The hydrosilylation of a,o-bis(trimethylsiloxy) methylhydridesiloxane (degree of polymerization % 53) with acrylic and methacrylic acid with various ratios of the initial compounds, in the presence of platinum hydrochloric acid, has been investigated. In the presence of platinum hydrochloric acid, competitive dehydrocondensation reactions take place with the formation of various oligomers with various chemical links. In the later stages of the reaction, threedimensional systems have been obtained. During dehydrocondensation, the reaction order, reaction rate constants, and activation energy have been determined. The structures of the synthesized oligomers have been determined with IR and NMR spectroscopy data. Gel permeation chromatography, differential scanning calorimetry, and X-ray analyses of the synthesized oligomers have been carried out.

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The energy characteristics of the tautomeric transformations of cytosine, thymine, and uracil have been calculated within the framework of the quantum chemistry theory of functional density. It was concluded that the directions of the tautomeric conversions are characterized by energies of activation calculated according to the theory of functional density.Prototropic tautomerism in nitrogen-containing heteroaromatic compounds has been well studied by experimental [1-4] and theoretical [5-11] methods, and general conclusions have been drawn that tautomeric keto and amino forms are canonical, the equilibrium constant depends on the structure of the compound and the solvent, and proton transfer is effected according to a cyclic dimer mechanism. Particular attention has been paid to the study of tautomeric conversions of pyrimidine bases with the aim of a qualitative description of the uncommon tautomeric forms and processes [12][13][14][15][16], and also clarification of the possibility of the existence of intermolecular hydrogen bonds [17][18][19]. Interest in the theoretical investigation of prototropic tautomeric conversions has grown with the appearance of calculating programs putting into effect the methods of the theory of functional density (TFD), which effectively reproduces the energy and electronic characteristics of complex molecular systems [20].

Friedel-Crafts alkylation reaction of vinyltri-methoxysilane with styrene was performed in the pres-ence of anhydrous AlCl3. Alkoxy(4-vinylphenethyl)silane has been obtained. The synthesized products were identified by 1H, 13C, COSY NMR, and FTIR spectroscopy. Calculations using the quantum-chemical non-empirical density functional theory (DFT) method for the reaction between vinyltrimethoxysilane and styrene performed for ortho-, meta- and para-positions were discussed. For the theoretical modeling an online prediction program "Priroda 04: A quantum-chemical program suite" was used. Composite materials based on wood sawdust with various dispersion qualities and synthesized trimethoxysilylated styrene as a binding and reinforcing agent with degrees of silylation (5 %), in the presence of various organic/inorganic additives, fire retardants, and antioxidants, have been developed at different temperatures and pressures via hot press method or extrusion. The physico-mechanical properties of composites have been investigated.