Equilibrium and Kinetics of the Extraction of Gallium(III) from Sodium Hydroxide Solutions with 7-Dodecenyl-8-quinolinol (Kelex 100)

1993 ◽  
Vol 58 (5) ◽  
pp. 1093-1102 ◽  
Author(s):  
Aleksandra A. Mitrovic ◽  
Slobodan K. Milonjic ◽  
Zoja E. Ilic ◽  
Radomir V. Stevanovic
Keyword(s):  
Sodium Hydroxide ◽  
Sodium Hydroxide Solution ◽  
Aqueous Sodium Hydroxide ◽  
Sodium Concentration ◽  
Extraction Kinetics ◽  
Aqueous Sodium Hydroxide Solution ◽  
Ph Values ◽  
Constant Ph ◽  
Equilibrium And Kinetics ◽  
Kinetics Of

The influence of hydroxide ions concentration of the aqueous sodium hydroxide solution, at constant sodium concentrations, on the gallium extraction with Kelex 100 was examined in the hydroxide concentration range from 0.02 to 0.5 mol dm-3. The percentage of extracted gallium increases from 51% to 98% within the investigated hydroxide concentration range. The influence of sodium concentrations (from 1 to 6 mol dm-3) on the gallium extraction was also studied at constant pH values. The decrease of extracted gallium is slight for the sodium concentration up to 3 mol dm-3, while for the higher ones it is pronounced. The extraction kinetics was studied using a mixer-type apparatus. The rate expression of the extraction reaction of gallium with Kellex 100, for both lower and higher hydroxide concentrations are ascertained.

scholarly journals A new protocol for the synthesis of 4,7,12,15-tetrachloro[2.2]paracyclophane

2016 ◽  
Vol 12 ◽  
pp. 2443-2449 ◽  
Author(s):  
Donghui Pan ◽  
Yanbin Wang ◽  
Guomin Xiao
Keyword(s):  
Organic Solvent ◽  
Sodium Hydroxide ◽  
Anion Exchange ◽  
Organic Waste ◽  
Silver Oxide ◽  
Sodium Hydroxide Solution ◽  
Aqueous Sodium Hydroxide ◽  
Product Yield ◽  
Aqueous Sodium Hydroxide Solution ◽  
Aqueous Sodium

We report a green and convenient protocol to prepare 4,7,12,15-tetrachloro[2.2]paracyclophane, the precursor of parylene D, from 2,5-dichloro-p-xylene. In the first bromination step, with H2O2–HBr as a bromide source, this procedure becomes organic-waste-free and organic-solvent-free and can appropriately replace the existing bromination methods. The Winberg elimination–dimerization step, using aqueous sodium hydroxide solution instead of silver oxide for anion exchange, results in a significant improvement in product yield. Furthermore, four substituted [2.2]paracyclophanes were also prepared in this convenient way.

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