DENSITY EFFECTS IN THE RAMAN SPECTRUM OF AMMONIA

1954 ◽  
Vol 32 (10) ◽  
pp. 653-661 ◽  
Author(s):  
C. A. Plint ◽  
R. M. B. Small ◽  
H. L. Welsh
Keyword(s):  
Aqueous Solution ◽  
High Pressure ◽  
Fine Structure ◽  
Raman Spectrum ◽  
Raman Spectra ◽  
Low Pressure ◽  
High Dispersion ◽  
Density Effects ◽  
Gas Pressures ◽  
Weak Satellite

The Raman spectra of ammonia as a high pressure gas, liquid, solid, and aqueous solution are compared with the spectrum of the low pressure gas. At gas pressures up to 80 atm. no appreciable hindering of rotation is present; a weak satellite of the ν1 band is an unexplained feature of the spectrum at high pressure. The spectra of the liquid, solid, and aqueous solution are interpreted without postulating dimerization; the three higher frequency maxima can be assigned to the 2ν4, ν1 and ν3 vibrations if it is assumed that hindering of rotation is almost complete. The rotational fine structure found by early workers for the aqueous solution could not be observed even at high dispersion.

Darstellung und spektroskopische Charakterisierung von Tetrachloro- und Tetrabromo-Oxalatoiridaten(IV) / Preparation and Spectroscopical Characterization of Tetrachloro- and Tetrabromoiridates(IV)

1982 ◽  
Vol 37 (12) ◽  
pp. 1553-1557 ◽  
Author(s):  
H. Schulz ◽  
W. Preetz
Keyword(s):  
Aqueous Solution ◽  
Fine Structure ◽  
Absorption Spectra ◽  
Raman Spectra ◽  
Point Group ◽  
Vibration Modes ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Ir And Raman

On treatment of [IrX6]2- with oxalate in aqueous solution at first [IrX4OX]3- (X = Cl, Br) is formed, which after extraction with pentylammonium ions into CH2Cl2 can be oxidised by X2 to give the corresponding pure Ir(IV) complexes [IrX4OX]2-. The IR and Raman spectra are assigned according to point group C2V- The UV/VIS absorption spectra show strong CT bands of transitions from "(π + σ)tlu"- and "πt2U"-ligand niveaus to t2g5 (IrIV). These are split into three components by spin-orbit coupling and corresponding to the different groups of ligands: Xtr2, Xc2, ox. The spectrum of (TBA)2[IrBr4OX] recorded at 10 K is highly resolved, showing a splitting of the Brtr2 → Ir(IV) and Bc2 → Ir(IV) transitions by 1000-1400 cm-1. In the NIR-region two d-d-transitions are observed superimposed with a fine structure by coupling with vibration modes

DENSITY EFFECTS IN THE RAMAN SPECTRUM OF CARBON DIOXIDE

1952 ◽  
Vol 30 (2) ◽  
pp. 99-110 ◽  
Author(s):  
H. L. Welsh ◽  
P. E. Pashler ◽  
B. P. Stoicheff
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Raman Spectrum ◽  
Relative Intensity ◽  
Intermolecular Forces ◽  
Anisotropic Scattering ◽  
Fermi Resonance ◽  
Intensity Effect ◽  
Density Effects ◽  
Frequency Changes

Two Raman tubes, one of quartz and one of glass, capable of withstanding pressures up to 75 and 300 atm. respectively, were used to study density effects in the Raman spectrum of carbon dioxide. The components of the ν1 band show changes in frequency and relative intensity with increasing density. An analysis shows that the frequency changes are due to a lowering of the frequency of 2ν2, in Fermi resonance with ν1, with increasing density. The intensity effect, however, is not completely explained by the change in the sharpness of the resonance. In the high pressure gas and in the liquid faint bands corresponding to the Raman inactive frequencies, ν2 and ν3, are observed. The effect of increasing density on the rotational Raman spectrum can be explained in terms of the broadening of anisotropic scattering by intermolecular forces.

Resonance Raman spectrum of a deuterated crystal violet: [p(CH3)2N•C6D4]3C+Cl−

1981 ◽  
Vol 59 (6) ◽  
pp. 964-967 ◽  
Author(s):  
S. Sunder ◽  
H. J. Bernstein
Keyword(s):  
Aqueous Solution ◽  
Raman Spectrum ◽  
Raman Spectra ◽  
Crystal Violet ◽  
Resonance Raman ◽  
Resonance Raman Spectrum ◽  
Dilute Aqueous Solution ◽  
Resonance Raman Spectra

Resonance Raman spectra have been obtained for a deuterated crystal violet [p(CH3)2N•C6D4]3C+Cl−, as a dilute aqueous solution. The assignment of some of the strong features seen in the spectra of crystal violet and deuterated crystal violet is discussed.

Ramanspektroskopische Untersuchungen an festen und in Wasser gelösten Polyboraten / Investigations of Solid Polyborates and their Aqueous Solutions by Raman Spectroscopy

1979 ◽  
Vol 34 (4) ◽  
pp. 585-590 ◽  
Author(s):  
Ralf Janda ◽  
Gert Heller
Keyword(s):  
Aqueous Solution ◽  
Raman Spectroscopy ◽  
Raman Spectrum ◽  
Aqueous Solutions ◽  
Raman Spectra ◽  
Solubility In Water

Abstract Raman spectra of solid H3BO3, Na2[B4O5(OH)4] · 8 H2O, K[B5O6(OH)4] · 2H2O and Na[B(OH)4] were recorded between 300 and 1500 cm-1 as well as of borax in aqueous solutions as a function of concentration and pH. Because of better solubility in water, the Raman spectrum of ammonium tetraborate in aqueous solution was also recorded as a function of pH. For comparisons the Raman spectra of solid (NH4)2[B4O5(OH)4] · 2 H2O, β-NH4[B5O6(OH)4] · 2 H2O, NH4[B5O6(OH)4] · 0,67 H2O and NH4[B5O6(OH)4] were considered. In solution, all lines in the Raman spectra could be assigned and the degree of depolarization measured. The assigned Raman frequencies can be used for the identification of unknown B-O-lines and therefore of unknown borate or polyborate structures.

Fouling Is the Beginning: Upcycling Biopolymer-Fouled Substrates for Fabricating High-Permeance Thin-Film Composite Polyamide Membranes

2020 ◽  
Author(s):  
Ruobin Dai ◽  
Hongyi Han ◽  
Tianlin Wang ◽  
Jiayi Li ◽  
Chuyang Y. Tang ◽  
...  
Keyword(s):  
Thin Film ◽  
High Pressure ◽  
End Of Life ◽  
Water Purification ◽  
Low Pressure ◽  
Polymeric Membranes ◽  
Membrane Recycling ◽  
Film Composite ◽  
Thin Film Composite ◽  
First Time

Commercial polymeric membranes are generally recognized to have low sustainability as membranes need to be replaced and abandoned after reaching the end of their life. At present, only techniques for downcycling end-of-life high-pressure membranes are available. For the first time, this study paves the way for upcycling fouled/end-of-life low-pressure membranes to fabricate new high-pressure membranes for water purification, forming a closed eco-loop of membrane recycling with significantly improved sustainability.

scholarly journals Quantitative and Qualitative Analysis of Some Inorganic Compounds by Raman Spectroscopy

1994 ◽  
Vol 48 (7) ◽  
pp. 875-883 ◽  
Author(s):  
Daniel R. Lombardi ◽  
Chao Wang ◽  
Bin Sun ◽  
Augustus W. Fountain ◽  
Thomas J. Vickers ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Raman Spectroscopy ◽  
Qualitative Analysis ◽  
Raman Spectra ◽  
Solid Phase ◽  
Inorganic Compounds ◽  
Core Material ◽  
Storage Tanks ◽  
Hanford Site ◽  
Sampling Probe

Raman spectra have been measured for a number of nitrates, nitrites, sulfates, ferrocyanides, and ferricyanides, both in the solid phase and in aqueous solution. Accurate locations of peak maxima are given. Limits of detection for some of the compounds are given for solutions and for solid mixtures in NaNO3. Preliminary measurements have been made on core material recovered from the storage tanks on the Hanford site in Richland, Washington. Representative spectra are presented, showing that it is possible to observe responses of individual components from measurements made directly on untreated cores, with the use of a fiberoptic sampling probe.

Nitroethane at high density: an experimental and computational vibrational study

2021 ◽  
Vol 23 (15) ◽  
pp. 9325-9336
Author(s):  
Akio Yoshinaka ◽  
Serge Desgreniers ◽  
Anguang Hu
Keyword(s):  
High Pressure ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Unit Cell ◽  
High Density ◽  
Monoclinic Unit Cell ◽  
Vibrational Study

Raman and IR vibrational spectra confirm two molecular units associated with the monoclinic unit cell of nitroethane under high pressure. Raman spectra are extremely sensitive to predicted effects of unit cell distortion due to changes in H-bonding.

scholarly journals High-Pressure Spectroscopy Study of Zn(IO3)2 Using Far-Infrared Synchrotron Radiation

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 34
Author(s):  
Akun Liang ◽  
Robin Turnbull ◽  
Enrico Bandiello ◽  
Ibraheem Yousef ◽  
Catalin Popescu ◽  
...  
Keyword(s):  
High Pressure ◽  
Phase Transitions ◽  
Synchrotron Radiation ◽  
Infrared Radiation ◽  
Room Temperature ◽  
Far Infrared ◽  
Low Pressure ◽  
Pressure Response ◽  
Spectroscopy Study ◽  
Far Infrared Radiation

We report the first high-pressure spectroscopy study on Zn(IO3)2 using synchrotron far-infrared radiation. Spectroscopy was conducted up to pressures of 17 GPa at room temperature. Twenty-five phonons were identified below 600 cm−1 for the initial monoclinic low-pressure polymorph of Zn(IO3)2. The pressure response of the modes with wavenumbers above 150 cm−1 has been characterized, with modes exhibiting non-linear responses and frequency discontinuities that have been proposed to be related to the existence of phase transitions. Analysis of the high-pressure spectra acquired on compression indicates that Zn(IO3)2 undergoes subtle phase transitions around 3 and 8 GPa, followed by a more drastic transition around 13 GPa.

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