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The most effective mechanism of protective action of organic phosphites–linear termination of kinetic chains on the inhibitor—has been established and the relative contribution of the other phosphite reactions (with hydroperoxides, their chain “self‐oxidation”) to the summary mechanism has been determined. The quantitative kinetic characteristics of efficiency and length of inhibitive action of different structure phosphites in the wide range of the phase state of the oxidized substrate (solid polymer, its melt, liquid phase) have been given. On this basis the regularities which allow the prediction of the structures of phosphites scavenging peroxy substrate radicals more effectively (effective inhibitors) have been formulated.

The studies dealing with the elucidation of the detailed mechanism and quantitative kinetics of the reactions of peroxycompounds with phosphites, sulphides, and aromatic amines are reviewed. It is shown how evidence has been obtained, by ESR of the existence of the one-electron amine oxidation stage, i.e. the stage involving the formation of radicalcations. The consecutive reactions of the radical-cations formed initially and their relation to the behaviour of the amines as polymerisation initiators are analysed. The characteristics of the detection of free radicals in reactions of phosphites and sulphides with hydroperoxides are examined and certain criteria of the latent, radical nature of these reactions are formulated. In the last section correlations of the Hammett equation type for rates of the reactions under consideration and also the correlation between the rate constants on the one hand and the ionisation potentials and electron affinities on the other are discussed within the framework of the one-electron oxidation-reduction mechanism. The bibliography includes 96 references. CONTENTS

Because of their unique structure, it has been proposed that carbon nanotube ropes may well provide an ideal container for the storage of molecular hydrogen. Indeed, there has been some experimental evidence of enhanced hydrogen uptake in doped Li and other alkali metal systems (Chen et al 1999 Science 285 91). We have therefore addressed this issue of hydrogen storage in Li-doped graphite and carbon nanotube systems theoretically with ab initio simulations. Our results find no evidence for such enhanced storage, based on the induced structural changes. In addition, we have also investigated the diffusion barriers for hydrogen to enter into nanotube interiors, both in the presence and absence of topological defects. Even if nanotube interiors are made accessible, the hydrogen uptake remains modest, i.e., less than 3.5 wt%. Mechanically or chemically processing nanotubes is therefore not likely to lead to greatly increased hydrogen storage. Even with its limitation, because of the use of the LDA and GGA approaches, the current investigation must be regarded as a means in the search for proper media that can successfully enhance hydrogen storage.

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