Vibration spectra of mixed crystals Sc(PO4, VO4) and Y(PO4, VO4)

1982 ◽  
Vol 47 (4) ◽  
pp. 1176-1183 ◽  
Author(s):  
Alexander Muck ◽  
Olga Smrčková ◽  
Bohumil Hájek
Keyword(s):  
Infrared Spectra ◽  
Group Analysis ◽  
Point Of View ◽  
Mixed Crystals ◽  
Site Symmetry ◽  
Lattice Vibrations ◽  
Vibration Spectra ◽  
Space Group

Infrared spectra of mixed crystals Sc(PO4, VO4) and Y(PO4, VO4) have been studied from the point of view of group analysis. These systems form substitution mixed crystals in tetragonal space group D194h. The anions having proper symmetry Td or D2d in site symmetry D2d exhibit in spectra lowering of the site symmetry to effective C2 as a result of lattice vibrations of the type T(B2).

Infrared absorption spectra of Ag3[PO4, VO4] mixed crystals

1979 ◽  
Vol 44 (3) ◽  
pp. 823-828 ◽  
Author(s):  
Bohumil Hájek ◽  
Alexander Muck ◽  
Olga Smrčková
Keyword(s):  
Mixed Crystal ◽  
Group Analysis ◽  
Factor Group ◽  
Mixed Crystals ◽  
Site Symmetry ◽  
Lattice Vibrations ◽  
Concentration Region ◽  
Site Group ◽  
Infrared Absorption Spectra ◽  
Effective Site

Ag3[PO4, VO4] mixed crystals were prepared in the whole concentration region. For 0-40 mol % vanadate, the mixed crystals are isostructural with the low-temperature modification of Ag3PO4 (Td4, Z = 2); the site group and factor group analysis was performed for this space group. Mixed crystals containing 60% vanadate and more are tetragonal with the structure of Ag3VO4. From the analysis of the infrared spectra it follows that in the cubic mixed crystal with 40 mol % Ag3VO4, the site symmetry T is additionally lowered to the effective site symmetry C3 due to the effect of the lattice vibrations of the types T(F) and R(F).

The infrared absorption spectra of mixed Ag3[AsO4, VO4] crystals

1979 ◽  
Vol 44 (11) ◽  
pp. 3346-3349 ◽  
Author(s):  
Bohumil Hájek ◽  
Alexander Muck ◽  
Olga Smrčková
Keyword(s):  
Absorption Spectra ◽  
Infrared Absorption ◽  
Factor Group ◽  
Mixed Crystals ◽  
Site Symmetry ◽  
Lattice Vibrations ◽  
Space Group ◽  
Infrared Absorption Spectra ◽  
Effective Site

Mixed Ag3[AsO4, VO4] crystals were prepared over the whole concentration range. In the 0-40% mol. Vanadate concentration range the mixed crystals are isostructural with Ag3AsO4 (T4d, Z = 2). Site- and factor group analyses were carried out for this space group and structure. Above 60 mol% vanadate, the mixed crystals are tetragonal with Ag3VO4 structure. It follows from the behaviour of the ν4AsO3-4 vibration that, in cubic mixed crystals with 40 mol% Ag3VO4, the site-symmetry T is reduced to effective site-symmetry C3 by the effect of lattice vibrations of the T(F) and R(F) types.

Infrared spectroscopic study of the YPO4-YCrO4 system

1985 ◽  
Vol 50 (10) ◽  
pp. 2139-2145
Author(s):  
Alexander Muck ◽  
Eva Šantavá ◽  
Bohumil Hájek
Keyword(s):  
Spectroscopic Study ◽  
Infrared Spectra ◽  
Point Of View ◽  
Mixed Crystals ◽  
Crystal Symmetry ◽  
Infrared Spectroscopic Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Infrared Spectroscopic ◽  
Diffraction Patterns

The infrared spectra and powder X-ray diffraction patterns of polycrystalline YPO4-YCrO4 samples are studied from the point of view of their crystal symmetry. Mixed crystals of the D4h19 symmetry are formed over the region of 0-30 mol.% YPO4 in YCrO4. The Td → D2d → D2 or C2v(GS eff) correlation is appropriate for both PO43- and CrO43- anions.

Infrared spectra of unannealed and of annealed Cu4(OH)6(NO3)2

1987 ◽  
Vol 65 (10) ◽  
pp. 2504-2508 ◽  
Author(s):  
Etalo A. Secco ◽  
Glen G. Worth
Keyword(s):  
Infrared Spectra ◽  
Group Analysis ◽  
Site Symmetry ◽  
Torsional Mode ◽  
Oh Groups ◽  
Distinct Individual ◽  
Striking Change ◽  
Bending Modes ◽  
Combination Bands ◽  
First Time

The infrared spectra over the range 4000–150 cm−1 of Cu4(OH)6(NO3)2 along with site group and factor group analysis are reported for the first time. The observed absorption frequencies associated with OH and NO3 modes show distinct individual spectral features in the unannealed and annealed Cu4(OH)6(NO3)2. Three distinct types of OH groups involving different degrees of H-bonding are evident. The multiple frequencies involving Cu—O—H bending modes further reflect the varying degrees of H-bonding and OH coupling in Cu(OH)4O2 and Cu(OH)5O entities paralleling their behavior in Cu4(OH)6SO4. The NO3 internal optic modes' activities, fundamentals along with overtones and combination bands, illustrate distinct interaction effects (OH and Cu) with respect to specific modes relative to halo-nitrates with same site symmetry. The presence of CuO in the sample after the anneal effected a striking change in ν3. The Cu—O, O—Cu—O, and OH torsional mode frequencies show consistent behavior with Cu4(OH)6SO4.

Crystal symmetry of the chlorate anion in host structures

1985 ◽  
Vol 50 (5) ◽  
pp. 1147-1152 ◽  
Author(s):  
Bohumil Hájek ◽  
Alexander Muck ◽  
Olga Smrčková
Keyword(s):  
Infrared Spectra ◽  
Group Analysis ◽  
Crystal Symmetry ◽  
Site Symmetry ◽  
Host Structure

The infrared spectra were studied for the pyramidal ClO3- anion (C3v) embedded in host structures of various symmetries. Small amounts of NaClO3 or KClO3 were incorporated in NaBrO3 (T4), NaIO3 (D162h), KBrO3 (C3v5), and KIO3 (C11) structures. The ClO3- anion was found to assume the site symmetry of the host structure anion, i.e. C3, Cs, C3v, and C1, respectively, in accordance with the results of group analysis.

Infrared spectra of the NO3- anion in NaClO4, Na2SO4, NaClO3, and NaIO3 host structures

1987 ◽  
Vol 52 (12) ◽  
pp. 2886-2889 ◽  
Author(s):  
Bohumil Hájek ◽  
Alexander Muck ◽  
Olga Smrčková
Keyword(s):  
Infrared Spectra ◽  
Group Analysis ◽  
Crystal Symmetry ◽  
Site Symmetry ◽  
Additional Symmetry ◽  
Host Structure

The planar NO3- ion (own symmetry D3h) was embedded in NaClO4, Na2SO4, NaClO3 and NaIO3 host structures containing tetrahedral (Td) or pyramidal (C3v) anions, and its infrared spectra were interpreted in terms of group analysis of the crystal symmetry. Where the correlation is satisfied, viz. in NaClO4, NaClO3 and NaIO3, the NO3- anion possesses the site symmetry of the host structure (C2v, C3 and Cs, respectively), whereas in Na2SO4 an additional symmetry lowering takes place (D2 → C2).

Spectroscopic properties of SO4 (and OH) in different molecular and crystalline environments. I. Infrared spectra of Cu4(OH)6SO4, Cu4(OH)4OSO4, and Cu3(OH)4SO4

1988 ◽  
Vol 66 (2) ◽  
pp. 329-336 ◽  
Author(s):  
Etalo A. Secco
Keyword(s):  
Infrared Spectra ◽  
Dipolar Coupling ◽  
Group Analysis ◽  
Spectroscopic Properties ◽  
Site Symmetry ◽  
Oh Groups ◽  
Distinct Individual ◽  
Multiple Frequencies ◽  
Bending Modes ◽  
First Time

The infrared spectra over the range 4000–50 cm−1 of three copper basic sulfates, viz. Cu4(OH)6SO4, Cu4(OH)4OSO4, Cu3(OH)4SO4 along with site group and factor group analysis for Cu4(OH)6SO4 are reported for the first time. The observed absorption frequencies associated with OH and SO4 activities show distinct individual structural features.Three distinct types of OH groups are present in Cu4(OH)6SO4 and Cu4(OH)4OSO4 but only two types are evident in Cu3(OH)4SO4. The two OH groups involved in the dehydroxylation reaction to give the oxycompound Cu4(OH)4OSO4 are tentatively identified. The multiple frequencies involving Cu—O—H bending modes further reflect the varying degrees of H-bonding and OH coupling in Cu(OH)4O2 and Cu(OH)5O entities.The SO4 internal optic modes' multiplet structure and frequencies in the basic sulfates illustrate the different extent of dipolar coupling effects (OH and Cu) with respect to specific modes relative to Li2SO4 with same site symmetry. The SO4 external optic modes relative to Li2SO4 are barely affected by neighboring OH groups.The Cu—O mode frequencies show parallel behavior with minor interaction effects in all compounds.

The infrared spectra of tetrahedral anions in mixed crystals

1984 ◽  
Vol 49 (8) ◽  
pp. 1756-1763 ◽  
Author(s):  
Bohumil Hájek ◽  
Olga Smrčková ◽  
Petr Záruba
Keyword(s):  
Infrared Spectra ◽  
Group Analysis ◽  
Mixed Crystals

Group Analysis of the infrared spectra of KClO4-KMnO4, KClO4-KBF4 and K2SO4-K2XO4 (where X is Se, Cr, Mn) mixed crystals was carried out. These systems form D2h16 orthorhombic substitution mixed crystals; the symmetry of the anion is Td. Analysis of the infrared spectra samples with sufficiently diluted studied anion revealed the expected decrease in symmetry to Cs symmetry.

Far Infrared Group Frequencies. V. Oximes and Aldoximes

1973 ◽  
Vol 27 (1) ◽  
pp. 22-26 ◽  
Author(s):  
S. M. Craven ◽  
F. F. Bentley ◽  
D. F. Pensenstadler
Keyword(s):  
Hydrogen Bond ◽  
Infrared Spectra ◽  
Low Frequency ◽  
Far Infrared ◽  
Torsional Vibrations ◽  
Lattice Vibrations ◽  
Dilute Solutions ◽  
Solid Samples ◽  
Bending Modes ◽  
Bond Stretch

The low frequency infrared spectra from 450 to 75 cm−1 of seven oximes and five aldoximes have been recorded for pure samples and for dilute solutions in cyclohexane. An intense characteristic band is present in the solution spectra at 367 ± 10 cm−1. This characteristic band shifts to 275 ± 10 cm−1 in the spectra of the OD compounds. The 367 ± 10 cm−1 and 275 ± 10 cm−1 bands are assigned to OH and OD torsional vibrations. A comparison of the solution spectra with spectra of the solid samples indicated that the OH … N hydrogen bond stretch of oximes and aldoximes occurs in 300 to 200 cm−1 region. Strong bands also are present in 140 to 100 cm−1 region which are due to OH … N bending modes or perhaps lattice vibrations.

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