The Vibrational Analysis of Cyclopentanone

1973 ◽  
Vol 51 (11) ◽  
pp. 1749-1766 ◽  
Author(s):  
V. B. Kartha ◽  
H. H. Mantsch ◽  
R. N. Jones

The infrared and Raman spectra of cyclopentanone, ααα′α′-d4-cyclopentanone, βββ′β′-d4-cyclopentanone and d8-cyclopentanone have been measured and a normal co-ordinate analysis performed based on a twisted C2 conformation. The 36 normal vibrations were computed using a selective valence force field comprising 16 diagonal and 16 off-diagonal force constants. The 4 isotopic species provided 144 frequencies to refine 15 diagonal force constants. The initial values of the constants were transferred from a force field for cyclohexanone computed in this laboratory. The infrared and Raman spectra were analyzed in terms of the potential energy distribution coefficients categorized as group frequencies, zone frequencies, and delocalized frequencies.

1972 ◽  
Vol 27 (8-9) ◽  
pp. 1193-1196 ◽  
Author(s):  
W. Krasser ◽  
K. Schwochau

The infrared and Raman spectra of the complex salts K5[Mn(CN)6], K5[Tc(CN)6] and K5[Re(CN)s] have been recorded in the range from 4000 to 40 cm-1. All expected fundamental vibrations have been observed and could be assigned to the irreducible representations of the sym­metry point group Oh . The calculation of the force constants is based on the concept of the generalized valence force field. The low CN-valence force constants indicate the relatively strong Π-bonding character of the metal carbon bond, which is especially pronounced for K5[Tc(CN)6).


1973 ◽  
Vol 27 (3) ◽  
pp. 209-213 ◽  
Author(s):  
John F. Jackovitz ◽  
Charles E. Falletta ◽  
James C. Carter

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−.


1977 ◽  
Vol 55 (19) ◽  
pp. 3413-3419 ◽  
Author(s):  
G. A. Crowder ◽  
Maurice Iwunze

Infrared and Raman spectra were obtained for 2-bromopentane, 3-bromopentane, 2-bromohexane, and 3-bromohexane. Vibrational assignments were made for several conformers of each compound with the aid of normal coordinate calculations. A 48 parameter modified valence force field was obtained that fit 221 frequencies of three conformers of 2-bromopentane, 4 conformers of 3-bromopentane, and 1 conformer of 2-bromobutane with an average error of 4.1 cm−1. This force field was transferred to the bromohexanes, with good results.


1976 ◽  
Vol 31 (12) ◽  
pp. 1589-1600 ◽  
Author(s):  
Lennart Lyhamn ◽  
S. J. Cyvin ◽  
B. N. Cyvin ◽  
J. Brunvoll

Abstract A complete vibrational analysis is performed for the 53 atomic PMo12O40 model of Td symmetry. The symmetry coordinates are classified into those of (a) ligand vibrations, (b) framework-ligand couplings, (c) framework vibrations, and (d) interligand vibrations. Simple valence force fields are estimated, and the influence of inclusion of redundancies on the calculated frequencies and symmetry force constants is investigated. Comments are made on calculated symmetry force constant values up to 345 mdyne/Å. Vibrational frequencies are calculated for the Mo3O7 and Mo3O13 units and for the PMo12O403- complex ion. For the latter compound the calculated values are compared with experimental data from infrared and Raman spectra.


1971 ◽  
Vol 49 (18) ◽  
pp. 2931-2936 ◽  
Author(s):  
J. W. Anderson ◽  
G. K. Barker ◽  
J. E. Drake And ◽  
R. T. Hemmings

The infrared and Raman spectra of the series of iodo(methyl)germanes, CH3GeI3, (CH3)2GeI2, and (CH3)3GeI have been recorded. A normal coordinate analysis based on a modified valence force field confirms the a priori assignments for all of the fundamental frequencies except the torsional modes.


1981 ◽  
Vol 36 (8) ◽  
pp. 850-858 ◽  
Author(s):  
Ralf Steudel

Abstract Infrared and Raman spectra of solid and dissolved S414N4 and of solid S415N4 have been recorded and assigned in accordance with the molecular point group D2d. 22 of the 28 fundamental vibrations of both molecules have been identified and used to calculate force constants applying a modified Urey-Bradley force field with 9 independent constants. Good agreement between observed and calculated wavenumbers was obtained, and both Urey-Bradley and valence force constants are given. The results indicate that-S4N4 basically contains eight SN single bonds and two extremely weak SS bonds.


1970 ◽  
Vol 25 (11) ◽  
pp. 1729-1731 ◽  
Author(s):  
A. Timidei ◽  
G. Zerbi

Abstract The possibility of reproducing the normal vibrations of methanol, CH3OH, and its deutero-derivatives CH3OD, CD3OH, CD3OD using a valence force field has been critically analyzed. A 13 parameter valence force field has been determined by least square calculations. The meaning of the obtained numbers and their validity in molecular spectroscopy are discussed and compared with the information already available in the literature. It is concluded that the vibrational modes of this molecule are fairly well known within the harmonic approximation.


1969 ◽  
Vol 47 (10) ◽  
pp. 1633-1637 ◽  
Author(s):  
H. Wieser ◽  
P. J. Krueger ◽  
E. Muller ◽  
J. B. Hyne

The infrared and Raman spectra of H2S3 and H2S4 in CCl4 and CS2 solutions are reported and a complete assignment is presented. On the basis of the spectra and their temperature and concentration dependence, H2S3 is considered to be in the GG and H2S4 in the GG′G conformation. A valence force field is derived which provides a least-squares fit between observed and calculated frequencies for both molecules simultaneously, with an average error of 1.5 cm−1 (or 0.4%) over all frequencies.


1979 ◽  
Vol 33 (4) ◽  
pp. 364-371 ◽  
Author(s):  
J. R. Durig ◽  
M. Jalilian

The Raman spectra (0 to 3600 cm−1) of gaseous (CH3)3SiCl and (CD3)3SiCl have been recorded. It was possible to resolve the symmetric and antisymmetric SiC3 deformations. The spectra are discussed in detail and previous vibrational assignments are compared. A normal coordinate calculation has been carried out utilizing a modified simple valence force field. The extent of the vibrational coupling has been determined. It is believed that the main force constants should be transferable to other substituted trimethylsilyl compounds and this transferability is demonstrated by some normal coordinate calculations for trimethylsilylisocyanate and trimethylsilylisothiocyanate.


1966 ◽  
Vol 21 (11) ◽  
pp. 1889-1898 ◽  
Author(s):  
G. Geiseler ◽  
L. Ratz

Infrared absorption spectra (4000—400 cm-1) and RAMAN spectra of the pentaerythritol halides have been examined. By comparison with spectra of similar compounds and by a normal coordinate analysis with the aid of the GF-Matrix-Method of WILSON and on the basis of a modified valence force field it was possible to assign a great deal of the normal vibrations. The influence of the halogen atoms on the frequency of characteristic vibrations has been discussed.


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