Organosilicon Chemistry I11
From Molecules to Materials
Edited by Norbert Auner and Johann Weis
@ WILEY-VCH
Weinheim . Berlin . New York . Chichester * Brisbane Singapore * Toronto This Page Intentionally Left Blank Organosilicon Chemistry I11 Edited by N. Auner and J. Weis
6B WILEY-VCH This Page Intentionally Left Blank Organosilicon Chemistry I11
From Molecules to Materials
Edited by Norbert Auner and Johann Weis
@ WILEY-VCH
Weinheim . Berlin . New York . Chichester * Brisbane Singapore * Toronto Prof. Dr. N. Auner Dr. J. Weis Institut fur Chemie Wacker-Chemie GmbH Fachinstitut fur Anorganische Geschaftsbereich S und Allgemeine Chemie Werk Burghausen Humboldt-Universitat zu Berlin Johannes-HeS-StraBe 24 Hessische StraBe 1-2 D-84489 Burghausen D-10115 Berlin Germany Germany
This book was carefully produced. Nevertheless, authors, editors and publisher do not warrant the information contained therein to be free of errors. Readers are advised to keep in mind that statements, data, illustrations, procedural details or other items may inad- vertently be inaccurate.
Editorial Director: Dr. Anette Eckerle Production Manager: Hans-Jochen Schmitt
Library of Congress Card No. applied for.
A catalogue record for this book is available from the British Library.
Deutsche Bibliothek Cataloguing-in-Publication Data: Organosilicon chemistry : from molecules to materials / ed. by Norbert Auner und Johann Weis. - Weinheim ;New York ;Basel ; Cambridge ; Tokyo : VCH 3 (1997) ISBN 3-527-29450-3
0 WILEY-VCH Verlag GmbH, D-69469 Weinheim (Federal Republic of Germany), 1998
Printed on acid-free and chlorine-free paper.
All rights reserved (including those of translation in other languages). No part of this book may be reproduced in any form - by photoprinting, microfilm, or any other means - nor transmitted or translated into machine language without written permission from the publishers. Registered names, trademarks, etc. used in this book, even when not specifically marked as such, are not to be considered unprotected by law. Printing: betz-druck, D-64291 Darmstadt Bookbinding: Wilh. Osswald, D-67433 Neustadt Printed in the Federal Republic of Germany This volume summarizes the lectures and poster contributions of the III. Miinchner Silicontage that were held in April 1996. This symposium as well as the two predecessors (in 1992 and 1994) were again jointly organized by the Gesellschaft Deutscher Chemiker and Wacker-Chemie GmbH. The number of participants from industry and university, especially of students and young scientists, was again pleasing and is convincing evidence for the great interest in this meeting; in addition it was appreciation for the effort of the organizers. Moreover the book reviews of Organosilicon Chemistry 11 - From Molecules to Materials from all over the world have encouraged us to continue the series with the current issue. The volumes of Organosilicon Chemistry are not considered to be textbooks in a common sense which should help students to pass basic examinations. These contributions from internationally renowned experts and researchers in a fascinating part of the rapidly growing field of main group chemistry describes current trends in organosilicon chemistry and provides summaries of the latest knowledge in this area. However, in order to facilitate students and "non-silicon" scientists an easier access to the ongoing research on the basis of the relevant historical background, we decided to split this volume in two parts, each with a comprehensive introduction, one on molecular and one on polymer and solid state (organo)silicon chemistry. During the I. Miinchner Silicontage the Wacker Silicon-Preis was awarded to the two pioneers of silicone chemistry - Prof Dr. Richard Muller and Prof. Dr. Eugene Rochow on the occasion of the SO* anniversary of the "Direct Process". In the course of the II. Miinchner Silicontage this award was conferred on Prof Dr. Edwin Hengge, Technische Universitat Graz, for his hndamental work in polysilane chemistry. At the III. Miinchner Silicontage Prof Dr. Hubert Schmidbaur was honoured by presenting the Wacker Silicon-Preis for his outstanding contributions in the field of the synthesis and characterization of organosilicon "molecules and materials". Right in the middle of the editorial phase of this volume, we were sad to hear of the unexpected decease of our friend Prof. Dr. Edwin Hengge. With him the organosilicon community has lost a passionate lecturer and researcher, unforgettable for his integrity and charming personality. Therefore it is the editors special wish that this volume shall keep alive the memory of an excellent organosilicon chemist! Collecting and publishing these papers it is our main intention to encourage students and young scientists to focus on organosilicon chemistry and to continue the work in the future! We want to light a beacon - outstanding success in the last few years should not deceive us, that there are still a lot of challenging problems to be solved in the hture: this includes basic research as well as the development of new materials. In August 1997
Pro$ Dr. Norbert Auner Dr. Johann Weis Acknowledgment
First of all we would like to thank the numerous authors for their intense cooperation, which made this overview of current organosilicon chemistry possible. The tremendous work load to achieve the attractive layout of this volume was mainly performed by Dr. Claus-Rudiger Heikenwalder and Dr. Mathias Kersten. We thank both for their admirable engagement!
Pro$ Dr. Norbert Auner Dr. Johann Weis Humboldt-Universitat Wacker-Chemie GmbH zu Berlin Munchen Contents
I Fascinating Organosilicon Compounds
Introduction ...... 1 N Auner, G. Fearon, J. Weis
More Compelling Evidence that Silicon is Better Than Carbon: The Thermal ...... 17 Isomerization of Olefins to Carbenes T. J. Barton, J. Lin, S. Qadi-Maghsoodi, M. D. Power, X.Zhang, Z. Ma, H. Shimizu, M. S. Gordon
NMR and Quantum Chemical Characterization of Silicon-Substituted Carbocations ...... 25 H,-U. Siehl, B. Miiller, 0.Malkina
Matrix Isolation Studies of the Reactions ofSilicon Atoms .31 G. Maier, H. P. Reisenauer, H. Egenolf
Cycloaddition Reactions of Dimethylaminomethylsilylene with Dienes and Heterodienes ...... 36 S. Meinel, J. Heinicke
Do Unsubstituted Silacyclobutadienes Exist? , ., . , , , , , , ., , ., .39 G. Maier, H. P. Reisenauer, J. Jung, A. Meudt, H. Pacl
A Thermally Stable Silylene: Reactivity of the Bis(amino)silylene Sl[tN(CH2tBu))2C&- 1,2] ...... 44 B. Gerhus, P. B. Hitchcock, M. F. Lappert
Pyrido[b]- 1 ,3,2h2-diazasilole: The First Stable Unsymmetrical Silylene ... 50 A. Oprea, J. Heinicke
A New Route to Silaheterocycles: Heterobutadiene Cycloaddition ...... 53 H. H. Karsch, P. Schliiter
Base Coordination: A Way to Nucleophilic Silylenes? ...... 58 J. Belzner
Isoelectronic Replacement of Si by P’: A Comparative Study of the Structures of the ...... 65 Spirocyclic En Compounds E[C(PMe2),(X)I2 (E = Si, Ge, Sn; X = PMe2,SiMes) and a Novel Spirocyclic 10 e-Phosphorus Cation(Pm) P[C(PPh2)2(SiMe3)]2’ H. H. Karsch. E. Witt
The Main Group Carbonyls mi-CO and R2Si-CO: An Ab Initio Study ...... 70 M. Tacke VIII Contents
Unprecedented Multistep Reactions of Decamethylsilicocene, (Me5Cs)zSi:,with C02, CSZ, ...... 76 COS, RNCS (R = Me, Ph), with CF3CCCF3, and with HMn(C0)5 P. Jutzi, D. Eikenberg
Rearrangement of Bis(hypersily1)silylene and Related Compounds - An Unusual Way to ...... 82 Three-Membered Rings K. W.Klinkhammer
Oxidation of Silenes and Silylenes: Matrix Isolation of Unusual Silicon Species ...... 86 WO Sander, M. Trommer,A. Patyk
New Silaheterocycles: Formation and Properties ...... 95 E. Kroke, M. Weidenbruch
Cycloaddition Reactions of 1,l-Dichloro-2-neopentyl-l-den with Monoterpenes ...... 10 1 C.-R. Heikenwalder, N. Auner
Silaspirocycles as Precursors for a 2-Silaallene ...... 106 B. Goetze, B. Herrscha), N. Auner
Catalytic Carbon-Carbon Hydrogenation of Silicon-Functionalized Olefins ...... 1 13 H.-U. Steinberger, N. Auner
Dieno- and Enophilicity of Sila-, Germa-, and Stannaethenes ...... 117 N. Wiberg, S. Wagner
Iminosilanes and Silaamidides: Synthesis and Reactions ...... ,120 J. Niesmann, A. Frenzel, U. Klingebiel
Metastable Compounds Containing Silicon-Phosphorus and Silicon-Arsenic Multiple Bonds: .... .126 Syntheses, Structures and Reactivity M. Driess, S. Rell, U. Winkler,H. Pritzkow
Silole and Germole Dianions and their Dilithium Derivatives - Are they Aromatic? ...... 144 T. Miiller, Y.Apeloig, H. Sohn, R. West
Supersilylmetal Compounds ...... ,152 N. Wiberg,K. Amelunxen,H. Noth, A. Appel, M. Schmidt, K. Polborn
Trialkylsilyl Substituted Homobimetallic Phosphanides of the Alkaline Earth Metals as ...... ,157 well as Zinc M. Westerhausen,B. Rademacher, M. Hartmann, M. Wieneke,M. Digeser
The Tris(trimethylsily1)silyl Substituent: An Old Hat With A New Feather ...... 162 A. Heine, L. Lameyer, D. Stalke Contents IX
Functionalized Trisilylmethanes and Trisilylsilanes as Precursors of a New Class of ...... ,172 Tripodal Amido Ligands M. Schubart, B. Findeis, H. Memmler, L. H. Gade
Methoxy-bis[tris(trimethylsilyl)silyl]methane: The First Geminal Di(hypersily1) Compound ...... 178 E. Jeschke, T. Gross, H. Reinke, H. Oehme
The Use of the Tris(trimethylsily1)silyl Group in Stabilization of Low Valent Gallium ...... 182 Compounds W. Kostler, G. Linti
Synthesis, Structure, and Reactions of Tris(trimethylsi1yl)silyl Gallanes and Gallates ...... 189 H. Urban, R. Frey, G. Linti
Novel Pathways in the Reactions of Vinylsilanes with Lithium Metal ...... 195 A. Maercker, K. Reider, U. Girreser
New Organosilicon Reagents : Synthesis, Structure, and Reactivity of ...... 206 (Lithiomethyl)(aminomethyl)silanes B. C. Abele, C. Strohmann
(Pheny1thiomethyl)silanesas New Bihnctional Assembling Ligands for the Construction ...... 21 1 of Heterometallic Complexes M. Knorr, S. Kneifel, C. Strohmann
Synthesis of 1,3-Disilacyclobutanes, 1,3-Digermacyclobutanes,and 1-Germa-3 -sila- ...... 217 cyclobutanes with New 1,3-Dimetallated Organoelement Building Blocks C. Strohmann, E. Wack
TrialkylsilyldiazomethaneDerivatives: Wonderfhl Chemical Building Blocks ...... 223 G. Bertrand
A New Route to Silaheterocycles:Nucleophilic Aminomethylation ...... ,237 H. H. Karsch, K. A. Schreiber
Infrared and Raman Spectra, ab initio Calculations, and Rotational Isomerism of ,241 Methylated Disilanes K. Schenzel, A. Jahn, M. Ernst, K. Hassler
1,2-Di-tert-butyltetrafluorodisiIane:A Highly Fluxional Molecule ...... ,248 R. Zink, K. Hassler, N. W. Mitzel, B. A. Smart, D. W. H. Runkin
Amino-Substituted Disilanes by Reductive Coupling ...... ,254 S. Mantey, J. Heinicke X Contents
Multifunctional Disilane Derivatives ...... ,257 H. Stuger, P. Lassacher, E. Hengge
New Transition Metal Substituted Oligosilanes ..... ,262 W Palitzsch, U. Bohme, G. Roewer
Regiospecific Chlorination and Oxygenation of Pentahydridodisilanyl Complexes of Iron ...... ,267 and Ruthenium S. Moller, H. Jehle, W. Malisch, W. Seelbach
Inter- and Intramolecular Oxidative Addition of Si-H Bonds ...... ,271 R. Karch, H. Gilges, U. Schubert
Novel Synthetic Approach to Molybdenum-Silicon Compounds: Structures and ...... ,275 Reactivities P. Jutzi, S. H. A. Petri
Unexpected Reactivity of Bis-1,2-[(bromodiphenyl)methyl]-l,1,2,2-tetramethyldisilane ...... 28 1 F. Pillong, 0. Schutt, C. Strohmann
Trichlorosilane/Triethylamine- An Alternative to Hexachlorodisilane in Reductive ...... ,286 Trichlorosilylation Reactions? L.-P. Muller, A. Zanin, J. Jeske, P. G. Jones, W.-W. du Mont
Disproportionation of Chloromethyldisilanesusing Lewis Base Heterogeneous Catalysts - ...... 291 A Way to Influence the Polymer Structure T Lange, N Schulze, G. Roewer, R. Richter
Supersilylated Bromodisilanes, Cyclotri-, and Cyclotetrasilanes ...... ,296 N Wiberg,H. Auer, Ch. M. M. Finger, K. Polborn
Syntheses and 29SiNMR Spectra of Halogenated Trisilanes and Cyclopentasilanes ...... ,301 K. Hassler, W Kdl, U. Poschl
Chlorination of Methylphenyloligosilanes:Products and Reactions ,307 C. Notheis, E. Brendler, B. Thomas
Selective Hydrogenation of Methylchlorooligosilanes ...... ,312 U. Herzog, G. Roewer
Electrochemical Formation of Cyclosilanes ...... 317 S. Graschy, C. Grogger, E. Hengge
Undecamethylcyclohexasilanyl Derivatives of Tin(1V) and Lead(1V) ...322 F. Uhlig, U. Hermann, K. Klinkhammer,E. Hengge Contents XI
New Results in Cyclosilane Chemistry: Siloxene-like Polymers ,327 A. Kleewein, b! Patzold, E. Hengge, S. Tasch, G. Leising
Stepwise Synthesis of Functional Polysilane Dendrimers , , , , , . .. . __...... ,333 C. Marschner, E. Hengge
Synthesis and Reactivity of Novel Polysilynes and Branched Copolysilanes ...... ,337 W. Uhlig
Unusual Polyhedra by Lithiation of Silazanes ...... ,342 G. Becker, S. Abele, U.Eberle, G. Motz, W. Schwarz
Isomeric Halosilylhydroxylamines:Preparation and Thermal Rearrangements .348 R. WolfgYamm,U. Klingebiel
Reactions of Hydridosilylamides ...... ,353 K. Junge, N. Peulecke, K. Sternberg, H. Reinke, E. Popowskr
Silylhydrazines: Precursors for Rings, Hydrazones and Pyrazolones ...... ,358 C Drost, U. Klingebiel, H. Witte-Abel
Products from Multiple Insertion Reactions between Diisocyanates and Antiheteroaromatic ...... ,364 1,4-Bis(trimethylsilyI)- 1,4-dihydropyrazine T. Sixt, F. M. Hornung, A. Ehlend, W. Kaim
Some Surprising Chemistry of Sterically Hindered Silanols ...... 369 P. D. Lickiss
Silanetriols: Preparation and Their Reactions ...... __ ,376 R. Murugavel, A. Voigt,M. G. Walawalkar, H. W. Roesky
Silsesquioxanes as Crown Ether Analogs ...... ,395 b! Dittmar, H. C. Marsmann, E. Rikowski
Azomethine-Substituted Organotrialkoxysilanes and Polysiloxanes ...... ,400 F. Mucha, G. Roewer
On the Reaction of (tB~~Sn0)~with Organochlorosilanes. Simple Formation of ...... ,403 [(tBu2SnO)2(tBu2SiO)] J. Beckmann, K. Jurkschat, D. Schollmeyer
Silanols and Siloxanes Substituted with the Chiral Iron Fragments Cp(OC)(RPhzP)Fe ...... ,407 [R = Ph, (H)(Me)(Ph)C(Me)N] W.Malisch. M Neumayer, K. Perneker. N. Gunzelmann. K. Roschmann XI1 Contents
Si-H Functionalized Ferrio-Trisiloxanes C~RS(OC)~F~-S~(M~)(OS~M~~H)~(R = H, Me) ...... ,412 J. Reising, W.Malisch, R. Lankat
Novel Siloxy-Bridged Di-, Tri-, and Tetranuclear Metal Complexes from Ferrio- and ...... 4 15 Tungsten-Silanols W.Malisch, J. Reising, M. Schneider
418 The 2-Dimethylaminomethyl-4,6-dimethylphenylSubstituent' A New Intramolecular Coordinating System with High Steric Demand U. Dehnert, J. Belzner
Reaction Behaviour of Hypervalent Silanes .... ,423 H. Lang, E. Meichel, M. Weinmann, M. Melter
Investigations of Nucleophilic Substitution at Silicon: An Unprecedented Equilibrium ...... ,429 between an Ionic and a Covalent Chlorosilane D. ScharvJ. Belzner
Ligand Exchange Mechanism in Novel Hexacoordinate Silicon Complexes ...... 435 D. Kost, S. Krivonos, I. Kalikhman
Ligand Exchange via Coordinative Si-N Bond Cleavage and Pseudorotation in Neutral ...... 446 Pentacoordinate Silicon Complexes I. Kalikhman. D. Kost
Phosphine Coordination to Silicon Revisited ...... 452 G. Muller, M. Waldkircher, A. Pape
Novel Sila-Phospha-Heterocycles and Hypervalent Silicon Compounds with Phosphorus ...... 460 Donors H. H. Karsch, R. Richter, E. Witt
Germanium Analogues of Zwitterionic Spirocyclic h5Si-Silicates ...... ,466 J. Heermann, R. Tacke, P. G. Jones
I1 Silicon Based Materials
Introduction ...... ,471 N Auner, G. Fearon, J. Weis
The Direct Process to Methylchlorosilanes: Reflections on Chemistry and Process ...... ,478 Technology B. Pachaly, J. Weis Contents XI11
On the Nature of the Active Copper State and on Promoter Action in Rochow Contact ...... 484 Masses H. Ehrich, D. Born, J. Richter-Mendau, H. Lieske
On the Acid- and Base- Catalyzed Reactions of Silanediols and Siloxanediols in Water ...... ,496 H. Kelling, W. Rutz, K. Busse, C. Wendler,D. Lange
Trace Analysis of Mono- and Trifhctional Groups in Polydimethylsiloxanes Using ...... 500 Reaction Headspace GC J. Graphoff
Synthesis and Investigation of the Surface Active Properties of New Silane Surfactants ...... ,504 S. Stadtrniiller, K.-D. Klein, K. Koppen, J. Venzrner
Carbohydrate-Modified Siloxane Surfactants: The Effect of Substructures on the ...... S10 Wetting Behaviour on Non Polar Solid Surfaces R. Wagner, L. Richter, Y. Wu,J. WeiJmiiller, J. Reiners, K.-D. Klein. D. Schaefer, S. Stadtmiiller
Synthesis and Application of o-Epoxy-Functionalized Alkoxysilanes 515 G. Speweslage, K. Stoppek-Langner, J. Grobe
Diffuse Reflectance IR and Time-of-Flight SIMS Investigation of Methoxysilane 520 SA-Layers on Silica and Alumina K. Stoppek-Langner, K. Meyer, A. Benninghoven
Ether-Substituted Triethoxy- and Diethoxymethylsilanes: Precursors for Hydrophilic, ...... 526 Elastic Consolidants for Natural Stones R. Fabis, C. Zeine, J. Grobe
Organosilicon Compounds for Stone Impregnation - Long-Term Effectivity and ...... 53 1 Weathering Stability C. Bruchertseifer, S. Briiggerhoff; K. Stoppek-Langner,J. Grobe, M. Jursch, H.-J. Gotze
Studies on the Regioselectivity of the Hydroformylation with Alkenylalkoxysilanes ., . , , , ., . , , .__. __. .,538 M. Wessels,J. Grobe
Novel Precursors for Inorganic-Organic Hybrid Materials ...... ,543 S. Kairies, K. Rose
Mesomorphic Properties of Poly(diphenylsi1oxane) ...... 550 B. R. Harkness, M. Tachikawa, I. Mita
Applications of Silicone Elastomers for Electrical and Electronic Fields ...... ,555 M. Takahashi XIV Contents
Cyclic Liquid Crystalline Siloxanes: Chemistry and Applications ...... ,566 F.-H. Kreuzer, N. Haberle, H. Leigeber, R. Maurer, J. Stohrer, J. Weis
Modified Polydimethylsiloxanes with Fluorescent Properties ,587 B. Strehmel, C. W. Frank, W. Abraham, M. Garrison
Sensitized Cationic Photocrosslinking of a,o-Terminated Disiloxanes: Cation Formation ...... ,594 in Nonpolar Media U. Miiller, A. Kunze, Ch. Herzig, J. Weis
Cationic Photoinitiators for Curing Epoxy-Modified Silicones ...... ,605 C. Priou
Photoconductivity in Polysilylenes: Doping with Electron Acceptors ...... 617 A. Eckhardt, V.Herden, W. Schnabel
Functionalized Polycarbosilanes as Preceramic Materials ,622 S. Back, H. Lang, M. Weinmann, W. Frosch
Novel Polyorganoborosilazanes for the Synthesis of Ultra-High Thermal Resistant Ceramics ..... ,628 L. M. Ruwisch, W. Dressler, S. Reichert, R. Riedel
Precursors for Silicon-Alloyed Carbon Fibers ...... ,632 J. Dautel, W. Schwarz
One-Pot Syntheses ofPoly(diorganylsily1ene-co-ethyny1ene)s . ,638 W. Habel, A. Moll, P. Sartori
Localization Phenomena of Photogenerated Charge Carriers in Silicon Structures: ...... ,643 From Organosilicon Compounds to Bulk Silicon T. Wirschem,S. Veprek
Functionalized Structure-Directing Agents for the Direct Synthesis of Nanostructured ...... ,649 Materials P. Behrens
Novel Aspects of the Chemical Modification of Silica Surface ...... ,670 V. Tertykh
Microporous Thermal Insulation: Theory, Properties, Applications ...... ,682 H. Katzer, J. Weis
Nitridosilicates - High Temperature Materials with Interesting Properties ,691 W. Schnick, H. Huppertz, 7: Schlieper Contents XV
Author Index ...... 705
Subject Index ...... , ., ., ...... , ...... 7 1 1 This Page Intentionally Left Blank List of Contributors
Prof. Dr. Yitzhak Apeloig Prof. Dr. Guy Bertrand Department of Chemistry Laboratoire de Chimie de Coordination du CNRS Technion - Israel Institute of Technology 205 route de Narbonne Technion City F-3 1077 Toulouse Cedex 32000 Haifa France Israel
Prof. Dr. T. Barton Dr. Uwe Bohme Department of Chemistry Institut fir Anorganische Chemie Ames Laboratory (U. S. Department of Energy) Technische Universitat Bergakademie Freiberg Iowa State University Leipziger StraRe 29 Ames, Iowa 5001 1 D-09596 Freiberg USA Germany
Prof. Dr. Gerd Becker Dr. Joachim Dautel Institut fir Anorganische Chemie Institut fur Anorganische Chemie Universitat Stuttgart Universitat Stuttgart Pfaffenwaldring 55 Pfaffenwaldring 55 D-70550 Stuttgart D-70569 Stuttgart Germany Germany
Prof. Dr. Peter Behrens Matthias Driess Institut fir Anorganische Chemie Lehrstuhl fir Anorganische Chemie I Ludwigs-Maximilians-UniversitatMunchen Fakultat fir Chemie MeiserstraRe 1 Ruhr-Universitat Bochum D-80333 Munchen UniversitatsstraRe 150 Germany D-44801 Bochum Germany
Dr. Johannes Belzner Prof. Dr. W.-W. du Mont Institut fir Organische Chemie Institut fir Anorganische und Analytische Chemie Georg-August-Universitat Gottingen Technische Universitat Braunschweig TammannstraBe 2 Hagenring 30 D-37077 Gottingen D-38106 Braunschweig Germany Germany XVIII List of Contributors
Dr. Gordon Fearon Dr. Christa Grogger Central Research and Development Institut fir Anorganische Chemie Dow Corning Corporation Technische Universitat Graz Midland, MI, 48686-09994 Stremayrgasse 16 USA A-8010 Graz Austria
Dr. Lutz H. Gade Dr. B. R. Harkness Institut fir Anorganische Chemie Dow Corning Asia Ltd Universitat Wurzburg Research Center Am Hubland 603 Kishi, Yamakita D-97074 Wurzburg Kanagawa 258-01 Germany Japan
Dr. Barbara Gehrhus Priv. Doz. Dr. Karl Hassler School of Chemistry and Molecular Sciences Institut fir Anorganische Chemie University of Sussex Technische Universitat Brighton BN1 9QJ Stremayrgasse 16 United Kingdom A-8010 Graz Austria
Dr. Jiirgen Granhoff Prof. Dr. Joachim Heinicke Hiils Silicone GmbH Institut fur Anorganische Chemie Analytical Department Emst-Moritz-Amdt-Universitat Greifswald D-01612 Nunchritz SoldtmannstraBe 16 Germany D- 17487 Greifswald Germany
Prof, Dr. Joseph Grobe Prof. Dr. Klaus Jurkschat Fachbereich Chemie der Universitat Dortmund Anorganisch-Chemisches-Institut Westfalische Wilhelms-Universitat Lehrstuhl fir Anorganische Chemie TI Wilhelm-Klemm-StraBe 8 D-4422 1 Dortmund D-48149 Miinster Germany Germany List of Contributors XIX
Prof. Dr. Peter Jutzi Dip1.-Ing. Alois Kleewein Fakultat fin Chemie Institut fhr Anorganische Chemie Universitat Bielefeld Technische Universitat Graz UniversitatsstraBe 25 Stremayrgasse 16 / IV D-336 15 Bielefeld A-8010 Graz Germany Austria
Prof. Dr. Wolfgang Kaim Prof. Dr. Uwe Klingebiel Institut fir Anorganische Chemie Institut fur Anorganische Chemie Universitat Stuttgart Georg- August-Universitat Gottingen Pfatlenwaldring 5 5 TammannstraBe 4 D-70550 Stuttgart D-37077 Gottingen Germany Germany
Prof. Dr. Hans Heinz Karsch Dr. Karl Wilhelm Klinkhammer Anorganisch-Chemisches Institut Institut fir Anorganische Chemie Technische Universitat Miinchen Universitat Stuttgart LichtenbergstraRe 4 Pfaffenwaldring 55 D-85747 Garching D-70550 Stuttgart Germany Germany
Dr. Hans Katzer Dr. Michael Knorr Wacker-Chemie GmbH Institut fir Anorganische Chemie Geschatsbereich S-Werk Kempten Universitat des Saarlandes Max-Schaidhauf-StraBe 25 Postfach 1 150 D-87437 Kempten D-66041 Saarbriicken Germany Germany
Prof. Dr. Hans Kelling Prof. Dr. Daniel Kost Fachbereich Chemie Department of Chemistry Universitat Rostock Ben Gurion University of the Negev BuchbinderstraBe 9 Beer-Sheva 84 105 D- 18051 Restock Israel Germany XX List of Contributors
Dr. F.-H. Kreuzer Prof. Dr. Adalbert Maercker Consortium fir elektrochemische Industrie GmbH Institut fir Organische Chemie Corporate Research Company of Universitat Siegen Wacker-Chemie GmbH D-57068 Siegen ZielstatterstraBe 20 Germany D-8 1379 Munchen Germany
Prof. Dr. Heinrich Lang Prof. Dr. Gunther Maier Institut fir Chemie Institut fir Organische Chemie Lehrstuhl f%r Anorganische Chemie Justus-Liebig-Universitat GieBen Technische Universitat Chemnitz Heirich-Buff-Ring 58 StraBe der Nationen 62 D-35392 GieBen D-09107 Chemnitz Germany Germany
Dr. Paul D. Lickiss Prof. Dr. Wolfgang Malisch Department of Chemistry Institut fir Anorganische Chemie Imperial College of Science Universitat Wurzburg Technology and Medicine Am Hubland London SW7 2AY D-97074 Wurzburg United Kingdom Germany
Prof. Dr. Heiner Lieske Dr. Christoph Marschner Institut fir Angewandte Chemie Berlin- Institut fir Anorganische Chemie Adlershof e.V. Technische Universitat Graz Abteilung Katalyse Stremayrgasse 16 Rudower Chaussee 5 A-8010 Graz D- 12484 Berlin Austria Germany
Dr. Gerald Linti Prof. Dr. Heinrich Christian Marsmann Institut fir Anorganische Chemie Fachbereich Chemie und Chemietechnik der Universitat (TH) Karlsruhe Universitat-GH Paderborn Engesserstrane Geb. 30.45 Warburger StraBe 100 D-76128 Karlsruhe D-33095 Paderborn Germany Germany List of Contributors XXI
Prof. Dr. Gerhard Miiller Dr. B. Pachaly Fakultat fir Chemie der Universitat Konstanz Wacker-Chemie GmbH UniversitatsstraRe 10 Geschaftsbereich S-Werk Burghausen D-78464 Konstanz Johannes-HeB-StraRe 24 Germany D-84489 Burghausen Germany
Dr. Thomas Miiller Prof. Dr. Eckhard Popowski Fachinstitut fur Anorganische und Allgemeine Fachbereich Chemie Chemie Universitat Rostock Humboldt-Universitat zu Berlin BuchbinderstraBe 9 Hessische StraBe 1-2 D-1805 1 Rostock D- 101 15 Berlin Germany Germany
Dr. U. Miiller Dr. C. Priou Institut fir Organische Chemie Rhone-Poulenc Chimie Martin-Luther-Universitat Halle-Wittenberg Silicone Division Geusaer StraBe 1 rue des freres Perret, B.P. 22 D-062 17 Merseburg F-69 191 Saint Fons cedex Germany France
Christina Notheis Dr. Ralf Riedel Institut fir Analytische Chemie Fachbereich Materialwissenschaft Technische Universitat Bergakademie Freiberg Fachgebiet Disperse Feststoffe Leipziger StraRe 29 Technische Hochschule Darmstadt D-09599 Freiberg PetersenstraRe 23 Germany D-64287 Darmstadt Germany
Prof. Dr. Hartmut Oehme Prof. Dr. Herbert W. Roesky Fachbereich Chemie Institut fir Anorganische Chemie der Universitat Abteilung Anorganische Chemie Gottingen Universitat Rostock TammannstraRe 4 BuchbinderstraBe 9 D-37077 Gottingen D- 18051 Restock Germany Germany XXII List of Contributors
Prof. Dr. Gerhard Roewer Prof. Dr. Wolfgang Schnick Institut fir Anorganische Chemie Laboratorium fir Anorganische Chemie Technische Universitat Bergakademie Freiberg Universitat Bayreuth Leipziger StraBe 29 UniversitatsstraBe 30 D-09596 Freiberg D-95440 Bayreuth Germany Germany
Dr. Klaus Rose Prof. Dr. Hans-Ullrich Siehl Fraunhofer-Institut fiir Silicatforschung Abteilung fiir Organische Chemie der Neunerplatz 2 Universitat Ulm D-97082 Wurzburg D-89069 Ulm Germany Germany
Prof. Dr. Wolfram Sander Prof. Dr. U. Schubert Lehrstuhl fur Organische Chemie I1 Institut fur Anorganische Chemie Ruhr-Universitat Bochum Technische Universitat Wien D-44780 Bochum Getreidemarkt 9 Germany A- 1060 Wien Austria
Prof. Dr. Peter Sartori Dr. Stefan Stadtmuller Anorganische Chemie Th. Goldschmidt AG Gerhard Mercator Universitat-Gesamthochschule- GoldschmidtstraBe 100 Duisburg D-45 127 Essen LotharstraBe 1 Germany D-47048 Duisburg Germany
Prof. Dr. Wolfram Schnabel Prof. Dr. Dietmar Stalke Hahn-Meitner-Institut Berlin GmbH Institut fir Anorganische Chemie Bereich Physikalische Chemie Universitat Wurzburg Glienicker StraBe 100 Am Hubland D- 14109 Berlin D-97074 Wurzburg Germany Germany List of Contributors XXIII
Dr. Karl Stoppek-Langner Prof. Dr. Reinhold Tacke Institut fur Anorganische Chemie Anorganisch-Chemisches-Institut Westfalische Wilhelms-Universitat Bayerische Julius-Maximilians-Universitat zu Wilhelm-Klemm-StraBe 8 Wurzburg D-48 149 Munster Am Hubland Germany D-97074 Wurzburg Germany
Dr. B. Strehmel Dr. Masaharu Takahashi Fachinstitut fur Physikalische und Theoretische Silicone-Electronics Materials Research Center Chemie Shin-Etsu Chemical Co., Ltd. Humboldt Universitat zu Berlin 1-10, Hitomi, Matsuida BunsenstraBe 1 Gunma 379-02 D-10117 Berlin Japan Germany
Priv.-Doz. Dr. Carsten Strohmann Prof. Dr. Valentin Tertykh Institut fir Anorganische Chemie Department of Chemisorption Universitat des Saarlandes Institute of Surface Chemistry Postfach 1 150 National Academy of Sciences D-6604 1 Saarbriicken Prospekt Nauki 3 1 Germany 252022 Kiev Ukraina
Dr. Harald Stiiger Dr. Frank Uhlig Institut fur Anorganische Chemie Lehrstuhl fur Anorganische Chemie I1 Technische Universitat Graz Universitat Dortmund Stremayrgasse 16 Otto-Hahn-StraBe 6 A-8010 Graz D-44227 Dortmund Austria Germany
Dr. Matthias Tacke Dr. Wolfram Uhlig University College Dublin Laboratorium fir Anorganische Chemie Department of Chemistry Eidgenossische Technische Hochschule Zurich Belfield ETH-Zentrum Dublin 4 CH-8092 Zurich Ireland Switzerland XXIV List of Contributors
Prof. Dr. Stan Veprek Institut hrChemie Anorganischer Materialien Technische Universitat Munchen LichtenbergstraBe 4 D-85747 Garching Germany
Dr. R. Wagner Max-Planck-Institut fir Kolloid-und Grenzflachenforschung Rudower Chaussee 5 D-12489 Berlin Germany
Prof. Dr. Manfred Weidenbruch Fachbereich Chemie Universitat Oldenburg Carl-von-Ossietzky-StraBe 9 D-26111 Oldenburg Germany
Prof. Dr. Matthias Westerhausen Institut fir Anorganische Chemie Ludwig-Maximilians-UniversitatMunchen MeisterstraBe 1 D-80333 Miinchen Germany
Prof. Dr. Nils Wiberg Institut fur Anorganische Chemie Ludwig-Maximilians-UniversitatMunchen MeisterstraBe 1 D-80333 Munchen Germany List of Contributors XXV
Editors:
Prof. Dr. Norbert Auner Dr. Johann Weis Fachinstitut fir Anorganische und AIlgemeine Wacker-Chemie GmbH Chemie Geschaftsbereich S Humboldt-Universitat zu Berlin Werk Burghausen Hessische StraBe 1-2 Johannes-Hen-StraBe 24 D-10115 Berlin D-84489 Burghausen Germany Germany This Page Intentionally Left Blank PART I
FASCINATING ORGANOSILICON COMPOUNDS
INTRODUCTION
Norbert Auner Gordon Fearon Johann Weis Hum boldt-Universitat Dow Corning Corporation Wucker-ChemieGmbH Berlin, Germany Midland, MI, USA Miinchen, Germany
To understand Group 14 - and especially organosilicon - chemistry some comparisons between silicon and carbon have to be considered. There are two major properties that distinguish silicon from carbon. Silicon atoms are about 50 % larger than carbon atoms and this increased size will have some ramifications and consequences, such as lower barriers to silicon-element bond rotations and less stable n-bonds. Furthermore, the smaller Pauling electronegativity of silicon results in differently polar silicon-element bonds compared to carbon and thus will change its reactivity and enable reactions not possible in carbon chemistry.
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The common environments exhibited for carbon and silicon show that silicon differs from carbon by its strongly reduced ability to form multiple bonds in comparison to its congener carbon but also in its capacity to form stable derivatives with more than four bonds. Carbon exhibits a maximum of four single covalent bonds, derivatives with more (e.g. five) nearest neighbors only exist in 'non classical (carbon bridged) ions', in a few carbon gold complexes and in some organometallic carbide compounds. The lack of multiple bonds seriously hampers synthetic strategies in silicon chemistry compared to the numerous possibilities available to the organic chemists. But this lack is counterbalanced by the ease of formation of silicon hypervalent species, the low activation energies 2 N. Auner, G. Fearon, J. Weis for nucleophilic substitution at silicon compared to carbon and the numerous reaction pathways at tetrahedral silicon centers that are not accessible to carbon. Although over years a hybridization state has often been used to describe the expanded octet geometries of silicon - this is by no means the exclusive bonding view for higher coordinate species - one has to take into account that the participation of d-orbitals in the description of bonding in silicon compounds was a subject of continuing debate and that nowadays an alternative explanation using multicenter bonding has been accepted. Besides other organizing principles, compounds of silicon might be ordered in terms of oxidation states and coordination numbers at the silicon centers. Tetravalent silicon mostly exhibits the oxidation state +4 (e.g. ,Six, X = halogen, H, organo group, 5502, Si3N4, Sic etc.), in Ca2Si however it is -4. Divalent silicon in the oxidation state +2 is found in compounds such as :SiX2, SiO or SiS which are available only at high temperatures and can be identified spectroscopically in the gas phase at low pressure andlor in low temperature matrices after condensation on a cold surface (T-1OK ). As examples for tri- and monovalent silicon with positive oxidation numbers +3 and +1 compounds Six3 and Six are named, which are formed competitively to silylenes :Six2 by photolysis and/or thermolysis of stable precursors Six. Negative oxidation states -3, -2 and -1 with tri-, di-, and monovalent silicon are represented in silicides, as exemplified by BaMgZSiz, CaSi, and CaSi2. In its compounds the silicon center is surrounded by at least one up to ten neighbors. Some representative specimens in various coordination numbers are listed below and discussed later in this introduction.
10 (CsMe5)zSi: (see page 9)
This list of compounds with silicon in the whole range of its coordination numbers and environments, including their synthesis and the investigation of their chemistry gives an impressive overview of organosilicon research currently going on worldwide.