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Binding of Cu(2+), Ni(2+) and Ag(+) ions to polyallylamine (PAA), polyethylenimine (PEI), poly(N-2-(2-pyridyl)ethylallylamine) (PEPAA), poly(N-2-(2-pyridyl)ethylethylenimine) (PEPEI), and N-2-(2-pyridyl)ethylchitosan (PEC) has been investigated using batch sorption experiments, spectrophotometric titration, ESR, and XPS to elucidate how the structure of polymer precursors affects the ion binding efficiency of their pyridylethylated derivatives. It has been shown that pyridylethylation increases the sorption capacities of PAA and PEI cross-linked with epichlorohydrin toward Ag(+) and Ni(2+) ions, but does not improve or decrease that toward Cu(2+) ions. PEC was the most efficient material for Ag(+) ion sorption with the sorption capacity of 1.21 mmol g(-1). The highest sorption capacity for Ni(2+) (0.62 mmol g(-1)) was found for PEPEI. According to density functional theory (DFT) calculations, lower Cu(2+) binding efficiency to PEPEI results from the "looser" structure of this complex in comparison with unmodified PEI. DFT calculations have also suggested that the Cu(2+) ion is four-coordinated in the complexes with PEPAA and PAA and five-coordinated in all other complexes, which have the structures of distorted square pyramids with Cu-N bond lengths varying significantly depending on the ligand nature. The results of the theoretical investigations of the Cu(2+) complex structures were supported by the ESR data, which revealed the decrease of A‖ and the increase of g‖ values with increasing deviation from the square planar geometry of complexes in the ligands in the order PEI < PEPEI < PEPAA.

The Depression of the Dynamic Jahn-Teller Effect BY R. L. DAVIDOVICH (b) A.M. ZIATDINOV (a), M. M. ZARIPOV (a), YU.V. YABLOKOV (a), and The phenomena connected with the Jahn-Teller distortion of complexes in the presence of degenerate electronic states result in consequences important in solid state physics (1, 2) . The study of transitions between the potential minima of Jahn-

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The structure and magnetic properties of multi-walled carbon nanotubes produced by catalytic pyrolysis of methane have been investigated by means of mutually complementary physical methods. The average sizes and number of carbon layers forming nanotubes, smearing of the density of states near the Fermi level, degeneracy temperature of gas of extrinsic current carriers, concentrations of localized spins and extrinsic two-dimensional current carriers have been determined. The conclusion has been drawn that ferromagnetic nanoparticles are present in the inner regions of nanotubes, including their tubular cavities. The difference in electronic structure near the Fermi level for carbon nanotubes and ordered graphite has been revealed. The possible reason is that the electronic states near zigzag-type sites of ends as well as edges of linear structural defects in nanotubes make greater contribution to the spectrum than that from similar sites of graphite.