Silicon Chemistry PDF
Preview Silicon Chemistry
Ulrich Schubert (ed.) Silicon Chemistry Springer-Verlag Wien GmbH Univ.-Prof. Dr. Ulrich Schubert Institut für Anorganische Chemie, Technische Universität, Wien, Österreich This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically those of translation, reprinting, re-use of illustrations, broadcasting, reproduction by photo copying machines or similar means, and storage in data banks. © 1999 Springer-Verlag Wien Originally published by Springer-Verlag Wien New York in 1999 Softcover reprint of the hardcover 1st edition 1999 Typesetting: Thomson Press (India) Ltd., New Delhi Printed on acid-free and chlorine-free bleached paper With 89 partly coloured Figures CIP data applied for Special Edition of "Monatshefte für Chemie / Chemical Monthly", Vol. 130, No. 1, 1999 ISBN 978-3-7091-7306-0 ISBN 978-3-7091-6357-3 (eBook) DOI 10.1007/978-3-7091-6357-3 Contents Editorial ............................................................ . Invited Reviews Schlenk C., Frey H. Carbosilane Dendrimers - Synthesis, Functionalization, Application 3 Veith M., Rammo A., Jarczyk M., Huch V Synthesestrategien zur Darstellung von unterschiedlich funktionalisierten Cyclosiloxanen sowie Additions- und Substitutionsreaktionen eines A1 (OHkAchtringes in einem molekularen Oligoalumosiloxan ................. 15 4 Contributions Schneider M., Neumann B., Stammler H.-G., Jutzi P. Structure Determining Effect of Alcohols and Water on the Shape of the Hydrogen Bonded Network in Adducts with (9-Methyl-fluoren-9-yl)-silanetriol ............. 33 Gun' ko Y. K, Nagy L., Briiser W, Lorenz V, Fischer A., Giej3mann S., Edelmann F. T., Jacob K, Vertes A. Silsesquioxane Chemistry II. Tin(IV) and Hafnium(IV) Compounds of Silsesquioxanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Ossadnik C., Veprek S., Marsmann C., Rikowski E. Photolumineszenzeigenschaften von substituierten Silsesquioxanen der Zusammensetzung Rn(Si01.5)n .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Kleewein A., Stuger H. Gezielte Synthese siloxenahnlicher Polymere 69 Vogg G., Zamanzadeh-Hanebuth N., Brandt M. S., Stutzmann M., Albrecht M. Preparation and Characterization of Epitaxial CaSi and Siloxene Layers on Silicon . . 79 2 Schneider A., Kairies S., Rose K Synthesis of Alkoxysilyl Substituted Cyclophosphazenes and their Properties in the Sol-Gel Process .................................................. 89 Tacke R., Heermann J., Piilm M., Gottfried E. A Zwitterionic A?Si-Silicate with an Almost Ideal Square-Pyramidal Si Coordination Polyhedron: Synthesis and Crystal Structure Analysis ......................... 99 Eujen R., Roth A., Brauer D. J. Preparation and Structure of l-(Trifluoro-methyl)silatrane 109 VI Contents Mucha F, Haberecht Jo, Bohme Uo, Roewer Go Hexacoordinate Silicon-Azomethine Complexes: Synthesis, Characterization, and Properties 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 . . . . . . . . . . . . . . . . . . . . . . . .. 117 Huber G., Schmidbaur H. Hexa(amino)disilanes with Saturated Cyclic Amino Ligands 133 Siegl H., Krumlacher W, Hassler K. Synthesis and Structure of P7[Si(SiMe3hh (Tri(hypersilyl)heptaphosphanortricyclane) 139 Helluy X., Kummerlen J., Marschner C., Sebald A. Solid-State Molecular Dynamics of (Ph3Si)Si(SiMe3h Studied by Variable Temperature l3C and 29Si MAS NMR Spectroscopy. . . . . . . . . . . . . . . . . . . . . . . . . .. 147 Weidenbruch M., Grybat A., Saak W, Peters E.-M., Peters K. Reactions of a Cyclotrisilane with Cha1cogen Transfer Reagents 157 Kruger Ro-P, Much H., Schulz Go, Rikowski Eo Zur Charakterisierung von Si-Polymeren durch fliissigchromatographische Verfahren in Kopplung mit MALDI-TOF-MS 0.00.0.0 .. 00 0 . . 0. 0. ......... 0. 0. 0. . 00 0 . . 163 Mueller Co, Frey H., Schmidt Co Phase Behaviour of Poly(di-n-decylsilane) 175 UhligW Synthese, Funktionalisierung und Vemetzung von Poly(silylenphenylenen) 181 Nesper Ro, Wengert So Sr12Mgl7.8Li202Si20, die erste Zintl-Phase mit einer Si3-Kette .... 0. ........... 0. .. 197 Kayser Co, Marschner Co Oligosilylanions and their Reactions with Zirconocene and Hafnocene Dichlorides . 0 203 u., Schubert Kalt Do, Gilges Ho Transition Metal Silyl Complexes LVIII. Silyl Group Exchange between (R)PhPt(SiR3h und HSiR3 0. ............. 0. 0. .. 0. ...... 0. ..... 0. 00 . . . . . .. 207 Lunzer F, Marschner Co, Winkler Bo, Peulecke N., Baumann W, Rosenthal U. Group IV Metallocene Bis(trimethylsilyl)acetylene Complexes as Catalysts in the Dehydrocoupling Polymerization of 1,2-Disubstituted Hydrodisilanes 0.0.0.0 215 Andrii Go, Falk F, Stafast Ho, Witkowicz Eo Deposition of Amorphous Hydrogenated Silicon (a-Si:H): in situ Gas Analysis by Time-of-Flight Mass Spectrometry 0. ...... 0. 00 . .. 0. 0. ..... 0. . . . . . . . . . . .. 221 Maier Go, Reisenauer Ho P, Egenolf Ho Reaktion von atomarem Silicium mit Methanol: Matrixspektroskopische Identifizierung von Methoxysilylen .... 0. 0. ... 0. . 0. 0. 0. . 0. .. 0. ... 0. 00 . ... o. 227 Wagner R., Wu Y., Vo Berlepsch H. Zum Spreitverhalten von Mischungen definierter Trisiloxantenside auf niederenergetischen Oberfllichen ... 0. 0. ... 0. 00 . 0. .. 00 . .. 0. ... 0. 0. 0. 0. .. 0. . 237 Editorial The central position of silicon in the periodic system of the elements, at the borderline between organic and inorganic chemistry on one hand and between metallic and nonmetallic elements on the other hand, results in a manifold and unique chemical behavior of its compounds, hardly paralleled by any other element. Furthermore, silicon and silicon compounds have contributed decisively to the technical progress. Technical applications range from mass commodities to highly sophisticated special materials, from ceramics to polymers, from medicine to microelectronics. To keep pace with scientific and technical developments in other industrial countries in this important area, the Deutsche Forschungsgemeinschaft (DFG) and the Fonds zur Forderung der wissenschaftlichen Forschung in Osterreich (FWF) decided to establish national priority programs (called Schwerpunktprogramm in Germany and Forschungs schwerpunkt in Austria). The programs are strongly linked to each other as well as to some Swiss groups and help to strengthen the scientific "silicon community" in the German-speaking countries. The German Schwerpunktprogramm "Specific phenomena in silicon chemistry: com pounds for the construction and understanding of extended systems with novel proper ties" was established by the DFG in October 1994 and started its work in July 1995 with 34 projects. The program was evaluated in 1997 and then extended into a second funding period with 35 projects. The Austrian Forschungsschwerpunkt "Novel approaches to the formation and reactivity of compounds with silicon-silicon bonds" was established in October 1996 and started its work in January 1997. At mid-term of the German program and the end of the first funding period of the Austrian program it appears appropriate to summarize part of the results in a special publication. I am very glad that the Editors of Monatshefte fur Chemie and Springer Verlag providing the opportunity on that occasion to publish a special issue of "Monats hefte fUr Chemie/Chemical Monthly", of which this volume is a special edition, and that most of the chemical groups participating in the projects agreed to contribute research papers. Although most of the papers are rather short due to page restrictions, this volume gives a very good overview on the current chemical (and partly physical) activities in the joint Austrian/German/Swiss program. My special thanks go to Isabella Krcmaricic and Dr. Hermann Kalchhauser for their technical assistance in publishing this volume. Ulrich Schubert Invited Review Carbosilane Dendrimers - Synthesis, Functionalization, Application Christian Schlenk and Holger Frey* Freiburger Materialforschungszentrum und Institut fur Makromolekulare Chemie, Albert Ludwigs Universitat Freiburg, D-79104 Freiburg, Germany Summary. This micro-review summarizes historical and recent developments in synthesis, functionalization, and characterization of carbosilane dendrimers. These compounds are the most important among the heteroatom-based dendrimers at present due to the flexibility of the synthetic route and to their chemical stability which allows versatile further functionalization. Synthesis as well as application potential of carbosilane dendrimers for catalysis, host-guest chemistry, liquid crystals, and novel polymer topologies is discussed. Keywords. Carbosilane; Dendrimer; Catalysis; Liquid crystals; Hyperbranched. Carbosilandendrimere - Synthese, Funktionalisierung und Anwendung Zusammenfassung. Der vorliegende Mikroreview faSt historische und aktuelle Entwicklungen bezuglich Synthese, Funktionalisierung und Charakterisierung von Carbosilandendrimeren zusam men. Wegen der Variabilitat der Syntheseroute und ihrer chemischen Stabilitat, die weitere Funktionalisierung erlaubt, zahlen diese Verbindungen zu den wichtigsten unter den Heteroatom dendrimeren. Synthese und Potential der Carbosilandendrimere auf den Gebieten der Katalyse, Wirt-Gast-Chemie, Flussigkristalle und neuer Polymertopologien werden diskutiert. 1. Introduction Dendrimers are three-dimensional, highly branched, monodisperse (in the ideal case) macromolecules with perfectly defined branching structure. Together with the hyperbranched polymers they represent the class of the cascade molecules. However, in contrast to the randomly branched hyperbranched polymers, dendrimers possess defined branches emanating from a central core (Fig. 1). The dendrimer scaffold can be subdivided into three regions: (i) the core from which the branching units emanate, (ii) the region of the inner repeat units, and (iii) the outer region with the end groups. The individual layers around the core are designated "generations". Dendrimers are built up by iterative stepwise reaction * Corresponding author 4 C. Schlenk and H. Frey Fig. 1. Schematic representation of the dendrimer structure sequences, either in the convergent [1, 2] or divergent [3] approach. In the divergent strategy, dendrimers are built from the central core outwards to the periphery. The convergent approach constructs the dendrimer from the periphery towards the central core. Some of the developments in the area of the heteroatom-based dendrimers have been summarized in recent reviews [4, 5]. Silicon chemistry offers several quantitative reactions suitable for the construction of perfect dendrimers, such as transformation of chlorosilanes with organometallic reagents, e.g. Grignard reagents, as well as Pt-catalyzed hydrosilylation. To date carbosilane, carbosilox ane, and small silane dendrimers have been described. At present, carbosilane dendrimers represent the most important class of Si-based dendrimers. They are kinetically as well as thermodynamically very stable molecules owing to the dissociation energy of the Si -C bond (306 kllmol), which is comparable to that of C-C bonds (345 kllmol), and the low polarity of the Si-C bond. This is an important prerequisite for further functionalization. This micro-review aims at a summary of the developments in the synthesis, functionalization, and character ization of carbosilane dendrimers as well as some of their potential applications. 2. Synthesis and Characterization 2.1. General Synthetic Strategy To date, all reported carbosilane dendrimers have been synthesized via the divergent approach (Fig. 2). Fetters et al. reported the use of a G 1 carbosilane dendrimer with 12 end groups for the synthesis of a star polymer as early as 1978 [6]. However, van der Made et al. [7,8], Roovers et al. [9, 10], and MuzaJarov et al. [11] independently reported the first syntheses aiming at carbo silane dendrimers of various generations. Starting from the central core (GO) possessing J alkenyl groups, the dendrimer is constructed using repeating sequences of alternating hydrosilylations with chlorosilanes and w-alkenylations with Grignard reagents. Van der Made et al. used tetraallylsilane as core, HSiC1 as hydrosilylation reagent, 3 Carbosilane Dendrimers 5 ~]~ 4 HSiR3_nCln ~ sil, 'm~" R3-n ] Si m 4 ----.... SiCln catalyst '[H'm ~ GO 4nXMg~ s'~~I~tl. G1 R = Me; X = CI, Br; m = 0, 1; n = 2, 3 Fig. 2. Divergent synthesis of a typical carbosilane dendrimer and allylmagnesium bromide as w-alkenylation reagent to obtain dendrimers up to the fifth generation. However, it should be emphasized that the molecular weight and the structural perfection of these dendrimers were not substantiated by appropriate analytical methods. Roovers et at. started from a tetravinylsilane core and used HMeSiCh and vinylmagnesium bromide to obtain dendrimers possessing a somewhat open structure. Dendrimers with an even more open structure were obtained by MuzaJarov and coworkers who chose HMeSiCh as hydrosilylation reagent, allylmagnesium chloride as w-alkenylation reagent, and triallylmethyl silane as a core. Obviously, the synthetic route to carbosilane dendrimers offers high flexibility and versatility. Not only the hydrosilylation reagent and the w-alkenylation reagent (to some extent) but also the core molecule can be varied without drastic changes in the reaction conditions. Table 1 summarizes the carbosilane dendrimers reported to date (core molecules, segment length, and branching multiplicity). The most popular core molecules are tetraallylsilane and tetravinylsilane, which lead to dendrimers of spherosymmetrical topology. To date, the branching multiplicity has been varied from two to three and the length of the alkyl spacer from two to three methylene units (cf. Table 1). The use of a long alkyl magnesium bromide as Grignard reagent has been reported in one case [8]. However, reaction between long alkylmagnesium bromide and tetrahedral silicon is problematic [12]. Numerous reports on the synthesis of carbosilane dendrimers with allyl end groups have been published by Kim et al. [42-44, 46] who used various core molecules (2,4,6,8-tetramethyl-2,4,6,8-tetravinyltetrasiloxane, diallylphenyl methylsilane, and triallylmethylsilane) and constructed the dendrimers with allylmagnesium bromide as Grignard reagent and either HSiCh or HMeSiCl as 2 hydrosilylation reagent. In further publications, these authors report the synthesis of carbosilane dendrimers terminated by phenylethynyl and p-bromophenoxy and biphenyl groups, respectively [47, 48]. In one case, the obtained products were characterized by MALDI-TOF mass spectrometry [48]. The synthesis of carbosilane dendrimers bearing 12 or 36 phenyl rings at the periphery has been reported by Friedmann and coworkers [37]. The obtained 6 C. Schlenk and H. Frey dendrimers were characterized by X-ray diffraction analysis and NMR spectros copy. NMR showed the retention of solvent with the second generation. Gossage et ai. described the synthesis and characterization of a carbosilane dendrimer with a functionalizable core [52, 53]: 4-triallylsilylphenol, whose phenolic hydroxy group was protected by a tert-butyldimethylsilyl group while constructing the dendrimer scaffold. After deprotection, this core permits facile attachment of transition metal complexes or molecular probes. Table 1. Carbosilane dendrimers reported to date: core molecules, segment structure, and branching multiplicity (b.m. Core (GO) Spacer b.m. Ref. Core (GO) Spacer b.m. Ref. ~( )~0- C3 3 [7, 8, 13-23} C3 2 [48] I( - 2 [24-34] -I( ~I (I I~; ~('\ C2 3 [35-37] C3 2 [49] ) 2 [9, 10, 38-41] ~ 1' o'~j'o/ 1~ 6 ~!;~ -1- -(~ o-(~ C3 2 [11,42] C3 2 [50] I( - ~I- sPl'~~- ~s~~ C3 3 [43] o C3 2 [51] 1 ( Ph 2 [44] 00 , +ko-o-( {~ C3 3 [45] 1(- C3 3 [52] ~I 1 \{ \l 0/ '0 sf 's;/ C3 312 [46] ./ , o's;,oI \\ [2] [47] J\
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