scholarly journals Vibrational Spectra and Force Constants of Tetrasulfurtetranitride, S4N4 [1]

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.

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).


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.


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.


1992 ◽  
Vol 47 (8) ◽  
pp. 1115-1118 ◽  
Author(s):  
P. Hollmann ◽  
W. Preetz

On heating the tetraethylammonium salt of [IrCl6]2- with trifluoroacetic acid the edge sharing bioctahedral anion [Ir2Cl10]2- is formed, the IR and Raman spectra of which are assigned according to point group D2h. Normal coordinate analyses, based on a general valence force field, for [M2X10]2-, M = Re, Os, Ir, Pt; X = Cl, Br have been performed, resulting in a good agreement of the calculated frequencies with the bands observed in the IR and Raman spectra. Due to the stronger bonding of the terminal as compared to the bridging ligands, the valence force constants fd(MXt) are significantly higher than fd(MXb).


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.


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−.


1972 ◽  
Vol 27 (5) ◽  
pp. 867-869 ◽  
Author(s):  
J. N. Rai ◽  
S. N. Tiwary ◽  
S. N. Rai

AbstractForce constants for nine ions belonging to Oh point group have been evaluated by using Orbital Valence Force Field. The constants have been compared with their values obtained by using Urey-Bradley Force Field. The validity of the two methods has been discussed


1978 ◽  
Vol 33 (8) ◽  
pp. 951-958 ◽  
Author(s):  
Ralf Steudel ◽  
Hans-Joachim Mäusle

Raman spectra of S8, 34S8, S12, and S12 · CS2 are reported and force constants have been calculated for S8 and S12 using a modified Urey-Bradley force field. The fundamental vibrations and molecular geometries of S8 and S12 have been used for the calculation of thermodynamic functions. The standard entropies, S0T, as well as the molar heat capacities, Cp, of sulfur species Sn are shown to depend linearly on the molecular size, n, as follows (in J · mole-1 · K-1):S0298 = 35.16n + 147.0, Cp(298 K) = 21.00 n - 11.7.By interpolation entropies for S9, S10 and S11 have been obtained, and these data are used to show that the concentrations of sulfur rings larger than S8 in sulfur vapor must be negligibly small.


1976 ◽  
Vol 31 (7) ◽  
pp. 847-852 ◽  
Author(s):  
H. D. Lutz ◽  
P. Willich ◽  
H. Haeuseler

Abstract Force constants and normal coordinates of MnS2 , FeS2 , RuS2, RuSe2, RuTe2, OsS2 and PtP2 are calculated based on the five ir active vibrations of the pyrite lattice. By setting up a valence force field consisting of short and long range M -X, X2 -X2 and M -M stretching constants it has proved possible to obtain good agreement between experimental and calculated frequencies with expection of FeS2 and RuS2 . The force constants corresponding to the shortest metal chalcogen distances (MnS2: 0.30, RuSe2: 0.88, RuTe2: 0.62, OsS2: 1.32, PtP2: 1.22 mdyn/Å) are mainly responsible for the ir frequencies. For RuSe2 and RuTe2, the forces between adjacent X2 groups are not negligible. Whereas the force constants of OsS2 and PtP2 are of comparable strength, the forces in MnS2 are significantly weaker than those in the other compounds. The normal coordinates of MnS2, OsS2 and PtP2 , and RuSe2 and RuTe2 show significant differences according to both the contribution of the 6 symmetry coordinates to the 5 ir active vibrations and the assignment of the spectra.


1975 ◽  
Vol 30 (3-4) ◽  
pp. 210-214 ◽  
Author(s):  
Rainer Mattes ◽  
Mohamed Moumen ◽  
Ingeborg Pernoll

The infrared and Raman spectra of potassium and tetramethylammonium salts of the dinuclear anions M2OX104- and M2NX8(H2O)23-, with M=Ru, Re and X=Cl, Br, have been registered and assigned on the basis of a normal coordinate analysis. The totally symmetric vibrations νsΜ2Ο (νsM2N), νsMXa,x(νsM—OH2) and δsOMX (δsNMX) show considerable mixing. The force constants of the bridge bonds are 3.9 mdyn/Å for the μ-oxo-and 5.1 mdyn/Å for the μ-nitrido-compounds, the respective stretch-stretch interaction constants 0.45 and 0.6 mdyn/Å.


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