Doklady Rossijskoj akademii nauk. Himiâ, nauki o materialah.

The one-pot synthesis of random multiblock copolymers of norbornene and cyclooctene has been performed for the first time. It is shown that the first generation Grubbs Ru-carbene complex makes it possible to obtain these copolymers directly from monomers. In the course of one-pot synthesis, the metathesis polymerization of norbornene, which has a markedly higher ring strain, occurs first. Then, cyclooctene polymerizes and simultaneously an interchain cross-metathesis reaction takes place, during which the block structure of the copolymer is formed. Compared to the previously studied interaction of polynorbornene and polycyclooctene, the one-pot method makes it possible to obtain copolymers with a higher molar mass at a lower catalyst consumption.

New 1,5,3,7-diazadiphosphacyclooctanes with N,O-, N,N-, N,S- and N,N,S-heterocyclic substituents at nitrogen atoms were synthesized. The influence of amines containing sp²-hybridized nitrogen atom on the ortho-position of the heterocyclic substituent on the result of a Mannich condensation of primary phosphines, paraformaldehyde and primary amines is revealed. The stabilization of intermediate acyclic products – aminomethyl(hydroxymethyl)arylphosphines and bis(aminomethyl)arylphosphines due to amino-imine tautomerism is a reason of the low yield of cyclic diphosphines on the base of above mentioned amines.

Using acetylacetone as an example, it was shown that the intramolecular hydrogen bond significantly affects the radiolytic transformations of organic compounds, suppressing the transfer of a proton from the primary radical cation to the molecule, and also contributing to the cleavage of the C–OH bond in the enol form. Due to these effects, the main heavy product of radiolysis at 295 K is 4-oxopent-2-en-2-yl acetate. Under boiling conditions (413 K), hydrogen bonds are eliminated, leading to the predominant formation of 4-hydroxy-2-pentanone, which is not detected at 295 K.

A novel approach for the preparation of hard elastic polymeric material based on ultra-high molecular weight polyethylene via the strategy of crazing of polymers has been proposed. This approach includes the process of deformation of the pristine films of ultra-high molecular weight polyethylene via environmental intercrystallite crazing mechanism and subsequent low-temperature spontaneous strain recovery upon stress relaxation. As a result, the material acquires new properties typical for hard elastic materials: restoration of the porous structure upon secondary loading in air up to ~20 vol. % with pore sizes in the nanometer range (up to 10 nm), high reversibility of deformation (50−85%), the effect of opening and closing pores upon cyclic loading. The mechanism of this phenomenon has been proposed and the areas of practical applications of such mechanoresponsive material have been indicated.