Normal Coordinate Analysis of Benitoite (BaTiSi3O9) and its Constituent Ring

1992 ◽  
Vol 291 ◽  
Author(s):  
Charles C. Kim ◽  
M. I. Bell ◽  
D. A. McKeown

ABSTRACTThe normal modes of vibration and their frequencies are calculated for benitoite, a mineral whose crystal structure (space group D23h) consists of three-membered silicate rings (Si3O9) linked by Ba+2 and Ti+4 ions. The calculation unambiguously assigns the normal modes to the lines in the Raman and infrared spectra and determines the atomic interactions. On the assumption that mode mixings and splittings due to inter-ring interactions are small, the normal frequencies of the isolated ring of C3h, symmetry are determined. The identification of normal modes characteristic of three-membered silicate rings may prove to be a valuable guide in the interpretation of the infrared and Raman spectra of amorphous silicates, potentially leading to new information on the ring statistics of these materials.

1972 ◽  
Vol 50 (16) ◽  
pp. 2691-2696 ◽  
Author(s):  
H. F. Shurvell ◽  
M. R. Gold ◽  
A. R. Norris

The infrared and laser–Raman spectra of liquid dimethyliodoarsine, (CH3)2AsI, have been recorded. Assignments of the observed frequencies have been made to the 24 normal modes of vibration of the molecule. A normal coordinate calculation has been carried out in support of the assignment.


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−.


1973 ◽  
Vol 51 (20) ◽  
pp. 3344-3353 ◽  
Author(s):  
John E. Bertie ◽  
Sham Sunder

The infrared spectra between 4000 and 10 cm−1 of t-butyl bromide-h9 and -d9 in the gas and liquid states, and the Raman spectra between 3500 and 10 cm−1 of the liquids under parallel and perpendicular polarizations, have been recordeds and assigned. The compatibility of the assignments for the light and heavy molecules has been checked by normal coordinate calculations, in which 14 valence force constants have reproduced 40 fundamental frequencies with an average error of 1.5%. The calculated thermodynamic properties of both molecules are presented for temperatures between 50 and 500 °K.


1998 ◽  
Vol 53 (2) ◽  
pp. 232-238 ◽  
Author(s):  
K. Dallmann ◽  
W. Preetz

Abstract In the reaction of K2[OsCl6] with boiling water/acetylacetone (1:1) a mixture of different chloro-acetylacetonato complexes is formed, from which [Os(acac)3] can be isolated by column chromatography with dichloromethane on silica gel. The crystal structure of [Os(acac)3] (mo­noclinic, space group P21/c,a = 13.968(5), b = 7.517(5), c = 16.455(5) Å ,β = 98.939(5)°, Z = 4) has been determined by single crystal X-ray diffraction analysis. High resolution IR and Raman spectra were measured at low temperature (10K). Based on the molecular parameters of the X-ray structure determination a normal coordinate analysis has been performed and the normal modes of vibration 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(OsO) = 3.19 and fd(OC) = 6.74 mdyn/Å.


1970 ◽  
Vol 48 (3) ◽  
pp. 410-416 ◽  
Author(s):  
F. Bessette ◽  
A. Cabana ◽  
R. P. Fournier ◽  
R. Savoie

The Raman and infrared spectra of liquid and crystalline SiF4 have been recorded. The assignment of some of the Raman bands of the crystal to longitudinal modes has been confirmed by the infrared reflection spectrum. These indicate that the crystal structure is not centrosymmetric. In other respects the spectra are also more complicated than is expected on the basis of the previously reported Td3 structure. Possible explanations are discussed.


1970 ◽  
Vol 48 (24) ◽  
pp. 3889-3902 ◽  
Author(s):  
J. E. Bertie ◽  
M. G. Norton

Infrared spectra have been recorded in the range 4000 to 20 cm−1 for methylene cyclopropane-h6 and -d6 in the gas phase, and from 4000 to 200 cm−1 for methylene cyclopropane-h6 in the liquid phase. Raman spectra have been recorded for the liquid phases of both species. The fundamental modes of vibration have been assigned using i.r. band contours and Raman depolarization ratios, with the exception of the i.r. inactive A2 modes which were not observed. An interesting feature is the occurrence of remarkably small isotope shifts for certain modes.


1977 ◽  
Vol 146 (1-3) ◽  
pp. 1-18 ◽  
Author(s):  
Manfred O. von Stengel

AbstractThe normal modes of vibration of various alkali feldspars were calculated on the basis of a simple harmonic valence force field. Infrared and Raman spectra were recorded over the whole frequency range. With 7 force constants for ordered feldspars and 5 constants for disordered feldspars the calculated frequencies could be fitted with an average deviation of 10–16 cm


1977 ◽  
Vol 30 (9) ◽  
pp. 1905 ◽  
Author(s):  
CG Barraclough ◽  
GE Berkovic ◽  
GB Deacon

The Raman spectra of phenylmercuric chloride, phenylmercuric bromide, phenylmercuric iodide and diphenylmercury, and the infrared and Raman spectra of diphenylmercury in solution are reported. Using the previously reported infrared spectra of these compounds, vibrations were assigned, normal coordinate analyses were performed and frequencies were calculated using a valence force field. Good agreement was achieved between observed and calculated frequencies. The structure of diphenyl-mercury in solution is discussed.


1981 ◽  
Vol 46 (11) ◽  
pp. 2613-2619 ◽  
Author(s):  
Jiří Toužín

Available data on infrared and Raman spectra of S4N4 in solid state and solutions have been verified and completed. On the basis of normal coordinate analysis an attempt has been made to define with more precision the interpretation of vibration spectra of this compound given in earlier reports.


1990 ◽  
Vol 55 (6) ◽  
pp. 1485-1490 ◽  
Author(s):  
Peter Schwendt ◽  
Milan Sýkora

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.


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