Novel Carbosiloxane Dendrimers with End-Grafted Highly Functionalized Building Blocks

This article concentrates on the divergent growth method for the preparation of SiOCH₂CH₂CH₂-based carbosiloxane dendrimers by applying repetitive hydrosilylation-alcoholysis cycles. The silicon atoms thereby act as the branching points producing a tetrahedral four directional core as well as 1→1 and 1→2 branching centres.     

Metallo-Carbosiloxan-Dendrimere mit Titanocendichlorid-Endgruppen

The synthesis of titanocenedichloride end-grafted carbosiloxane dendrimers of the 1^st and 2^nd generation is reported. To find the optimal reaction conditions, Me₂ClSiH (1) was reacted with (η⁵-C₅H₄SiMe₂CHCH₂)(η⁵-C₅H₅)TiCl₂ (2). The best result could be obtained with the Karstedt catalyst, whereby exclusively the β-isomer ((η⁵-C₅H₄SiMe₂CH₂CH₂SiMe₂Cl)(η⁵-C₅H₅)TiCl₂, 3) is formed. Under similar conditions Me₃SiOCH(Me)(CH₂)₄SiMe₂H (4) reacts with 2 to give (η⁵-C₅H₄SiMe₂CH₂CH₂SiMe₂(CH₂)₄CH-(Me)OSiMe₃)(η⁵-C₅H₅)TiCl₂ (5). When using MeSi(OCH(Me)(CH₂)₄SiMe₂H)₃ (6), Si(OCH(Me)(CH₂)₄SiMe₂H)₄ (8) and MeSi[O(CH₂)₃SiMe(OCH(Me)(CH₂)₄SiMe₂H)₂]₃ (10) instead of 1 and 4, the respective metallo dendrimers MeSi[OCH(Me)(CH₂)₄-SiMe₂CH₂CH₂SiMe₂(η⁵-C₅H₄)(η⁵-C₅H₅)TiCl₂]₃ (7), Si[OCH(Me)(CH₂)₄SiMe₂CH₂CH₂SiMe₂(η⁵-C₅H₄)(η⁵-C₅H₅)TiCl₂]₄ (9) and MeSi{O(CH₂)₃SiMe[OCH(Me)(CH₂)₄SiMe₂CH₂CH₂SiMe₂(η⁵- C₅H₄)(η⁵-C₅H₅)TiCl₂]₂}₃ (11) can be isolated.Compounds 3, 5, 7, 9 and 11 were characterised by elemental analysis as well as IR and NMR spectroscopy (¹H, ¹³C{¹H}, ²⁹Si{¹H}).     

Coordination Polymers. 9. Chelate Polymers Derived from Bisphenolic Complexes and Propylenediamine

Chelate polymers derived from bis(2,4-dihydroxybenzaldehyde)propyl-enediimine M and bis(2,4-dihydroxyacetophenone)propylenediimine M (M = Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺) with aromatic acid chlorides were prepared by interfacial polycondensation. Also, chelate polysiloxanes were obtained from the same monomers and α,ω-dichloropolydimethyl-siloxane. The spectral, thermal, magnetic, and electrical properties of the polychelates were studied.     

Carbosiloxandendrimere mit terminalen SiH-Bindungen

An efficient method for the preparation of carbosiloxane dendrimers with end-grafted SiH-bonds is given by using the alcohols HOCH(Me)(CH₂)₄SiMe_3 − nH_n (4a: n = 1, 4b: n = 2, 4c: n = 3), which themselves are accessible by the hydrosilylation of MeCOCH₂CH₂CHCH₂ (1) with the chlorosilanes HSiMe_3 − nCl_n (2a: n = 1, 2b: n = 2, 2c: n = 3) and hydrogenation of the latter species with Li[AlH₄]. Alcohols 4a-4c can be used as starting materials for the preparation of carbosiloxane dendrimers of the 1^st-3^rd generation. For the synthesis of the 1^st generation dendrimers, Me_4 − mSiCl_m (5a: m = 1, 5b: m = 2, 5c: m = 3, 5d: m = 4) is reacted with 4a-4c in presence of NEt₃ as base. The dendritic molecules Me_4 − mSi[OCH(Me)(CH₂)₄SiMe_3 − nH_n]_m (n = 1: 6a, m = 1; 6b, m = 2; 6c, m = 3; 6d, m = 4. n = 2: 7a, m = 1; 7b,m = 2; 7c, m = 3; 7d, m = 4. n = 3: 8a, m = 3; 8b, m = 4) are thereby obtained in excellent yield. Carbosiloxane dendrimers of the 2^nd and 3^rd generation with a MeSiO₃- or SiO₄-core can be isolated from the reaction of MeSi(OCH₂CH₂CH₂SiMe₂Cl)₃ (9), MeSi(OCH₂CH₂CH₂SiMeCl₂)₃ (11), Si(OCH₂CH₂CH₂SiMe₂Cl)₄ (13) and MeSi(OCH₂CH₂CH₂SiMe(OCH₂CH₂CH₂SiMe₂Cl)₂)₃ (15) with 4a or 4b, respectively, under similar reaction conditions. Thereby MeSi[OCH₂CH₂CH₂SiMe₂OCH(Me)(CH₂)₄SiMe₂H]₃ (10), MeSi[OCH₂CH₂CH₂SiMe[OCH(Me)(CH₂)₄SiMe_3 − nH_n]₂]₃ (12a, n = 1; 12b, n = 2), Si[OCH₂CH₂CH₂SiMe[OCH(Me)(CH₂)₄SiMe₂H]₂]₄ (14) and MeSi[OCH₂CH₂CH₂SiMe[OCH₂CH₂CH₂SiMe₂OCH(Me)(CH₂)₄SiMe_3 − nH_n]₂]₃ (16) are formed as colourless oils.Compounds 3, 4, 6-8, 10, 12, 14 and 16 were characterised by elemental analysis as well as spectroscopic (IR, NMR) and mass spectrometric (ESI-TOF) studies.     

紫外光引发硅氢加成反应制备超支化聚碳硅氮烷

在二乙酰丙酮铂存在下, 以紫外光引发AB4型单体双(N,N-二烯丙基胺基)甲基硅烷发生硅氢加成反应, 制备了超支化聚碳硅氮烷. 聚合产物通过FTIR, 1H NMR, 13C NMR和29Si NMR谱和体积排除色谱/激光光散射联用技术进行表征. 与常规加热条件下Karstedt's催化剂催化的硅氢加成聚合相比, 光引发聚合的反应速度快. 波谱分析表明, 聚合过程中以α位硅氢加成反应为主. 光引发聚合制备的超支化聚碳硅氮烷支化度(DB)和平均支化数(ANB)分别为0.46和0.53, 与理论值相近. 其重均分子量为12500 g/mol, 分子量分布系数为2.1, Mark-Houwink方程指数α为0.44, 与热聚合制备的超支化聚碳硅氮烷的参数相近.     

长链超支化聚合物的合成研究进展

长链超支化聚合物(HyperMacs)凭借其含有大量的功能端基和可调控的链结构等优点已经引起国内外科研人员越来越广泛的关注。HyperMcs除了拥有超支化聚合物固有的低粘度、溶解性好、含有大量的功能性端基的特点外,同时拥有高剪切敏感性、熔体弹性、冲击强度和零剪切粘度,因而在药物载体、能量存储及传递和纳米催化剂等方面可能拥有更为广泛的应用。本文根据HyperMacs合成方法的不同,分别从迭代法和ABx线型大分子单体法两个主要方面对其研究进展进行了总结和评述,并在此基础上展望了该类聚合物的研究方向和发展趋势。     

New poly(amide-imide) siloxane copolymers by polycondensation

Some new poly(amide-imide) siloxane copolymers have been synthesized by solution polycondensation of some aromatic diamines with siloxanic diacids having preformed imide rings. Two polycondensation techniques were used: polycondensation of aromatic diamines with diacid chlorides and direct polycondensation of aromatic diamines with diacids in the presence of organic phosphites, following the Yamazaki-Higashi phosphorylation technique. In all cases the reactions were carried out using equimolecular amounts of the two monomers, in polar aprotic solvents and inert atmosphere.The obtained compounds were characterized by elemental C, H and Si analysis, solubility tests, IR and ¹H-NMR spectrometry. Thermogravimetric curves were also recorded. All data agree with the proposed structures.     

SYNTHESIS OF POLYSILOXANE-SUPPORTED SELENAETHER PLATINUM COMPLEX AND ITS CATALYTIC PROPERTY FOR HYDROSILYLATION OF OLEFINS

A new type of selenious polymer, silica-bound polybispropoxyethyl-selenidesilsesquioxane,and its platinum complex were synthesized from bis-allyloxyethyl selenide via hydrosily-lation with triethoxysilane, followed by immobilized on fumed silica, and then reactingwith potassium chloroplatinite under nitrogen atmosphere in acetone. It was found thatthe platinum complex can catalyze the hydrosilylation of olefins with triethoxysilane effec-tively The effects of the nature of the substrate, the amount of complex used, and thereaction temperature on the catalytic activity were investigated.     

聚γ-(β-氰乙硫基)两基硅氧烷铑配合物的合成与催化硅氢化性能

γ-巯丙基三乙氧基硅烷与丙烯腈加成，得到γ－（β-氰乙硫基）丙基三乙氧基硅烷，后者依次与气相法二氧化硅、三氯化铑作用，合成了聚γ-（β-氰乙硫基）丙基硅氧烷铑配合物，研究了其催化烯烃与三乙氧基硅烷硅氢加成反应的特性。     

SYNTHESIS AND CATALYTIC BEHAVIOR OF POLYSILOXANESUPPORTED FULLERENE PLATINUM OR RHODIUM COMPLEXES*

Two polysiloxanes with pendant fullerene moieties and their platinum or rhodium complexes havebeen prepared from C_(60) via amination with ω-decenylamine, followed by hydrosilylation with triethoxysilaneand immobilization on fumed silica or by hydrosilylation with methyldichlorosilane and polycondensationwith polydimethylsiloxanol, and then by reacting them with potassium chloroplatinite or rhodium chloride inacetone respectively under argon atmosphere. It was found that the four noble metal complexes are effectivecatalysts for the hydrosilylation of olefins with triethoxysilane. The regioselcctivity of platinum complexesfor styrene increases remarkably by introducing C_(60) moiety. Factors influencing catalytic activity and themechanism have been investigated.     

有机硅聚合物负载环硫乙烷铂配合物的合成与催化性能

<正> 有机硅聚合物负载硫醚与铂的配合物可作为烯烃硅氢加成的有效催化剂,但其中部分配合物的回收再用性能不太理想,合成亦比较繁琐。考虑到环硫乙烷中硫原子的未共用电子对远比一般硫醚中硫原子的未共用电子对更加暴露,有可能与过渡金属形成更稳定的配合物,从而减少催化过程中金属的流失,我们合成了气相法二氧化硅固载的聚-4-氧杂-6,7-环硫庚基硅氧烷铂配合物,研究了该配合物对烯烃硅氢加成反应的催化性能。本文报道所得到的一些结果。     

CROSSLINKABLE SILYLDIHYDROARYLENES

ABSTRACT

Crosslinkable silyldihydroarylenes were synthesized starting from 1,4-(dimethylhydrosilyl)dihydronaphthalene and 9,10-(dimethylhydrosilyl) dihydro-anthracene via catalytic addition of the Si-H reactive groups to the unsaturated bond of triethoxyvinylsilane. Subsequent condensation of the alkoxyl groups leads to bridged polysilsequioxanes which could be used to generate protective layers. IR, and ¹H-NMR spectral analyses were performed in order to determine the chemical structure of the bis(triethoxysilylethylene)dihydroarylenes. During crosslinking swelling measurements were performed in order to determine the optimal conditions of the process.     

Wetting Behavior of Tetrasiloxane Surfactants Containing Glucosamide on Low-Energy Surface

The wetting behavior of aqueous solutions of two types of siloxane surfactant (dicephalic and gemini) on two hydrophobic substrates was investigated. Solutions of dicephalic surfactant demonstrate rapid and complete wetting on Parifilm surface and only partial wetting on Teflon. An increase in surfactant concentration results in a transition from partial to complete wetting. The solutions of gemini surfactant show only partial wetting on both Teflon and Parifilm. It is demonstrated that wetting behavior depends crucially on surfactant structure; substrate surface affects the wetting behavior of siloxane surfactant.     

Determination of decamethylcyclopentasiloxane in air using commercial solid phase extraction cartridges

Decamethylcyclopentasiloxane (D₅), a high production volume chemical used in personal care products, has been designated for regulation in Canada and is under review in the EU because of concerns about its persistence and potential for bioaccumulation in the environment. D₅ is a volatile compound expected to be found primarily in air, but there is little information on atmospheric concentrations due to the lack of sensitive analytical methods. Here a simple and sensitive method to determine D₅ in ambient air is presented. The challenge in the environmental analysis of D₅ is avoiding contamination. Our method is based on the high trapping efficiency of the sorbent Isolute ENV+, combined with a comparably high sampling rate. A small amount of sorbent (10 mg) is eluted in a small volume of n-hexane (0.1–0.6 mL), which is injected onto a GC/MS system without further processing. The simplicity of the method enables the use of a field blank for every sample to trace contamination. The method provides low limits of quantification (∼0.3 ng/m³), good repeatability and limited breakthrough (∼1%). By lowering the limit of quantification compared to published work by almost two orders of magnitude, it became possible to quantify D₅ in ambient air at locations remote from strong point sources. The concentrations at a rural Swedish site ranged from 0.7 to 8 ng/m³ over a period of 4 months.     

聚γ-[N,N-双(β-乙硫乙基)胺基]丙基硅氧烷铑配合物的合成及其催化硅氢化性能

从二(β-氟乙基)烯丙胺出发,通过乙硫醚化、硅氢加成、气相法二氧化硅固载,再与三氯化铑作用,合成了标题配合物,它们是烯烃与三乙氧基硅烷的硅氢加成反应的有效催化剂,对其催化特性进行了研究。     

Hyperbranched Aromatic Polyesters

Summary: Having developed a theoretical model of hyperbranched polymerization involving AB₂ and B₂ monomers we present preliminary results of a test of its validity for the system consisting of 4,4-bis(4-hydroxyphenyl)pentanoic acid (AB₂ monomer) and bisphenol A (B₂ monomer). The monomers reacted at room temperature to yield the title hyperbranched polyesters. Diisopropylcarbodiimide (condensation water remover) along with an effective catalyst were used for that purpose. The total of AB₂ monomer was introduced at once to a reactor containing B₂ core monomer or it was divided into 3 or 5 equal portions and each of them introduced after the monomers previously present have reacted to a predetermined conversion. GPC measurements of the resulting molecular mass distribution gave inconclusive results because of poor reproducibility of polymer isolation/purification procedure and/or insufficient accuracy of GPC technique.     

超支化有机硅基聚合物

超支化有机硅基聚合物(HBOSP)是一类新型功能性半有机半无机聚合物,在催化剂载体、陶瓷前驱体、发光材料和耐热材料等领域都有非常广阔的应用前景.本文概述了近10年来利用ABx、A2-Bx或A2-B'Bx-1以及Bf-ABx型单体制备新型结构HBOSP的进展,以及对这类聚合物的分子量及其分布和支化度调控的研究进展;着重总结了近年来针对该类聚合物的端基功能化改性及其应用情况,并在此基础上展望了该类聚合物的研究趋势.     

超支化聚碳硅氮烷的合成与表征

聚碳硅氮烷是一种新型含硅有机金属聚合物,其主链由硅氮碳连接而成,侧链为有机基团;与其它含硅聚合物(聚硅氮烷、聚碳硅烷等)类似,聚碳硅氮烷适于用做力学性能极佳且耐高温氧化的氮化硅(Si3N4)和氮化硅/碳化硅(Si3N4/SiC)复相陶瓷的前驱体.[1]超支化聚合物具有溶解性好、粘度低     

Expanded ring N-heterocyclic carbene complexes of zero valent platinum dvtms (divinyltetramethyldisiloxane): Highly efficient hydrosilylation catalysts

The synthesis and characterisation of a series of new 6- and 7-membered NHC (N-heterocyclic carbene) complexes 7-12 of zero valent platinum dvtms (divinyltetramethyldisiloxane), [Pt(NHC)(dvtms)] are reported. A number of the complexes were investigated as catalyst precursors in the hydrosilylation of a range of unsaturated substrates, including alkynes, alkenes and a ketone with triethylsilane and bis(trimethylsiloxy)methylsilane (MD’M), at low catalyst loading (0.005 mol %); in general, the activity, and the selectivity for 1-functionalised product was found to be high.