Journal articles: 'Ion solutions – Spectra'

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Watling, Helen. "Spectroscopy of Concentrated Sodium Aluminate Solutions." Applied Spectroscopy 52, no. 2 (February 1998): 250–58. http://dx.doi.org/10.1366/0003702981943310.

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Sodium aluminate solutions have been investigated by infrared absorption and Raman scattering in a broad concentration range in order to detect possible changes in aluminate ion species and distribution. Concentration-dependent changes in spectra include shifts in frequency at maximum band intensity, a loss of proportionality in band intensities, and the appearance of new vibrational bands or the increased asymmetry of existing ones. Changes in infrared spectra correlate well with those observed for Raman spectra and are consistent with the presence of more than one aluminate ion species in equilibrium in concentrated aluminate solutions. Assuming that the observed effects are due to changed solution speciation, it is found that the maximum concentration of Al(OH)4 occurs in solutions of 4–5 M aluminum, and that other species become relatively more abundant as the aluminum concentration is increased. Comparison of solution spectra with spectra of crystalline aluminates indicates that new species are likely to be oligomeric and polymeric anions in which aluminum is mainly 4-coordinate, but the possibility of low concentrations of aluminate species containing 6-coordinate aluminum cannot be excluded.

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Lin, Jie, Jing Zhou, and Chris W. Brown. "Identification of Electrolytes in Aqueous Solutions from Near-IR Spectra." Applied Spectroscopy 50, no. 4 (April 1996): 444–48. http://dx.doi.org/10.1366/0003702963906096.

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Dissolution of electrolytes causes characteristic changes in the near-IR spectrum of water. These changes result from a decrease in the concentration of water; charge-dipole interactions between ions and water molecules; formation of hydrogen bonds between oxygen or nitrogen atoms in some ions and water molecules; production of H+ and OH− ions from dissociation and hydrolysis; absorptions due to OH, NH, and CH groups in some ions; and intrinsic colors of some transition metal ions. Changes in spectra were used for identification of electrolytes in aqueous solutions. Near-IR spectra of 71 solutions of single electrolytes were measured and used to develop a spectral library. This near-IR spectral library was processed with principal component regression (PCR) and used for the identification of single and multiple electrolytes in aqueous solutions with the use of their spectra. Most of the unknown electrolytes were identified correctly. For the others, very similar electrolytes were selected with one ion identified correctly. The near-IR spectral library of aqueous solutions of electrolytes can be used as a simple and fast approach for the identification of electrolytes.

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James, DW, and PG Cutler. "Ion Ion Solvent Interactions in Solution .XI. Spectroscopic Studies of Group-2 Perchlorates in Acetone." Australian Journal of Chemistry 39, no. 1 (1986): 149. http://dx.doi.org/10.1071/ch9860149.

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Solutions of Mg(ClO4)2 and Sr (ClO4)2 in acetone have been studied at various concentrations up to saturation by using infrared absorption, Raman scattering and multinuclear n.m.r (1H, 13C, 17O, 25Mg, 35Cl). Solvation numbers of c. 4.5 (Mg2+) and c. 5.5 (Sr2+) were determined from component band analysis of the c. 800 cm-1 acetone band in the Raman spectra. The solvent shell about the Mg2+ had a high level of steric crowding. There was a small amount of solvent-shared ion-pair formation at all oncentrations in solutions of Mg(ClO4)2 which showed little concentration dependence. In solutions of Sr (ClO4)2 there was evidence for the formation of both solvent-shared associated-ion species and ion-contact species. The solvent-shared species appeared to have two alternative configurations in one of which the anion was both polarized and highly hindered. There was a salt-promoted reaction in which the perchlorate was reduced to chloride and the solution darkened. This reaction prevented the use of Raman spectra to quantify the association equilibria.

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Elbers, G., and G. Lehmann. "Electron Paramagnetic Resonance and Optical Absorption Spectra of VO2+ in CsCl Single Crystals." Zeitschrift für Naturforschung A 40, no. 5 (May 1, 1985): 511–15. http://dx.doi.org/10.1515/zna-1985-0517.

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In vanadium-doped CsCl crystals grown from aqueous solutions anisotropic EPR spectra due to VO2+ are observed and analyzed at room temperature. Evidence is presented that isotropic spectra of this ion observed in this and other compounds are due to inclusions of growth solution and not to rapid rotation of the vanadyl ion in the solid as normally assumed. At 77 K a well resolved vibrational progression of about 820 cm −1 is observed in the first ligand field band of this ion. The optical absorption spectra indicate the presence of a second valence state of vanadium, most likely V3+, in varying proportions depending on the crystal growth temperature.

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Shaver, Jeremy M., Kenneth A. Christensen, Jerilyn A. Pezzuti, and Michael D. Morris. "Structure of Dihydrogen Phosphate Ion Aggregates by Raman-Monitored Serial Dilution." Applied Spectroscopy 52, no. 2 (February 1998): 259–64. http://dx.doi.org/10.1366/0003702981943329.

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The aggregation of dihydrogen phosphate ion has been studied by Raman spectroscopy during serial dilution of highly concentrated (>5 M) solutions. Factor analysis has been used to recover monomer and aggregate spectra from families of 600–2000 spectra obtained during dilution to about 0.1 M. Spectra of the free aquated dihydrogen phosphate ion and its dimer, trimer, and tetramer have been obtained. There is some evidence for the existence of longer chain aggregates. The serial dilution procedure has been verified by dilution of 2.3 M glycine solution. Only spectra of monomer and dimer ions are recovered. For the well-understood glycine system, the band positions and intensities and the dimerization concentration-dependence are in agreement with previously reported values.

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Hijji, Yousef Mohammad, Hani Darwish Tabba, Rajeesha Rajan, Hamzeh Mohammad Abdel-Halim, Musa Ibrahim El-Barghouthi, and Hutaf Mustafa Baker. "Selective colorimetric molecular probe for cyanide ion detection in aqueous solution." European Journal of Chemistry 9, no. 4 (December 31, 2018): 338–46. http://dx.doi.org/10.5155/eurjchem.9.4.338-346.1777.

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5-Nitro-2-hydroxybenzaldehyde (1) demonstrated to be a sensitive, and a selective molecular probe for cyanide ion (CN-) in aqueous media. In acetonitrile, compound 1 shows sensitivity and selectivity for cyanide, acetate and fluoride, in comparison to other investigated anions using both visual and spectroscopic means. In aqueous solution, the color becomes intense yellow upon addition of cyanide, while acetate showed this effect to a much lower extent. Significant spectral changes were also detected with the appearance of two new absorption bands at 358 and 387 nm. This was accompanied by concomitant intensity decrease for the band at 314 nm. Fluoride, dihydrogen phosphate, chloride, bromide, perchlorate, and azide showed negligible color and spectral changes for the probe in aqueous solutions. On the other hand, hydrogen sulfate caused fainting of the yellow color and gave a spectrum similar to that of the sensor in polar aprotic solvents. The cyanide ion was detected at micro molar levels in aqueous solutions with a stoichiometry of 1:1 for CN: probe in acetonitrile as the solvent. Cyanide, hydroxide, acetate, fluoride and dihydrogen phosphate showed identical changes to color and spectra, indicating a hydrogen bonding and a deprotonation mechanism.

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Kurgyis, Bálint, and Máté Csanád. "A Particle Emitting Source From an Accelerating, Perturbative Solution of Relativistic Hydrodynamics." Universe 5, no. 9 (September 4, 2019): 194. http://dx.doi.org/10.3390/universe5090194.

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The quark gluon plasma is formed in heavy-ion collisions, and it can be described by solutions of relativistic hydrodynamics. In this paper we utilize perturbative hydrodynamics, where we study first order perturbations on top of a known solution. We investigate the perturbations on top of the Hubble flow. From this perturbative solution we can give the form of the particle emitting source and calculate observables of heavy-ion collisions. We describe the source function and the single-particle momentum spectra for a spherically symmetric solution.

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Alam, M. Kathleen, James E. Franke, Thomas M. Niemczyk, John D. Maynard, Mark R. Rohrscheib, M. Ries Robinson, and R. Philip Eaton. "Characterization of pH Variation in Lysed Blood by Near-Infrared Spectroscopy." Applied Spectroscopy 52, no. 3 (March 1998): 393–99. http://dx.doi.org/10.1366/0003702981943572.

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Near-infrared spectra (1300–2500 nm) collected from lysed blood solutions were shown to correlate with the pH of the solutions measured potentiometrically. Cross-validated partial least-squares (PLS) models were developed from these spectral data, which provided standard error of prediction (SEP) values below 0.05 pH units for a pH range of 1.0 (6.8–7.8). Experiments were designed to eliminate possible correlation between pH and other components in the blood in order to ensure that variations in the spectral data correlated to pH were due to hydrogen ion changes only. Further work was performed to discern the primary source of pH information in the lysed blood spectra by using spectra collected from plasma and histidine solutions. The blood, plasma, and histidine data sets were compared with the use of loading vectors from principal component analysis (PCA). These loading vectors show that variations in the spectra of the titrated amino acid histidine mimic those seen in lysed blood, but not those seen in plasma. These results suggest that histidine residues of hemoglobin are providing the spectral variation necessary for pH modeling in the lysed blood solutions. It is further shown that the observed pH-sensitive histidine bands do not arise from the exchangeable proton on the imidazole ring of histidine; rather they arise from the variation in the C–H bonds of the C2 and/or the C4 carbons of the imidazole ring as they are influenced by the titration of the nitrogen-bound proton of the imidazole ring.

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Nakahara, Masaumi, Yuichi Sano, and Kazunori Nomura. "Influence of plutonyl ion on electrochemical characterization of zirconium in plutonium nitrate solutions." Radiochimica Acta 108, no. 9 (September 25, 2020): 701–6. http://dx.doi.org/10.1515/ract-2019-3228.

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AbstractWith the aim of evaluating the corrosion behavior of a Pu evaporator made from Zr in the Rokkasho Reprocessing Plant (RRP), the electrochemical characterization of Zr was investigated in Pu nitrate solutions. Before and after experiments, spectra of Pu nitrate solutions were recorded, and Pu4+ was oxidized to PuO22+ by heating these solutions. The ratio of PuO22+ in 3 mol dm−3 HNO3 was higher than that in 7 mol dm−3 HNO3 in our experiments. The maximum open circuit potential of Zr in the Pu nitrate solution was approximately 1 V in the Pu nitrate solution containing 7 mol dm−3 HNO3. However, there were no significant changes at high PuO22+ concentrations, and this value remained below the passivity breakdown potential under our experimental conditions. In this study, Zr showed high corrosion resistance, even though many PuO22+ ions existed in the Pu nitrate solution containing 7 mol dm−3 HNO3.

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10

Chen, Guo Bao, Hong Ying Yang, and Hai Jun Li. "An In Situ Characterization for the Bioleaching Process of Natural Pyrite Using Electrochemical Noise Technique." Advanced Materials Research 1130 (November 2015): 268–72. http://dx.doi.org/10.4028/www.scientific.net/amr.1130.268.

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An in situ characterization has been carried out for several active systems (sulfuric acid, ferric iron, 9k medium and bioleaching solutions) to investigate the bioleaching process of natural pyrite using electrochemical noise (ECN) technique. Spectral noise impedance spectra obtained from power spectral density (PSD) plots for the different systems were compared. It has been observed that the bioleaching system obtained the lowest noise resistance Rsn 0.101MΩ. The reaction mechanism was proposed based on experimental data analysis. The bioleaching process of natural pyrite has been identified as the main function of bio-battery reactions, which distinguishes from the chemical oxidation reaction for the ferric ion and 9k solutions.

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11

Drogobuzhskaya, Svetlana V., Anna A. Shirokaya, and Sergey A. Solov’ev. "SORPTION EXTRACTION OF PLATINUM METALS FROM CHLORIDE – SULFATE AND SULFATE ACIDIC SOLUTIONS BY POLYACRYLONITRILE FIBERS FIBAN." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 62, no. 11 (November 20, 2019): 117–25. http://dx.doi.org/10.6060/ivkkt.20196211.5982.

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The sorption of platinum group metals by fibers FIBAN AK-22 and A-5 from acidic chloride-sulfate and sulfate solutions was studied under static conditions. FIBAN contains primary, secondary and tertiary amino groups. The degree of extraction of platinum metals is calculated. The optimal conditions of sorption from the model solutions are determined. The influence of the temperature regime on the sorption process is established. It is shown, that all platinum group metals are quantitatively extracted from acidic chloride-sulfate solutions by fiber FIBAN AK-22 regardless of the concentration of chloride ions, H2SO4 and temperature absorption. Extraction exceeds 96% at a concentration of sulfuric acid up to 3 mol/dm3 and chloride ion up to 1 mol/dm3. Extraction of osmium is maximum at a concentration of sulfuric acid and chloride ion 3 mol/dm3. The degree of extraction of platinum group metals on FIBAN A-5 is from 50 to 85% and is maximum at elevated temperature and concentrations of H2SO4 and chloride ion 1 mol/dm3 and decreases with increasing concentration of sulfuric acid. Electronic spectra of platinum metal solutions were obtained and the state of platinum metals in chloride and chloride-sulfate solutions was estimated. After the introduction of sulfuric acid into the system, changes in the electronic spectra of platinum (IV), ruthenium and osmium solutions were noted. The spectra of palladium, rhodium and iridium solutions have not changed. When extracting platinum metals from production sulfate solutions of complex composition with a high content of macro components (Ni, Cu, Fe, Te and Se), the efficiency of fiber AK-22 is shown. The advantages of fiber FIBAN AK-22 over FIBAN A-5 are noted.

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12

KRACHNI, O., L. GUERBOUS, and L. LOUAIL. "EVOLUTION OF LUMINESCENCE SPECTRA OF Ce3+-ION IN THE SOLID SOLUTIONS Ca1-xSrxS." Modern Physics Letters B 20, no. 22 (September 30, 2006): 1405–16. http://dx.doi.org/10.1142/s0217984906011657.

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Luminescence spectra of Ce 3+-ion in Ca 1-x Sr x S solid solutions have been investigated. It has been shown that the evolution of Ce 3+ excitation and emission spectra through the concentration range may be interpreted in correlation with the variations, with the host lattice composition, of the lattice constant, the local structure in the activator neighborhood and the band gap. Under activator excitation, in addition to the two conventional bands, an additional band peaking at about 650 nm was observed (mainly in SrS ) and was related to the contamination of the samples as a consequence of extended storage. Except for this band, the luminescence properties did not change relatively to those obtained previously on the same samples. The most drastic modification affected SrS:Ce 3+, despite the fact that all the samples have been stored in the same conditions.

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13

Schwendt, Peter, and Karol Liščák. "Spectral Investigation of Stability of the Peroxo Complexes M2[V2O2(O2)4H2O] . aq (M = N(CH3)4, N(C4H9)4) in Solutions." Collection of Czechoslovak Chemical Communications 61, no. 6 (1996): 868–76. http://dx.doi.org/10.1135/cccc19960868.

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Infrared spectra of solutions of M2[V2O2(O2)4H2O] . aq (M = N(CH3)4, N(C4H9)4) in heavy water and acetonitrile indicate that in concentrated solutions (c >= 0.5 mol dm-3) the asymmetric structure of the [V2O2(O2)4H2O]2- anion remains preserved for some time. Electronic spectra suggest that in more dilute solutions (c = 10-3-10-4 mol dm-3) of the M2[V2O2(O2)4H2O] . aq complexes in water and acetonitrile the dinuclear ion decomposes faster to [VO(O2)2H2O]-, followed by a relatively slow liberation of the peroxidic oxygen and formation of vanadate ions. The dinuclear complex is more stable in dilute chloroform solutions. The 51V NMR spectrum of an aqueous solution of [N(CH3)4]2[V2O2(O2)4H2O] (c = 1.3 mol dm-3) taken after a partial decomposition suggests the simultaneous presence of [V2O2(O2)4H2O]2-, [VO(O2)2H2O]-, (VnO3n)n- (n = 4, 5, 6), [HmV10O28](6-m)-, and other unidentified species.

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14

Chinh, Nguyen Thuy, Hoang Thai, Trang Do Mai Tran, Tuyet Thi Nguyen, Oanh Nhat Nguyen, Mai Thi Tran, and Trang Thi Thu Nguyen. "ADSORPTION OF MERCURIC ION FROM AQUEOUS SOLUTIONS USING MODIFIED FLY ASH." Vietnam Journal of Science and Technology 56, no. 6 (December 17, 2018): 688. http://dx.doi.org/10.15625/2525-2518/56/6/12664.

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In this study, fly ash was treated with NaOH solution (FAN) before modifying with (3-mercaptopropyl) triethoxysilane - MPTMS (FAMPS). By using FTIR, FESEM, XRD, EDX, and BET techniques, the change in structure, composition and morphology of FAN and FAMPS was evaluated. The FTIR spectra of FAN and FAMPS showed that there is no chemical reaction between the MPTMS and FAN. After modification, the FAMPS has a rough surface with composition difference from the FAN. Mercuric ion adsorption behavior as well as adsorptionisotherm models (Langmuir and Freundlich) of the FAN and FAMPS were also investigated and discussed. Thanks to FAN modification, the mercuric ion removal percent of the FAMPS was higher than that of the FAN. Owing to the adsorption data, Freundlich isotherm modelwas fitted for the mercuric ion adsorption process.

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Robers, B., and M. Stockhausen. "Comparison of ESR Spectra of Two Cu(II) Salts in Some Amide Solutions." Zeitschrift für Naturforschung A 50, no. 8 (August 1, 1995): 779–84. http://dx.doi.org/10.1515/zna-1995-0811.

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Abstract X-band ESR spectra of liquid solutions of Cu(II)nitrate and Cu(II)chloride in N-methyl-formamide and four N,N-disubstituted amides are reported and discussed with respect to the occurrence of ion pairs or higher ionic aggregations. Nitrate solutions allow to distinguish two complex types of moderate asymmetry at most. Chloride solutions indicate a succession of at least three complex types with strongly increasing asymmetry.

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Shen, Yuneng, Gang-Hua Deng, Chuanqi Ge, Yuhuan Tian, Guorong Wu, Xueming Yang, Junrong Zheng, and Kaijun Yuan. "Solvation structure around the Li+ ion in succinonitrile–lithium salt plastic crystalline electrolytes." Physical Chemistry Chemical Physics 18, no. 22 (2016): 14867–73. http://dx.doi.org/10.1039/c6cp02878k.

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Balakin, Alexander A., Alexander F. Dodonov, Mikhail I. Markin, Lyudmila I. Novikova, Ilia V. Soulimenkov, Victor L. Talroze, Bogdan A. Budnik, Kim F. Haselmann, and Roman A. Zubarev. "Polymer Track Membranes for Extraction of Ions from Aqueous Solutions at Atmospheric Pressure." European Journal of Mass Spectrometry 8, no. 2 (April 2002): 79–84. http://dx.doi.org/10.1255/ejms.475.

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The possibility of the application of the electromembrane technique for production of ions of biological molecules at atmospheric pressure is demonstrated. This technique has previously only been used for extraction of ions from liquids directly into vacuum. The membrane technique for ion extraction at atmospheric pressure was tested with both time-of-flight and Fourier transform ion cyclotron resonance mass spectrometers. The mass spectra of intact molecular ions obtained from aqueous solutions of peptides and proteins are presented. The possible mechanisms of non-destructive ion extraction are discussed. The new technique is promising for achieving absolute sensitivity (charging every analyte molecule) and for performing spatially-resolved analysis of liquid biological samples.

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Dietrich, Paul M., Lydia Gehrlein, Julia Maibach, and Andreas Thissen. "Probing Lithium-Ion Battery Electrolytes with Laboratory Near-Ambient Pressure XPS." Crystals 10, no. 11 (November 20, 2020): 1056. http://dx.doi.org/10.3390/cryst10111056.

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In this article, we present Near Ambient Pressure (NAP)-X-ray Photoelectron Spectroscopy (XPS) results from model and commercial liquid electrolytes for lithium-ion battery production using an automated laboratory NAP-XPS system. The electrolyte solutions were (i) LiPF6 in EC/DMC (LP30) as a typical commercial battery electrolyte and (ii) LiTFSI in PC as a model electrolyte. We analyzed the LP30 electrolyte solution, first in its vapor and liquid phase to compare individual core-level spectra. In a second step, we immersed a V2O5 crystal as a model cathode material in this LiPF6 solution. Additionally, the LiTFSI electrolyte model system was studied to compare and verify our findings with previous NAP-XPS data. Photoelectron spectra recorded at pressures of 2–10 mbar show significant chemical differences for the different lithium-based electrolytes. We show the enormous potential of laboratory NAP-XPS instruments for investigations of solid-liquid interfaces in electrochemical energy storage systems at elevated pressures and illustrate the simplicity and ease of the used experimental setup (EnviroESCA).

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Alho, M., C. S. Wedlund, H. Nilsson, E. Kallio, R. Jarvinen, and T. I. Pulkkinen. "Hybrid modeling of cometary plasma environments." Astronomy & Astrophysics 630 (September 20, 2019): A45. http://dx.doi.org/10.1051/0004-6361/201834863.

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Context. The ESA Rosetta probe has not seen direct evidence of a fully formed bow shock at comet 67P/Churyumov–Gerasimenko (67P). Ion spectrometer measurements of cometary pickup ions measured in the vicinity of the nucleus of 67P are available and may contain signatures of the large-scale plasma environment. Aims. The aim is to investigate the possibility of using pickup ion signatures to infer the existence or nonexistence of a bow shock-like structure and possibly other large-scale plasma environment features. Methods. A numerical plasma model in the hybrid plasma description was used to model the plasma environment of a comet. Simulated pickup ion spectra were generated for different interplanetary magnetic field conditions. The results were interpreted through test particle tracing in the hybrid simulation solutions. Results. Features of the observed pickup ion energy spectrum were reproduced, and the model was used to interpret the observation to be consistent with a shock-like structure. We identify (1) a spectral break related to the bow shock, (2) a mechanism for generating the spectral break, and (3) a dependency of the energy of the spectral break on the interplanetary magnetic field magnitude and bow shock standoff distance.

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20

Rahim, Shermin, and John Milne. "Studies on the interaction of selenite and selenium with sulphur donors. Part 4. Thiosulfate." Canadian Journal of Chemistry 74, no. 5 (May 1, 1996): 753–59. http://dx.doi.org/10.1139/v96-082.

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Raman and Se-77 NMR spectroscopy confirm that when selenous acid is reduced by thiosulfate in water selenopentathionate and tetrathionate are formed.[Formula: see text]Depending upon the stoichiometry and pH, two isomers of the selenopentathionate ion, O- and S-bonded, are formed. Insufficiently acid solutions cause decomposition to selenium and tetrathionate ion.[Formula: see text]Fresh solutions prepared from crystalline sodium selenopentathionate and water undergo slow decompositon. NMR and Raman spectra show the presence of both the O-bonded and S-bonded linkage isomers. The O-bonded isomer facilitates the formation of tetrathionate. Addition of thiosulfate to selenotrithionate solution or sulfite to selenopentathionate solution yields trithionate with no indication of dithionate or tetrathionate formation. This suggests that simple S—S bond formation at selenium does not occur but that there may be direct attack of the incoming ligand on the attached ligand. Key words: selenite, thiosulfate, selenopentathionate, Se-77 NMR, Raman spectroscopy, linkage isomerism.

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Andsager, D., J. Hilliard, and M. H. Nayfeh. "Behavior of porous silicon emission spectra during quenching by immersion in metal ion solutions." Applied Physics Letters 64, no. 9 (February 28, 1994): 1141–43. http://dx.doi.org/10.1063/1.110832.

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Jürgensen, Astrid. "X-ray absorption spectroscopy of aqueous solutions in the X-ray energy region from 1800 to 3700 eV." Canadian Journal of Chemistry 87, no. 5 (May 2009): 601–11. http://dx.doi.org/10.1139/v09-023.

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A methodology for the X-ray XANES and EXAFS analyses of aqueous solutions was developed for the Double Crystal Monochromator (DCM) beamline of the Canadian Synchrotron Radiation Facility (CSRF). The technique is based on the implementation of a liquid cell, which is compatible with the standard solid-state sample holding mechanism used at the beamlines of CSRF and the Canadian Light Source (CLS). Aluminized Mylar film with a thickness of 5 μm has been thoroughly investigated for use as a window material for the cell, and found acceptable for the collection of the S, Cl, and K K-edge spectra of ions in aqueous solution, but not for P K-edge or Rb L2,3-edge spectra. Some of the limitations of this methodology, such as diffusion of the solution through the window and the detection limit at low ion concentration, are investigated and discussed.

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Spinner, E., P. Yang, PTT Wong, and HH Mantsch. "The Vibrational-Spectrum of Sodium Propionate CH3CH2CO2Na, CH3CD2CO2Na, CD3CH2CO2Na and CD3CD2CO2Na in Aqueous-Solution and in the Solid-State." Australian Journal of Chemistry 39, no. 3 (1986): 475. http://dx.doi.org/10.1071/ch9860475.

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Infrared absorption spectra of aqueous solutions and KBr discs, reflection spectra of the diluted powders and of an oriented thin film, and Raman spectra of the powdered solids have been measured for CH3CH2CO2Na, CH3CD2CO2Na, CD3CH2CO2Na and CD3CD2CO2Na. Selective deuteration makes possible complete vibrational assignments in the CH and CD stretching regions where band overlap is extensive, but produces complicated changes in 1200- 800 cm-1 range. Average methyl CH stretching frequencies are higher in propionate ion than in paraffins in spite of the interposed methylene group. In the solids the CO stretching vibrations show more frequency splittings than expected for the number of molecules per unit cell (2), and some orientational disorder is indicated. The shape of the anions was not established; there is no evidence indicating the presence of more than one conformation in solution.

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Ball, Sheila, and John Milne. "Studies on the interaction of selenite and selenium with sulfur donors. Part 3. Sulfite." Canadian Journal of Chemistry 73, no. 5 (May 1, 1995): 716–24. http://dx.doi.org/10.1139/v95-091.

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Elemental selenium dissolves in sulfite solution to form selenosulfate ion: Se + SO32− = SeSO32−.The formation constants for this equilibrium at temperatures from 0 to 35 °C are reported for the first time. The isomeric thioselenate anion, SSeO32−, is not, however, produced by the reaction of sulfur with selenite nor is the selenoselenate ion, Se2O32−, formed from selenium and selenite. Selenotrithionate is formed rapidly from the reaction of selenous acid with sulfite and hydrogen sulfite according to: HSeO3− + 3 HSO3− = Se(SO3)22− + SO42− + 2H2O.Two isomers of the selenotrithionate ion are observed by Se-77 NMR and Raman spectroscopy, one with O-bonded Se, Se(OSO2)22−, and the other with S-bonded Se, Se(SO3)22−. Both isomers are formed in reactions with hydrogen sulfite but only the O-bonded isomer is formed in sulfite solutions at ambient temperatures. The Raman and Se-77 NMR spectra of the various sulphur–selenium anions formed are given and the parallel with the reactions of selenous acid and thiols is discussed. Keywords: selenium, sulfite, selenosulfate, selenotrithionate, Se-77 NMR, Raman spectroscopy, equilibria, aqueous solutions.

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Bai, Yun Shan, Lu De Lu, and Jian Chun Bao. "Characterization and their Fluorescence of Fe³⁺-Doped La₂Zr₂O₇ Nanocrystals by a Salt-Assistant Combustion Method." Advanced Materials Research 306-307 (August 2011): 1257–61. http://dx.doi.org/10.4028/www.scientific.net/amr.306-307.1257.

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Nanocrystalline Fe3+-doped La2Zr2O7 series solid solutions were prepared by a convenient salt-assisted combustion process using glycine as fuel. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The results showed the La ion can be partially replaced by Fe ion. The partial substituted products were still single-phase solid solutions and the crystal form remained unchanged. TEM images reveal that the products are composed of well-dispersed square-shaped nanocrystals. The method provides a convenient and low-cost route for the synthesis of nanostructures of oxide materials. The fluorescence of La1.8Fe0.2Zr2O7 nanocrystals was evaluated by the UV-visible absorption spectra and the fluorescence spectra. The results indicate that (LaxFe1-x)2Zr2O7 nanocrystals prepared by this method are a kind of potential fluorescent-emitted material.

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Böhm, Fabian, Vinay Sharma, Gerhard Schwaab, and Martina Havenith. "The low frequency modes of solvated ions and ion pairs in aqueous electrolyte solutions: iron(ii) and iron(iii) chloride." Physical Chemistry Chemical Physics 17, no. 29 (2015): 19582–91. http://dx.doi.org/10.1039/c5cp03157e.

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THz/FIR spectra of aqueous FeCl₂ and FeCl₃ solutions have been dissected into the contributions of different complex species, which were then used to identify the composition of unknown mixed solutions.

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Ozeki, Toru, Kazuko Murata, Hiroshi Kihara, and Seiichiro Hikime. "Studies on the Interaction of Molybdate Ion and Magnesium Ion Observed in the Raman Spectra of the Mixture Solutions." Bulletin of the Chemical Society of Japan 60, no. 10 (October 1987): 3585–89. http://dx.doi.org/10.1246/bcsj.60.3585.

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Vasic, Vesna, Suzana Premovic, Mira Cakar, Bojan Radak, and Gordana Milovanovic. "Spectrophotometric investigations of the reaction between gold(III) and potassium iodide." Journal of the Serbian Chemical Society 65, no. 5-6 (2000): 345–52. http://dx.doi.org/10.2298/jsc0006345v.

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The equilibria of the complex formation between AuCl4-n(OH)n - and I- was studied spectrophotometrically in aqueous solutions containing KI:Au(III)?2 in the acidity range from 1 M HCl to pH 7 at 25?C. From the hydrogen ion and Cl-ion dependence of the absorption spectra, it was found that AuCl2I2 - and Au(OH)2I2 - complexes were formed. The equilibrium constants of complex formation were determined.

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29

Cho, Keunchang, Yong Soon Jang, Myoung-Seon Gong, Kwan Kim, and Sang-Woo Joo. "Determination of Cyanide Species in Silver and Gold Plating Solutions by Raman Spectroscopy." Applied Spectroscopy 56, no. 9 (September 2002): 1147–51. http://dx.doi.org/10.1366/000370202760295377.

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Raman spectra of silver and gold cyanide complexes have been investigated in order to determine the speciation of aqueous plating solutions. We have examined the ionic species in the concentration ranges of 0.003 ∼ 0.5 M for the metals and 0.1 ∼ 2.5 M for the cyanide ion. When the initial concentration of [Ag(CN)2]− was below ∼0.1 M, [Ag(CN)4]3– did not appear prominent even at high CN−/Ag(I) ratios of 3 ∼ 10, differing from the case of previous infrared measurements. Concentrations of the metal cyanide complexes and CN− ion as low as 0.001 ∼ 0.01 M could be determined with an error of less than ∼3% from the analysis of Raman peak areas.

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Živanović, Slavoljub C., Ružica S. Nikolić, and Goran M. Nikolić. "The Influence of Mg(II) and Ca(II) Ions on Rutin Autoxidation in Weakly Alkaline Aqueous Solutions." Acta Facultatis Medicae Naissensis 33, no. 3 (September 1, 2016): 163–71. http://dx.doi.org/10.1515/afmnai-2016-0018.

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Summary Rutin (quercetin-3-O-rutinoside) is one of the most abundant bioflavonoids with various biological and pharmacological activities. Considering the ubiquitous presence of Mg(II) and Ca(II) ions in biological systems we decided to investigate their influence on the autoxidation of rutin in weakly alkaline aqueous solutions. Changes in UV-Vis spectra recorded during the rutin autoxidation in aqueous solution at pH 8.4 revealed that this process was very slow in the absence of metal ions. The presence of Mg(II) and, especially Ca(II) ion, increased the transformation rate of rutin. UV-Vis spectra recorded after prolonged autoxidation indicated the formation of humic acidlike products in the presence of Mg(II) and Ca(II) ions. Four new compounds formed during the initial stage of rutin autoxidation in the presence of Mg(II) and Ca(II) ions were detected by HPLCDAD. Based on the analysis of their DAD UV-Vis spectra and comparison of their retention times with the retention time value for rutin, we concluded that the initial rutin transformation products were formed by the water addition on double bond in ring C and hydroxylation of ring B. A very small decrease of the initial rutin concentration (4%) was observed by HPLC-DAD in the absence of metal ions for the period of 90 minutes. However, rutin concentration decrease was much larger in the presence of Mg(II) and Ca(II) ions (14% and 24%, respectively). The more pronounced effect of Ca(II) ion on the rutin autoxidation may be explained by the stronger binding of Mg(II) ion to rutin and thus greater stabilizing effect on reaction intermediates caused by its higher ionic potential (charge/ionic radius ratio) in comparison to Ca(II) ion. The results of this study may contribute to the better understanding of interactions of Mg(II) and Ca(II) ions with natural phenolic antioxidants which are important for their various biological activities.

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31

Sastry, M. I. S., and Surjit Singh. "Raman spectral studies of solutions of alkali metal perchlorates in dimethyl sulfoxide and water." Canadian Journal of Chemistry 63, no. 7 (July 1, 1985): 1351–56. http://dx.doi.org/10.1139/v85-231.

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Raman spectra of solutions of alkali metal perchlorates in dimethyl sulfoxide (DMSO) in the Cl—O, C—S, and S=O stretching regions, as well as of perchlorates in aqueous solutions in the Cl—O stretching region are reported. The results are discussed in terms of half-bandwidths, relative intensities, and depolarization ratios. For H2O the half-bandwidth of the Cl—O stretching band at ~935 cm−1 is almost double the value in DMSO solutions. Solutions of perchlorates in DMSO show two symmetric bands in the Cl—O stretching region, whereas in aqueous solutions only one band is observed. The half-bandwidths in perchlorate solutions in DMSO for the C—S stretching band increase with increase in concentration of perchlorate compared to that of liquid DMSO. The band contours in the S=O stretching region in DMSO solutions also show significant changes. These observations are explained on the basis of formation of ion pairs of metal perchlorates in solutions of DMSO and ion hydrates in the case of aqueous solutions.

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32

Rull, Fernando. "Raman Spectroscopic Study of the Ion Association of Lithium Sulfate Aqueous Solutions." Zeitschrift für Naturforschung A 50, no. 2-3 (March 1, 1995): 292–300. http://dx.doi.org/10.1515/zna-1995-2-322.

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Abstract A Raman spectroscopic study of Li2SO4 aqueous solutions as function of concentration and temperature was performed. The dynamic properties of the sulfate ions were studied by a band profile analysis of their internal modes using Fourier transform methods. This analysis reveals the perturbation of the SO4-2 vibrations due to ionic interactions. From the v1 (SO4-2) band profile the spectroscopic ionic association constant was calculated in the range from 5 to 80 °C. The large difference found between the values thus obtained for the association constant and the values obtained from macroscopic measurements is interpreted, assuming that Raman spectra reflect only the short-range forces acting on the ions. Using the Bjerrum equation to calculate the contribution for the long-range forces, good agreement is found between the spectroscopic and macroscopic results.

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Li, Ying-Sing, Jingcai Cheng, and Yu Wang. "Surface-enhanced Raman spectra of dyes and organic acids in silver solutions: chloride ion effect." Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 56, no. 11 (October 2000): 2067–72. http://dx.doi.org/10.1016/s1386-1425(00)00268-7.

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34

Bel'tyukova, S. V., N. V. Rusakova, Yu V. Korovin, Yu A. Popkov, N. A. Nazarenko, and S. M. Chesnov. "Band intensity for the spectra of Gd(III) ion absorption and luminessence in complexonate solutions." Journal of Applied Spectroscopy 63, no. 5 (September 1996): 644–50. http://dx.doi.org/10.1007/bf02606855.

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35

Rinne, Klaus F., Stephan Gekle, and Roland R. Netz. "Dissecting ion-specific dielectric spectra of sodium-halide solutions into solvation water and ionic contributions." Journal of Chemical Physics 141, no. 21 (December 7, 2014): 214502. http://dx.doi.org/10.1063/1.4901927.

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36

Bock, Hans, and Markus Kleine. "Elektronentransfer und Ionenpaar-Bildung, 48 [1] Titrationen von Tetraphenyl-p-benzochinon mit Natrium- und Kaliummetall in aprotischen Lösungen / Electron Transfer and Ion Pair Formation, 48 [ 1 ] Titrations of Tetraphenyl-p-benzoquinone with Sodium and Potassium Metals in Aprotic Solutions." Zeitschrift für Naturforschung B 51, no. 9 (September 1, 1996): 1222–28. http://dx.doi.org/10.1515/znb-1996-0902.

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UV/VIS and ESR spectra of electron transfer reaction products in aprotic (cH⊕ < 0,1 ppm) solution can be measured in an especially designed and sealed glass apparatus and provide information on unknown facets of the microscopic pathway through the network of interdependent equilibria. For tetraphenyl-p-benzoquinone in tetrahydrofuran, single-electron reduction by a sodium metal mirror produces a red solution and, unexpectedly, after addition of 2.2.2. cryptand, contact with a potassium metal mirror generates a green (!) one. For both, ESR/ENDOR spectra prove the presence of tetraphenyl-p-benzoquinone radical anion. UV/VIS measurements provide the clue: In the equilibrium revealed by repetetive spectra recording, M·⊖solv + Me⊕solv ⇄ [M·⊖···Me⊖]solv, the radical anion is green (vm = 16900 cm-1) and the contact ion pair red (vm=18900 cm-1 ). On ion pair formation, therefore, the excitation energy of the radical anion increases by 0.25 eV.

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Littlejohn, David, Susan A. Walton, and Shih-Ger Chang. "A Raman Study of the Isomers and Dimer of Hydrogen Sulfite Ion." Applied Spectroscopy 46, no. 5 (May 1992): 848–51. http://dx.doi.org/10.1366/0003702924124592.

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Raman spectra of aqueous solutions of hydrogen sulfite ion (SHO3−) were collected over temperatures of 275 to 340 K. The change in peak intensities with temperature was used to assign peaks to the hydrogen sulfite isomers. The HOSO2− isomer has a peak at 1023 cm−1 and the HSO3− isomer has a peak at 1052 cm−1. The relative strengths of the peaks were determined and used to measure the equilibrium quotients for hydrogen sulfite ion. Q1 = [HOSO2−]/[HSO3−] Q2 = [S2O52-]/[SHO3−]2 No evidence was found for a hydrogen sulfite dimer other than disulfite ion, S2O52-.

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38

Rudolph, Wolfram W., and Gert Irmer. "Raman spectroscopic characterization of light rare earth ions: La3+, Ce3+, Pr3+, Nd3+and Sm3+– hydration and ion pair formation." Dalton Transactions 46, no. 13 (2017): 4235–44. http://dx.doi.org/10.1039/c7dt00008a.

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Raman spectra of aqueous La³⁺, Ce³⁺, Pr³⁺, Nd³⁺and Sm³⁺– perchlorate solutions were measured and weak strongly polarized Raman bands were detected at 343 cm⁻¹, 344 cm⁻¹, 347 cm⁻¹, 352 cm⁻¹and 363 cm⁻¹, respectively. Figure: Raman spectrum of a 0.202 mol L⁻¹Ce(ClO₄)₃solution.

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39

Rusakova, Natalya, Nikolay Semenishyn, and Yuriy Korovin. "Heteronuclear lanthanide-containing complexes on the base of modified porphyrins and their luminescent properties." Journal of Porphyrins and Phthalocyanines 14, no. 02 (February 2010): 166–69. http://dx.doi.org/10.1142/s1088424610001817.

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The mono- and heteronuclear complexes of the general formula M-ATPP-Ln-L ( Ln = Yb , Lu; M = Zn , Cu , 2H ; ATPP - mono-p-aminotetraphenylporphyrin; L = EDTA - ethylenediaminetetraacetic acid or DTPA - diethylenetriaminepentaacetic acid) were prepared and characterized by elemental analysis, MS, 1H NMR, UV-vis and luminescent spectra. In all compounds the lanthanide ion is coordinated by aminopolycarboxylic fragment only. The spectra of metal complexes were compared with those of free-base porphyrins. Luminescence studies showed that porphyrin fragment of ligands absorbed the visible light and transferred the energy to lanthanide (ytterbium) ion emitting in the near IR-region. Efficiency of the 4f-luminescence has been determined for d-f-metal containing porphyrin complexes in comparison with the mononuclear Yb-containing complexes in DMF solutions.

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40

Kunkely, Horst, and Amd Vogler. "Optical Outer-Sphere Charge Transfer in Ion Pairs with Peroxoborate as Donor." Zeitschrift für Naturforschung B 55, no. 12 (December 1, 2000): 1121–23. http://dx.doi.org/10.1515/znb-2000-1203.

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Peroxoborate and the oxidizing cations [Co(NH3)6]3+, [Ru(NH3)6]3+ and N,N′-dimethyl-4,4′- bipyridinium2+ (paraquat2+) form ion pairs in aqueous solutions which display outer-sphere charge transfer (OSCT) bands in their absorption spectra. This CT involves an electronic transition from the peroxo substituents of peroxoborate to the cations. When 10,10′-dimethyl- 9,9′-biacridinium2+ (lucigenin2+, LG2+) is used as an electron acceptor an OSCT absorption is not observed owing to the instability of the ion pair LG2+ peroxoborate which undergoes a chemiluminescent conversion to N-methylacridone.

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41

Du, Lili, Xin Lan, Zhiping Yan, Ruixue Zhu, and David Phillips. "Time-Resolved Spectroscopic Study of N,N-Di(4-bromo)nitrenium Ions in Selected Solutions." Molecules 23, no. 12 (December 3, 2018): 3182. http://dx.doi.org/10.3390/molecules23123182.

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Nitrenium ions are important reactive intermediates in chemistry and biology. In this work, femtosecond and nanosecond transient absorption (fs-TA and ns-TA) along with nanosecond time-resolved resonance Raman (ns-TR3) experiments were employed to examine the photochemical pathways of N-(4,4′-dibromodiphenylamino)-2,4,6-trimethylpyridinium BF4− (salt (DN) from just absorption of a photon of light to the production of the important N,N-di(4-bromophenyl)nitrenium ion 2. In acetonitrile (MeCN), the formation of halogenated diarylnitrenium ion 2 was observed within 4 ps, showing the vibrational spectra with strong intensity. The nucleophilic adduct reaction of ion 2 with H2O was also examined in aqueous solutions. The direct detection of the unique ortho adduct intermediate 3 shows that there is an efficient and exclusive reaction pathway for 2 with H2O. The results shown in this paper give new characterization of 2, which can be used to design time-resolved spectroscopy investigations of covalent addition reactions of nitrenium ions with other molecules in future studies.

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Ketenoglu, Didem, Georg Spiekermann, Manuel Harder, Erdinc Oz, Cevriye Koz, Mehmet C. Yagci, Eda Yilmaz, et al. "X-ray Raman spectroscopy of lithium-ion battery electrolyte solutions in a flow cell." Journal of Synchrotron Radiation 25, no. 2 (February 21, 2018): 537–42. http://dx.doi.org/10.1107/s1600577518001662.

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The effects of varying LiPF6salt concentration and the presence of lithium bis(oxalate)borate additive on the electronic structure of commonly used lithium-ion battery electrolyte solvents (ethylene carbonate–dimethyl carbonate and propylene carbonate) have been investigated. X-ray Raman scattering spectroscopy (a non-resonant inelastic X-ray scattering method) was utilized together with a closed-circle flow cell. Carbon and oxygenK-edges provide characteristic information on the electronic structure of the electrolyte solutions, which are sensitive to local chemistry. Higher Li+ion concentration in the solvent manifests itself as a blue-shift of both the π* feature in the carbon edge and the carbonyl π* feature in the oxygen edge. While these oxygenK-edge results agree with previous soft X-ray absorption studies on LiBF4salt concentration in propylene carbonate, carbonK-edge spectra reveal a shift in energy, which can be explained with differing ionic conductivities of the electrolyte solutions.

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Gospodchikov, E. D., T. A. Khusainov, and A. G. Shalashov. "Recovery of the Two-Dimensional Ion Distribution Function in a Magnetic Mirror from Measurements of Collective Thomson Scattering Spectra." Plasma Physics Reports 47, no. 6 (June 2021): 503–17. http://dx.doi.org/10.1134/s1063780x21060052.

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Abstract A method is proposed for tomography of the distribution function of energetic ions that are adiabatically trapped in an open magnetic trap, according to the diagnostic data by the method of collective Thomson scattering. This method is based on measurements of the scattering spectra from successive plasma cross sections corresponding to different values of the magnetic-field strength along a single line of force. It is shown that the problem of restoring the ion distribution function in the velocity space from the measurement data in this situation is reduced to an integral equation of the first kind that allows an analytical solution. Several ways to construct exact and approximate solutions of the resulting integral equation are considered.

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44

Brooker, Murray H., and Nanping Wen. "Raman studies of cyanate: Fermi resonance, hydration and hydrolysis to urea." Canadian Journal of Chemistry 71, no. 10 (October 1, 1993): 1764–73. http://dx.doi.org/10.1139/v93-219.

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Raman spectra were measured for potassium cyanate in the solid phase and as aqueous solutions in H2O and D2O for freshly prepared and for aged solutions. The results indicated that the assignment of the Fermi doublet, ν1 and 2ν2, for solid potassium cyanate was reversed from the assignment for the aqueous solution. The Fermi doublet has an associated pair of hot bands at 1191 and 1315 cm−1 which originate from the 638 cm−1 ν2 state, 010. Assignment of the hot bands was confirmed by studies of solid potassium cyanate at liquid-N2 temperature, room temperature, and at 473 K. Raman spectra of aged aqueous potassium cyanate revealed that the cyanate ion hydrolyzed slowly and spontaneously at room temperature (even without added ammonium) to produce urea and a carbamate, carbonate equilibrium mixture in parallel reactions. Hydrolysis of cyanate in aqueous ammonium chloride solution resulted in almost total conversion of cyanate to urea. The reaction was not reversible under ambient conditions. Differences in peak frequencies and half-widths were observed for the cyanate dissolved in H2O compared to solutions in D2O. The results provide evidence for strong hydrogen bonding of cyanate to water and are consistent with greater structure in the D2O solution. Theoretical ab initio calculations indicated that the water molecules hydrogen bond well at both the oxygen and nitrogen atoms of cyanate although the hydrogen bond to nitrogen was found to be slightly stronger.

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45

Smith, Gerald J., Roderick J. Weston, Ying Tang, Yinrong Lu, and Jolon M. Dyer. "Photoproducts of 7-Hydroxycoumarins in Aqueous Solution." Australian Journal of Chemistry 65, no. 10 (2012): 1451. http://dx.doi.org/10.1071/ch12292.

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Near-UV irradiation of aqueous solutions of 7-hydroxy-6-methoxycoumarin (scopoletin) and 6,7-dihydroxycoumarin (esculetin) resulted in the formation of dimers. Substantially greater amounts of the 7-hydroxy-6-methoxycoumarin photodimer were produced compared with that of 6,7-dihydroxycoumarin. Fluorescence spectra indicated that the initial photolytic reaction involves the excited state of the phenolate form of the monomeric coumarin. The electro-spray ionization (ESI) mass spectrum suggested that the major product (with a sodiated quasimolecular ion at m/z 405) from the photolysis of scopoletin in water had formed by oxidative dimerisation and possibly had a 3,3′-bond. A second dimer (with a sodiated quasimolecular ion at m/z 407) was probably a 2 + 2 cyclodimer. This work concluded that photolysis of coumarins in water results in oxidative dimerisation whereas photolysis in the solid state or in organic solvents results in cyclodimerisation. Minor monomeric photoproducts were a dihydroxy-6-methoxycoumarin from 7-hydroxy-6-methoxycoumarin and a trihydroxycoumarin from 6,7-dihydroxycoumarin. During ESI-mass spectrometry (ESI-MS), sodiated quasimolecular ions of the photodimer formed more readily than protonated quasimolecular ions and the sodiated ions did not fragment readily. Protonated quasimolecular ions of the monomeric coumarins formed more readily than their sodiated counterparts and the protonated ions fragmented to create daughter ion spectra that were useful for chemical structural assignment.

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46

Corbeil, Marie-Claude, André L. Beauchamp, Serge Alex, and Rodrigue Savoie. "Interaction of the methylmercury cation with glycine and alanine: a vibrational and X-ray diffraction study." Canadian Journal of Chemistry 64, no. 9 (September 1, 1986): 1876–84. http://dx.doi.org/10.1139/v86-309.

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The complexes (CH3Hg)Gly, (CH3Hg)(L-Ala), and (CH3Hg)(DL-Ala) were prepared by reacting CH3HgOH with glycine (HGly) and alanine (HAla). Crystals of (CH3Hg)(DL-Ala) are monoclinic, space group P21/c, a = 9.460(2), b = 8.794(2), c = 8.723(2) Å, β = 97.49(2)°, Z = 4. The structure was refined on 935 MoKα reflections to R = 0.042. The complex results from displacement of an alanine NH3+ proton by the CH3Hg+ ion, which is linearly bonded to the —NH2 group. An intramolecular Hg … O contact of 2.63 Å is also formed with a carboxylate oxygen. The Raman and infrared spectra of solid (CH3Hg)Gly and (CH3Hg)(L-Ala) are compared with those of the ligands. Raman spectra of aqueous solutions at different pH indicate that the NH2-bonded structure is retained in solution, although no complexation via the carboxylate occurs.

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47

Mohr, Siegfried, Gert Heller, Ulrich Timper, and Karl-Heinz Woller. "Neue Untersuchungen an Borsäureestern von Brenzcatechin und einiger Catecholamine in wäßriger Lösung und an Feststoffen / New Investigations of Boric Acid Esters of Catechole and of Some Catecholamines in Aqueous Solutions and on Solids." Zeitschrift für Naturforschung B 45, no. 3 (March 1, 1990): 308–22. http://dx.doi.org/10.1515/znb-1990-0306.

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The orthoborate ion [B(OH)4]⁻ in aqueous solutions between pH 5 and 12 forms stable boric acid esters with catechole and the catecholamines DOPA, α-methyldopa, dopamine, noradrenaline, adrenaline, and adrenalone. The stoichiometries of the esters in solution, their dependence of pH value and concentration were evaluated by 11B NMR spectra and confirmed by Raman investigations in the catechole system. Additionally, Raman spectra and crystal structure investigations on solid crystalline esters confirm these results. The 1:1 esters show in the 11B NMR spectrum a chemical shift δ of around 8.1 ppm, the 2:1 esters of around 13.5 ppm. The Raman spectra of the catechole ester show lines at 744 cm-1, 826 cm-1, and 1011 cm-1 for the 1:1 ester as well as at 798 cm-1 and 840 cm-1 for the 2:1 ester. Besides the 1:1 and 2:1 ester, a 3:1 compound is found as a solid for catechole. Raman spectra of this compound, unstable in aqueous solution, showed a superposition of the 2:1 ester and free catechole. The crystal structure of the triethylammonium salt, which is monoclinic, space group Cc = Cs4 (No. 9) with a = 925.3(3), b = 1781.1(2), and c = 1444.4(2) pm; β = 94.22(4)°; Ζ = 4; Dc = 1.229 Mg · m-3, shows that two molecules of catechole are esterified with the orthoborate ion in the form of a spiran-like four-coordinated boron atom, while the third molecule of catechole is freely inserted into the crystal. The crystal structure of adrenaloneborate-monohydrate, which is also monoclinic, space group P21/c = C2 h5 (No. 14) with a = 942.4(4), b = 888.1(3), and c = 1337.8(3) pm; β = 96.86(5)°; Ζ = 4; Dc = 1.452 Mg-m-3, shows two condensed rings, the aromatic ring being condensed through the two phenolic O atoms with the boron atom, so building a dioxaborolane ring. The two OH-groups at the boron atom build Η-bridges with the water molecule. It may be a zwitter ion with a negative boron atom and a positive nitrogen atom.

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Lyons, LE, and TL Young. "Alkaline Selenide, Polyselenide Electrolytes: Concentrations, Absorption-Spectra and Formal Potentials." Australian Journal of Chemistry 39, no. 3 (1986): 511. http://dx.doi.org/10.1071/ch9860511.

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Spectrophotometric, titrimetric, electron spin resonance and 77Se nuclear magnetic resonance studies made on the alkaline selenide, selenium electrolyte showed that soluble selenium species existed in four oxidation states, none of the species was a radical, and the mean state of oxidation of the Se-saturated solution was equivalent to Se3.82. It was concluded that the species were Sen2- with n = 1, 2, 3 and 4, or their protonated forms. On the basis of the Nernst equation, we analysed independently (A) the titration Eredox against the mean state of oxidation of the solution and (B) the absorption spectra of solutions with different mean states of oxidation. Thus formal redox potentials E′ were determined as E′12 = -0.935, E′13 = -0.931 and E′14 = -0.914 V against s.c.e. for the couples Se2-, Se22-; Se2-, Se32-; and Se2-, Se42- respectively in 1 mol dm-3 KOH supporting electrolyte at 304 K. It followed that E′23 = -0.919 for Se32-,Se32- and E′34 = -0.778 for Se32-,Se42-. The concentration of each species at each redox potential and the absorption spectrum of each distinct oxidation state were found. Excellent fits and agreement between the two analyses were observed. Ultraviolet absorption spectra showed that the reduced ion was approximately 50% protonated in 1 mol dm-3 KOH supporting electrolyte.

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Hayashi, Tetsusuke, Ping Gu, and Masayuki Watanabe. "Excitonic States of Pb Ion Clusters in Pb1-xCdxI2Solid Solutions Studied with Time-Resolved Emission Spectra." Journal of the Physical Society of Japan 63, no. 6 (June 15, 1994): 2089–92. http://dx.doi.org/10.1143/jpsj.63.2089.

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50

Nikolic, Goran, Milorad Cakic, Zarko Mitic, Ruzica Nikolic, and Ljubomir Ilic. "Correlation between UV-VIS spectra and the structure of Cu(II) complexes with hydrogenated dextran in alkaline solutions." Chemical Industry 59, no. 1-2 (2005): 9–14. http://dx.doi.org/10.2298/hemind0502009n.

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UV-VIS spectrophotometric investigations of Cu(II) complexes with hydroge-nated dextran showed that the complexation of Cu(II)-ions began at pH > 7. The formation of Cu(II) complexes with dextran monomer units was observed at pH 7-12. With further increase in solution pH > 12, the Cu(II)-dextran complex decomposed to Cu(OH)42~-ions and dextran. With increasing solution pH the absorption maximum of complex solutions increased and shifted to shorter wavelength (hypsochromic shift) compared with uncomplexed Cu(II). The UV spectra displayed bathochromic shifts. The changes of UV-VIS spectra with increasing in solution pH confirmed the formation of different kinds of complex species. The correlation between the results of UV-VIS spectrophotometry and the central metal ionligand coordination predicted that the copper binding within the complex depended on the pH and participation H2O molecules. Dextran complexes with Cu(II) were formed by the displacement of water molecules from the coordination sphere of copper by OH groups. The analysis indicated that the Cu(II) center was coordinated to two glucopyranose units of dextran. The spectrophotometric parameters of the investigated complexes were characteristic of a Cu(II)-ion in a square-planar or tetragon ally distorted octahedral coordination.

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Journal articles on the topic 'Ion solutions – Spectra'

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