Conjugated Polymeric Materials: Opportunities in Electronics, Optoelectronics, and Molecular Electronics NATO ASI Series Advanced Science Institutes Series A Series presenting the results of activities sponsored by the NATO Science Committee, which aims at the dissemination of advanced scientific and technological knowledge, with a view to strengthening links between scientific communities. The Series is pUblished by an international board of publishers in conjunction with the NATO Scientific Affairs Division A LBe Sciences Plenum Publishing Corporation B Physics London and New York C Mathematical Kluwer Academic Publishers and Physical Sciences Dordrecht, Boston and London D Behavioural and Social Sciences E Applied Sciences F Computer and Systems Sciences Springer-Verlag G Ecological Sciences Berlin, Heidelberg, New York, London, H Cell Biology Paris and Tokyo Series E: Applied Sciences -Vol. 182 Conjugated Polymeric Materials: Opportunities in Electronics, Optoelectronics, and Molecular Electronics edited by J. L. Bredas University of Mons, Mons, Belgium and R. R. Chance Exxon Research and Engineering Co., Annandale, New Jersey, U.S.A. Kluwer Academic Publishers Dordrecht / Boston / London Published in cooperation with NATO Scientific Affairs Division Proceedings of the NATO Advanced Research Workshop_ on Conjugated Polymeric Materials: Opportunities in Electronics, Optoelectronics, and Molecular Electronics Mons, Belgium September 3-8, 1989 Library of Congress Cataloging in Publication Data ISBN-13: 978-94-010-7416-2 e-ISBN-13: 978-94-009-2041-5 DOl: 1O.l007/978-94-009-2041-5 Published by Kluwer Academic Publishers, P.O. Box 17, 3300 AA Dordrecht, The Netherlands. Kluwer Academic Publishers incorporates the publishing programmes of D. Reidel, Martinus Nijhoff, Dr W. Junk and MTP Press. Sold and distributed in the U.S.A. and Canada by Kluwer Academic Publishers, 101 Philip Drive, Norwell, MA 02061, U.S.A. In all other countries, sold and distributed by Kluwer Academic Publishers Group, P.O. Box 322, 3300 AH Dordrecht, The Netherlands. Printed on acid-free paper All Rights Reserved © 1990 by Kluwer Academic Publishers Softcover reprint of the hardcover 1s t edition 1990 No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical, including photo copying, recording or by any information storage and retrieval system, without written permission from the copyright owner. TABLE OF CONTENTS Preface IX Theory of Conjugated Polymers and Molecular Crystals 1 R. Silbey Survey of Electrically Conducting Organic Materials 11 H. Naannann New Developments in the Synthesis and Doping of Polyacetylene and Polyaniline 53 A.G. MacDiarmid and AJ. Epstein Synthesis, Characterization, and Applications of Substituted Polyacetylenes Derived from Ring-Opening Metathesis Polymerization of Cyc100ctatetraenes 65 EJ. Ginsburg, c.B. Gorman, R.H. Grubbs, F.L. Klavetter, N.S. Lewis, S.R. Marder, 1.W. Perry, and M.J. Sailor Synthesis and Characterization of a Water Soluble Polyparaphenylene Vinylene Derivative 83 S. Shi and F. Wudl Molecular Organization and Electrical Properties of Mixed Langmuir- Blodgett Multilayer Thin Films of Polypyrrole 91 J. Cheung, R.B. Rosner, M.F. Rubner, X.Q. Yang, 1. Chen, and T.A. Skotheim The Electronic and Chemical Structure of Poly(3-hexylthiophene) Studied by Photoelectron Spectroscopy 101 W.R. Salaneck, R. Lazzaroni, N. Sato, M. Logdlund, B. Sjogren, M.P. Keane, S. Svensson, A. Naves de Brito, N. Correia, and S. Lunell Poly-l,2-Azepines by the Photopolymerization of Phenyl Azides: A New Route to Processible Conducting Polymers 115 E.W. Meijer, S. Nijhuis, F.C.B.M. Van Vroonhoven, and E.E. Havinga Polyheteroarylmethines, Syntheses and Physical Properties 133 R. Becker, G. Blochl, and H. Braunling Conformation of Conjugated Polymers in Good Solvent 141 J.P. Aime vi Electronic Structure of Processable Conducting Polymers 149 R. Lazzaroni, M. Logdlund, S. Stafstrom, W.R. Salaneck, D.D.C. Bradley, R.H. Friend, N. Sato, E. Ortl, and J.L. Bredas Bridged Mixed Valence Phthalocyaninato-Metal Compounds 163 A. Hirsch and M. Hanack Polyaniline Processed From Sulfuric Acid and in Solution in Sulfuric Acid: Electrical, Optical, and Magnetic Properties 171 Y. Cao, P. Smith, and AJ. Heeger Polyaniline versus Polyacetylene, or, Rings versus Bonds and the Roles of Barriers and Crystallinity 195 AJ. Epstein and A.G. MacDiarmid Linear Polyenes: The Interplay Between Electronic Structure, Geometric Structure, and Nonlinear Optical Properties 207 lM. Toussaint, F. Meyers, and lL. Bredas Semiconductor Device Physics in Conjugated Polymers 221 J.H. Burroughes, C.A. Jones, R.A. Lawrence, and R.H. Friend Chemistry and Physics of Molecular-Based Polymers Exhibiting a Spontaneous Magnetization 247 O. Kahn Ion Implanted Polyparaphenylene: Modifications of Lateral and in Depth Concentration Profiles upon Annealing 263 G. Froyer, Y. Pelous, M. Gauneau, R. Chaplain, A. Moliton, and B. Ratier The Electroactive Nature of Polyaniline. The Nature of the Chromaphores 273 AP. Monkman Transport in Oriented Polyacetylene 285 M. Galtier, M. Rolland, A Montaner, and A Alibenamara Transient Photoconductivity in Poly acetylene and Molecular Electronic Aspects 293 S. Roth, J. Anders, and J. Reichenbach Dehydrochlorination of Polyvinylchloride by Phase Transfer Catalysis 299 S. Dhainaut, A Perichaud, P. Bernier, S. Lefrant, and A. le Mehaute Vinylene-Linked Low-Band-Gap Conducting Polymers: Electronic Structure and Defects 305 H. Eckhardt, K.Y. Jen, L.W. Shacklette, and S. Lefrant vii Organic Conjugated Materials for Optoelectronic and Applications 321 J.e. Dubois Nonlinear Optics of Conjugated Polymers: Progress in Science and Prospects for Technology 341 S. Etemad, W-S. Fann, P.D. Townsend, G.L. Baker, and J. Jackel Transition Dipoles of Polyacetylene Oligomers 353 B.E. Kohler and J.A. Pescatore, Jr. Linear Optical Properties of a Series of Polyacetylene Oligomers 365 H.E. Schaffer, R.R. Chance, K. Knoll, R.R. Schrock, and R. Silbey Novel Linear and Nonlinear Optical Effects in Polydiacetylenes 377 D. Bloor, DJ. Ando, P.A. Norman, A.F. Drake, S. Mann, A.R. Oldroyd, B.S. Wherrett, A.K. Kar, W. Ji , and T. Harvey Nonlinear Optical Properties of Ultrathin Polymer Films 387 D. Neher, A. Kaltbeitzel, A. Wolf, C. Bubeck, and G. Wegner Third Harmonic Generation of Poly thiophene Derivatives 399 H. Sasabe, T. Wada, T. Sugiyama, H. Ohkawa, A. Yamada, and A.F. Garito Third Order Hyperpolarizability of Poly thiophene and Thiophene Oligomers 409 F. Charra and J. Messier Exciton Relaxation in PDA-4BCMU: from Crystals to Films 421 M.1. Nowak, GJ. Blanchard, GJ. Baker, S. Etemad, and Z.G. Soos Photoinduced Absorption and Nonlinear Optical Response in a Polycondensed Thiophene-Based Polymer (PTT) 429 G. Ruani, A.J. Pal, R. Zamboni, C. Taliani, and F. Kajzar Study of Second Harmonic Generation of a Hemicyanine Dye in Floating and Deposited Organic Monolayers 443 A. Scheelen, P. Winant, and A. Persoons Nonlinear Optics in Solid Schiff Bases 451 E. Hadjoudis, 1. Moustakali-Mavridis, and 1. Zyss Triplet Exciton-Polarons in Polydiacetylene Single Crystals 457 H. Sixl and W. RUhle Diffraction by Holographic Gratings in Diacetylene Crystals 471 Th. Vogtmann, H-D. Bauer, I. MUller, and M. Schwoerer viii Scanning Tunneling Microscopy at the Polymer-Metal Interface 483 J.P. Rabe and S. Buchholz Nonlinear Optics Coefficients of Polyenes: Size and Alternation Dependence 495 Z.G. Soos, G.W. Hayden, and P.C.M. McWilliams Electronic Structure and Static Electric Dipole Polarizability of Acetylenic Analogs of Carbocyanines 509 V.P. Bodart, J. Delhalle, and J.M. Andre Macrocycles as Molecular Units to Build up Electroresponsive Materials: A Comparative Theoretical Investigation of the Electronic and Optical Properties of Phthalocyanine and Related Systems 517 E. Ortf and J.L. Bredas Control of Intramolecular Interferences Through Benzene and Cyclophane Using Donor and Acceptor Groups 531 P. Sautet and C. Joachim Organic Crystals and Quadratic Nonlinear Optics: The Transparency- Efficiency Trade-off 545 J. Zyss Conducting Polymer Electromechanical Actuators 559 R.H. Baughman, L.W. Shacklette, R.L. Elsenbaumer, E. Plichta, and C. Becht Working Group Reports: - Prospects in Synthesis and Processibility of Conjugated Polymers 583 - Molecular Electronics Prospects 587 - Theoretical Developments 591 - Optoelectronics Prospects 595 - Electronics Properties 597 Index 599 PREFACE This book constitutes the Proceedings of the NATO Advanced Research Workshop on Conjugated Polymers held at the University of Mons, Belgium, during the first week of September 1989. The Workshop was attended by about fifty scientists representing most of the leading research groups within NATO countries, that have contributed to the development of conjugated polymeric materials. The program was focused on applications related to electrical conductivity and nonlinear optics. The attendance was well balanced with a blend of researchers from academic, industrial, and government labs, and including synthetic chemists, physical chemists, physicists, materials scientists, and theoreticians. The Workshop provided an especially timely opportunity to discuss the important progress that has taken place in the field of Conjugated Polymers in the late eighties as well as the enormous potential that lies in front of us. Among the recent significant developments in the field, we can cite for instance: (i) The discovery of novel synthetic routes affording conjugated polymers - that are much better characterized, especially through control of the molecular weight; - that can be processed from solution or the melt; the early promise that conducting polymcrs would constitute materials combining the electrical conductivities of metals with the mechanical properties of plastics is now being realized; - that can reach remarkably high conductivities. (ii) The exploitation of the high nonlinear optical responses that are inherent to conjugated materials, either for second-order or third-order effects. The detailed investigation of the dynamics of the excited state relaxation has proven proves to be an area of important basic and applied interest. (iii) The novel chemistry and physics of the polyanilines and other families of polymers where a simple protonation process can lead to an insulator-to-conductor transition. The influence of ring motions in the transport properties is a topic of growing interest. Furthermore, polyaniline fibers appear to display most promising mechanical properties. (iv) The achievement of electronic devices such as MISFET's in which conjugated polymers in the semiconducting state play an active role in the device physics. Five working groups were organized, that during the week actively discussed the prospects of conjugated polymers in the areas of synthesis and processabiIity, technological potentials, exploitation of the electronic properties, nonlinear optics, molecular electronics, and the key needs in tem1S of theoretical efforts. The reports of the working groups, which are collected at the end of the Proceedings, highlight the exciting opportunities for conjugated polymers into the 1990's. ix x That the Workshop ran smoothly and efficiently was due to the collaboration and hard work of many people. Thanks are due to the University of Mons, especially the President of the University, Professor Y. Van Haverbeke, and the Administrator, Mr. 1. Quenon, who fully supported the endeavor; the staff of the Restaurant Universitaire; and the staff of the Cite Universitaire. Nothing could have been accomplished without the tremendous help from the members of the Laboratory for Chemistry of Novel Materials at the University of Mons: especially Ms. F. Meyers who took care of all the organizational details from the very beginning and served as Scientific Secretary of the Workshop, Mr. I.M. Toussaint, Dr. G. Lambin, Dr. R. Lazzaroni, and Dr. 1. Orszagh as well as Mrs. M. Cornez and Mrs. 1. Sauveniere. The generous financial support from the NATO Division of Scientific Affairs was what made the Workshop possible. The genuine interest in the Workshop of the NATO team, especially Professor 1. Ducuing, Dr. C. Sinclair, and Professor L. Da Cunha is gratefully acknowledged. Support was also received from Exxon Research & Engineering Company. Finally, we wish to stress the fact that all the participants that presented a talk or a poster, did write a chapter for these Proceedings, thus making this book very comprehensive. It would also be impossible not to mention the fruitful late-evening sessions around special Belgian beers (simply the best) and the high-tech touch brought by Professor MacDiarmid. He used his own portable machine to fax his working group report to his secretary at Penn in order to have it typed overnight. Never forget the human factor, though! Professor MacDiarnlid had to phone her back and dictate the report because she was not able to read his handwriting! 1.L. Bredas, R.R. Chance December 1989