scholarly journals Infrared and Raman spectra of cubic form of magnesium caesium arsenate hexahydrate

2018 ◽  
Vol 37 (2) ◽  
Author(s):  
Viktor Stefov ◽  
Violeta Koleva ◽  
Metodija Najdoski ◽  
Adnan Cahil ◽  
Zuldjevat Abdija
Keyword(s):  
Raman Spectra ◽  
Room Temperature ◽  
Spectral Characteristics ◽  
Normal Modes ◽  
Water Molecules ◽  
Infrared And Raman Spectra ◽  
Cubic Form ◽  
The Matrix ◽  
Deuterated Sample ◽  
Ft Ir

Fourier transform infrared (FT-IR) spectra recorded at room temperature (RT) and at the boiling temperature of liquid nitrogen (LNT), as well as Raman spectra recorded at room temperature for the cubic polymorph of magnesium cesium arsenate hexahydrate (MgCsAsO4·6H2O) and its partially deuterated analogues, were interpreted with respect to the normal modes of the water molecules and the arsenate ions and water librations. The spectral characteristics of MgCsAsO4·6H2O were compared to the cubic form of the phosphate analogue. A spectral similarity between the two isostructural salts was established, except for the obvious differences due to the nature of the anions (AsO43– vs PO43–). The spectroscopic data for the uncoupled OD stretching mode of the matrix-isolated HDO molecules revealed that the hydrogen bonds formed in the arsenate salt were stronger than those in the phosphate. In the Raman spectrum of the protiated compound, only one very intensive band at 811 cm–1 was observed in the region of the stretching vibrations of the AsO43– ion, which was insensitive to deuteration. In accordance with the expectation, one band appeared in the same spectral range in the infrared spectra of the protiated and highly deuterated sample at 792 cm–1 and 810 cm–1, respectively, which can be attributed with certainty to the asymmetric stretching ν3(AsO4) modes.

scholarly journals INFRARED SPECTRA OF THIOSACCHARINATES OF CADMIUM AND LEAD COMPARISON WITH THE ANALOGOUS METAL SACCHARINATES

2017 ◽  
Vol 27 (1-2) ◽  
Author(s):  
Gligor Jovanovski ◽  
Adnan Kahil ◽  
Orhideja Grupče
Keyword(s):  
Infrared Spectra ◽  
Room Temperature ◽  
Spectral Characteristics ◽  
Crystalline Hydrate ◽  
Water Molecules ◽  
X Ray ◽  
Weak Hydrogen Bonds ◽  
Deuterated Analogue ◽  
The Fourier Transform ◽  
Cadmium And Lead

A b s t r a c t: The Fourier transform (FT) infrared spectra of thiosaccharinates of cadmium and lead in the 4000–400 cm–1 region were studied. Although the observed resemblance between the spectra recorded in KBr pellets suggests a possible similarity between their structures as well, the powder X-ray diagrams show that these two compounds are not isomorphous. The presence of broad and intense bands in the region of the HOH stretchings shows that thiosaccharinate of cadmium is a crystalline hydrate and the spectral picture in the region of the O-D stretchings of the isotopically isolated HOD molecules in the partially deuterated analogue indicates that present in its structure are at least two types of crystallographically different water molecules involved in the formation of weak hydrogen bonds. The room temperature (RT) spectrum of lead thiosaccharinate in the region of the ν(HOH) modes differs significantly from the spectrum recorded at the boiling temperature of liquid nitrogen (LNT), which may perhaps be interpreted as an indication that a phase transition is taking place on lowering the temperature. The spectrum of lead thiosaccharinate was recorded in a Nujol mull as well. While the KBr and Nujol spectra are essentially identical in the region below 1600 cm–1, no bands are observed in the HOH stretching region of the mull spectra. In fact, it was shown that the appearance of the spectra of lead thiosaccharinates depends on the emulsion preparation rate. A comparison of the spectral characteristics of the thiosaccharinates of cadmium and lead with those of the corresponding saccharinates (their crystal structures are known) was made, special attention being paid to the analysis of the SO2 stretching region in the saccharinate and thiosaccharinate compounds.

The Vibrational Spectrum and Urey-Bradley Force Constants of the Trifluoromethyltrifluoroborate(1-) Anion

1973 ◽  
Vol 27 (3) ◽  
pp. 209-213 ◽  
Author(s):  
John F. Jackovitz ◽  
Charles E. Falletta ◽  
James C. Carter
Keyword(s):  
Potential Energy ◽  
Vibrational Spectrum ◽  
Energy Distribution ◽  
Force Field ◽  
Raman Spectra ◽  
Normal Modes ◽  
Force Constants ◽  
Potential Energy Distribution ◽  
Infrared And Raman Spectra ◽  
Normal Coordinate

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−.

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

1992 ◽  
Vol 291 ◽  
Author(s):  
Charles C. Kim ◽  
M. I. Bell ◽  
D. A. McKeown
Keyword(s):  
Crystal Structure ◽  
Raman Spectra ◽  
Infrared Spectra ◽  
Normal Modes ◽  
Infrared And Raman Spectra ◽  
Normal Coordinate ◽  
Structure Space ◽  
New Information ◽  
Atomic Interactions ◽  
Modes Of Vibration

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.

The Vibrational Spectra and Crystal Structure of Acenaphthylene

1973 ◽  
Vol 51 (3) ◽  
pp. 402-404 ◽  
Author(s):  
A. Bree ◽  
R. A. Kydd ◽  
V. V. B. Vilkos ◽  
R. S. Williams
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Room Temperature ◽  
Infrared And Raman Spectra ◽  
Depolarization Ratio ◽  
X Ray

A study of the polarized infrared and Raman spectra of acenaphthylene single crystals has been made. These results, together with Gordon and Yang's preliminary X-ray work, suggest that the molecules pack in some disordered arrangement in the solid at room temperature. Most of the A1 fundamentals were identified in the Raman solution spectrum from their low depolarization ratio, and a few tentative assignments of nontotally symmetric fundamentals were made.

THE VIBRATIONAL SPECTRA OF SULPHURYL AND THIONYL HALIDES

1961 ◽  
Vol 39 (11) ◽  
pp. 2171-2178 ◽  
Author(s):  
R. J. Gillespie ◽  
E. A. Robinson
Keyword(s):  
Raman Spectrum ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Normal Modes ◽  
Infrared And Raman Spectra ◽  
Fundamental Frequencies

New assignments are proposed for the fundamental frequencies of SOF2, SOCl2, SO2Cl2, SO2F2, and SO2FBr, based on new measurements of the Raman spectrum of SO2Cl2 and previous measurements of the infrared and Raman spectra of these molecules. The fundamental frequencies of these molecules are found to be related to each other and to those of similar molecules when the normal modes are described in terms of characteristic vibrations of the SO, SO2, S(Hal), and S(Hal)2 groups.

The Importance of Interactions at the Molecular Level: A Spectroscopic Study of a New Composite Sorber Material

2017 ◽  
Vol 71 (10) ◽  
pp. 2278-2285 ◽  
Author(s):  
Valentina Crocellà ◽  
Elena Groppo ◽  
Alessandro Dani ◽  
Alberto Castellero ◽  
Silvia Bordiga ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Raman Spectroscopy ◽  
Composite Material ◽  
Composite System ◽  
Molecular Level ◽  
Water Molecules ◽  
Magnesium Perchlorate ◽  
The Matrix ◽  
Ft Ir ◽  
Ir And Raman

The functional properties of a new composite material having water vapor getter properties have been investigated by a large arsenal of characterization techniques. The composite system is originated by combining two constituents having very different chemical natures, a magnesium perchlorate (Mg(ClO4)2) salt and a polymeric acrylic matrix. In particular, Fourier transform infrared (FT-IR) and Raman spectroscopy have been fundamental to understand the type of interactions between the salt and the matrix in different hydration conditions. It was found that in the anhydrous composite system the dispersed Mg(ClO4)2 salt retains its molecular structure, because Mg2+ cations are still surrounded by their [ClO4]– counter-anions; at the same time, the salt and the polymeric matrix chemically interact each other at the molecular level. These interactions gradually vanish in the presence of water, and disappear in the fully hydrated composite system, where the Mg2+ cations are completely solvated by the water molecules.

Matrix-Isolation Studies and Ring Conformation of 1,3-Dithietane

1979 ◽  
Vol 33 (4) ◽  
pp. 361-364 ◽  
Author(s):  
V. F. Kalasinsky ◽  
E. Block ◽  
D. E. Powers ◽  
W. C. Harris
Keyword(s):  
Solid State ◽  
Raman Spectra ◽  
Crystal Packing ◽  
Mutual Exclusion ◽  
Infrared And Raman Spectra ◽  
Molecular Symmetry ◽  
Free Molecule ◽  
Ring Conformation ◽  
Argon Matrix ◽  
The Matrix

The infrared and Raman spectra of 1,3-dithietane have been recorded with the sample in the solid state and trapped in an argon matrix at 18K. The number of coincidences between the infrared and Raman spectra of the matrix-isolated sample is consistent with C2v molecular symmetry in which the ring has a puckered conformation. In the solid state a number of bands disappear upon annealing, and the observed mutual exclusion for the annealed solid can be interpreted in terms of D2h, symmetry. Whereas the matrix probably represents the “free” molecule, the planarity of the ring in the annealed solid can be attributed to crystal packing.

Infrared and Raman Spectra of Bis(Melaminium) Sulfate Dihydrate

2003 ◽  
Vol 2003 (8) ◽  
pp. 518-521 ◽  
Author(s):  
M.K. Marchewka
Keyword(s):  
Raman Spectra ◽  
Vibrational Spectra ◽  
Crystalline State ◽  
Room Temperature ◽  
Spectral Features ◽  
Infrared And Raman Spectra ◽  
X Ray ◽  
Internal Vibrations

Room temperature powder infrared and Raman measurements for the new melaminium salt, bis(2,4,6-triamino-1,3,5-triazin-1-ium) sulfate dihydrate, 2C3H7N6+·SO42-·2H2O, in the crystalline state, were carried out. The vibrational spectra in the region of internal vibrations of the ions corroborate recent X-ray data of Janczak et al. Some spectral features of this new crystal are referred to those of other crystalline melaminium salts.

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