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Monomeric and polymeric β-naphthylamine and dithizone organosilicon derivatives were synthesized. The organosilicon polymers were studied as sorbents of heavy (FeIII, HgII) and noble (AgI, AuIII, RhIII, PdII, PtIV) metal ions, as well as of CeIII and TbIII. They were found to possess high sorption activity toward platinum group metals and iron. The monomers and polymers obtained exhibit metal chromatic properties. Their reactions virtually with all the elements studied, except cerium and terbium, are accompanied by coloration.

Trekrezan activated the in vivo expression of the PGC-1α gene in rat muscle tissues. Quantification of mitochondria in tissues and gene expression analysis for genes involved in regulatory energy metabolism cascades revealed that the mechanisms of the energy metabolism regulation are probably coupled with protein biosynthesis as well as with innate immunity. The immunostimulatory and adaptogenic drug trekrezan was found to induce concerted in vivo stimulation of the expression of the gene coding tryptophanyl-tRNA synthetase and its activity in the expression of the PGC-1α gene.

Convenient and efficient procedures have been developed for the synthesis of tris(2-hydroxyethyl)-ammonium 4-halo-2-methylphenoxyacetates (halocresacins). 4-Chloro-2-methylphenoxyacetic acid necessary for the preparation of chlorocresacin has been obtained by chlorination of 2-methylphenoxyacetic acid with sulfuryl chloride in the presence of aluminum powder. Bromocresacin has been synthesized by reaction of triethanolamine with 4-bromo-2-methylphenoxyacetic acid prepared by bromination of 2-methylphenoxyacetic acid with molecular bromine. Fluoro- and iodocresacins have been synthesized by exchange reaction of chlorocresacin with potassium fluoride and sodium iodide, respectively.

A series of new pentacoordinate intramolecular organosilicon complexes F(Ar)Si(OCH2CH2)2NMe (Ar = 4-MeC6H4 (1), 4-MeOC6H4 (2), 4-ClC6H4 (3), 2-BrC6H4 (4), 3-NO2C6H4 (5)) has been synthesized by transsilylation of aryltrifluorosilanes ArSiF3 by N-methyl-bis(2-trimethylsiloxyethyl)amine. Compounds 1–5 have been fully characterized by 1H, 13C, 19F, 29Si NMR spectroscopy and X-ray diffraction analysis (for compound 3). Variable-temperature 19F NMR studies of 5 indicate stereodynamic process of the ligand exchange with activation barrier Δ G c ≠ of 13.1 kcal mol−1.

⎯ (previously O=NR3 or O → NR3) continue to attract interest of synthetic, theoretical, and applied chemists. They are already used in cosmetics, as bio medical agents, and as oxidants in a number of organic reactions (catalytic epoxidation and dihydroxylation of alkenes, catalytic oxidation of alcohols, etc.) [1, 2]. The most general method of their synthesis is the oxi dation of tertiary amines with hydrogen peroxide, per oxy acids, dioxiranes, and oxaazapyridines [1].

The review summarizes the data on the synthesis, physicochemical properties, structure, and pharmacological activity elucidation of salts and ionic liquids synthesized based on 2-hydroxyethylamines, aryl chalcogenylacetic acids, and essential metals. The practical application prospects of these novel compounds in medicine and biotechnology are discussed.

Polymer analogous reaction has been used to partially substitute chlorine atoms of polyvinyl chloride with 2-thiobenzimidazole fragments. 13C NMR and IR spectroscopy studies have shown that the vinylene units are present in the modified polymer. The copolymer product has been used to prepare the membrane with proton conductivity of 1 × 10−2 to 0.04 S/cm at 25–195°C.

IR spectra of 1-germatranol, 1,1-quasi-germatrandiole, 1,1,1-hypogermatrantriole with a general formula (HO)4−nGe(OCH2CH2)nNR3−n (n = 1–3) are obtained. At the B3LYP/aug-cc-pVDZ density functional level the equilibrium structures and vibrational spectra of these compounds along with their hydrogen-bonded dimers are calculated. Based on the calculations the band assignment is performed in the IR spectra of 1-germatranol, 1,1-quasi-germatrandiole, and 1,1,1-hypogermatrantriole. The existence of dimers is manifested in the IR spectra as the absence of bands in the frequency ranges characteristic of the bending vibrations of Ge-OH groups and the presence of bands in the vibrational range of hydrogen-bonded germatranyl groups.

Compounds belonging to three novel groups of oncological drugs (metal polyacrylates, ferrocene derivatives, and polysuccinimide) showed antitumor activity. The most efficient compounds, viz., gold polyacrylate (auracryl), 2-[(1-ferrocenylethyl)sulfanyl]pyrimidine (LS-17), and polysuccinimide, inhibit the growth of murine solid tumors by 70–95% and are recommended for further thorough preclinical studies of their antitumor properties and mechanisms of action.

By single crystal X-ray diffraction the crystal and molecular structure of 1-(3-ammoniopropyl)silatrane chloride (I) is determined. One of three cations in the asymmetric unit of the crystal of I differs from the other two by the length of the coordination N → Si bond. The opposite electronic effects in two geometrically similar cations are transferred inductively through a three-carbon chain.

[4], and their precursors: triethanolamine (TEA) and diethanolamine (DEA) [6],which are systematically and extensively studied by thescientific school by M.G. Voronkov for 50 years, continues to attract the attention of many researchers [5, 7].Until now, the main attention in describing stereoelectronic structure of silatranes and quasisilatranes hasbeen paid to the presence and nature of N→Siintramolecular coordination bond and N→Si–X axialfragment [1–5] and their basicity [8]. It was firmlyestablished (mainly by Xray diffraction) that silatranes have

By X-ray diffraction the crystal and molecular structure of iodoprotatrane (tris(2-hydroxyethyl)ammonium iodide I[HN(CH2CH2OH)3]+ (IP) at 120 K and 293 K is determined. The IP cation, as in all protatranes, has the endo conformation. The N-H bond is surrounded by three CH2CH2OH groups. The stability of this configuration is explained by the intramolecular trifurcated inductive interaction with three oxygen atoms through the space of the nitrogen atom. In the IP crystal packing, each iodine anion is linked by three strong OH...I (2.63 A) and three weak I...H (3.13 A) hydrogen bonds with six cations from the CH2N group. This indicates a greater nucleophilicity of the iodine atom.

Application of tris(2-hydroxyethyl)amine and zinc bis(2-methylphenoxyacetate) complex (zincatrane) in experimental atherosclerosis in rabbits leads to decrease in the levels of cholesterol and total lipids in blood platelets (Tc) and monocytes (Mc). The results of enzymatic analysis show that atherogenesis is accompanied by increased activity of acid cholesterol esterase by 66% in Mc and by 55% in Tc compared to standard values. Intramuscular administration of zincatrane at a dose of 10 mg kg−1 decreases the activity of acid cholesterol esterase by almost 35% in Mc and by 26% in Tc compared to the control group. It has been also revealed that zincatrane possesses heparin-like effect, which is expressed in increased thrombin clotting time, blood clotting time and plasma recalcification time as well as in the decreased thrombocyte aggregation. It is assumed that zincatrane stimulates production of endogenous heparin.

This review takes an indepth look at adaptogens (compounds that increase the body's protective resources) and related pharmacological groups of drugs: immunomodulators, actoprotectors, antihypoxants, antioxidants, radioprotective and radiosensitizer compounds. The mechanisms and biochemical characteristics of drug action of these medical substances are discussed in relation to their structure. Bibliography: 212 references.

Series of germatrane compounds with OH functionality and Ge⋯N transannular bonding, i.e. 1-germatranol (I), 1,1-quasigermatranol (II) and 1,1,1-hypogermatranol (III) with general formula (HO)4 − nGe(OCH2CH2)nNR3 − n (R = H, Me; n = 1–3) are synthetized and their solid state IR spectra are recorded. Equilibrium structures and vibrational spectra of monomeric and centrosymmetric dimeric species of these compounds are predicted by the DFT B3LYP/aug-cc-pVDZ method. The assignment of the vibrational spectra of I–III was carried out based on theoretical IR spectra scaled with factors obtained earlier for halogermatranes to take account of the substantial and systematic discrepancy between Ge⋯N interatomic distance of the gas phase and theoretical predictions on the one hand and X-ray solid state data on the other. Dimeric models provide a good agreement between experimental and predicted frequencies, including GeOH bending modes, of I, crystalline state of which is formed by dimers, and slightly worse for II, in which some weaker O–H⋯O and N–H⋯O hydrogen bonds are not considered in the dimeric model. However, this model for III is poor since it does not take into account hydrogen bonding of “free” OH and NH2 groups. Despite the steady decrease of the Ge⋯N interatomic distance, corresponding frequencies demonstrate the substantial increase on going from I to II and practically no increase from II to III.

C- and N-Amino-1,2,4-triazoles react with 1-iodopropan-2-one in the absence of bases and phasetransfer catalysts (40°C, 9-12 h) to furnish 3-amino-1,4-bis(2-oxo-propyl)-4H-1,2,4-triazolium triiodide and 4-amino-1-(2-oxopropyl)-4H-1,2,4-triazolium iodide. The alkylation of 1,2,4-triazol-4-amine with 1-iodopropan-2-one and 1,3-diiodopropan-2-one in the presence of elemental iodine led to the formation of 4-amino-1-(2-oxopropyl)-4H-1,2,4-triazolium triiodide and 2-oxopropane-1,3-diylbis(4-amino-4H-1,2,4-triazolium) bis(triiodide). Triiodides are oily fluids possessing electric conductivity of 1.1 × 10−3 Ω m−1 opening the route to new types of electroconducting ionic liquids.

This review is focused on our and literature data on reactions of acyl iodides RC(O)I with organic (alcohols, ethers, esters, carboxylic acids, amino acids, tertiary amines, nitrogen heterocycles, carbamides, thiocarbamides, and thiols) and organoelement compounds (alkoxy silanes, siloxanes, silylamines, silazanes, silicon-containing amines, and ethynyl silanes, germanes, and stannanes). Photolysis of acyl iodides in arene medium yields a-diketones, products of photochemical Friedel-Crafts acylation and iodination of arenes, and polyarylenation.

The observed featured and regularities of nucleophilic substitution of chlorine in poly(vinyl chloride) upon its reaction with sodium and potassium derivatives of pyrazole, 3,5-dimethylpyrazole, and 2-thiobenzimidazole, and with sodium thiophenolate have been understood in the frame of hard and soft acids and bases theory.

Intercalated polymer-silicate nanocomposites are obtained by the mechanochemical method from smectite clay, zeolite-containing roches, and polythiophene. Their structure and morphology are studied by the methods of scanning and transmission electron microscopy, as well as X-ray phase, thermal, and IR-spectroscopic analyses.

Data on the ion-exchange and complexing organosilicon adsorbents published during the last 10–12 years, including the results of systematic research of the authors, are summarized and analyzed. The following types of substances are considered: silicas with covalently grafted modifiers, silicas and aluminosilicates with non-covalently grafted modifiers and carbofunctional polyorganylsilsesquioxanes prepared by polycondensation of appropriate organosilicon monomers. Adsorbents of these types find extensive practical use, in particular, as analytical reagents for determination of metals in natural and artificial specimens, agents for isolation of valuable elements from industrial wastes and agents for removal of especially hazardous components from wastes and effluents. The bibliography includes 109 references.

The reaction proceeds by route (3) to give 3,3,5,5,7,7 hexamethylcyclo 1 methoxyphosphory loxytrisiloxane (I) and 3,3,5,5,7,7,9,9 octamethylcy clo 1 methoxyphosphoryloxytetrasiloxane (II) in 38 and 33% yields, respectively. The reaction also leads to permethylcyclosiloxanes (Ме2SiO)m: III (m = 3), IV (m = 4), and V (m = 5) in 4, 15, and 10% yield, respectively, and methyl chloride. MeO(O)P O SiMe2 O O

We have synthesized the germanium- and tin-containing organosilicon compounds Et3GeN(SiMe3)2 and Et3SnN(SiMe3)2 as new precursors for the preparation of materials by chemical vapor deposition. The compounds were characterized by NMR, IR and UV spectroscopies and thermal analysis. Using vapor pressure measurements, we obtained temperature dependences of their saturated vapor pressure. We assessed their thermal stability and calculated the thermodynamic characteristics of vaporization of the organosilicon compounds.

By X-ray diffraction the crystal and molecular structure of N-methyl-bis(2-hydroxyethyl)ammonium (4-chlorphenylsulfonyl)acetate 4-ClC6H4SO2CH2COO−·CH3N+H(CH2CH2OH)2 synthesized by the interaction of (4-chlorphenylsulfonyl)acetic acid with N-methyl-bis(2-hydroxyethyl)amine is studied.

According to the X-ray diffraction data, the crystal and molecular structure of tris(2-hydroxyethyl) ammonium fluoride (F−N+H(CH2CH2OH)3, fluoroprotatrane, substantially differs from other halo protatranes X−N+H(CH2CH2OH)3 (X = Cl, Br, and I). At X = F, to the endo-molecular LP of the nitrogen atom the HF molecule having the minimum ionic radius in a series of X− anions is bonded. The geometry of fluoroprotatrane and the cation packing in the crystal are analyzed.

Photochemical reactions of acyl iodides RC(O)I (R = Me, Ph) with aryl halides, fluoro-, chloro-, and bromobenzenes, 1,4-dibromobenzene, 2- and 3-bromotoluenes, and 4-bromo-1,2-dimethylbenzene, were studied. Acetyl iodide reacted with chloro- and bromobenzenes and 1,4-dibromobenzene according to the exchange pattern to give iodobenzene and 1,4-diiodobenzene, respectively. No halogen exchange was observed in the reactions of acetyl iodide with fluorobenzene and hexafluorobenzene. Benzoyl iodide failed to react with chloro- and brombenzene under UV irradiation but underwent polycondensation with formation of black nonfusible oligomers which were found to possess paramagnetic and semiconducting properties. Ultraviolet irradiation of a mixture of MeCOI with 2- or 3-bromotoluene, as well as with 4-bromo-1,2-dimethylbenzene, also led to the formation of polymeric products as a result of polycondensation of aryl iodides formed initially via replacement of bromine by iodine. Irradiation of benzoyl iodide in 2- or 3-bromotoluene involved recombination of benzoyl radicals to give benzil as the only product.

A capability of triethanolamine (TEA) and its organosilicon derivatives methyl-, chloromethyl-, and ethoxy silatrane (MS, CMS, and ES, respectively) in low and ultra-low concentrations (from 10−3 to 10−13 M) to increase pea (Pisum sativum L.) thermotolerance and the relation of this process with heat-shock protein (HSP) accumulation in the roots were studied. Low and ultra-low concentrations of CMS and MS improved seedling survival under conditions of the heat shock (45°C). This process was not accompanied by stress protein accumulation. ES and CMS affected seedling survival and HSP accumulation differently in dependence on the temperature and preparation concentration.

Reaction of cobalt chloride with 1-(1-silatranylmethyl)-1,2,4-triazole in benzene afforded complex CoCl2·2L (L = 1-(1-silatranylmethyl)-1,2,4-triazole). It was isolated as the solvate [CoCl2·2L]·CH2Cl2 (1) by recrystallization from dichloromethane and structurally characterized by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group P21/m with a = 6.798(2) E, b = 20.326(5) E, c = 11.005(3) E, and Z = 4. The cobalt atom is in slightly distorted square-planar environment, coordinated to two nitrogen atoms from two ligands and two chloride ions.

Synthesis of germatranes XGe(OCH2CH2)3N (1), quasigermatranes X2Ge(OCH2CH2)2NR (R = H, Me) (2), and hypogermatranes X3Ge(OCH2CH2)NH2 (3) containing highly electronegative substituents at the Ge atom was described. An exchange reaction of the corresponding hydroxygermatranes with ammonium salts was used for their preparation. The synthesized compounds 1–3 were studied by IR spectroscopy.

X-ray diffraction is used to determine the crystal and molecular structure of the complex of N-(1-silatranylmethyl)-3,5-dimethylpyrazole with cobalt dichloride (I). This is yet another example of the participation of the endocyclic oxygen atom of the silatrane fragment in complexation with a metal atom. Metal dichloride interconnects two heterocyclic systems of dimethylpyrazole (DMP) and silatrane (Sa). The coordination polyhedron of the cobalt atom is a tetrahedron.

The interaction of tricoordinated cations of the 14th group elements generated by the nuclear chemical method with representatives of π-(aryls, olefins) and n-electron-donating (alcohols, ethers) compounds was studied. A comparative analysis of these interactions was carried out on the basis of the results obtained and revealed the differences in the reaction mechanisms of the carbenium ion compounds and mezoid cations. No drastic differences in the behavior of silylium and germylium cations was observed. The possibility of isomerization of the mezoid cations to donor-acceptor complexes of the [HM+·H2] type was experimentally shown for the first time for dimethylgermylium cations taken as an example. The quantum chemical calculations of the studied cations and adducts of their interactions in terms of the functional density theory prove the reaction mechanisms proposed.

The interaction of ethanolamines Me 3− n N(CH 2 CH 2 OH) n ( n = 1–3) with arylheteroacetic acids Ar Y CH 2 COOH (Ar = 2-CH 3 C 6 H 4 , 4-ClC 6 H 4 ; Y = O, S, SO 2 ) as well as acetic acid itself has been studied. For isolated state, the geometries and electronic structures of the complexes obtained were calculated using DFT method at B3LYP/6-311+G ** level of theory. The energy of the compounds has been calculated by means B3LYP/6-311+G ** and MP2/6-311+G ** //B3LYP/6-311+G ** methods. It has been shown that proton transfer (PT) and hydrogen bonding (HB) complexes are formed from triethanolamine (TEA) and the studied acids, while only НВ complexes is generated from diethanolamine and ethanolamine derivatives. The TEA complexes are stabilized by N H + ⋯O − (PT) or O Н⋯N (HB) hydrogen bonds and O H⋯O bonds of its hydroxyl groups and oxygen atoms of acid. The N H + ⋯О − and О H⋯N bonds in the complexes have a partial covalent character as predicted by the quantum theory of atoms in molecule (QTAIM). According to the second-perturbation energies E (2) in the NBO scheme, highest charge transfer is along the О H⋯N hydrogen bond for HB complexes of TEA with Ar Y CH 2 COOH. The GIAO calculated 15 N NMR chemical shifts are well correlated with NBO electron charges on the nitrogen atom for both type complexes.

The silatranes basicity study results are summarized. A large amount of experimental data obtained 25-40 years ago is critically reviewed. It is shown that the reactivity and physicochemical properties of silatranes are determined by their basicity, which depends on the stereoelectronic structure.

Studies and developments of chemisorbed protective and modifying coatings on the surface of glass conducted at the Institute of Chemistry of Silicates under the supervision of Academician M.G. Voronkov are considered.

The crystal and molecular structure of the complex of 2-(1-silatranylmethylthio)-4,5-benzo-1,3-thiazole with CoCl2 and MeCN (I) is determined by single crystal X-ray diffraction. The geometry of the silatranylmethyl moiety in complex I is compared to the geometry of 1-(2′-benzthiazolylthiomethyl) silatrane. Molecular packing in the crystal is analyzed.

Silicon carbonitride layers have been obtained by chemical deposition from the gas phase with thermal (LPCVD) and plasma (PECVD) activation of the gas mixture of helium with the new volatile siliconorganic compound tris(diethylamino)silane (Et 2N)3SiH (TDEAS) in the temperature region 373–1173 K. Thermodynamic simulation of the deposition processes from the gas mixture (TDEAS + He) in the temperature interval 300–1300 K and pressure interval P tot 0 from 1 × 10−2 to 10 mm Hg has revealed the possibility of varying the equilibrium composition of the condensed phase depending on the synthesis temperature and the composition of the initial gas mixture. Physicochemical and functional properties of obtained layers were studied by complex of modern methods. It has been established that the chemical composition of the silicon carbonitride layers obtained by the PECVD method, depending on the deposition conditions, approaches that of silicon oxynitride or nitride, and the composition of those obtained by the LPCVD method approaches that of silicon carbide. The presence of nanocrystals with a phase composition close to the standard α-Si3N4 phase and of carbon inclusions has been found in the layers.

N-Organylbis(trimethylsilyl)amines of the general formula RN(SiMe3)2 (R = Me3Si, Et3Ge) were synthesized by reaction of sodium bis(trimethylsilyl)amide with the corresponding trialkylsilyl(germyl) halide. Their IR, UV, and 1H, 13C, and 29Si NMR spectra were studied, and saturated vapor pressures and thermal stabilities were determined. The possibility of using the RN(SiMe3)2 compounds as precursors in chemical vapor deposition of films with specified composition was estimated by thermodynamic modeling.

Ways of phenyltrifluorosilane application in organoelementalal and organic synthesis are summarized and systematized for the first time. The methods of its synthesis, physicochemical properties, and reactivity are considered. Special attention is paid to the original experimental results obtained by the authors.

A method of synthesis of phenylhalosilazanes by the reaction of phenyl(fluoro)chlorosilanes PhSiF3–nCln (n = 0–3) with hexamethyldisilazane at room temperature is elaborated. The thermolysis of 1,1,1-trimethyl-3-phenyl-3,3-difluorodisilazane affords cyclic phenylfluorosilazanes (PhSiFNHSiMe3)n (n = 3–5). The process may occur via the intermediate formation of phenylfluorosilimine.

RnSi(NEt2)4 − n aminosilanes have been synthesized by reacting the RnSiCI4 − n (R = H, CH3; n = 1, 2) organylchlorosilanes with diethylamine. Using IR, UV, and NMR (1H, 13C, and 29Si) spectroscopies and elemental analysis, we have identified the reaction products and determined their spectroscopic characteristics. Vapor pressure measurements have been used to determine the saturated vapor pressure as a function of temperature and calculate the thermodynamic characteristics of vaporization. Thermodynamic modeling of chemical vapor deposition processes has been performed with the aim of predicting the phase composition of the deposit as a function of the nature of the precursor and process conditions.

In vitro experiments performed on rabbits showed that tris-2-(hydroxyethyl)ammonium orthocresoxyacetate (trecrezan) increases the cytokine activity of total tryptophanyl mRNA synthase (TRSase) via stimulation of the synthesis of a specific mRNA synthase (TRSase). This explains the mechanisms of the hypolipidemic, immunomodulatory, and adaptogenic actions of trecrezan.

DFT(B3LYP) analysis of thermodynamic stability of tris(2-hydroxyethyl)ammonium fluoride was carried out and its possible isomeric structures were localized. The potential surface of interaction of the found isomeric forms with tetraethoxysilanes was studied. Optimal gradient channel of formation of 1-fluorosilatrane was localized.

219 Compounds containing asymmetric silicon atom have long attracted the attention of researchers [1–4]. The known methods of synthesis of chiral silicon com pounds containing simultaneously two different halo gen atoms are based either on the treatment of hydro carbylfluorosilanes with aluminum chloride [5] and their analogs containing Si–H bonds with copper chloride [6], or irradiation of reaction mixtures of hexafluoro and pentafluorochlorobenzene [7] or 1,4 dichlorotetrafluorobenzene [8] with trichloro and methyldichlorosilanes by accelerated electrons. We have found a simplest and convenient method for the synthesis of compounds of such a type. It is based on the displacement of one of the chlorine atoms in phenyl(fluoro)dichlorosilane (I) by OR, OC(O)R, OSiMe3, NHSiMe3, OSiMe2OSiMe3, and other groups. All compounds resulting from this reac tion were previously unknown.

190 Our systematic study in the area of carbofunctional organosilicon monomers and ion exchange and com plexing sorbents derived from them [1, 2] revealed compounds showing metallochromic properties. Such compounds are organosilicon derivatives of dithiocar bamic acid, biguanidine, and iminoguanidine [3], which are not only new organosilicon ionites and complexones but also of interest as test systems of new generation. Test methods developed on the basis of the test systems assume ever greater importance from year to year as express methods demanding no complex instrumentation for detection of elements and their semiquantitative and sometimes quantitative determi nation [4]. The general approach of all chemical test methods consists most frequently in the use of analyt ical reactions and reagents that ensure a visual effect (coloration of different intensity). In continuation of our studies, thiuram disulfide derivatives already used as chromogenic reagents attracted our attention. In particular, tetraethylthi uram disulfide is not only an efficient anti alcohol medicine (Antabuse) but is also used in analytical practice due to formation of colored complexes with a number of elements [5, 6]. For example, it forms with Cu(II) a yellow brown chelate complex known as Mercupral and used as a reagent for determination of silver and mercury [7].

The reaction of elemental sulfur with poly(vinyl chloride) is studied in 1,2,4-trichlorobenzene and without any solvent under various conditions. Black polymers containing 3.77–57.64% chemically bonded sulfur and, according to IR spectroscopy, including >C=C C=S groups in macromolecules are obtained. It is shown that the diffraction curves of poly(vinyl chloride) and of the reaction product containing 7.82% almost coincide but that the thermal stability of the latter is considerably higher than that of the initial polymer. The prospects of the practical use of the products of the reaction of poly(vinyl chloride) with elemental sulfur are demonstrated.

The effect of organic solvents miscible with water (acetone, methyl ethyl ketone, 2-propanol, 2-ethoxyethanol, dimethylformamide) on the composition, structure, and crystal transformations of polyborasiloxanes formed by hydrolytic polycocondensation of tetraethoxysilane with boric acid under the conditions of base catalysis (NH4OH) was studied.

Reactions of silicon fluorides with picolinic acid (PicH) and its O-trimethylsilyl derivative afforded neutral hexa- or pentacoordinate complexes F2SiPic2 (5) and PhFSiPic2 (6). According to NMR data, complex 5 with SiO2N2F2 fragment exists as a mixture of two isomers with equivalent 5a and non-equivalent 5b fluorine atoms in a 1.5:1 ratio. Quantum chemical calculations at the B3LYP/6-311G** level confirm the stability of the lowest-energy transstructure of 5a.