Microphase Structure of Oligoesteracrylate Networks Obtained by Anionic Polymerization in Various Solvents

The microheterogeneous structure of network polymers obtained from oligoestercrylates of anionic polymerization has been studied. The parameters of microheterogeneity of these networks were calculated in the basis of wide- and small-angle x-ray diffraction. The causes of a very distinct microheterogeneity of oligoestercrylate gels and a model of microphase structure of such gels were found within the scope of nonlinear thermodynamics of the irreversible processes.     

Synthesis and isomerization reaction of 2-(benzoxazol-2-yl)-1,3-tropolones

An acid-catalyzed reaction of 2-methylbenzoxazole with 3,4,5,6-tetrachloro-1,2-benzoquinone leads to 2-(benzoxazol-2-yl)-5,6,7-trichloro-1,3-tropolone and 2-(benzoxazol-2-yl)-4,5,6,7-tetrachloro-1,3-tropolone. 1,3-Tropolones upon reflux in ethyl alcohol undergo the rearrangement resulted in the seven-membered ring contraction to form ethyl 2-(benzoxazol-2-yl)-5,6-dichloro-3-hydroxybenzoate and ethyl 2-(benzoxazol-2-yl)-4,5,6-trichloro-3-hydroxybenzoate. The molecular structure of the latter was established by X-ray diffraction analysis.     

Synthesis, structure, and biological activity of the cis-[4-amino-2,2,6,6-tetramethylpiperidine-N,N′]dichloropalladium(ii) complex

A previously unknown palladium complex was synthesized by the reaction of 4-amino-2,2,6,6-tetramethylpiperidine with PdCl₂. The X-ray diffraction study showed that the complex formed by 4-amino-2,2,6,6-tetramethylpiperidine with PdCl₂ is a chelate, in which the bidentate ligand adopts a boat conformation with the nitrogen atoms occupying cis positions at the palladium atom. The resulting cis-[4-amino-2,2,6,6-tetramethylpiperidine-N,N′]dichloro-palladium(ii) complex exhibits strong antimetastatic activity against experimental B16 melanoma at moderate toxicity.     

Electric conductivity of porous glass modified by oxides of bivalent cobalt, nickel, and copper

Multiply repeated operations of porous glass impregnation by aqueous solutions of bivalent cobalt, nickel, and copper nitrates followed by the thermal decomposition of the deposited salts provide a gradual accumulation of oxides in the carrying agent. In all cases, as the surface of glass open channels is filled with oxides, a section of substantial increase in conductance is detected, in which a tentative oxide monolayer is formed. Relations established between conductivity and its activation energy are treated on the basis of the conception of intervalence mechanism of electron transfer in the systems under consideration.     

Conformational structure of liquid-crystalline polyesters with mesogens and spacers in the main chain

The conformations of thermotropic polyesters with alternating mesogens and poly(methylene) spacers in the main chain were investigated by conformational calculations using the data of linear-dichroism IR-spectroscopy, X-ray analysis and differential scanning calorimetry. The conformations of monomeric units and of the macromolecules as a whole in different phase-aggregated states were estimated. It is shown that in the liquid-crystalline (LC) state the polymer chains are strongly extended. The results are compared with the data of various theories of LC ordering.