- A novel photosensitive silicone ladder polymer: Synthesis, photochemical, and thermal characteristics
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A negative working photosensitive silicone ladder polymer (PVSQ) based on polyphenylsilsesquioxane with vinyl groups as a reactive substituents in the side chain, and 2,6-bis(azidobenzylidene)4-methylcyclohexanone (BA) as a photocrosslinker, has been developed. The monodisperse PVSQ was synthesized by co-polymerization of trichlorophenylsilane and trichloro(vinyl)silane with potassium hydroxide in isobutyl methyl ketone. The PVSQ film showed excellent transparency above 280 nm and high solubility in organic solvents. The photosensitive PVSQ containing 3 wt% of BA showed the sensitivity of 40 mJ cm-2 when it was exposed to 365 nm light (i-line) followed by development with a mixture solution of anisole and xylene at 25 °C. The photosensitive PVSQ film also showed high thermal stability (decomposition temperature: 520 °C) and low dielectric constant (3.2/1 MHz), demonstrating a high potential for application to LSI production.
- Yasuda, Naoki,Yamamoto, Shigeyuki,Adachi, Hiroshi,Nagae, Suguru,Wada, Yuji,Yanagida, Shozo
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- Structural Control of Fully Condensed Polysilsesquioxanes: Ladderlike vs Cage Structured Polyphenylsilsesquioxanes
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Through fine-tuning of the myriad of reaction conditions for an aqueous base-catalyzed hydrolysis-polycondensation reaction, a facile synthesis of structurally controlled polyphenylsilsesquioxanes was developed. Mechanism and kinetic studies indicated that the condensation reaction proceeded through a T1 structured dimer, which was quantitatively and in situ formed through mild hydrolysis of a phenyltrimethoxysilane (PTMS) monomer, to give either the cage-structured polyhedral oligomeric silsesquioxanes (POSS) or the corresponding ladderlike silsesquioxane (LPSQ) with excellent yields. Ladderlike and POSS materials were selectively achieved at higher and lower initial concentrations of PTMS, respectively, and an in-depth spectroscopic analysis of both compounds clearly revealed their structural differences with different molecular weights.
- Choi, Seung-Sock,Lee, Albert S.,Hwang, Seung Sang,Baek, Kyung-Youl
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- Transparent red -emitting silicone resin for color conversion and encapsulation of NUV light-emitting diodes
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Herein, a novel transparent phenyl vinyl silicone resin nanocomposite containing exfoliated fluorescent Eu-containing hydrotalcite-like compound (EFHSN) is developed to serve as a dual role of color conversion and encapsulation material. Excited by near-NUV light, the EFHSN emits a strong characteristic red light (614?nm). Meanwhile, the EFHSN shows not only excellent transparency (T?>?95%) in the UV-Vis region and high refractive index (1.46) but also superior thermal stability, which could meet the need of commercial encapsulation materials and optical application. Therefore, the EFHSN is expected to be used in InGaN-based NUV light-emitting diodes and flexible optoelectronic device.
- Chen, Hong,Wang, Yao,Lin, Jianhui,Shuai, Minmin,Zhu, Haidi,Zhang, Wengong,Ling, Qidan
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- Ruthenacyclic Carbamoyl Complexes: Highly Efficient Catalysts for Organosilane Hydrolysis
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The ruthenacyclic carbamoyl complexes [RuX{2-NHC(O)C5H3NR}(CO)2(NCMe)] (R = H and Me; X = Br and SC6H3-o,o-Me2) are excellent catalysts for the hydrolysis of organosilanes, particularly towards primary silanes, generating hydrogen under ambient conditions within seconds. These complexes are structural mimics of the [Fe]-hydrogenase active site and like the natural enzyme, a labile ligand at the sixth coordination site is essential to the catalytic activity.
- Barik, Chandan Kr,Ganguly, Rakesh,Li, Yongxin,Leong, Weng Kee
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- Kinetics and Mechanism of Hydrolysis of a Silicate Triester, Tris(2-methoxyethoxy)phenylsilane
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The kinetics of hydrolysis in dilute aqueous solution of tris(2-methoxyethoxy)phenylsilane to phenylsilanetriol have been studied.The hydrolysis exibits specific acid and general base catalysis, the latter with a Broensted β value of 0.7.The specific acid catalysis mechanism is probably A-2 (kH3O+/D3O+ = 1.24, ΔS = -39 cal deg-1 mol-1).At high pH (>10) the rate of appearance of the triol is limited by the rate of hydrolysis of one of the intermediates in the hydrolysis sequence, bis(2-methoxyethoxy)phenylsilanol, which, under these conditions, forms an inert anion.At lower pH the hydrolysis of bis(2-methoxyethoxy)phenylsilanol is several times faster than that of tris(2-methoxyethoxy)phenylsilane while that of the second intermediate, 2-methoxyethoxyphenylsilanediol, is probably faster than the above two hydrolyses at all pHs.It is argued that the form of general base catalysis observed suggests that the base-catalyzed reactions involve either an SN2**-Si or SN2*-Si mechanism with formation of a pentacoordinate intermediate.Generalization of the argument used here is explored.
- McNeil, K. J.,DiCaprio, J. A.,Walsh, D. A.,Pratt, R. F.
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- METHOD FOR PRODUCING SILANOLS AND NOVEL SILANOLS
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PROBLEM TO BE SOLVED: To provide a method for efficiently producing silanols useful as functional chemicals, and to provide novel silanols. SOLUTION: There is provided a method for producing silanols including a reaction step of reacting alkoxysilanes having Si-OR bonds (R represents a hydrocarbon group having 1 to 6 carbon atoms) with water or heavy water in the presence of a catalyst, wherein a method for producing silanols having an Si-OR' bond (R' represents a hydrogen atom or a deuterium atom) is characterized in that the catalyst is an inorganic solid acid catalyst having a regular pore structure. There is also provided novel silanols obtained thereby. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
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Paragraph 0053-0054; 0059; 0087-0088
(2021/08/13)
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- Synthesis of a Gold–Metal Oxide Core–Satellite Nanostructure for In Situ SERS Study of CuO-Catalyzed Photooxidation
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This work reports on an assembling–calcining method for preparing gold–metal oxide core–satellite nanostructures, which enable surface-enhanced Raman spectroscopic detection of chemical reactions on metal oxide nanoparticles. By using the nanostructure, we study the photooxidation of Si?H catalyzed by CuO nanoparticles. As evidenced by the in situ spectroscopic results, oxygen vacancies of CuO are found to be very active sites for oxygen activation, and hydroxide radicals (*OH) adsorbed at the catalytic sites are likely to be the reactive intermediates that trigger the conversion from silanes into the corresponding silanols. According to our finding, oxygen vacancy-rich CuO catalysts are confirmed to be of both high activity and selectivity in photooxidation of various silanes.
- Bai, Lu,Fan, Chenghao,Hu, Yanfang,Li, Yonglong,Liu, Jun,Shi, Faxing,Xie, Wei,Yang, Ling,Zhang, Kaifu,Zhao, Yaran
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p. 18003 - 18009
(2020/08/21)
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- Endogenous X-C=O species enable catalyst-free formylation prerequisite for CO2reductive upgrading
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CO2, the main component of greenhouse gas, is currently developed as a promising surrogate of carbon feedstock. Among various conversion routes, CO2undergoing catalytic reduction can furnish hydrogen/energy carriers and value-added chemicals, while specific metal-containing catalysts or organocatalysts are often prerequisite for smooth proceeding of the involved reaction processes. In this work, both formic acid and N-containing benzoheterocyclic compounds (including various benzimidazoles, benzothiazole, and benzoxazole) along with silanols could be synthesized with high yields (>90%) from catalyst-free reductive upgrading of CO2under mild conditions (50 °C). The endogenous X-CO species, derived from the N-methyl-substituted amide-based solvent [Me2N-C(O)-R], especially PolarClean, and O-formyl group [O-C(O)-H] of in situ formed silyl formate, were found to play a prominent promotional role in the activation of the used hydrosilane for reductive CO2insertion, as demonstrated by density functional theory (DFT) calculations and isotopic labeling experiments. Moreover, reaction mechanisms and condition-based sensitivity assessment were also delineated.
- Dai, Wenshuai,Li, Hu,Saravanamurugan, Shunmugavel,Wu, Hongguo,Yang, Song
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supporting information
p. 5822 - 5832
(2020/10/21)
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- Silanol Compound, Composition, and Method for Producing Silanol Compound
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The purpose of the present invention is to provide silanol compounds that can be used as raw materials of siloxane compounds and the like, and a composition of the silanol compounds, as well as to provide a production method that makes it possible to produce silanol compounds at excellent yield. A composition comprising 5 mass % to 100 mass % of a silanol compound represented by Formulas (A) to (C) can be prepared by devising to produce silanol compounds under water-free conditions, to produce silanol compounds in a solvent having the effect of suppressing the condensation of silanol compounds, and to perform other such processes, the composition being able to be used as a raw material or the like of siloxane compounds because the silanol compounds can be stably present in the resulting composition.
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Paragraph 0182; 0184; 0188-0194; 0196; 0200; 0208
(2017/07/14)
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- Trapping Aluminum Hydroxide Clusters with Trisilanols during Speciation in Aluminum(III)–Water Systems: Reproducible, Large Scale Access to Molecular Aluminate Models
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To gain molecular level insights into the properties of certain functions and units of extended oxides/hydroxides, suitable molecular model compounds are needed. As an attractive route to access such compounds the trapping of early intermediates during the hydrolysis of suitable precursor compounds with the aid of stabilizing ligands is conceivable, which was tested for the aluminum(III)/water system. Indeed, trisilanols proved suitable trapping reagents: their presence during the hydrolysis of AliBu2H in dependence on the amount of water used allowed for the isolation of tri- and octanuclear aluminum hydroxide cluster complexes [Al3(μ2-OH)3(THF)3(PhSi(OSiPh2O)3)2] (1) and [Al8(μ3-OH)2(μ2-OH)10(THF)3(p-anisylSi(OSiPh2O)3)4] (2). 1 can be regarded as the Al(OH)3cyclic trimer, where six protons have been replaced by silyl residues. While 2 features a unique [Al8(μ3-OH)2(μ2-OH)10]12+core. In contrast to most other known aggregates of this type, 1 and 2 can be readily prepared at reasonable scales, dissolve in common solvents, and retain an intact framework even in the presence of excessive amounts of water. This finding paves the way to future research addressing the reactivity of the individual functional groups.
- Lokare, Kapil Shyam,Frank, Nicolas,Braun-Cula, Beatrice,Goikoetxea, Itziar,Sauer, Joachim,Limberg, Christian
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supporting information
p. 12325 - 12329
(2016/10/13)
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- In a method of manufacturing a condition anhyride silanolated
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PROBLEM TO BE SOLVED: To provide a method capable of synthesizing silanol under an anhydrous condition and a mild condition, adapting to substrates having various substituents, and producing siloxanes freely at an excellent yield, while having high structure controllability.SOLUTION: By a hydrogen addition reaction in which benzyloxy-substituted silanes are used as a silanol precursor, and a metal in the group 9 or 10 on the periodic table or a metal compound is used as a catalyst, corresponding silanols can be produced safely and easily at a high yield under an anhydrous condition and a mild condition, and especially object silanols can be isolated easily by using a carbon-carrying catalyst.
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Paragraph 0032
(2018/03/24)
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- Synthesis of colloidal Janus nanoparticles by asymmetric capping of mesoporous silica with phenylsilsesquioxane
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Colloidal mesoporous silica nanoparticles asymmetrically capped with non-porous phenylsilsesquioxane have been prepared by adding phenyltriethoxysilane to an aqueous dispersion of mesostructured silica-surfactant composite nanoparticles. The integration of colloidal stability, mesoporosity and the Janus structure is quite promising for materials design applicable in various fields, including catalysis, biomedicine and coatings.
- Ujiie, Hiroto,Shimojima, Atsushi,Kuroda, Kazuyuki
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supporting information
p. 3211 - 3214
(2015/06/03)
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- Nonhydrolytic synthesis of silanols by the hydrogenolysis of benzyloxysilanes
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The hydrogenolysis of benzyloxysilanes was smoothly catalyzed by Pd/C in THF to give corresponding silanols under nonhydrolytic conditions. The reaction proved to be applicable to various benzyloxysilanes giving silanemonools, diol, and triol.
- Igarashi, Masayasu,Matsumoto, Tomohiro,Sato, Kazuhiko,Ando, Wataru,Shimada, Shigeru
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supporting information
p. 429 - 431
(2014/04/17)
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- A tripodal trisilanol ligand and its complexation behavior towards Cu I, CuII, and ZnII
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A three-step synthetic route for a new tripodal branched trisilanol ligand PhSi(OSiPh2OH)3 (LH3) was developed. X-ray diffraction analysis revealed that the trisilanol crystallizes as a dimer with a cyclic hydrogen-bonding network. The reaction of LH3 with three equivalents of CunMesn (Mes = mesityl) led to a hexanuclear compound [L2Cu6] (1), which was characterized by single-crystal X-ray diffraction analysis as well as by solution NMR spectroscopy. The crystal structure of 1 revealed that the compound features a hexagonal planar CuI6 ring, which is the first of its kind in an oxygen environment. Deprotonation of the ligand with n-butyllithium and subsequent reaction with CuBr2 resulted in the dinuclear Cu II complex [L2Cu2][Li(THF2)] 2 (2, THF = tetrahydrofuran), which contains a new siloxide ligand formed from L3- by the elimination of a SiOPh2 unit, as evidenced by X-ray diffraction analysis. To check if the "Ph 2SiO" elimination is a general behavior of this trisilanol, the reaction with ZnBr2 was investigated under analogous conditions. However, this led to the isolation of [L2Zn2][Li(OEt)] 2 (3) without any rearrangement of the siloxide ligand. A tripodal branched trisilanol ligand PhSi(OSiPh2OH)3 (LH 3) was synthesized. Its reaction with three equivalents of Cu nMesn (Mes = mesityl) led to a hexanuclear compound [L2Cu6] with a planar CuI6 ring. Deprotonation of LH3 with n-butyllithium and subsequent reaction with either CuBr2 or ZnBr2 resulted in dinuclear complexes. In the case of CuBr2, the original ligand eliminates a "Ph 2SiO" unit. Copyright
- Schax, Fabian,Braun, Beatrice,Limberg, Christian
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p. 2124 - 2130
(2014/05/06)
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- A tripodal trisilanol ligand and its complexation behavior towards CuI, CuII, and ZnII
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A three-step synthetic route for a new tripodal branched trisilanol ligand PhSi(OSiPh2OH)3 (LH3) was developed. X-ray diffraction analysis revealed that the trisilanol crystallizes as a dimer with a cyclic hydrogen-bonding network. The reaction of LH3 with three equivalents of CunMesn (Mes = mesityl) led to a hexanuclear compound [L2Cu6] (1), which was characterized by single-crystal X-ray diffraction analysis as well as by solution NMR spectroscopy. The crystal structure of 1 revealed that the compound features a hexagonal planar CuI6 ring, which is the first of its kind in an oxygen environment. Deprotonation of the ligand with n-butyllithium and subsequent reaction with CuBr2 resulted in the dinuclear CuII complex [L′2Cu2][Li(THF2)]2 (2, THF = tetrahydrofuran), which contains a new siloxide ligand formed from L3- by the elimination of a SiOPh2 unit, as evidenced by X-ray diffraction analysis. To check if the "Ph2SiO" elimination is a general behavior of this trisilanol, the reaction with ZnBr2 was investigated under analogous conditions. However, this led to the isolation of [L2Zn2][Li(OEt)]2 (3) without any rearrangement of the siloxide ligand. A tripodal branched trisilanol ligand PhSi(OSiPh2OH)3 (LH3) was synthesized. Its reaction with three equivalents of CunMesn (Mes = mesityl) led to a hexanuclear compound [L2Cu6] with a planar CuI6 ring. Deprotonation of LH3 with n-butyllithium and subsequent reaction with either CuBr2 or ZnBr2 resulted in dinuclear complexes. In the case of CuBr2, the original ligand eliminates a "Ph2SiO" unit.
- Schax, Fabian,Braun, Beatrice,Limberg, Christian
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p. 2124 - 2130
(2015/04/27)
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- Highly selective oxidation of organosilanes with a reusable nanoporous silver catalyst
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Room temperature highly selective oxidation of organosilanes to organosilanols and organosilyl ethers is achieved in liquid-phase with dealloyed nanoporous silver catalysts. In both cases, aromatic and aliphatic silanes can be effectively converted into the corresponding silanols and silyl ethers by using water and alcohols as oxidant, respectively. Moreover, hydrogen gas is the only by-product and the catalyst can be recycled for several times without evident loss of activity and selectivity.
- Li, Zhiwen,Zhang, Congcong,Tian, Jing,Zhang, Zhonghua,Zhang, Xiaomei,Ding, Yi
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- POLYSILOXANE COMPOUND AND METHOD OF PRODUCING THE SAME
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A polysiloxane represented by the formula (1) or (2): where R, R1, R2, m and n are defined in the specification.
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Page/Page column 20
(2011/08/04)
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- Catalytic oxidation of silanes by carbon nanotube-gold nanohybrids
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Turning over silanes: The first nanotube-based catalytic system for silane oxidation is reported (see scheme). The reusable gold-nanotube hybrid cleanly oxidizes both alkyl and aryl silanes in high yields, under mild reaction conditions, and compares most favorably to any other catalytic system in terms of overall efficacy and turnover values. Copyright
- John, Jubi,Gravel, Edmond,Hagege, Agnes,Li, Haiyan,Gacoin, Thierry,Doris, Eric
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supporting information; experimental part
p. 7533 - 7536
(2011/10/04)
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- The enzymatic cleavage of Si-O bonds: A kinetic analysis of the biocatalyzed hydrolysis of phenyltrimethoxysilane
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Previously we reported the ability of trypsin to mediate the cross-linking of alkoxysily-functionalized silicone polymers. Although enzymes and silicon-containing compounds are not necessarily incompatible species, the exact mechanism of how enzymes process silicon substrates is not fully understood. The focus of this current work was to examine the reaction kinetics associated with the processing of an alkoxysilane substrate by enzymes using 29Si NMR so as to gain a greater insight into the actual reaction mechanism, especially those involving more complex silicone systems. A series of time course 29Si NMR experiments using D2O revealed that the trypsin-mediated hydrolysis of a single alkoxy moiety in water is a pseudo-first order reaction. The relative effect of the enzyme was determined to be β = 3.549 while the relative effect of water was γ = 3.325. Prolonged contact with phenyltrimethoxysilane was not sufficiently deleterious to the enzyme and did not induce the complete and irreversible denaturation of trypsin. Computational evidence suggests that while in the active site of the enzyme, serine addition to silicon to forms a pentacoordinate species and is favoured over histidine addition.
- Frampton, Mark B.,Simionescu, Razvan,Dudding, Travis,Zelisko, Paul M.
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experimental part
p. 105 - 112
(2011/01/03)
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- Nanostructured materials as catalysts: Nanoporous-gold-catalyzed oxidation of organosilanes with water
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Pores to the fore: Nanoporous gold shows a remarkable catalytic activity for the oxidation of organosilane compounds with water. The catalyst is easily recoverable and can be reused several times without leaching and loss of activity. Copyright
- Asao, Naoki,Ishikawa, Yoshifumi,Hatakeyama, Naoya,Menggenbateer,Yamamoto, Yoshinori,Chen, Mingwei,Zhang, Wei,Inoue, Akihisa
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experimental part
p. 10093 - 10095
(2011/03/16)
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- Study of the supramolecular Architecture-Directed synthesis of a Well-Defined Triple-Chain ladder polyphenylsiloxane
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High molecular weight (Mw) triple-chain ladder polyphenylsiloxane (TCLP) was synthesized by a supramolecular architecture-directed approach. First,. a bis(phenyldihydroxysiloxy) dimethoxysilane ladder monomer was self-assembled via hydrogen bonding interactions in acetonitrile/toluene (1:1, v/v) solution to form a ladder superstructure (LS). Then the LS was used as a template to direct the whole polymerization process. Lyophilization and surface-enhanced synchronous growth polycondensation process of the LS gave a ladder dimethoxysiloxy-bridged polyphenylsiloxane (DCLP) with gaseous triethylamine as condensation catalyst. Then DCLP was hydrolyzed to form a triple-chain ladder superstructure (TCLS), which was further converted into the target TCLP via subsequent in situ dehydration condensation. The three ladder entities formed during the polymerization, that is, LS, DCLP, and TCLP, have been well characterized. X-ray diffraction shows two Bragg reflections representing the ladder width and ladder thickness, respectively. 29Si NMR analysis illustrates narrow peaks with the peak width at half-height of 0.5-2.5 ppm for the repeat units of the entities, indicating fine ladder regularity. In addition, an investigation of the dependence of the intrinsic viscosity [η] on molecular weight (M w) in Mark-Houwink-Sakurada equation gave the exponent factor α = 1.19, suggesting the target TCLP had a semirigid ladder structure. Meanwhile, high-resolution transmission electron microscopy observations showed a regular morphological structure for TCLP with a molecular width of ca. 1.4 nm. This value is quite close to the X-ray diffraction data. Dynamic mechanical analysis experiments also indicated TCLP has high storage modulus and high thermal stability.
- Ren, Zhongjie,Xie, Ping,Jiang, Shidong,Yan, Shouke,Zhang, Rongben
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experimental part
p. 2130 - 2136
(2011/10/08)
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- High performance siloxane-containing polymers
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Catalytic cross-dehydrocoupling polymerization of silane and water, and deaminative polymerisation between silanol and aminosilane are used to synthesize a variety of silicon-containing polymers with controlled structure. n-Hexylamine-2-ethylhexoate was used to catalyze silanol condensation. Among transition metal derivatives investigated, Pd2(dba)s is the most active catalyst for the dehydrocoupling polymerisation, and deaminative polymerisation proceeded smoothly by heating. Optically active siloxane materials of branched structure were obtained from (S,S)-1,3-dimethyl-1,3- diphenyldisiloxanediol and (S,S)-1,5-di(1-naphthyl}-1,5-diphenyl-1,5-divinyl-3- methyltrisiloxane (>99% ee) as optically active building blocks.
- Kawakami, Yusuke,Imae, Ichiro,Oishi, Motoi,Seino, Makoto,Liu, Yang
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- Polyorganosilsesquioxane and process for preparing the same
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Provided are polyorganosilsesquioxane and process for preparing the same. The polyorganosilsesquioxane is obtained by various methods including polymerization of an organosilanetriol as starting materials. The polyorganosilsesquioxane has convenience in handling and controlling the rate of polymerization, and structure of highly regular form, and be imparted high functionality and various characteristics as compared to a conventional polyorganosilsesquioxane.
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- Phenylsilanetriol - Synthesis, stability, and reactivity
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Crystalline phenylsilanetriol, PhSi(OH)3 (1) was obtained by smooth hydrolysis of phenyltrimethoxysilane and characterised by different analytical methods (wide angle X-ray powder diffraction, NMR, IR, thermogravimetric analysis). The title-compound is surprisingly stable in the solid state but slowly condenses in acetone solution. Reaction of 1 with Me3SiCl and Me2(CH2 Cl)SiCl gave the corresponding tris-triorganylsiloxy substituted derivatives in high yields.
- Korkin,Buzin,Matukhina,Zherlitsyna,Auner,Shchegolikhina
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p. 313 - 320
(2007/10/03)
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- Palladium-Catalyzed Cross-Coupling of Silanols, Silanediols, and Silanetriols Promoted by Silver(I) Oxide
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Palladium-catalyzed cross-coupling of aryl- or alkenylsilanols, silanediols, and silanetriols with a variety of iodoarenes by the catalysis of palladium(0) and in the presence of silver(I) oxide furnished the coupling products in good to excellent yields. The reactions of silanediols or silanetriols under similar conditions proceeded much faster than those of silanols to afford the corresponding coupling products in excellent yields within shorter reaction periods (5-12 h). The measurement of the X-ray diffraction (XRD) pattern of the silver residue after the reaction revealed that silver(I) oxide was converted to silver(I) iodide.
- Hirabayashi, Kazunori,Mori, Atsunori,Kawashima, Jun,Suguro, Masahiro,Nishihara, Yasushi,Hiyama, Tamejiro
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p. 5342 - 5349
(2007/10/03)
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