INFRARED AND RAMAN SPECTRA OF 1-CHLOROPROPYNE AND 1-CHLOROPROPYNE-d3

1955 ◽  
Vol 33 (7) ◽  
pp. 1226-1249 ◽  
Author(s):  
D. W. Davidson ◽  
H. J. Bernstein

The infrared spectra of 1-chloropropyne and 1-chloropropyne-d3 have been investigated in the vapor state, in solution, and, in part, in the liquid over the spectral region 3 to 35 μ. Intensities of the infrared bands have been measured from the spectra of the solutions. The Raman spectra of the compounds in the liquid state, together with standard intensities and depolarization ratios of the Raman bands, were obtained. A complete assignment, based on a normal-coordinate calculation of the fundamentals, has been made. Coriolis coupling coefficients of three of the perpendicular-type fundamentals of CH3≡CCl were determined and those of the other two shown to be near unity. Two coupling coefficients for CD3C≡CCl were obtained. The potential function and isotope effects on Raman intensity and Raman displacement of the CCl stretching vibration are discussed.

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.


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.


1971 ◽  
Vol 25 ◽  
pp. 813-832 ◽  
Author(s):  
G. Hagen ◽  
Kjeld Schaumburg ◽  
Karl-Axel Wilhelmi ◽  
A. A. Lindberg ◽  
Inger Lagerlund ◽  
...  

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−.


2010 ◽  
Vol 65 (3) ◽  
pp. 357-s374 ◽  
Author(s):  
Wolfgang Förner ◽  
Hassan M. Badawi

The structures and conformational stabilities of phenylphosphonic acid and phenylthiophosphonic acid were investigated using calculations mostly at DFT/6-311G** and ab initio MP2/6-311G** level. From the calculations the molecules were predicted to exist in a conformational equilibrium consisting of two conformers which as enantiomers have the same energy, but rather unexpected dihedral angles XPCC (X being O or S) which are not equal to zero. The antisymmetric potential function for the internal rotation was determined for each one of the molecules. In these functions the conformers with zero dihedral angles appear to be stable minima (also optimization converges to this), but the vibrational frequency for the torsion turned out to be imaginary, indicating that they are maxima with respect to this symmetry coordinate. Only optimization without any restrictions and starting from a non-zero torsional angle converged to a real minimum with such a geometry (“non-planar”). For that minimum structure infrared and Raman spectra were calculated, and those for phenylphosphonic acid were compared to experimental data, showing satisfactory agreement. This gives confidence to present the spectra of phenylthiophosphonic acid as a prediction. The rather low intensity of the OH bands in the experimental infrared spectrum (as compared to normal organic acids) indicates rather weak hydrogen bonding. Normal coordinate calculations were carried out, and potential energy distributions were calculated for the molecules in the non (near)-planar conformations providing a complete assignment of the vibrational modes to atomic motions in the molecules. From the rather low rotational barriers we conclude, in agreement with results from the literature (for other P=O compounds) based on localized orbitals that conjugation effects are absent - or at least negligible - as compared to electrostatic and steric ones in determining the structures of the stable conformers in the phenyl derivatives. The P=O (and also the P=S) bond is highly polarized according to our analysis of Mulliken populations. The polarization turned out to be smaller in the thiophosphonic acid due to the smaller electronegativity of sulfur as compared to oxygen.


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