10.1021/ic0492800
The study focuses on the synthesis, characterization, and structural analysis of copper(II)-thiosulfate complexes with tripodal tetraamine ligands, specifically tren, Bz3tren, Me6tren, and Me3tren. The reaction of [Cu(L)(H2O)]2+ with thiosulfate in aqueous solution results in a color change indicative of thiosulfate coordination to Cu(II). The research explores the formation of complexes, their stability, and the impact of different ligands on the oxidation of thiosulfate. Single-crystal X-ray diffraction analyses were conducted on three thiosulfate complexes, revealing a trigonal bipyramidal geometry around the copper(II) center. The study also includes the determination of thiosulfate binding constants for each Cu(II)-amine complex, with the aim of finding alternatives to the traditional cyanidation process in gold processing. The results show that the complexes with Bz3tren and Me3tren exhibit the highest thiosulfate binding constants reported to date, while the complex with Me6tren is less stable and more prone to oxidize thiosulfate. This research contributes to the development of more environmentally friendly and efficient gold-processing methods.