Extraction of metals using poly[N-(dithiocarboxylato)-iminoethenehydrogenoiminioethene]

The concentration and selective extraction of copper(II) rhodium(III), and iridium(III) using a copolymer functionalised with dithiocarbamate groups. Spectroscopic evidence for the nature of the binding sites

“…At very low loading, the e.s.r. spectrum is considerably different, demonstrating that (at least) two different sites are available for Cu2+ in (1). The All parameter is no longer attributable to a pseudo-tetrahedral geometry, and the spectrum is rhombic in type.…”

“…site is five-co-ordinate but at higher loading the co-ordination appears to be CuS,N2 and is a model for 'blue' copper proteins. The ligand-field strength of the CS2-groups in (1 ) is significantly lower than expected, which is ascribed to strain in the polymer backbone causing weaker M-S bonds and accounts for the ease of elution of the metals. The poor selectivity of (1) for RulIl over Cull is due to two factors: the rhodium and copper co-ordinate to different sites, and the co-ordination of rhodium limits the sites available to copper.…”

“…'Coordinating polymers' are taken to mean those which are able to form a bond which has a marked degree of covalent character with a metal. In the particular case of the title copolymer (1) ('PIED) the dithiocarbamate groups might be expected to be strong chelating, bidentate (SS) ligands and hence capable of forming strong bonds with platinum group metals which would enable the copolymer to act as a scavenging reagent. We were hoping for separation ratios Rh/Cu > 1 OOO because of the known high capacity of the copolymer (1) for Rh and Ir.2 In addition to these groups there are nitrogen-containing groups which can be seen in the idealised repeating unit of Scheme 2.…”

New hydrogel containing sulfur compound prepared by ? irradiation and its application for metal recovery

“…A literature survey shows little information about preparation of hydrogels by radiation polymerization, especially those containing sulfur groups. However, a few studies, including recovery for metal ions by hydrogels containing sulfur groups, were reported 1–6. So, the present work is aimed at the γ‐radiation polymerization synthesis of a specific hydrogel containing a sulfur compound.…”

Selective ion exchange polymers

“…Similar polymers f o r the c o l l e c t i o n o f heavy metals are dithiocarbmates and t h e i r derivatives. Polydithiocarbmate was made from polyethyleneimine by condensation with cS2 (42,43,44) or formaldehyde (45). ' (ee3*) state.…”