Structures, properties, and applications of soluble polyazulene and azulene containing copolymers 1

STRUCTURES, PROPERTIES, AND APPLICATIONS OF SOLUBLE POLYAZULENE AND AZULENECONTAINING COPOLYMERS WANG FUKE (M Sc, Fudan Univ.) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF CHEMISTRY NATIONAL UNIVERSITY OF SINGAPORE 2003 i Acknowledgments I would like to express my sincere gratitude to my supervisor, Associate Professor Lai YeeHing for his invaluable guidance, constant advice through this project. I would also like to express my appreciation to Associate Professor Kocherginsky, N and Dr Yuri for their kind help in the EPR measurements. In addition, I wish to express my heartful thanks to all graduate students in my research lab. In particular, I would like to than Dr. Xu J. W., Ms. Wang W. L., Ms. Lin Y., Ms. Zhou. C. Z., Ms. Lu H. F. Mr. Wang J. H. for their advice and friendship. Thanks also go to Ms. Tan G. K. of the X-ray Diffraction Lab of Department of Chemistry for her assistance in analysis of the single crystal structures, all staff of Central Instrumental Lab, Thermal Analysis Lab, Honors Lab, and Chemical Store for their help. I dedicate this project of work to my girl friend who has provided me with so much support and encouragement, just when I needed them most. Last but not least, I would like to express my gratitude to the National University of Singapore for the award of research scholarship and for providing me with the opportunity to carry out the research work reported in this thesis. ii Content Acknowledgements ii Content iii Summary xi Glossary of Symbols xix Glossary of Abbreviations xxi List of publications xxiii Table of the prepared compounds and polymers xxiv Chapter introduction 1. Conducting polymers 1.1 The conductivities of conjugated polymers 1.2 Mechanism of Polymer Conductivity 1.3 Electrical Conductivity Measurement 11 2. Conjugated polymers band gap engineering 12 2.1 Band-gap of conjugated polymers 12 2.2 Reduction of band gap conjugated polymers 13 2.2.1 Minimization of bond-length alternation 14 2.2.2 Reduction of band gap by donor-acceptor systems 16 3. Advanced materials based on π-conjugated polymer 19 3.1. Chromic effect conjugated polymers 20 3.2. Conjugated polymes-inorganic hybrids 22 iii 4. Azulene and Polyazulenes 26 4.1. Unique structure and interesting properties of azulene 27 4.2 Recent application of azulene and its derivatives in materials science 29 4.3 The polyazulenes (PAZs) 31 5. Oligomers Approach 34 5.1 Monomers and Oligomers: model compound for understanding of polymer properties 36 5.1.1 Structure/property relationships 36 5.1.2 The doping mechanism revealed from the oligomers approach 39 5.1.3 The crystal structure of oligomers 41 5.2 Monomers and Oligomers – New approach for advanced materials 43 • Molecular electronic 43 • FET 44 • Optical application 45 6. Project objective 45 7. References 47 Chapter The First Aptly Characterized 1,3-polyazulene: true polyazulene and its ethynylene derivatives for steric hindrance release 57 Introduction 57 Results and Discussion 59 Synthesis of polyazulene 59 Synthesis of poly(azulene-ethynylene) and poly(azulene-ethynylene-thienyl) 60 Thermal Analysis 61 iv Solubility Test 62 64 HNMR Characterization FT-IR spectrum 65 Electronic Spectra 67 EPR Measurement 70 Conductivities Mesurement 74 XRD and morphology study 75 Cyclic voltammogram 77 Conclusions 78 References 80 Chapter Stimuli-Responsive Conjugated Copolymers Having Electro-Active Azulene Units in the Main Chain 81 Introduction 81 Results and Discussion 83 Monomer Synthesis and Characterization 83 Monomers characterization 84 UV-vis Spectra and EPR studies 87 Polymers synthesis and characterization 89 Gel properties study 94 v Thermal analysis 96 UV-vis and UV-vis-NIR Spectroscopic Study 99 EPR studies 102 XRD analysis 105 Morphology of the neutral and doped copolymers 106 Electrochemical Analysis 107 Electrochemical Impedance Spectroscopy study 110 Electrical Conductivity 112 Conclusions 113 References 115 Chapter Crystal Structures of Monomers and Oligomers Containing Azulene Unit – Model Compounds for the 119 Corresponding Polymers Introduction 119 Results and Discussion 120 Model compounds design and synthesis 120 Characterization 122 Structural Analysis 126 Structure of Monoa and Monob. 126 Structure of Oligoa and Oligob 131 vi Structure of MonoO6 138 UV-vis Spectra and NMR studies 140 Cyclic voltammogram study 146 Conclusions 149 References 152 Chapter Reason for the high conductivity of the azulene containing copolymers by studying their monomer-TCNQ charge-transfer crystal structures and corresponding polymers154 TCNQ charge-transfer complex Introduction 154 Results and Discussion 157 Synthesis of the monomers and their charge-transfer complex 157 Characterization 159 Single-crystal structure analysis 161 Crystal structure of Monoa.TNB 161 Crystal structure of Monoc.TCNQ 166 UV-vis spectrum of the complex 172 Post-synthesis and characterization charge-transfer complex of conjugated polymers and TCNQ 175 Electronic Spectrum and EPR study 179 Conductivity measurement of the CT complex 181 Conclusions 181 References 184 vii Chapter Coordination of Multinuclear Transitional Metal Cluster to π-Conjugated Polymers: A New Strategy towards 186 Tunable Hybrids Introduction 186 Results and Discussion 189 Model Compounds Synthesis and Characterization 189 Model compound synthesis 189 Structural Characterization 190 Solid-state crystal structure of model compounds 193 UV/vis spectra and MLCT effect in the model compounds 198 Synthesis of hybrids of polymer and ruthenium carbonyl cluster 200 The chromium of ruthenium carbonyl cluster coordination to the polymers revealed by HNMR and FT-IR 202 Morphologies Studies 205 Thermal Properties 207 Optical and electronic properties studies 209 Electrical chemistry study 211 Sensitivities of the hybrids to iodine and TFA 213 Conclusions 216 References 218 Chapter Novel polyradicals stabilized by the vertical and horizontal delocalization of the electrons 220 Introduction 220 viii Results and Discussion 223 Monomer synthesis and characterization of the cation radical 223 Polymers synthesis and characterization 227 Thermal properties 229 Electrochemical Properties 230 Electronic spectroscopy study 231 EPR spectroscopy study 234 Conclusions 236 References 237 Chapter Conjugation control by changing the main backbone conjugation type or by side aromatic substituent 239 Introduction 239 Molecular design 242 Results and discussion 243 Part 1. Conjugation control by changing the main backbone conjugation type 243 Model compounds synthesis and characterization 243 Structure analysis of the model compounds 248 Polymers synthesis and characterization 252 Optical properties 255 Part 2. Conjugation control by side aromatic substituents 257 Model compounds synthesis and characterization 257 Structural analysis 260 UV-vis spectra study 263 ix Electrochemical properties 265 Synthesis and characterization of conjugated polymers bearing phenyl pendant group 267 UV-vis and CV studies 270 Conclusions 272 References 275 Chapter Experiment Section 277 Materials 277 Solvents 277 Chemicals 277 Instrumentation 278 Synthesis 281 Synthesis of main compounds monomers 281 Synthesis of polymers 311 Chapter 10 Conclusions and Suggestions for future work 320 Conclusions 320 Suggestions 323 Appendix 324 x greatly decreased ([...]... CO PA -1, x = 0.5, y = 0.5; PA-2, x = 1. 0, y = 0 Ru PB -1, x = 0.5, y = 0.5; PB-2, x = 1. 0, y = 0 c OC8H17 OH B OH 2,5-Dioctyoxy -1, 4-phenyl S S S OC S R R NC S S NC R R R R PAzBzC8 n 1, 3-Diphenyl -azulene R = C8H17 PAzBzOC8 R = OC8H17 R xxvii Chapt.7 diboronic acid HO B HO C8H17 C8H17 OH B OH 2,5-Dioctyl -1, 4-phenyl diboronic acid C10H 21 C4H9 S S CO2Et S CO2Et S S n S CO2Et CO2Et P26A M26A C10H 21 Chapt.8... show the preparation of a truly xi soluble 1, 3 -polyazulene by dehalogenative polycondensation of 1, 3-dibromoazulene, using an organonickel catalyst Furthermore, 1, 3 -polyazulene was characterized by 1 HNMR spectroscopy, IR, and elemental analysis, which shows that azulene still kept its unique structure in the polymer backbone Most interestingly, the polymer exhibits high conductivity and paramagnetic properties... of azulene- containing polymers and to develop novel materials, copolymers containing azulene moiety and 3-aklyl-thiohene were prepared and investigated (Chapter 3) The resulting copolymers showed high thermal stability in air and good solubility in most organic solvents Interestingly, chromic effect upon protonation and reversible protonation-deprotonation (P-DP) processes was observed via UV-vis and. .. S n S CO2Et CO2Et P26A M26A C10H 21 Chapt.8 DPTA1 Me CO2Et S CO2Et S S n CO2Et S CO2Et P26B M26B xxviii C10H 21 S S CO2Et S S S n S CO2Et 2-thenyl-6-(3’-decyl-thenyl) -azulene- 1, 3DPTA2 dicarboxylic acid diethyl ester C6H13 C6H13 Pol4Ph C10H 21 S S CO2Et S S S n S CO2Et 2-thenyl-6-(4’-decyl-thenyl) -azulene- 1, 3- DPTA3 dicarboxylic acid diethyl ester C6H13 C6H13 Pol3Ph xxix ... system containing azulene and benzene in the polymer backbone via 1, 3-conjugation of azulene In this system, upon potonation or doping, radicals will align into the five-membered ring of azulene, which will be stabilized by the following two approaches: the un-paired electrons of the radicals is delocalized to the tropolynium cation of the azulene s seven-membered ring in the vertical direction and to... Conjugated Copolymers Having Electro-Active Azulene and Bithiophene Units in the Polymer Skeleton: Effect of Protonation and p-Doping on Conducting Properties, Macromolecules, 2004, Accepted xxiii Table Polymers and main compounds prepared in this thesis Chapter Main compounds in each chapter Polymers or Oligomers No n n TMS TMS 1, 3-DIethynyl -azulene Chapt.2 1, 3-Bis-trimethylsilanylethynyl- Polyazulene. .. cations as well as anions, azulene should be predestinated to be a building block for the construction of new materials with interesting chemical and physical properties However, up to now, only polyazulene has been prepared without detailed characterization because of its insolubility The reported HNMR spectrum for polyazulene indicates destruction of the unique structure of azulene Thus, in Chapter... relationship, doping mechanism, and the coordination mode of the formation of hybrids The focus of this work has been to develop novel materials by inserting the intact azulene into the polymer backbone This is attractive because of the special optical and electrical properties of azulene As a non-alternated 10 -π electron aromatic system with pronounced polarizability and a tendency to form stabilized... conjugation of the resulting materials, that is control of the band gap of the resulting materials, was investigated (Chapter 8) from two points of view: the main backbone electronic geometry, and the side conjugation In the first approach, we greatly lowered the band gap of the resulting materials by changing the 1, 3coupling to the 2,6-coupling azulene in the main backbone The latter is the more favourable of. .. coupling, and their crystals were prepared These compounds were characterized by NMR, FT-IR and 2-D NMR techniques Their single crystal structures showed that a large torsion angle existed between the azulene ring and the thiophene ring in these model compounds In general, this explains the amorphous structure of the resulting copolymers and the identification of the UV-vis spectra of these copolymers . 11 9 Introduction 11 9 Results and Discussion 12 0 Model compounds design and synthesis 12 0 Characterization 12 2 Structural Analysis 12 6 Structure of Monoa and Monob. 12 6 Structure of. Impedance Spectroscopy study 11 0 Electrical Conductivity 11 2 Conclusions 11 3 References 11 5 Chapter 4 Crystal Structures of Monomers and Oligomers Containing Azulene Unit – Model Compounds. STRUCTURES, PROPERTIES, AND APPLICATIONS OF SOLUBLE POLYAZULENE AND AZULENE- CONTAINING COPOLYMERS WANG FUKE (M Sc, Fudan Univ.)