scholarly journals Hydration and Ion Pair Formation in Aqueous Lu3+- Solution

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3237 ◽  
Author(s):  
Wolfram Rudolph ◽  
Gert Irmer
Keyword(s):  
Raman Spectroscopy ◽  
Geometry Optimization ◽  
Bond Distance ◽  
Equilibrium Concentration ◽  
Anisotropic Scattering ◽  
Chloro Complex ◽  
Complex Species ◽  
Hydration Enthalpy ◽  
Deuterated Analog ◽  
Dielectric Continuum

Aqueous solutions of Lu3+- perchlorate, triflate and chloride were measured by Raman spectroscopy. A weak, isotropic mode at 396 cm−1 (full width at half height (fwhh) at 50 cm−1) was observed in perchlorate and triflate solutions. This mode was assigned to the totally symmetric stretching mode of [Lu(OH2)8]3+, ν1LuO8. In Lu(ClO4)3 solutions in heavy water, the ν1LuO8 symmetric stretch of [Lu(OD2)8]3+ appears at 376.5 cm−1. The shift confirms the theoretical isotopic effect of this mode. In the anisotropic scattering of aqueous Lu(ClO4)3, five bands of very low intensity were observed at 113 cm−1, 161.6 cm−1, 231 cm−1, 261.3 cm−1 and 344 cm−1. In LuCl3 (aq) solutions measured over a concentration range from 0.105–3.199 mol·L−1 a 1:1 chloro-complex was detected. Its equilibrium concentration, however, disappeared rapidly with dilution and vanished at a concentration < 0.5 mol·L−1. Quantitative Raman spectroscopy allowed the detection of the fractions of [Lu(OH2)8]3+, the fully hydrated species and the mono-chloro complex, [Lu(OH2)7Cl]2+. In a ternary LuCl3/HCl solution, a mixtrure of chloro-complex species of the type [Lu(OH2)8−nCln]+3−n (n = 1 and 2) were detected. DFT geometry optimization and frequency calculations are reported for Lu3+- water cluster in vacuo and with a polarizable dielectric continuum (PC) model including the bulk solvent implicitly. The bond distance and angle for [Lu(OH2)8]3+ within the PC are in good agreement with data from structural experiments. The DFT frequencies for the Lu-O modes of [Lu(OH2)8]3+ and its deuterated analog [Lu(OD2)8]3+ in a PC are in fair agreement with the experimental ones. The calculated hydration enthalpy of Lu3+ (aq) is slightly lower than the experimental value.

A Study of Uranyl (VI) Chloride Complexes in Aqueous Solutions under Hydrothermal Conditions using Raman Spectroscopy

MRS Advances ◽  
2020 ◽  
Vol 5 (51) ◽  
pp. 2623-2629
Author(s):  
Diwash Dhakal ◽  
Nadib Akram ◽  
Robert A. Mayanovic ◽  
Hakim Boukhalfa ◽  
Hongwu Xu
Keyword(s):  
Raman Spectroscopy ◽  
Nuclear Waste ◽  
Nuclear Reactor ◽  
Aqueous Media ◽  
Chloride Concentration ◽  
Spent Fuel ◽  
Hydrothermal Conditions ◽  
Chloride Complexes ◽  
Complex Species ◽  
Uranyl Chloride

ABSTRACTThe transport and deposition of uranium under hydrothermal conditions in the Earth’s crust has been a subject of ongoing study but is yet to be completely understood. In addition, there is little known about the fate of nuclear waste, consisting of uranium from spent fuel and other radioactive materials, upon storage in repositories or in nuclear reactor facilities. Because the nuclear waste often comes in contact with aqueous fluids in storage environments, studies of uranyl complexation with chloride and other ligands in aqueous media, to high temperature and pressure conditions, are needed. The primary purpose of this study was to investigate the speciation of aqueous uranyl (VI) chloride complexes, in solutions having a 0.05 M uranyl concentration and [Cl] concentrations ranging from 0.2 M to 6 M, under hydrothermal conditions. The aqueous uranyl chloride complexes in the samples were studied using Raman spectroscopy and the hydrothermal diamond anvil cell (HDAC), at temperatures up to 500 °C and pressures up to ~ 0.5 GPa. The uranyl bond stretching band feature occurring in the ~810 to 870 cm-1 region was fitted using the Voigt peak shape to determine the speciation of the equilibrium uranyl chloride complexes present in the samples. As expected, the n integer value of the UO2Cln+2-n complex species increases with the increase in temperature and chloride concentration, generally trending toward charge neutrality at high temperatures.

Kristall- und Molekülstruktur des dimeren (Tetramethylcyclobutadien)dibromo-nickel(II) / Crystal and Molecular Structure of the Dimeric (Tetramethylcyclobutadiene)dibromo-nickel(II)

1979 ◽  
Vol 34 (6) ◽  
pp. 859-862 ◽  
Author(s):  
Ulf Thewalt ◽  
Reinhard Hemmer ◽  
Hans Albert Brune
Keyword(s):  
Average Distance ◽  
Bond Distance ◽  
Nickel Atom ◽  
Chloro Complex ◽  
Monoclinic Space Group ◽  
Ring Plane ◽  
Compound A ◽  
X Ray ◽  
Crystallographic Symmetry ◽  
Limits Of Error

Abstract The title compound, A, has been prepared from the corresponding chloro complex by reaction with potassium bromide in aqueous solution. A crystallizes in the monoclinic space group P21/n with Z = 2 and lattice parameters a = 11.748(5), b = 10.419(4), c = 8.383(4) Å and β = 95.35(5)°. An X-ray analysis shows that A posseses crystallographic symmetry 1̄, that within the limits of error, the π-bonded cyclobutadiene ring is a square with an average C-C bond distance of 1.464 Å, and that the methyl groups are displaced away from the nickel atom, the average distance between the ring plane and the methyl C atoms being 0.20 Å.

scholarly journals Determination of the Cu(III)–OH Bond Distance by Resonance Raman Spectroscopy Using a Normalized Version of Badger’s Rule

2017 ◽  
Vol 139 (12) ◽  
pp. 4477-4485 ◽  
Author(s):  
Andrew D. Spaeth ◽  
Nicole L. Gagnon ◽  
Debanjan Dhar ◽  
Gereon M. Yee ◽  
William B. Tolman
Keyword(s):  
Raman Spectroscopy ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Bond Distance

scholarly journals Cupric and Chloride Ions: Leaching of Chalcopyrite Concentrate with Low Chloride Concentration Media

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 639 ◽  
Author(s):  
Cynthia M. Torres ◽  
Yousef Ghorbani ◽  
Pía C. Hernández ◽  
Francisca J. Justel ◽  
Matías I. Aravena ◽  
...  
Keyword(s):  
Chloride Concentration ◽  
Xrd Analysis ◽  
Formation Constants ◽  
Chloride Ions ◽  
Chloro Complex ◽  
Copper Extraction ◽  
Chloro Complexes ◽  
Complex Species ◽  
Leaching Solution ◽  
Chalcopyrite Concentrate

In this paper, the effect of the cupric and chloride ions concentrations on copper dissolution from chalcopyrite concentrate was studied in acidified media. Variables included three different concentrations of Cu2+ (0.5, 1.5, and 2.5 g L−1), four different concentrations of Cl− (0, 5, 7, and 10 g L−1), two different pH values of 1 and 2, and a constant temperature of 60 °C. Results indicated that addition of Cl− to the system improves copper extractions, especially at higher concentrations of Cu2+. Initial copper concentrations in the leaching solution did not significantly affect the copper extraction when Cl− was not present. Better copper extractions were obtained at pH 1 as compared with pH 2. As the Cu2+ and Cl− concentrations were increased, higher values of redox potential were obtained. According to the formation constants of the chloro-complexes, the predominant species in the Cu2+/Cl− system in the studied interval were CuCl+ and Cu2+. Using a model of copper speciation in the experimental range predicted for a single copper concentration with increasing Cl− concentration, the Cu2+ concentration decreased significantly while the concentration of the chloro-complex species CuCl+ increased. In the leached residue, evidence of sulfur formation was found using SEM and corroborated by XRD analysis. When chloride is present in the medium, the amounts of copper and iron in the residue decrease, confirming a positive effect of chloride on the extraction of copper from concentrate for the studied conditions.

Photochemical Evolution of Interstellar/Precometary Organic Material

1997 ◽  
Vol 161 ◽  
pp. 23-47 ◽  
Author(s):  
Louis J. Allamandola ◽  
Max P. Bernstein ◽  
Scott A. Sandford
Keyword(s):  
Origin Of Life ◽  
Building Blocks ◽  
Complex Species ◽  
Infrared Observations ◽  
Interstellar Ice ◽  
Polycyclic Aromatic ◽  
Ultraviolet Photolysis ◽  
The Origin Of Life ◽  
Simple Molecules ◽  
Complex Organic

AbstractInfrared observations, combined with realistic laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the building blocks of comets. Since comets are thought to be a major source of the volatiles on the primative earth, their organic inventory is of central importance to questions concerning the origin of life. Ices in molecular clouds contain the very simple molecules H2O, CH3OH, CO, CO2, CH4, H2, and probably some NH3and H2CO, as well as more complex species including nitriles, ketones, and esters. The evidence for these, as well as carbonrich materials such as polycyclic aromatic hydrocarbons (PAHs), microdiamonds, and amorphous carbon is briefly reviewed. This is followed by a detailed summary of interstellar/precometary ice photochemical evolution based on laboratory studies of realistic polar ice analogs. Ultraviolet photolysis of these ices produces H2, H2CO, CO2, CO, CH4, HCO, and the moderately complex organic molecules: CH3CH2OH (ethanol), HC(= O)NH2(formamide), CH3C(= O)NH2(acetamide), R-CN (nitriles), and hexamethylenetetramine (HMT, C6H12N4), as well as more complex species including polyoxymethylene and related species (POMs), amides, and ketones. The ready formation of these organic species from simple starting mixtures, the ice chemistry that ensues when these ices are mildly warmed, plus the observation that the more complex refractory photoproducts show lipid-like behavior and readily self organize into droplets upon exposure to liquid water suggest that comets may have played an important role in the origin of life.

Raman spectroscopy and X-ray diffraction of lithium niobate at temperatures up to 1300○-4.80pt○C

2005 ◽  
Vol 126 ◽  
pp. 101-105 ◽  
Author(s):  
B. Moulin ◽  
L. Hennet ◽  
D. Thiaudière ◽  
P. Melin ◽  
P. Simon
Keyword(s):  
Raman Spectroscopy ◽  
Lithium Niobate ◽  
X Ray Diffraction ◽  
X Ray
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