(s):  
Raman Spectra ◽  
Vibrational Spectra ◽  
Phenyl Group ◽  
Normal Coordinate Analysis ◽  
Infrared And Raman Spectra ◽  
Normal Coordinate ◽  
Bending Vibrations ◽  
Depolarization Ratios

The infrared and Raman spectra of triphenyl compounds of Group VA elements PPh3, AsPh3, SbPh3, and BiPh3 (Ph represents the phenyl group), have been reported in the 530–100 cm−1 region. The metal-phenyl stretching and bending vibrations have been assigned with the aid of approximate normal coordinate analysis and depolarization ratios of Raman lines.

Infrared spectra of KH2F3 and the structure of the H2F3− ion

1967 ◽  
Vol 45 (12) ◽  
pp. 1347-1350 ◽  
Author(s):  
A. Ažman ◽  
A. Ocvirk ◽  
D. Hadži ◽  
Paul A. Giguère ◽  
Michel Schneider
Keyword(s):  
Solid State ◽  
Infrared Spectra ◽  
Infrared Absorption ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Hydrogen Atoms ◽  
Normal Coordinate ◽  
Bending Modes

The infrared absorption of KH2F3 and KD2F3in the solid state was measured between 4 000 and 200 cm−1 The observed bands can be assigned to the stretching and bending modes of the bent H2F3− ion. A normal coordinate analysis was carried out to determine the Urey–Bradley force constants. The results suggest that the hydrogen atoms are not exactly halfway between two fluorine atoms, contrary to the case of the HF2− ion.Les spectres infrarouges de KH2F3 et KD2F3 à l'état solide ont été mesurés entre 4 000 et 200 cm−1 afin d'identifier les vibrations fondamentales de l'anion H2F3−. Les constantes de forces de rappel selon le modèle de Urey–Bradley ont pu être déterminées par analyse des coordonnées normales. Les résultats indiquent que les atomes d'hydrogène ne sont pas exactement à mi-chemin entre deux atomes de fluor, contrairement au cas de l'ion HF2−.

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