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Functional Dendritic Materials Using Click Chemistry: Synthesis, Characterizations and Applications

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Functional Dendritic Materials Using Click Chemistry: Synthesis, Characterizations and Applications FUNCTIONAL DENDRITIC MATERIALS USING CLICK CHEMISTRY: SYNTHESIS, CHARACTERIZATIONS AND APPLICATIONS Per Antoni AKADEMISK AVHANDLING Som med tillstånd av Kungliga Tekniska Högskolan i Stockholm framlägges till offentlig granskning för avläggande av teknisk doktorsexamen fredagen den 13 juni 2008, kl 14.00 i sal F3, Lindstedtsvägen 26, KTH, Stockholm. Avhandlingen försvaras på engelska. Opponent: Prof. Stefan Hecht från Humboldt University, Tyskland. Copyright © 2008 Per Antoni All rights reserved Paper I © 2007 The Royal Society of Chemistry Paper II © 2008 The Royal Society of Chemistry TRITA-CHE-Report 2008:47 ISSN 1654-1081 ISBN 978-91-7415-017-9 ABSTRACT The need for new improved materials in cutting edge applications is constantly inspiring researchers to developing novel advanced macromolecular structures. A research area within advanced and complex macromolecular structures is dendrimers and their synthesis. Dendrimers consist of highly dense and branched structures that have promising properties suitable for biomedical and electrical applications and as templating materials. Dendrimers provide full control over the structure and property relationship since they are synthesized with unprecedented control over each reaction step. In this doctoral thesis, new methodologies for dendrimer synthesis are based on the concept of click chemistry in combination with traditional chemical reactions for dendrimer synthesis. This thesis discusses an accelerated growth approach, dendrimers with internal functionality, concurrent reactions and their applications. An accelerated growth approach for dendrimers was developed based on AB2‐ and CD2‐monomers. These allow dendritic growth without the use of activation or deprotection of the peripheral end‐groups. This was achieved by combining the chemoselective nature of click chemistry and traditional acid chloride reactions. Dendrimers with internal azide/alkyne functionality were prepared by adding AB2C monomers to a multifunctional core. Dendritic growth was obtained by employing carbodiimide mediated chemistry. The monomers carry a pendant C‐functionality (alkyne or azide) that remains available in the dendritic interior resulting in dendrimers with internal and peripheral functionalities. The orthogonal nature of click chemistry was utilized for the simultaneous assembly of monomers into dendritic structures. Traditional anhydride chemistry and click chemistry were carried out concurrently to obtain dendritic structures. This procedure allows synthesis of dendritic structures using fewer purification steps. Thermal analyses on selected dendrimers were carried out to verify their use as templates for the formation of honeycomb membranes. Additionally, a light emitting dendrimer was prepared by coupling of azide functional dendrons to an alkyne functional cyclen core. A Europium ion was incorporated into the dendrimer core, and photophysical measurements on the metal containing dendrimer revealed that the formed triazole linkage possesses a sensitizing effect. SAMMANFATTNING Förfrågan efter nya och mer avancerade applikationer är en pågående process vilket leder till en konstant utveckling av nya material. För att förstå relationen mellan en applikations egenskaper och dess sammansättning krävs full förståelse och kontroll över materialets uppbyggnad. En sådan kontroll över uppbyggnaden hos material hittas i en undergrupp till dendritiska polymerer som kallas dendrimerer. I den här doktorsavhandlingen belyses nya metoder för att framställa dendrimer med hjälp av selektiva kemiska reaktioner. Sådana selektiva reaktioner kan hittas inom konceptet klickkemi och har i detta arbete kombinerats med traditionell anhydrid‐ och karbodiimidmedierad kemi. Denna avhandling diskuterar en accelererad tillväxtmetod, dendrimerer med inre och yttre reaktiva grupper, simultana reaktioner och applikationer baserade på dessa dendritiska material. En accelererad tillväxtmetod har utvecklats baserad på AB2‐ och CD2‐ monomerer. Dessa monomerer tillåter tillväxt av dendrimerer utan att använda sig av skyddsgruppkemi eller aktivering av ändgrupper. Detta gjordes genom att kombinera kemoselektiviteten hos klickkemi tillsammans med traditionell syraklorid kopplingar. Dendrimerer med inre alkyn‐ eller azidfunktionalitet syntetiserades genom att använda AB2C‐monomerer. Den dendritiska tillväxten skedde med hjälp av karbodiimidmedierad kemi. Monomererna som användes bär på en C‐ funktionalitet, alkyn eller azid, och på så sätt byggs får interiören i de syntetiserade dendrimeren en inneburen aktiv funktionell grupp. Ortogonaliteten hos klickkemi användes för att sammanfoga monomerer till en dendritisk struktur. Traditionell anhydridkemi‐ och klickemireaktioner utfördes samtidigt och på så sätt kunde dendritiska strukturer erhållas med färre antal uppreningssteg. En ljusemitterande dendrimer syntetiserades genom att koppla azidfunktionella dendroner till en alkynfunktionell cyclenkärna. Europiumjoner inkorporerades i kärnan varpå dendrimerens fotofysiska egenskaper analyserades. Mätningarna visade att den bildade triazolen hade en sensibiliserande effekt på europiumjonen. Termiska studier på några av de syntetiserade dendrimerer utfördes för att se om några av dem kunde fungera som templat vid framställning av isoporösa filmer. LIST OF PAPERS The thesis is a summary of the following papers: I. “A chemoselective approach for the accelerated synthesis of well‐defined dendritic architectures” P. Antoni, D. Nyström, C. J. Hawker, A. Hult and M. Malkoch, Chemical Communications, 2007, 22, 2249‐2251. II. “Europium confined cyclen dendrimers with photophysically active triazoles” P. Antoni, M. Malkoch, G. Vamvounis, D. Nyström, A. Nyström, M. Lindgren and A. Hult, Journal of Materials Chemistry, 2008, DOI: 10.1039/b802197j III. “One‐pot dendritic growth and post‐functionalization of multifunctional dendrimers: Synthesis and application” P. Antoni, Y. Hed, D. Nyström, A. Nordberg, H. von Holst, A. Hult and M. Malkoch, Angewandte Int. Ed., to be submitted IV. “Click chemistry as a tool for accelerated and one‐pot synthesis of dendrimers: thermal study and application” P. Antoni, D. Nyström, P. Lundberg, A. Hult and M. Malkoch, Journal of the American Chemical Society, to be submitted My contribution to the appended papers: I. All of the experimental work, all of the analysis and most of the preparation of the manuscript. II. Most of the experimental work, half of the analysis and most of the preparation of the manuscript. III. Most of the experimental work, most of the analysis and most of the preparation of the manuscript. IV. Most of the experimental work, most of the analysis and most of the preparation of the manuscript. This thesis contains unpublished results. Scientific contributions not included in this thesis: V. “Dendritic structures with interior and exterior functionalities” P. Antoni, A. Hult and M. Malkoch. Provisional US patent application Serial No. 61/051,212 Swedish patent ID: 0801015-9 VI. “Characterization of poly(norbornene) dendronized polymers prepared by ring‐ opening metathesis polymerization of dendron bearing monomers” A. Nyström, M. Malkoch, I. Furo, D. Nyström, K. Unal, P. Antoni, G. Vamvounis, C. Hawker, K. Wooley, E. Malmström, A. Hult, Macromolecules, 2006, 39(21), 7241‐7249. VII. “Self‐Assembly of Poly(9,9ʹ‐dihexylfluorene) to Form Highly Ordered Isoporous Films via Blending” G. Vamvounis, D. Nyström, P. Antoni, M. Lindgren, S. Holdcroft, A. Hult, Langmuir, 2006, 22(9), 3959‐3961. VIII. “UV‐curable hyperbranched nanocomposite coatings” L. Fogelström, P. Antoni, E. Malmström, A. Hult, Progress in Organic Coatings, 2006, 55(3), 284‐290. IX. “Highly‐ordered hybrid Organic‐inorganic isoporous membranes from polymer modified nanoparticles” D. Nyström, P. Antoni, E. Malmström, M. Johansson, M. Whittaker, A. Hult, Macromolecular Rapid Communications, 2005, 26(7), 524‐528. X. “Bioglues” A. Nordberg, P. Antoni, A. Hult, H. von Holst and M. Malkoch, Manuscript XI. “Bouncing Water Droplets on Superhydrophobic Cellulose Surfaces” D. Nyström, J. Lindqvist, E. Östmark, P. Antoni, A. Carlmark, A. Hult, E. Malmström, Journal of Materials Chemistry, to be submitted XII. “Intelligent Dual‐Responsive Cellulose Surfaces via Surface‐Initiated ATRP” J. Lindqvist, D. Nyström, E. Östmark, P. Antoni, A. Carlmark, M. Johansson, A. Hult, E. Malmström, Biomacromolecules, accepted for publication XIII. “Honeycomb Patterned Membranes from Polymer‐Modified Silica Nanoparticles” D. Nyström, P. Antoni, E. Östmark, D. Nordqvist, L. Fogelström, E. Malmström, J. Örtegren, M. Lindgren, A. Hult, Journal of Materials Chemistry, to be submitted XIV. “Biocompatible Allylic Adhesives for Bone Fracture Stabilization” A. Nordberg, P. Antoni, A. Hult, H. von Holst and M. Malkoch. Patent manuscript TABLE OF CONTENTS 1 PURPOSE OF THE STUDY ....................................................................................1 2 INTRODUCTION .....................................................................................................2 2.1 POLYMERS........................................................................................................2 2.1.1 Dendrimers ..................................................................................................3 2.1.1.1 Divergent growth approach.................................................................................. 5 2.1.1.2 Convergent growth approach............................................................................... 6 2.1.2 Evolution of Dendrimers..............................................................................8
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