AMOS-E

Abstract A homopolymer of N,N-bis(vinyloxyethyl)thiuramdisulphide was synthesized via cationic polymerization and investigated as a sorbent of the ions of mercury and precious metals. The effect of the nature and concentration of acid, phase contact time on the extraction of metals was revealed; sorption capacities of the polymer and metal partition coefficients were estimated. It was shown that the sorbent exhibits high sorption activity to metal ions in the cationic form: with respect to mercury (Hg 2+ ) from 1 M HNO 3 solution 1100 mg/g, 1M H 2 SO 4 990 mg/g, 1 M HCl 280 mg/g; with respect to silver (Ag + ) from 1 M HNO 3 850 mg/g, from 1 M H 2 SO 4 900 mg/g. A mechanism of the interaction of active groups of the sorbent with metal ions was proposed on the basis of IR spectroscopic data. The homopolymer of N,Nbis(vinyloxyethyl)thiuramdisulphide sorbs mercury and silver ions selectively from a mixture of copper, nickel, iron and zinc salts. The possibility to use the sorbent for concentrating precious metals and for an alytical purposes was demonstrated. A method of sorbent regeneration was developed

Zinc(II) Hexafluoroacetylacetonate Complexes of Alkoxyamines: NMR and Kinetic Investigations. First Step for a New Way to Prepare Hybrid Materials

International audienceA series of Zn(hfac)(2) alkoxyamines (diethyl(2,2-dimethyl-1-(tert-butyl-(1-pyridylethoxy)amino)propyl)phosphonate) coordinated at ortho, meta and para positions of their pyridyl moiety were prepared and their homolysis rate constants k(d) measured. Up to a 30-fold increase in k(d) was observed for the meta-(Zn-RR/SS) and para-(Zn-RR/SS) regioisomers. Moreover, the activation is also controlled by the amount of pyridine, used as a ligand competitor. XRD, H-1 and P-31 NMR spectra show very different structures for each complexes in solid state and in solution depending on the diastereosiomers and on the regioisomers