The process of non-catalytic hydrolytic polycondensation of dialkoxydiorganosilanes under elevated pressure has been investigated. It is shown that non-catalytic hydrolytic polycondensation of diethoxydimethylsilane in an autoclave proceeds with complete monomer conversion for 10 min forming predominantly linear oligomers. Complete conversion of diethoxymethylphenylsilane is achieved by stirring or by increasing of the process temperature. In the hydrolytic polycondensation of dialkoxydimethylsilanes in the autoclave without stirring the reactivity of monomer is regularly decreased with increasing of length of the alkoxy-groups in the series of MeO—EtO—PriO—PrnO—BunO.

The process of condensation of dimethyldiethoxysilane in the active medium in a presence of acetyl chloride, trifluoroacetic acid, and sulfocationites has been investigated. Their impact on the rate and selectivity of the process has been estimated. The prospects of the application of sulfocationites for the polycondensation of dimethyldiethoxysilane in anhydrous acetic acid with an 99% yield have been demonstrated.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The possibility to synthesize stereoregular tris-cis-tris-trans- dodeca[(phenyl)(hydroxy)]cyclododecasiloxane (tris-cis-tris-trans-[PhSi(O)OH]12) in an inorganic liquid medium – aqueous carbonic acid solution – was shown. The interaction of polyhedral phenylcoppersodiumsiloxane, {[(C6H5Si(O)O−]12(Cu2+)4(Na+)4}*(L)m (L = Bun OH, H2O), with carbonic acid can be considered as a new ‘green’ method to obtain functional organosiloxane macrocycles. In contrast to the known methods, no organic solvents were used during the reaction. The identification of the structure of the end compound was performed by means of NMR and Infrared spectroscopy as well as X-ray crystallography.

Образцы трис-цис-трис-транс-додекафенилциклододекасилоксандодекаола (додекаол) с различной кристаллической структурой были исследованы с помощью методов ТГА и РСА. Было установлено, что эти образцы проявляют мезоморфные свойства. Их температурное поведение и тип образуемых ими мезофаз напрямую связаны с типом Н-связанных макроциклосилоксановых фрагментов, формирующих исходную кристаллическую структуру. В свою очередь, тип упорядочения мезофазы определяет структуру конечных продуктов поликонденсации. Показано, что полифункциональный макроциклический силоксановый додекаол может быть использован как мономер для получения ковалентно связанного «двутяжевого листового полимера».

Crystalline sodium tolylsiloxanolate anions, based on cis-tritolylcyclotrisiloxanolate, cis-[PhSi(O)O−]3 (1) or cis-tetratolylcyclotetrasiloxanolate, cis-[TolSi(O)O−]4 (2), assembled into a chain or double layer supramolecular structure through coordination with sodium cations and hydrogen bonding contacts have been obtained for the first time. Molecular and crystal structures of {(Na+)3[TolSi(O)O−]3}·7H2O (1a) and {(Na+)4[TolSi(O)O−]4}·7.5n-BuOH (2a), {(Na+)4[TolSi(O)O−]4}·8n-BuOH (2b) have been determined by single-crystal X-ray analysis. The molecular and crystal structures of [(Na+)3[TolSi(O)O−}3]·2H2O (1b) have been determined by X-ray powder diffraction. The mutual transformation of the compounds into each other has been demonstrated. Reaction of the sodium salts with chlorotrimethylsilane resulted in the formation of the corresponding cis-tri[(tolyl)(trimethylsiloxy)]cyclotrisiloxane, cis-[TolSi(O)(OSiMe3)]3 (3), and cis-tetra[(tolyl)(trimethylsiloxy)]cyclotetrasiloxane, cis-[TolSi(O)(OSiMe3)]4 (4), in high yield. Their molecular and crystalline structures have been confirmed by single crystal X-ray analysis, NMR spectroscopy, and mass spectrometry.

Properties of colloidal solutions formed in the course of hydrolytic condensation of phenyltrialkoxysilanes are studied upon the synthesis of organosiloxanolates of alkali metals and cage-like bimetallic organometalsiloxanes containing alkali and transition (Ni, Cu) or rare-earth (Eu) metals. Sizes and shapes of particles are determined by the dynamic and static light scattering methods. The aggregation stability of colloidal solutions is studied as a function of solvent nature and concentration of phenyltrialkoxysilane. Data obtained make it possible to suggest that disclosed aggregates are the nuclei of crystalline phase. Conditions of the existence of stable colloidal aggregates of sodium phenylsiloxanolate and Ni/Na-phenylsiloxane are determined. It is shown that, upon the dissolution of crystalline Ni/Na-phenylsiloxane in butanol, particles whose sizes are comparable with molecules of organometalsiloxanes are formed in the initial solution.

New stereoregular cis-penta[(phenyl)(trimethylsiloxy)]cyclopentasiloxane cis-[PhSi(O)(OSiMe3)](5) was synthesized. According to the data from DSC, X-ray diffraction, and polarization microscopy, the noncrystallizable cyclopentasiloxane exists in the mesomorphic state throughout the temperature range below the temperature of destruction and is transformed into mesomorphic glass below the glass transition temperature. This compound possesses the polymesomorphic properties and forms two mesomorphic modifications. The type of mesomorphic ordering for these modifications was determined.

Organocyclosiloxanes of various chemical structures were studied by mass spectrometry using different ionization methods. The electron ionization mass spectra contain no peaks of molecular ions, and the main fragment ions are formed due to complicated rearrangements in a molecular ion, which provides no comprehensive view about the molecular structure. The desorption spectra exhibit peaks of quasimolecular and fragment ions, which characterize both molecular weights and chemical structures of the compounds under study.

The formation of polyhedral copper/sodium(potassium) organosiloxanes was examined as a result of hydrolytic condensation of organotrialkoxysilanes in the presence of copper(ii) and sodium or potassium ions. High selectivity of the synthesis of copper/sodium(potassium) organosiloxanes having desired structures can be achieved by choosing the reaction conditions.

Size exclusion chromatography was employed to elucidate the structure of the organosiloxane moiety in trimethylsiloxy derivatives of organometallosiloxanes containing Na, K, Ni, Mn, Cu, and Fe. An efficient technique of trimethylsilylation of organometallosiloxanes was developed to minimize alterations in their structure. The TMS derivatives of organometallosiloxanes were found to exist mostly as a more or less polydisperse mixture of cyclic poly[phenyltrimethylsiloxy siloxane]s. The preferred size of the cycles depends primarily on the nature of the metal in organometallosiloxane.

The synthesis of individual Ni-, Mn-, and Na-containing cage-like organometallosiloxanes has been performed. A possible mechanism of the formation of stable metallosiloxane frameworksvia a transition complex and coordinately bound ion pairs has been proposed. Both monometallic and bimetallic organometallosiloxanes containing only atoms of a transition metal or two different (transition and non-transition) metals, respectively, have been prepared.

An X-ray structural investigation of the interaction products of anhydrous trivalent neodymium, gadolynium, and dysprosium chlorides with sodium phenylsiloxanolate was carried out. The synthesized compounds with the general formula Na6[PhSiO2]8M4(μ4-O)[O2SiPh]8 · 10EtOH · 8H2O (M = Nd, Gd, Dy) were found to be isomorphous isostructural sandwich complexes. The macrocyclic octaphenyloctasiloxanolate ligands in the complexes have anall-cis-configuration and are arranged in co-axial antiparallel pairs and coordinate the square planar groups of the four Nd3+, Gd3+, or Dy3+ ions stabilized by an additional central μ4-bridging O2− ligand. Six Na+ counterions form the outer coordination sphere of the complexes such that four of them coordinate the siloxane macrocycle O atoms in pairs in analogy with crown-ether complexes.

The product of the reaction between anhydrous lanthanum trichloride and potassium vinylsiloxanolate, K5[VinSiO2]8La4(μ4-OH)[O2SiVin]8 · 5n-BuOH·2H2O has been studied by X-ray diffraction. The compound is a «sandwich»-type complex where macrocyclic vinyloctasiloxanolate ligands with regularcis-configuration have co-axial and antiparallel orientation. These ligands coordinate a planar «cationic layer» formed by four La3+ ions and stabilized by an additional μ4-OH− bridge ligand. A three-dimensional cage structure of complex lanthansiloxanolate pentaanions linked through the coordinated K+ counter-ions is formed in the crystal studied.

The structure of K2{[EtSiO2]6K2Cu4[O2SiEt]6} · 4n-BuOH, a novel mixed sandwich-like complex of K+ and Cu2+ with two 6-membered macrocyclic ethylsiloxanolate ligands, was established by means of X-ray study. The ligands have an all-cis configuration and a crown conformation. Four Cu2+ and two K+ ions form a planar hexagon sandwiched between antiparallel coaxial macrocyclic ligands. The K+ ions occupy two opposite apices of the hexagon. The Cu2+ ions have square-planar coordination with four siloxanolate OM atoms, while the K+ ions, are coordinated with two O atoms of the solvating butanol molecules, in addition to four OM atoms. The electric neutrality of the whole complex is due to the two outer-sphere K+ counter-ions, each located over one of the two siloxanolate macrocycles, i.e., over the «decks» of the sandwich and coordinated with endocyclic siloxane OSi atoms, as in crown-ether complexes.