Dialkyl Pyridinedicarboxylates' Extraction Ability toward Copper(II) from Chloride Solutions and Its Modification with Alcohols

Abstract

Dipentyl pyridinedicarboxylates (denoted hereafter as L) with different positions of the ester groups were synthesized and used for copper(II) extraction from chloride solutions containing up to 10 mol‚L -1 Cl -. The effect of decanol addition on copper extraction was studied. A molecular modeling technique was used to estimate the structures of extractants, copper complexes, and associates with alcohol. It was found that the ability of pyridinecarboxylates to extract copper depends on the aqueous phase composition and the position of the ester groups in the pyridine ring. All the investigated compounds except dipentyl pyridine-2,6-dicarboxylate extract copper(II) by formation of CuCl 2 L 2 complexes. Dipentyl pyridine-2,6-dicarboxylate forms another type of complex, probably CuCl 2 L. However, this compound is not suitable for copper extraction as its copper complex precipitates. Dipentyl pyridine-3,5-dicarboxylate was found to be the most suitable extractant among the various compounds listed. Finally it is shown that the possibilities to modify the extraction ability of pyridinecarboxylates with a hydrophobic alcohol such as decanol are relatively weak. Some enhancement was, however, observed when 20% of decanol was added to the organic phase containing dipentyl pyridine-3,5-dicarboxylate.

Palladium(II) Extraction and Extractant Adsorption at a Liquid/Liquid Interface

“…Pyridinecarboxamides are more basic and stronger extractants [21][22][23] than pyridinecarboxylates. [24][25][26] As a result, some reagent protonation and a successive transfer of hydrochloric acid is observed.…”

Copper Extraction from Ammoniacal Solutions with LIX 84 and LIX 54

“…Molecular modeling was used to obtain information on association in a manner similar to that reported previously . Low molecular 2-hydroxy-5-propylacetophenone oxime and 1-phenylhexane-1,3-dione were considered as models.…”

Photo‐degradation of hydrophobic esters of pyridinecarboxylic acids as copper extractants from chloride media and their copper complexes

“…The extraction of copper(II) from chloride solutions with model esters has been described by Szymanowski and colleagues 5–12. The ability of pyridinecarboxylates to extract copper depends significantly upon the chloride concentration and the number and positions of the ester groups in the pyridine ring.…”

“…The structure of these extractants means that copper transfer to the organic phase is only possible by solvation with the esters studied, apart from dialkyl pyridine‐2,6‐dicarboxylate, forming CuCl 2 L 2 complexes (L = extractant) 6, 8…”