Pulse radiolysis studies of chloride complexes of thallium(II). Absorption spectra and stability constants of thallium chloride(1+) ion, thallium dichloride, and thallium trichloride(1-) ion

1974 ◽  
Vol 78 (9) ◽  
pp. 892-899 ◽  
Author(s):  
R. W. Dodson ◽  
H. A. Schwarz
Keyword(s):  
Absorption Spectra ◽  
Stability Constants ◽  
Pulse Radiolysis ◽  
Chloride Complexes ◽  
Thallium Chloride

scholarly journals Desing of optical chemosensors for detection of cyanide ions in water environments

2019 ◽  
Vol 15 (1) ◽  
pp. 82-87
Author(s):  
Alexandra Alexandrovna Kudrevatykh ◽  
Lyubov Stepanovna Klimenko ◽  
Timofey Petrovich Martyanov
Keyword(s):  
Aqueous Medium ◽  
Absorption Spectra ◽  
Stability Constants ◽  
Molecular Interactions ◽  
Color Change ◽  
Cyanide Ion ◽  
Colorimetric Test ◽  
Optical Chemosensors ◽  
Aqueous Mixture ◽  
The Stability

Molecular interactions with various anions in the form of tetrabutylammonium salts in DMSO and DMSO-aqueous mixture were studied spectrophotometrically. It turned out that the solutions of 1-hydroxy-2-acylaminoanthraquinones in DMSO, originally yellow, became dark purple with the addition of cyanide, fluoride, phosphate, and acetate ions. The addition of other salts did not cause changes in the absorption spectra. When switching to aqueous DMSO, a contrasting color change in the solution was observed only with the addition of the cyanide ion. The stability constants of the complexes and the metrological characteristics of the processes were determined. On the basis of 1hydroxy-2-benzoylaminoanthraquinone, colorimetric test strips were made and tested for the detection of CN-ions in an aqueous medium.

A spectrophotometric study of Fe(II)-chloride complexes in aqueous solutions from 10 to 100°C

2001 ◽  
Vol 79 (2) ◽  
pp. 131-144 ◽  
Author(s):  
Renhai Zhao ◽  
Pujing Pan
Keyword(s):  
Stability Constants ◽  
Near Infrared ◽  
Chloride Concentration ◽  
Pitzer Model ◽  
Nonlinear Least Squares ◽  
Ionic Species ◽  
Spectrophotometric Study ◽  
Chloride Complexes ◽  
Near Ir ◽  
Coordination Change

The absorption spectra of Fe(II)-chloride solutions were measured in both the UV (ultraviolet) and near-IR (near infrared) regions at temperatures ranging from 10 to 100°C with chloride concentrations from 0.1 to 16 mol kg-1. The stability constants of all Fe(II)-chloride complexes were derived from the spectra using a non-negative nonlinear least-squares computer program (SQUAD). Earlier work on this system reported in the literature was rigorously reassessed. The activity coefficients of the ionic species were calculated using both the Pitzer model and the Helgeson model. The results obtained with UV and near-IR spectra and with different activity coefficient calculation models are in general agreement. Other useful thermodynamic data, including the Gibbs energies, enthalpies, and entropies for complex formation, were also obtained. It was found that the Fe(II)-chloride complexes gradually undergo a configuration transformation from octahedral to tetrahedral coordination as the temperature and (or) chloride concentration increases. This coordination change is of significant importance to the nuclear reactors, as the presence of the tetrahedral complex can increase the solubility of iron in steam generator crevices.Key words: Fe(II)-chloride complexes, stability constants, solution thermodynamics, spectrophotometry, reactor chemistry.

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