具有生物活性的有机硅化合物研究近况

生物有机硅化合物的研究进展迅速,而且越来越受到人们的重视。实际上,它是有机硅化学的一个新的分支。本文对有机硅化合物的毒理学、有机硅药物化学以及有机硅农药作了简要的论述。     

Synthesis of some triphenylmethyl- and triphenylethylsiloxanes

Summary For the first time 8 pure oxygen-captaining organosilicon compounds were prepared; some of them can be utilized for the preparation of high-molecular organosilicon polymers.     

Infrared laser synthesis and properties of magnetic nano‐iron–polyoxocarbosilane composites

Nano‐magnetic, thermally stable iron‐based composites were obtained by a one‐step procedure consisting of continuous‐wave infrared laser‐induced and ethylene‐sensitized co‐pyrolysis of gaseous iron pentacarbonyl and hexamethyldisiloxane in argon. The simultaneously occurring formation of iron from iron pentacarbonyl and that of organosilicon polymer from hexamethyldisiloxane yield iron nanoparticles surrounded by an organosilicon polymer shell. The particles were characterized by spectral analyses, electron microscopy, thermal gravimetry and magnetic measurements. They become superficially oxidized in the atmosphere. Their composition, thermal behaviour and magnetic properties depend on the flow rates of the precursors and the total pressure of the procedure. Magnetization curves, exchange bias H_ex at T = 5 K and AC susceptibility were studied in the temperature range 5–400 K. The values of H_ex verified the observed degree of the particle surface oxidation. The system of the iron nanoparticles is in a ferromagnetic blocked state and the temperature dependence of the coercivity and susceptibility is in accord with the transmission electron microscopy data. Copyright © 2005 John Wiley & Sons, Ltd.     

Insecticidal potency of certain organosilicon compounds

A small series of organosilicon compounds were screened for efficacy against the housefly Musca domestica. The activity of organosilicon compounds is attributed to the silicon atom, the presence of halogens and the alkyl groups.     

Effects of cyclonic plasma deposited organosilicon nano-coating on 316 stainless steel and its surface characterization

Cyclonic atmospheric pressure plasma is developed to synthesize the organosilicon nano-coating on 316 L stainless steel surface with hexamethyldisilazane (HMDSN) and HMDSN/N₂ monomers. The modified 316 L stainless steel surface characteristics of cyclonic plasma deposited organosilicon nano-coating were evaluated by the static contact angle measurement, FTIR, SEM, AFM, and XPS detections. The chemical analysis with FTIR and XPS depicts that cyclonic plasma deposited nano-coating obtains the relatively inorganic characteristics. The surface morphological determination with SEM and AFM refers cyclonic plasma deposited 316 L stainless steel surface roughness alteration with switching monomer inputs. This study shows the potential of chamber-less deposition to create the plasma deposited organosilicon nano-coating for 316 L stainless.     

Laser‐induced synthesis of iron–iron oxide/methylmethoxysilicone nanocomposite

The IR laser irradiation of a gaseous mixture of iron pentacarbonyl–methoxytrimethylsilane–ethene in argon induces ethene‐photosensitized decomposition of iron pentacarbonyl into elemental iron and decomposition of methyltrimethoxysilane into species that polymerize into methylmethoxysilicone. These two concurrent gas‐phase processes allow formation of iron–iron oxide/methylmethoxysilicone nanocomposite. Spectral analyses and electron microscopy reveal the nanocomposite as consisting of iron clusters oxidized in outer layers and covered with the organosilicon polymer. The procedure shows its potential for gas‐phase synthesis of iron‐based clusters embedded in a polymer matrix. Copyright © 2004 John Wiley & Sons, Ltd.     

Synthesis and optical properties of fluorene‐based polymers incorporating organosilicon unit

The synthesis and optical properties of polymers bearing the repeating unit of terfluorene and various organosilicon groups were investigated. Polymers with high molecular weight and good solubility could be obtained by Suzuki coupling polymerization from silylene‐containing fluorene‐based dibromo monomers and 9,9‐dihexylfluorene‐2,7‐bis(trimethyleneborate). From UV spectra of polymers bearing acyclic silylene bridge, the organosilicon units not only interrupted a π‐conjugation but also contributed to an electronic communication between connected fluorenes. The emission maximum wavelengths (ca. 400 nm) blue‐shifted when compared with that of polyfluorene (418 nm) and the fluorescence quantum yields were considerably high (>0.82) in the CHCl₃ solution. On the other hand, rather broad emission was observed at 480 nm and the fluorescence quantum yield was quite low (0.004) in the solution‐state PL spectrum of tetraphenylsilole‐containing polymer. The polymer emitted visible green light in the spin‐coated film. The fluorescence peak intensity at 486 nm gradually decreased when the film was illuminated with the UV light of 359 nm in air. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4786–4794, 2007     

生物有机硅化合物研究新进展

本文概述了近十几年生物有机硅化学的新进展。全文分三部分:1)利用有机硅基取代有机药物中的活性官能团的硅基化反应;2)有机药物中的某一碳原子被硅原子取代的硅药(sila-drugs)研究;3)在有机药物中没有类似结构的具有生物活性的新型有机硅化合物研究。     

Research and synthesis of organosilicon nonthrombogenic materials containing sulfobetaine group

A novel organosilicon sulfobetaine was synthesized through the reaction of organosilicon containing tertiary amino with 1,3-propanesulfone. Then this organosilicon sulfobetaine was coated onto polyurethane and organosilicon surface to improve their blood compatibility. The existence of sulfobetaine structure on the surface of materials was revealed by ATR-FTIR and XPS. The thermo-capability of synthesized silicone rubber, containing sulfobetaine was revealed by TGA. The blood compatibilities of organosilicon sulfobetaine and other materials such as silicone and PU as reference coated with them were evaluated by platelet-rich plasma adhesion experiment. The novel segmented silicone rubber containing sulfobetaine structure showed perfect blood compatibility.     

Organosilicon compounds containing the furan ring

Hydrolysis of organosilicon esters of 3-(2furyl)acrylic or cinnamic acids, and cohydrolysis with organyltrialkoxysilanes gives organosilicon resins, which solidify when illuminated with UV light.For Part XIII see [1].     

Structure-reactivity relationships in organosilicon chemistry revisited

Available quantitative data of the reactivity of organosilicon compounds were subjected to correlation analysis. As an alternative to the carbon chemistry values, the scale of steric constants E _S (Si) can be used for organosilicon compounds and the inductive effect is best expressed by two terms, involving the parameter of electronegativity of substituents. Alkyl substituents contribute to the reactivity exclusively through their steric effects, steric and polar effects in silicon compounds are additive and the resonance effect is insignificant. The correlation analysis can be employed in investigations of organosilicon reactions along with other methods.      

A novel insight into the inductive effect in silicon chemistry

A revision of quantitative literature data for the reactivity of organosilicon compounds in light of conceptions stemmed from organic chemistry has been carried out. It has been found that in structure-reactivity analysis for organosilicon compounds, differently of carbon compounds, the inductive effect of substituents, at least in nucleophilic displacement reactions at silicon, must be expressed by two terms involving that for electronegativity. A protocol for the correlation analysis in organosilicon chemistry is now available.     

3-dinitrobenzoylhydrazones of organosilicon carbonyl compounds

Conclusions The reaction of 3,5-dinitrobenzoylhydrazide with organosilicon aldehydes and ketones was investigated. It was shown that this reagent forms readily crystallizing 3,5-dinitrobenzoylhydrazones and is suitable for the identification of organosilicon carbonyl compounds.     

Reactivity of Waterlogged Archeological Elm Wood with Organosilicon Compounds Applied as Wood Consolidants: 2D 1H–13C Solution-State NMR Studies

Some organosilicon compounds, including alkoxysilanes and siloxanes, proved effective in stabilizing the dimensions of waterlogged archaeological wood during drying, which is essential in the conservation process of ancient artifacts. However, it was difficult to determine a strong correlation between the wood stabilizing effect and the properties of organosilicon compounds, such as molecular weight and size, weight percent gain, and the presence of other potentially reactive groups. Therefore, to better understand the mechanism behind the stabilization effectiveness, the reactivity of organosilicons with wood polymers was studied using a 2D ¹H–¹³C solution-state NMR technique. The results showed an extensive modification of lignin through its demethoxylation and decarbonylation and also the absence of the native cellulose anomeric peak in siloxane-treated wood. The most substantial reactivity between wood polymers and organosilicon was observed with the (3-mercaptopropyl)trimethoxysilane treatment, showing complete removal of lignin side chains, the lowest syringyl/guaiacyl ratio, depolymerization of cellulose and xylan, and reactivity with the C6 primary hydroxyls in cellulose. This may explain the outstanding stabilizing effectiveness of this silane and supports the conclusion that extensive chemical interactions are essential in this process. It also indicates the vital role of a mercapto group in wood stabilization by organosilicons. This 2D NMR technique sheds new light on the chemical mechanisms involved in organosilicon consolidation of wood and reveals what chemical characteristics are essential in developing future conservation treatments.     

Hydrosilylation,hydrogermylation, and hydrostannylation of some ethylene and acetylene organosilicon derivatives

Conclusions The regioselectivity of the hydrometallation of unsaturated organosilicon componds increases with increasing electron donor properties of the organosilicon substituent. The silatranyl group which has the greatest electron donor effect orients the adding group toward the -carbon of the multiple bond.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1424–1427, June, 1987.     

Organosilicon compounds in supercritical carbon dioxide: Synthesis,polymerization, modification,and production of new materials

The main promising opportunities for the advantageous combination of organosilicon compounds and supercritical carbon dioxide both as a solvent and as a reagent in chemical processes are analyzed. The main processes of polymerization and modification of polymer matrices that are performed in supercritical СО₂ with the use of organosilicon materials of various types are outlined. Methods for the obtaining organosilicon polymers and polymer-inorganic composites and methods for the application of siloxane stabilizers in the dispersion polymerization of monomers in supercritical СО₂ are described. Studies of the insertion of a СО₂ molecule into Si–H, Si–N, and Si–O–Me bonds in reactions that feature exceptionally high chemical selectivity and afford a wide spectrum of products potentially useful for application in the chemistry of polymer materials are considered. It is shown that the silylation of surfaces of various types and morphologies in the medium of supercritical СО₂ is a rapidly developing green approach that makes it possible to obtain highly uniform defect-free coatings with variable desired functionality.     

The influence of an organosilicon modifier on the properties of a compound based on epoxy-urethane oligomer

To improve the performance characteristics of products made of highly-filled polymer compositions, modification of a compound based on epoxy-urethane oligomer was performed. The SH 198 amino functional organosilicon oligomer was used as a modifier. The performed studies established that an organosilicon modifier increases the gel time and the curing time of the composition based on epoxy-urethane oligomer, shows the plasticizing effect on a compound, decreases its glass transition temperature from 16.5 to 9°C, and increases the deformation in the temperature range of from–40 to +50°C.     

Synthesis and properties of novel dialkylaminocarbenium salts

Novel dialkylaminocarbenium salts with metallocomplex counter ions were prepared by the reaction of phosgene with either DMF or tetramethylurea in the presence of metal chlorides. Reactions of organosilicon amides with phosgene gave corresponding carbenium salts, while organosilicon ureas yielded aminoiminocarbenium salts. Dialkylaminochlorocarbenium salts were reduced with hydrosilanes to give dialkylaminocarbenium, salts and can be easily hydrolyzed to afford either amides or ureas. Pathways of the reaction with water and alcohols depend on the nature of reagent and the reaction conditions. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1035–1040, May 1997.     

Highly Selective Hydrothiolation of Unsaturated Organosilicon Compounds Catalyzed by Scandium(III) Triflate

The first use of a Lewis acid catalyst in the addition reaction of both aromatic and aliphatic thiols to unsaturated organosilicon compounds is reported. In catalytic tests, scandium(III) triflate demonstrates high catalytic activity in this process. Under mild conditions (25 °C, room temperature, 1–10 h) a number of thioether‐functionalized organosilicon species are obtained with appreciable selectivity. This study constitutes the first example of allylsilane hydrothiolation that gives the Markovnikov regioisomer as the main product. Ethynylsilanes are also successfully used in the hydrothiolation reaction in the presence of Sc(OTf)₃.     

某些新的氟代有机硅化合物的合成

本文用含硅氢键化合物与含双键的氟化合物的加成反应,制备了一系列未见报导的含氟有机硅化合物。在用氯丙烯与2,2,3,3-四氟丙醇制2,2,3,3-四氟丙基烯丙醚时,对方法进行了改进,提高了产率。本文还报道了含氟有机硅聚合物方面的工作。