M. G. Krakovyak

Specifics of structural organization and properties of lysine dendrimers of different generations and related supramolecular structures

Lysine dendrimers of different generations containing covalently attached anthracene-based luminescent labels (one label per six dendrimer molecules) and fifth-generation heterodendrimers containing various amino acid units located between lysine fragments were synthesized. Homodendrimers were studied by means of the polarized luminescence technique. It was found that the packing density of lysine fragments in macromolecules increases with an increase in the generation number. Their capability of forming supramolecular structures changes in this case; the number of polymacromolecular associates produced in the solution and on the polymer matrix in interpolymer complexes decreases and their complexing power in the reaction with low-molecular-mass compounds increases. It was found that dendrite molecules acquire a looser structure on passing to heterodendrimers and their complexing ability varies in the corresponding manner; the number of polymacromolecular associates in the solution and on the polymer matrix in the interpolymer complexes increases and binding of low-molecular-mass compounds is reduced.

Water-soluble complexes of poly(N-vinylamides) of various structures with C60 and C70 fullerenes

By the example of the interaction of fullerene C60 and poly(N-vinylpyrrolidone), the effect of formation conditions of water-soluble fullerene-containing donor-acceptor polymer systems on their composition and structure has been studied. On the basis of these results, a new technique has been developed for preparing water-soluble polymer systems of this kind with the use of o-dichlorobenzene as a component of the reaction medium. This technique has been employed to prepare water-soluble fullerene-containing complexes of poly(N-vinylamides) of various structures (polymers and copolymers of N-vinylpyrrolidone and N-vinylcaprolactam) containing up to 3–5 wt % of C60 and C70 fullerenes. These values are 3–6 times higher than those described previously.

Luminescence of terbium and europium ions in metal-polymer complexes based on poly(amido acids) with main-chain arylcarboxyamide groups

Poly(amido acids) with main-chain metal-binding ligands methylene-bis(anthranilic acid) and their linking fragments of a widely varied structure have been synthesized. The chemical structure of poly(amido acids) that affect the luminescence of Tb3+ and Eu3+ ions and interact with them is studied, and the mechanism of this effect is advanced.

Bridge Bond Formation in Polymer Systems

Abstract Polymer systems with intra and/or interchain bridge bonds of various types (covalent, electrostatic, coordination, etc.) have drawn the attention of numerous researchers for many years. A considerable interes in crosslinked polymers is due to the fact that when their topological structure is varied, they can acquire quite different properties; they can be soluble or lose solubility, exibiting a certain extent of swelling capacity. Their physicomechanical properties can also change drastically in the condensed state. The specific propertieis displayed by polymers with bridge bonds extend the possibilities and prospects of using polymer systems in technology, medicine, biotechnology, and agriculture (as construction materials, polymer glasses with high mechanical strength and high thermal stability, rubbers, ion-exchange resins and sorbents, immobilizing media for the stabilization of natural and synthetic catalysts, insoluble polymer reagents which are used, for instance, in peptide synthesis, the...

Structural transformations in macromolecules of synthetic nonionogenic polymers and DNA in salt-containing aqueous solutions

The influence of salt additives on structural transformations in macromolecules of synthetic polymers free of ionogenic groups and DNA molecules has been determined with the use of the nanosecond dynamics luminescent method. When polyvalent metal salts are added, a coil-globule transition is observed in macromolecules of poly(N-n-propylmethacrylamide), while structural transformations occur in DNA macromolecules in aqueous solutions, processes that are accompanied by the passage of low-molecular-mass organic cations intercalated into DNA into solution. These transformations make themselves evident when polyvalent metal ions are added in an amount of one Mt3+ ion per ten phosphate groups of DNA. The same effect takes place when salts of polycations are added to solutions of DNA-polycation interpolyelectrolyte complexes.

Interaction of polymers with fullerene C60

The fundamentals of the method for estimating the fullerene-binding power of polymer macromolecules and supramolecular formations are developed for fullerene C60. Polymers with covalently attached anthracene groups (one group per macromolecule) whose luminescence decreases in the presence of fullerene in solution in direct proportion to the stability of the fullerene-polymer complex are used. The effect of the anthracene mark on the fullerene-binding power of a luminescent-marked polymer is taken into account or discarded on the basis of an analysis of the interaction between fullerene and low-molecular models of luminescent marks.