Carbon-Functional Orga nosil icon Compounds MODERN INORGANIC CHEMISTRY Series Editor: John P. Fackler, Jr. Texas A&M University METAL INTERACTIONS WITH BORON CLUSTERS Edited by Russell N. Grimes HOMOGENEOUS CATALYSIS WITH METAL PHOSPHINE COMPLEXES Edited by Louis H. Pignolet THE JAHN-TELLER EFFECT AND VIBRONIC INTERACTIONS IN MODERN CHEMISTRY I. B. Bersuker MOSSBAUER SPECTROSCOPY APPLIED TO INORGANIC CHEMISTRY Edited by Gary J. Long CARBON-FUNCTIONAL ORGANOSILICON COMPOUNDS Edited by Vaclav Chvalovsky and Jon M. Bellama A Continuation Order Plan is available for this series. A continuation order will bring delivery of each new volume immediately upon publication. Volumes are billed only upon actual shipment. For further information please contact the publisher. Carbon-Functional Orga nos ili con Compounds Edited by Vaclav Chvalovsky Institute of Chemical Process Fundamentals Czechoslovak Academy of Sciences Prague, Czechoslovakia and Jon M. Bellama Department of Chemistry University of Maryland College Park, Maryland Plenum Press • New York and London Library of Congress Cataloging in Publication Data Main entry under tille: Carbon-functional organosilicon compounds. (Modern inorganic chemistry) Includes bibliographical references and index. I. Organosilicon compounds. l. Chvalovsky, Vaclav. Il. Bellama, Jon M., 1938- 1lI. Series. QD412.S6C37 2984 547'.08 84-3438 ISBN 978-1-4757-0383-2 ISBN 978-1-4757-0381-8 (eBook) DOI 10.1007/978-1-4757-0381-8 © 1984 Plenum Press, New York Softcover reprint of the hardcover 1s t edition 1984 A Division of Plenum Publishing Corporation 233 Spring Street, New York, N.Y. 10013 All rights reserved No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the Publisher PREFACE The term "carbon-functional organosilicon compound" is used for organosilicon compounds in which a functional group is bonded to an organic moiety that is in turn con nected to silicon via a Si-C bond. Thus, only Si-Cn-Y com pounds (Y designates a functional group) will be discussed in this book 1 Si-O-Cn-Y compounds will in general not be considered, although the latter group does include a large number of natural substances containing silylated hydroxyl groups. (Because of the differing importance of various Y groups, the reader will find some deviation from this restriction). Finally, compounds containing a silyl group as the functional group are not considered. An overview of the field of organosilicon chemistry would show that in the last several decades the commercial synthesis of organosilicon products has increased substan tially, both in annual production and also in the increasing variety of compounds produced. This increase in the number of commercially available carbon-functional monomers and polymers (silicone polymers) is most remarkable and is occurring because new applications are continually being found for these compounds. As might be expected, the number of publications in this field is also increasing. The important position of silicon in the periodic table - between carbon, aluminum, and phosphorus - means that an understanding of the nature of the bonds in organosilicon compounds is quite important in order to understand the bonding in these other areas. In general, silicon compounds can be readily prepared, and most of them are relatively stable 1 thus, it is possible by comparing analogous organic and organosilicon compounds to draw some general conclusions concerning the effects of the comparative electropositivity, the greater atomic volume, the potential utilization of vacant orbitals, or the higher polarizability of silicon. v PREFACE The purpose of this volume is to provide information about carbon-functional organosilicon compounds from four different viewpoints, each of which will be useful to industrial research and other scientific workers. The first chapter considers the practical applications and uses of carbon-functional organosilicon compounds (1) in laboratory procedures of organic chemistry and biochemistry, and (2) in production of composite materials from plastics and resins containing inorganic fillers. Although carbon-functional silanes also have begun to find application as regulators of living processes, only basic data on the biological activity of silanes are reported in this chapter. This topic has been recently reviewed [1] in a special volume of the series "Topics in Current Chemistry". The effects of intramolecular interactions on the chemical properties of carbon-functional organosilicon compounds are treated in Chapter 2. This general interpretation will be of interest to the reader interested in the utilization of silanes in synthesis. Chapter 3 summarizes the effects of structure on the NMR spectral parameters of carbon-functional silanes and provides information about (1) the interpretive power of NMR in the study of the structure of these compounds, and (2) the nature of their intramolecular interactions. The first part of the chapter briefly considers 29Si NMR spectroscopy and gives information that is required for a better understanding of this specialized field. For a more detailed treatment the reader is referred to recent reviews [2,3]. In Chapter 4, the goal is to discuss from a theoreti cal point of view the effect of structure on the proper ties of organosilicon compounds. The review does not duplicate the recent review by Kwart and King [4]. Finally, we would like to thank Professor R. Zahradnik (J. Heyrovsky Institute of Physical Chemistry and Electrochemistry of the Czechoslovak Academy of Sciences) for valuable comments and suggestions. PREFACE vii References [1] Tacke R., Wannagat U., Voronkov M.G.: Bioactive Organo Silicon Compounds. Berlin-Heidelberg-New York: Springer (1979). [2] Schraml J., Bellama J.M.: 29Si-Magnetic Resonance in the Determination of Organic Structures by Physical Methods, Vol. 6. New York: Academic Press (1978). [3] Kintzinger J.P., Marsmann H.: Oxygen-17 and Silicon-29 in NMR-Basic Principles and Progress, Vol. 17. Berlin Heidelberg-New York: Springer (1981). [4] Kwart H., King K.G.: d-Orbitals in the Chemistry of Silicon, Phosphorus and Sulfur. Berlin-Heidelberg-New York: Springer (1977). CONTENTS 1. SOME APPLICATIONS OF CARBON-FUNCTIONAL ORGANOSILICON COMPOUNDS Vaclav Chvalovsk~ 1.1 INTRODUCTION 1 1.2 THE PRODUCTION OF CARBON-FUNCTIONAL ORGANOSILICON COMPOUNDS 2 1. 3 USES AS DERIVATIZING AGENTS FOR NATURAL SUBSTANCES 4 1.4 USES AS STATIONARY PHASES FOR GAS-LIQUID CHROMATOGRAPHY 9 1.5 USES IN SURFACE TREATMENT OF INORGANIC MATERIALS 10 1.5.1 As Coupling Agents for Inorganic Fillers of Polymers 11 1.5.2 For Immobilization of Peptides and Proteins on Solid Carriers 18 1.5.3 For Immobilization of Metal Complex Catalysts 25 1. 6 REFERENCES 28 2. INTRAMOLECULAR INTERACTION IN THE CHEMICAL BEHAVIOR OF CARBON-FUNCTIONAL ORGANOSILICON COMPOUNDS Josef Pola 2.1 INTRODUCTION 35 2.2 SUBSTITUENT EFFECTS OF SILYL GROUPS IN ORGANIC REACTIONS 39 ix x CONTENTS 2.2.1 Reactions of Organometallic Compounds 39 2.2.2 Reactions of Alkenes 40 2.2.3 Reactions of Aromatic Compounds 46 2.2.4 Reactions of Compounds with Keto, Carboxyl, and Carbalkoxyl Groups 53 2.2.5 Reactions of Amines 55 2.2.6 Reactions of Alcohols, and Their Esters, Acetals, and Ethers 59 2.2.7 Reactions of Thiols and Sulfides 72 2.2.8 Reactions of Alkyl Halides 73 2.3 REACTIONS WITH PATHWAY DOHINATED BY THROUGH-SPACE INTERACTION BETWEEN SILICON AND A FUNCTIONAL GROUP 82 2.3.1 Reactions Involving 1,2-Interaction 83 2.3.2 Reactions Involving 1,3-Interaction 93 2.3.3 Reactions Involving 1,4-Interaction 98 2.3.4 Reactions Involving 1,5- or 1,6-Interaction 107 2.4 REFERENCES III 3. NMR SPECTROSCOPY IN THE INVESTIGATION AND ANALYSIS OF CARBON-FUNCTIONAL ORGANOSILICON COMPOU~IDS Jan Schraml 3.1 INTRODUCTION 121 3.2 29Si NMR SPECTROSCOPY 123 3.2.1 Experimental Aspects 123 3.2.2 29Si Chemical Shifts - Basic Facts 129 3.2.3 29Si Shielding Theory and Model 132 3.2.4 29Si Spin-Spin Coupling Constants 142 3.3 ALIPHATIC CARBON-FUNCTIONAL COMPOUNDS 142 3.3.1 IH NMR Spectroscopy 143 3.3.2 l3C NMR Spectroscopy 153 3.3.3 29Si NMR Spectroscopy 155 3.3.4 Typical Results 161 CONTENTS xi 3.4 AROMATIC CARBON-FUNCTIonAL COMPOUNDS 202 3.4.1 NMR Spectroscopy of Functional Groups 203 3.4.2 NMR Spectroscopy of Silyl Groups Sixlx2X3 212 3.4.3 NMR Spectroscopy of the Connecting Chain 217 3.5 CONCLUSIONS 219 3.6 REFERENCES 220 4. THEORETICAL ASPECTS OF BONDING IN ORGANOSILICON CHEMISTRY Robert Ponec 4.1 INTRODUCTION 233 4.2 VALENCE SHELL EXPANSION FROM THE POINT OF VIEW OF QUANTUM THEORY 234 4.2.1 The Concept of Orbitals 234 4.2.2 Classification of Atomic Orbitals 235 4.2.3 Transformation Properties of d Orbitals 237 4.2.4 d Orbitals and Hybridization 241 4.2.5 Other Factors Influencing the Utilization of d Orbitals in Bonding 245 4.2.6 The Variational Principle and d Orbital Participation 247 4.3 HYPERCONJUGATION 250 4.3.1 General Introduction 250 4.3.2 Hyperconjugation in Organosilicon Chemistry 250 4.3.3 Theoretical Aspects of Hyperconjugation 254 4.3.4 Hyperconjugation and the Accuracy of a Localized Description of Bonding 257 4.4 ELECTRONEGATIVITY 259 4.5 ELECTRONIC EFFECTS OF SILYL SUBSTITUENTS AND THE POSSIBILITIES OF THEIR CHARACTERIZATION 263 4.5.1 Linear Free Energy Relationships 263