Intermolecular vibrational coupling associated with the 2ν2 features of the Raman spectrum of strontium nitrate

1987 ◽  
Vol 87 (10) ◽  
pp. 5617-5620 ◽  
Author(s):  
U. A. Jayasooriya ◽  
S. F. A. Kettle ◽  
E. Lugwisha
Keyword(s):  
Raman Spectrum ◽  
Strontium Nitrate ◽  
Vibrational Coupling

Fundamental and Overtone Vibrational Transitions in the Raman Spectrum of h.c.p. Solid Hydrogen

1972 ◽  
Vol 50 (13) ◽  
pp. 1471-1479 ◽  
Author(s):  
William R. C. Prior ◽  
Elizabeth J. Allin
Keyword(s):  
Raman Spectrum ◽  
Relative Intensity ◽  
Argon Laser ◽  
Solid Hydrogen ◽  
Frequency Separation ◽  
Frequency Change ◽  
Quadrupolar Interaction ◽  
Vibrational Coupling ◽  
Frequency Shifts ◽  
Vibrational Overtone

The use of an argon laser of high intensity has made it possible to observe the vibrational overtone of solid hydrogen and to study the fundamental over a wider concentration range than previously. At ortho concentrations below ~ 15% the Q1(1) line has two components. The dependence on concentration and temperature of the frequency separation and relative intensity of these components is accounted for by the quadrupolar interaction between ortho molecules. Differences in the frequency shifts of the Q1(0) and the Q1(1) and of the Q2(0) and the Q1(1) lines in mixtures of all concentrations are also related to the quadrupolar interactions. The overtone lines show almost no frequency change with concentration. This is explained by a much smaller vibrational coupling due to the isotropic interactions in the ν = 2 than in the ν = 1 state. Confirmation of this is found in the small enhancement of the intensity of Q2(1) relative to Q2(0). The measurement of the frequency of Q2(0) makes it possible to determine the parameters μ1, and μ2, specifying the change in the intramolecular potential by the isotropic interactions, from transitions involving J = 0 states alone.

Preresonance Raman spectra and excitation profiles of some chemically and isotopically substituted trans-4-benzylideneoxazolin-5-ones

1978 ◽  
Vol 56 (2) ◽  
pp. 240-245 ◽  
Author(s):  
D. J. Phelps ◽  
R. G. Carriere ◽  
K. Kumar ◽  
P. R. Carey
Keyword(s):  
Raman Spectrum ◽  
Absorption Band ◽  
Raman Spectra ◽  
Phenyl Group ◽  
Low Energy ◽  
Coupling Scheme ◽  
Raman Intensity ◽  
Vibrational Coupling ◽  
Intensity Enhancement ◽  
Phenyl Rings

Resonance and preresonance Raman spectra of nine substituted trans-4-benzylidene- Δ2-oxazolin-5-ones are reported. The seven analogs with phenyl in the 2 position of the oxazolinone ring have either an electron donating or attracting group on one of the phenyl rings. Although shifts in λmax of up to 100 nm are observed the Raman spectra are very similar to that of the unsubstituted trans isomer. However, in the substituted compounds modes from the benzylidene portion may become weakly intensity enhanced. Replacing the 2-phenyl group by 2-methyl in the oxazolinone ring results in quite gross changes in the Raman spectrum. Substitution by 15N in the ring of a 2-methyloxazolinone reveals that a change in the vibrational coupling scheme occurs. Excitation profiles for the 2-phenyl and the 2-methyl analogs of 4-(p-nitrobenzylidene)oxazolinone indicate that in each compound ail intensity enhanced modes are coupled to the intense low energy absorption band near 350 nm and the intensity enhancement fits the FB2 terms of Albrecht and Hutley. However, differences in the relative intensity of the benzylidene nitro feature in the 2-methyl and 2-phenyl analogs, taken with the excitation profiles, suggest that in the 2-methyl compound the electronic transition responsible for Raman intensity enhancement is no longer primarily located in the C=C—N=C—Ph moiety.

Vibrational spectra of ammonium ammine-oxo-diperoxovanadate

1982 ◽  
Vol 47 (6) ◽  
pp. 1549-1555 ◽  
Author(s):  
Peter Schwendt ◽  
Miloslav Pisárčik
Keyword(s):  
Raman Spectrum ◽  
Bond Length ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Normal Coordinate Analysis ◽  
Wave Number ◽  
Infrared And Raman Spectra ◽  
Normal Coordinate ◽  
Mass Model ◽  
Vibrational Coupling

Infrared and Raman spectra of solid NH4[VO(O2)2NH3], ND4[VO(O2)2ND3], 14/15NH4[VO(O2)214/15NH3] (about 50% 15N) and Raman spectrum of solution of NH4[VO(O2)2NH3] have been measured. Interpretation of the spectra was complemented by normal coordinate analysis in the approximation of point mass model (NH3). The results have shown that there exists coupling of vibrations of two V(O2) groups, which enables an explanation of differences between spectra of the mono- and diperoxo complexes. The vibrational coupling of VO and OO bonds within one V(O2) group probably causes small sensitivity of wave number of v(O-O) band to changes of d(O-O) bond length.

THE RAMAN SPECTRA OF LIQUID AND SOLID H2, D2, AND HD AT HIGH RESOLUTION

1962 ◽  
Vol 40 (1) ◽  
pp. 9-23 ◽  
Author(s):  
S. S. Bhatnagar ◽  
Elizabeth J. Allin ◽  
H. L. Welsh
Keyword(s):  
Raman Spectrum ◽  
High Resolution ◽  
Raman Spectra ◽  
Vibrational Frequencies ◽  
Dispersion Forces ◽  
Present Communication ◽  
Linear Dispersion ◽  
Vibrational Coupling

The Raman spectra of liquid (~18° K) and solid (~2° K) n-H2, p-H2, n-D2, o-D2(80%), and HD were photographed with a reciprocal linear dispersion of 3 to 6 cm−1 per mm. The S0 rotational lines show broadening of a few cm−1 but the Q1 vibrational lines are very sharp. The S0(0) transition of p-H2 and o-D2 is a triplet of sharp lines, but the corresponding transition in HD is not split. The vibrational frequencies in the liquid are lowered by 7 to 9 cm−1 and in the solid by 8 to 11 cm−1 from the gas values. The Raman spectrum of p-H2 has been discussed in detail by Van Kranendonk. In the present communication the vibrational shifts in the various solids are correlated by representing them as the sums of shifts due to dispersion forces, overlap forces, and vibrational coupling.

The vibrational Raman spectrum of compressed solid hydrogen

1979 ◽  
Vol 57 (3) ◽  
pp. 442-448 ◽  
Author(s):  
E. J. Allin ◽  
S. M. Till
Keyword(s):  
Raman Spectrum ◽  
Excitation Energy ◽  
Solid Hydrogen ◽  
Vibrational Coupling ◽  
Angular Momenta ◽  
Type Interaction

The frequencies of the pure vibrational lines, Q(0) and Q(1), in the Raman spectrum of solid H2 have been measured when the solid was subjected to a number of pressures between 400 and 1000 kg cm−2, corresponding to solid densities up to ~ 1250 amagat. Most samples studied had orthohydrogen concentrations ≥ 0.60. For these the frequency of Q(0) increased as the density increased but that of Q(1) showed little change. This can be explained if it is assumed that (i) the isotropic repulsive overlap interaction between a pair of molecules increases more rapidly than the attractive dispersion-type interaction, (ii) the effect of vibrational coupling between molecules in the same J-state increases asp2, and (iii) the lowering of the excitation energy of the ν = 1,J = 1 stale by electric quadrupolar interactions increases as ρ5/3. There is evidence that at higher densities ordering of the molecular angular momenta may occur at temperatures up to 4 K. The intensity of Q(1) relative to Q(0) is further enhanced at higher densities.

To β or not to β: A first look at the Raman spectrum of pure β-UO3

2020 ◽  
Author(s):  
Brianna Barth ◽  
Spano Tyler ◽  
Jeremiah Gruidl ◽  
Michael Lance ◽  
Roger Kapsimalis ◽  
...  
Keyword(s):  
Raman Spectrum

The Raman spectrum of solid hydrogen

1965 ◽  
Vol 26 (11) ◽  
pp. 615-620 ◽  
Author(s):  
E.J. Allin ◽  
A.H. M ◽  
V. Soots ◽  
H.L. Welsh
Keyword(s):  
Raman Spectrum ◽  
Solid Hydrogen

RAMAN SPECTRUM OF AgGaS2

1975 ◽  
Vol 36 (C3) ◽  
pp. C3-183-C3-184 ◽  
Author(s):  
D. J. LOCKWOOD ◽  
H. MONTGOMERY
Keyword(s):  
Raman Spectrum

GAS PHASE RAMAN SPECTRUM OF TCNQ AND PRESSURE DEPENDENCE OF THE MODES IN CRYSTALS OF TNCQ°

1981 ◽  
Vol 42 (C6) ◽  
pp. C6-323-C6-325
Author(s):  
C. Carlone ◽  
N. K. Hota ◽  
H. J. Stolz ◽  
M. Elbert ◽  
H. Kuzmany ◽  
...  
Keyword(s):  
Raman Spectrum ◽  
Gas Phase ◽  
Pressure Dependence
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