Sergey A. Milenin

Synthesis of diethoxy(phenyl)silane and its polycondensation in acetic acid

Low-temperature reaction between phenylmagnesium chloride and triethoxysilane at lowered affords diethoxy(phenyl)silane, whose polycondensation in acetic acid gives oligomeric (phenyl)hydrosiloxanes.

Investigation of Melts of Polybutylcarbosilane Dendrimers by 1 H NMR Spectroscopy

Melts of polybutylcarbosilane (PBC) dendrimers from third (G3) up to sixth (G6) generations are investigated by 1H NMR spectroscopy in a wide temperature range up to 493 K. At room temperature, NMR spectra of G3-G5 dendrimers exhibit resolved, solution-like spectra (“liquid” phase). In contrast, the spectrum of the G6 dendrimer is characterized by a single unresolved broad line at whole temperature range, which supports the presence of an anomalous phase state of G6 at temperatures higher than glass transition temperature. For the first time, an unexpected transition of G5 dendrimer from a molecular liquid state to an anomalous state/phase upon temperature increase has been detected using NMR data. Specifically, an additional wide background line appears in the G5 spectrum above 473 K, and this line corresponds to a G5 state characterized by restricted molecular mobility, i.e., a state similar to the “anomalous” phase of G6 melt. The fraction of the G5 dendrimers in “anomalous” phase at 493 K is approximately 40%. Analysis of the spectral shapes suggests that changes in the G5 dendrimers are reversible with temperature.

Synthesis and structure of new polyhedral Ni, Na- and Cu, Na-metallasiloxanes with tolyl substituent at the silicon atom

Two new polyhedral tolyl-containing metallasiloxanes, {(Na+)2[TolSi(O)O−]6(Ni2+)4(Na+)4(OH−)2[TolSi(O)O−]6}*(EtOH)14(H2O)2 and {[CuSi(O)O−]12(Cu2+)4(Na+)4}*(EtOH)8}, and two new large stereoregular cyclosiloxanes, cis-[TolSi(O)OSiMe3]6 and tris-cis-tris-trans-[TolSi(O)OSiMe3]12, have been synthesized and their structures have been determined by X-ray crystallography.

Synthesis of alkoxybenzylmethylsilanes and polybenzylmethylsiloxane polymers on their basis

An efficient solvent-free procedure for the preparation of alkoxybenzylmethylsilanes by organomagnesium synthesis was developed. The reaction conditions gave the high yields of the target products. A number of benzylmethylsiloxane polymers was synthesized by polycondensation of alkoxybenzylmethylsilanes in anhydrous acetic acid. The products obtained can become a good alternative to phenylsiloxanes in some practical applications.

Aerobic Co or Cu/NHPI-catalyzed oxidation of hydride siloxanes: synthesis of siloxanols

A highly efficient preparative method for the synthesis of siloxanols based on aerobic Co(OAc)2 or Cu(OAc)2/NHPI-catalyzed oxidation of hydride siloxanes using “green”, commercially available, simple inexpensive reagents and mild reaction conditions has been proposed. This is a general reaction for the synthesis of mono-, oligo- and polymeric siloxanols with various structures (linear, branched and cyclic).

Synthesis of methyl(1-aminophosphonate)siloxane oligomers

A synthesis of 1-aminophosphonate derivative of methylsiloxane oligomer was developed. A methodology of the introduction of 1-aminophosphonate fragment not only into the stable siloxane structures, but also into hydrolytically unstable alkoxyfunctional organosilicon compounds was suggested.

Development of a method for introducing 1-aminophosphonate fragment in a siloxane matrix

GRAPHICAL ABSTRACT ABSTRACT A versatile synthetic method for the preparation of 1-aminophosphonate derivatives of methylsiloxane oligomers was developed. The introduction of trimethylsilyl amino protecting groups promotes hydrosilylation. The proposed modeling technique allows entering 1-aminophosphonate fragment into the siloxane skeleton of the matrix structure, as well as into the hydrolytically unstable alkoxy-functionalized organosilicon compounds.