scholarly journals Methods of determination and extractants used in the isolation of platinum (review)

2021 ◽  
Vol 134 (1) ◽  
pp. 24-33
Author(s):  
M. Kiikbay ◽  
◽  
G. Qanai ◽  
C.C. Dosmagambetova ◽  
K.S. Tosmaganbetova ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Fire Hazard ◽  
Organic Substances ◽  
Solubility In Water ◽  
Extraction Capacity ◽  
Organic Reagents ◽  
Methods Of Determination ◽  
Organic Sulfides ◽  
Physico Chemical ◽  
Sulfur Containing

There is carried out a systematic review of the literature on methods for determining platinum (IV) ions and extractants used for their extraction in the article. The article considers chemical, physical, and physico-chemical methods of determination. Also, the authors of the article focused on selective and sensitive spectroscopic methods. There are considered several groups of such reagents and extractants as organophosphorus (tributyl phosphate, di-2-ethylhexylphosphoric acid) diphenylthiourea, high-molecular aliphatic alcohols, organic sulfides isolated from high-sulfur oils, binary extractants based on oxygen-containing and sulfur-containing acids, as well as secondary (R_2 〖NН〗_2А), tertiary (R_3NНA) amines, diamines, and quaternary ammonium bases (R_4NA). They were used for the extraction of platinum from multicomponent objects. Practically common to all the extractants used (chloroform, diethyl ether, carbon tetrachloride, etc.) are their rather high solubility in water, toxicity, volatility, fire hazard. Therefore, it is of fundamental importance to select such extraction systems that combine the effectiveness of organic reagents and the use of such extractants that would eliminate the disadvantages of liquid organic solvents. As such extractants, so-called low-melting organic substances can be used, which do not dissolve in water, are non-toxic, fire-safe, have a high extraction capacity, selectivity, and sensitivity to low content of elements. Therefore, it is fundamentally important to select such extraction systems, which would combine the efficiency of organic reagents and the use of such extractants that eliminate the disadvantages of liquid organic solvents. As such extractants can be used so-called fusible organic substances, which are insoluble in water, non-toxic, fire-safe, have a high extraction capacity, selectivity, sensitivity to low element content.

Theoretical Exploration of 2,2’-Bipyridines as Electro-Active Compounds in Flow Batteries

2019 ◽  
Author(s):  
Mariano Sánchez-Castellanos ◽  
Martha M. Flores-Leonar ◽  
Zaahel Mata-Pinzón ◽  
Humberto G. Laguna ◽  
Karl García-Ruiz ◽  
...  
Keyword(s):  
Redox Potential ◽  
Active Material ◽  
Chemical Properties ◽  
Small Subset ◽  
Solubility In Water ◽  
Protonation Reaction ◽  
Redox Active ◽  
Physico Chemical ◽  
Pka Value ◽  
Flow Batteries

Compounds from the 2,2’-bipyridine molecular family were investigated for use as redox-active materials in organic flow batteries. For 156 2,2’-bipyridine derivatives reported in the academic literature, we calculated the redox potential, the pKa for the first protonation reaction, and the solubility in aqueous solutions. Using experimental data on a small subset of derivatives, we were able to calibrate our calculations. We find that functionalization with electron-withdrawing groups leads to an increase of the redox potential and to an increase of the molecular acidity (as expressed in a reduction of the pKa value for the first protonation step). Furthermore, calculations of solubility in water indicate that some of the studied derivatives have adequate solubility for flow battery applications. Based on an analysis of the physico-chemical properties of the 156 studied compounds, we down-select five molecules with carbonyl- and nitro-based functional groups, whose parameters are especially promising for potential application as negative redox-active material inorganic flow batteries.

Theoretical Exploration of 2,2’-Bipyridines as Electro-Active Compounds in Flow Batteries

2019 ◽  
Author(s):  
Mariano Sánchez-Castellanos ◽  
Martha M. Flores-Leonar ◽  
Zaahel Mata-Pinzón ◽  
Humberto G. Laguna ◽  
Karl García-Ruiz ◽  
...  
Keyword(s):  
Redox Potential ◽  
Active Material ◽  
Chemical Properties ◽  
Small Subset ◽  
Solubility In Water ◽  
Protonation Reaction ◽  
Redox Active ◽  
Physico Chemical ◽  
Pka Value ◽  
Flow Batteries

Compounds from the 2,2’-bipyridine molecular family were investigated for use as redox-active materials in organic flow batteries. For 156 2,2’-bipyridine derivatives reported in the academic literature, we calculated the redox potential, the pKa for the first protonation reaction, and the solubility in aqueous solutions. Using experimental data on a small subset of derivatives, we were able to calibrate our calculations. We find that functionalization with electron-withdrawing groups leads to an increase of the redox potential and to an increase of the molecular acidity (as expressed in a reduction of the pKa value for the first protonation step). Furthermore, calculations of solubility in water indicate that some of the studied derivatives have adequate solubility for flow battery applications. Based on an analysis of the physico-chemical properties of the 156 studied compounds, we down-select five molecules with carbonyl- and nitro-based functional groups, whose parameters are especially promising for potential application as negative redox-active material inorganic flow batteries.

Adsorption behaviour of neutral organic substances at the free surface of polar organic solvents

2003 ◽  
Vol 552 ◽  
pp. 77-83 ◽  
Author(s):  
J Dąbkowski ◽  
R Pruszkowska-Drachal ◽  
M Dąbkowska ◽  
Z Koczorowski ◽  
S Trasatti
Keyword(s):  
Free Surface ◽  
Organic Solvents ◽  
Organic Substances ◽  
Adsorption Behaviour ◽  
Polar Organic Solvents

Precipitation and Coagulation of Organic Substances in Bleachery Effluents of Pulp Mills

1993 ◽  
Vol 27 (11) ◽  
pp. 193-199 ◽  
Author(s):  
S. Beulker ◽  
M. Jekel
Keyword(s):  
Organic Matter ◽  
Magnesium Hydroxide ◽  
Chemical Treatment ◽  
Organic Substances ◽  
Soluble Organic Matter ◽  
Pulp Mills ◽  
High Chemical ◽  
Physico Chemical ◽  
Chlorinated Organic ◽  
High Concentrations

The formation of chlorinated organic substances in bleachery effluents of pulp mills is avoided by changing the bleaching processes to nonchlorinating agents. However, high concentrations of poorly biodegradable and colored lignins are remaining. Precipitation can be one option in physico-chemical treatment of these waters. The influence of alum, lime and magnesium hydroxide as precipitation agents for two different bleachery wastewaters was investigated under various conditions. Alum prove to be the most effective precipitant. Application at an Al/DOC-ratio of 0.5 (g/g) yields a reduction of about 60 % of the soluble organic matter in chlorine-bleachery effluents at the pH = 5.5. Oxygen-bleachery effluents require only half of this specific dosage. Lime precipitation also causes low residual concentrations, but the high chemical demand leads to problems in application. The precipitation with magnesium hydroxide cannot be applied, because remaining concentrations of organic materials are quite high. The changes in bleaching processes are responsible for a new kind of wastewater, which has a significantly lower demand of precipitant

Supercapacitors Based on Propylene Carbonate with Addition of Sulfur Containing Organic Solvents

2015 ◽  
Vol 64 (20) ◽  
pp. 21-30 ◽  
Author(s):  
J. Eskusson ◽  
A. Janes ◽  
T. Thomberg ◽  
E. Lust
Keyword(s):  
Organic Solvents ◽  
Propylene Carbonate ◽  
Sulfur Containing

scholarly journals Ruthenacarborane–Phenanthroline Derivatives as Potential Metallodrugs

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2322
Author(s):  
Martin Kellert ◽  
Imola Sárosi ◽  
Rajathees Rajaratnam ◽  
Eric Meggers ◽  
Peter Lönnecke ◽  
...  
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Organic Solvents ◽  
Side Product ◽  
Ambient Conditions ◽  
Carbonyl Ligand ◽  
Single Crystal Diffraction ◽  
Solubility In Water ◽  
Low Solubility

Ruthenium-based complexes have received much interest as potential metallodrugs. In this work, four RuII complexes bearing a dicarbollide moiety, a carbonyl ligand, and a phenanthroline-based ligand were synthesized and characterized, including single crystal diffraction analysis of compounds 2, 4, and 5 and an observed side product SP1. Complexes 2–5 are air and moisture stable under ambient conditions. They show excellent solubility in organic solvents, but low solubility in water.

scholarly journals Optimization of Curcumin Nanocrystals as Promising Strategy for Nose-to-Brain Delivery Application

Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 476 ◽  
Author(s):  
Angela Bonaccorso ◽  
Maria Rosa Gigliobianco ◽  
Rosalia Pellitteri ◽  
Debora Santonocito ◽  
Claudia Carbone ◽  
...  
Keyword(s):  
Desirability Function ◽  
Point Of View ◽  
Degree Of Crystallinity ◽  
Solubility In Water ◽  
Innovative Strategy ◽  
Drug Permeability ◽  
Physico Chemical ◽  
Mean Size ◽  
The Central Nervous System ◽  
Model Drug

Intranasal (IN) drug delivery is recognized to be an innovative strategy to deliver drugs to the Central Nervous System. One of the main limitations of IN dosing is the low volume of drug that can be administered. Accordingly, two requirements are necessary: the drug should be active at a low dosage, and the drug solubility in water must be high enough to accommodate the required dose. Drug nanocrystals may overcome these limitations; thus, curcumin was selected as a model drug to prepare nanocrystals for potential IN administration. With this aim, we designed curcumin nanocrystals (NCs) by using Box Behnken design. A total of 51 formulations were prepared by the sonoprecipitation method. Once we assessed the influence of the independent variables on nanocrystals’ mean diameter, the formulation was optimized based on the desirability function. The optimized formulation was characterized from a physico-chemical point of view to evaluate the mean size, zeta potential, polidispersity index, pH, osmolarity, morphology, thermotropic behavior and the degree of crystallinity. Finally, the cellular uptake of curcumin and curcumin NCs was evaluated on Olfactory Ensheathing Cells (OECs). Our results showed that the OECs efficiently took up the NCs compared to the free curcumin, showing that NCs can ameliorate drug permeability.

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