Synthesis, silver (I) extraction and silver (I) binding studies of novel N 1 , N 3 -bis(2-(benzylthio)ethyl)propanediami
- PDF / 1,592,796 Bytes
- 14 Pages / 595.276 x 790.866 pts Page_size
- 20 Downloads / 183 Views
ORIGINAL PAPER
Synthesis, silver (I) extraction and silver (I) binding studies of novel N1,N3‑bis(2‑(benzylthio)ethyl)propanediamide derivatives Abiodun D. Aderibigbe1,2 · Andrew J. Clark1 Received: 21 May 2020 / Accepted: 6 August 2020 © Institute of Chemistry, Slovak Academy of Sciences 2020
Abstract Solvent or liquid–liquid extraction represents a highly valuable technique for the selective recovery of metals from the aqueous phase due to the ease of operation and short turnaround times. Ligands bearing soft donor atoms including nitrogen and sulfur are ideal candidates for selective silver recovery due to their preference for silver binding. Herein, novel N1,N3-bis(2(benzylthio)ethyl)propanediamide derivatives bearing sulfur and nitrogen donor atoms were prepared in low to high yields and tested for Ag+ extraction from ternary aqueous solutions also containing Cu2+ and Pb2+ following a well-established solvent extraction protocol. It was observed that electronics effects at the 4-aryl position in the propanediamide (or malondiamide) derivatives had a significant effect on the selectivity, but little effect on the efficiency of A g+ extraction with the 4-methoxy analogue proving the most selective. Steric hindrance provided by dimethyl substitutions at the α-positions to the sulfur atoms had negative effects on Ag+ extraction efficiency and selectivity, while diethyl steric hindrance at the methylene center lowered selectivity but increased extraction efficiency for Ag+. Detailed binding studies reveal that one of the malondiamide derivatives which lacked the electronic and steric hindrance groups studied coordinated A g+ in a 1:1 fashion suggesting a tetrahedral complex geometry. Overall, the results show that simple modification of the electronics and sterics of the N1,N3-bis(2-(benzylthio)ethyl)propanediamides, can improve their selectivity for A g+ recovery from the aqueous phase. Graphic abstract
Keywords Malondiamide derivatives · Selective silver(I) extraction · Electronics · Sterics · Job plot · 1H NMR titration Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11696-020-01307-x) contains supplementary material, which is available to authorized users. * Abiodun D. Aderibigbe [email protected] Extended author information available on the last page of the article
Introduction As the world population increases, the demand for products like phones, laptops, batteries and jewelry, containing precious metals like silver is certain to increase as well
13
Vol.:(0123456789)
(Taillades and Sarradin 2004; Sahan et al. 2019). Unfortunately, silver just like other metals is a non-renewable resource. Therefore, to meet the increasing demand, the supply of silver must be guaranteed. Two major options that have been explored to guarantee the supply of silver and indeed other metals is the search for new primary sources or new metal ore deposits (Kolpakova et al. 2019), and the secondary sources or urban mining, in other words, recycl
Data Loading...
