Photochemistry of Co(sep)3+-oxalate ion pairs: a novel system for dihydrogen evolution from aqueous solutions

1985 ◽  
Vol 24 (6) ◽  
pp. 848-851 ◽  
Author(s):  
Fernando Pina ◽  
Quinto G. Mulazzani ◽  
Margherita Venturi ◽  
Mauro Ciano ◽  
Vincenzo Balzani
Keyword(s):  
Aqueous Solutions ◽  
Ion Pairs ◽  
Oxalate Ion

ChemInform Abstract: PHOTOCHEMISTRY OF CO(SEP)3+-OXALATE ION PAIRS: A NOVEL SYSTEM FOR DIHYDROGEN EVOLUTION FROM AQUEOUS SOLUTIONS

1985 ◽  
Vol 16 (31) ◽  
Author(s):  
F. PINA ◽  
Q. G. MULAZZANI ◽  
M. VENTURI ◽  
M. CIANO ◽  
V. BALZANI
Keyword(s):  
Aqueous Solutions ◽  
Ion Pairs ◽  
Oxalate Ion

Ionization of Water in Concentrated Potassium Halide Media

2000 ◽  
Vol 53 (5) ◽  
pp. 369 ◽  
Author(s):  
Faradj K. Samani ◽  
Stephen G. Capewell ◽  
Pal M. Sipos ◽  
Peter M. May ◽  
Glenn Hefter
Keyword(s):  
Ionic Strength ◽  
Aqueous Solutions ◽  
High Precision ◽  
Excellent Agreement ◽  
Ion Pairs ◽  
Formation Constants ◽  
Glass Electrode ◽  
Ionic Product ◽  
Ionization Of Water ◽  
Potassium Halide

The ionic product of water, pKw = –log[H+][OH–], has been determined as a function of ionic strength (I ) in concentrated aqueous solutions of KCl, KBr and KI at 25˚C by high-precision glass electrode potentiometric titrations. The pKw values obtained are in excellent agreement with, but generally more precise than, literature data. At I > 1 M the pKw values increase smoothly and show systematic differences in the order KCl < KBr < KI, consistent with the decreasing H+-acceptor ability of the medium anions. Analogous behaviour is observed in MCl solutions, with pKw values varying in the order NaCl < KCl < CsCl. Formation constants of MOH0 ion pairs derived from these data are consistent with literature values.

Infrared spectrum of HDO in aqueous solutions of perchlorates and tetrafluoroborates

1970 ◽  
Vol 48 (19) ◽  
pp. 3019-3025 ◽  
Author(s):  
George Brink ◽  
Michael Falk
Keyword(s):  
Aqueous Solutions ◽  
Pure Water ◽  
Ion Pairs ◽  
Low Frequency ◽  
Frequency Component ◽  
High Frequency Component ◽  
Water Molecules ◽  
Oh Groups ◽  
Cation Effect ◽  
Crystalline Hydrates

The OH and OD stretching bands of HDO in aqueous solutions containing the ions ClO4− and BF4− are split into two components. The high-frequency component, A, does not shift with temperature. It is interpreted as due to OH groups involved in weak [Formula: see text] or [Formula: see text] hydrogen bonds. This interpretation is in line with the corresponding OH frequencies of other systems containing ClO4− ions, such as methanolic solutions and crystalline hydrates. Solvent-separated ion pairs may account for the observed cation effect on band A. The low-frequency component, B, varies with temperature almost exactly like the corresponding band of pure water. It is interpreted to be due to those OH groups which are not associated with the anion. Components A and B are not resolved in solutions of most electrolytes because the distribution of strengths of interactions of OH groups with most anions overlaps that of [Formula: see text] interactions between water molecules.

NaSO 4 ? ion pairs in aqueous solutions at pressures up to 2000 atm

1975 ◽  
Vol 4 (3) ◽  
pp. 225-236 ◽  
Author(s):  
F. H. Fisher ◽  
A. P. Fox
Keyword(s):  
Aqueous Solutions ◽  
Ion Pairs

scholarly journals STRUCTURE OF NEAREST ENVIRONMENT OF IONS IN AQUEOUS CESIUM IODIDE SOLUTIONS FROM X-RAY DIFFRACTION DATA

2017 ◽  
Vol 60 (7) ◽  
pp. 21
Author(s):  
Pavel R. Smirnov ◽  
Oleg V. Grechin ◽  
Elena A. Voevodina
Keyword(s):  
Aqueous Solutions ◽  
Diffraction Data ◽  
Ion Pairs ◽  
Diffraction Method ◽  
Cesium Iodide ◽  
Distribution Functions ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quantitative Parameters

Comparatively large amount of works has been devoted to the investigation of the nearest environment of cesium ions in aqueous solutions. But up to date there are no precise quantitative parameters of it. Information about influence of concentration on cesium salts solutions structure is also absent. In order to get the coordination number of Cs+ ion and its dependence on the amount of dissolved salt the set of aqueous solutions of cesium iodide have been studied by X-ray diffraction method in wide concentration range under ambient conditions. Radial distribution functions (RDFs) of the solutions investigated have been calculated from experimental intensity curves of X-ray scattering. Interpretation of experimental peaks on RDFs has been made. On the basis of experimental results and literature information some physically reasonable models of solution have been constructed. Theoretical RDFs have been calculated for every model. Then an optimization procedure has also been made. On the ground of the best fitness between experimental and theoretical RDFs the optimal models for every solution have been found. All quantitative parameters have been tabulated and analyzed. Hydration numbers of Cs+ and I- increase with dilution, reaching in the solution of molar ratio 1:80 values 6.3 and 4.1, respectively. Interparticle distances of Cs+–ОН2 and I- –ОН2 are equal approximately to 0.312 and 0.359 nm. The ions do not form the second coordination shells. It has been determined that contact ion pairs Cs+–I- exist in whole concentration range investigated.Forcitation:Smirnov P.R., Grechin O.V., Voevodina E.A. Structure of nearest environment of ions in aqueous cesium iodide solutions from X-ray diffraction data. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 7. P. 21-26.

Additivity of molar metachors of chlorides in aqueous solutions

1989 ◽  
Vol 54 (10) ◽  
pp. 2657-2666
Author(s):  
Jiří Čeleda ◽  
Jana Žilková
Keyword(s):  
Surface Tension ◽  
Aqueous Solutions ◽  
Ion Pairs ◽  
Chloro Complexes ◽  
Divalent Metals ◽  
Degree Of Dissociation ◽  
Molar Ratios ◽  
Mixed Solutions ◽  
Solutions Of Electrolytes ◽  
Electrostatic Contribution

For the molar metachor, a quantity expressing the electrostatic contribution from free (nonassociated and noncomplexed) ions to the surface tension of aqueous solutions of electrolytes, its additivity was verified for completely dissociating chlorides of univalent and divalent metals at concentrations up to 5 mol dm-3. Owing to this property, the degree of dissociation could be estimated for associating components of solutions containing also completely dissociated electrolytes. Measurements revealed that NaCl, LiCl, MgCl2 and CaCl2 in mixed solutions are completely dissociated whereas ZnCl2, CdCl2 and UO2Cl2 at molar ratios NaCl:MeCl = 2:1 and higher ( at cCl- = 5 mol dm-3) are completely transformed into electroneutral and anionic chloro complexes, the latter forming ion pairs and triplets with Na+ ions.

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