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Stable Lanthanide Cryptates As Building Blocks for Solid Phase Peptide Synthesis - Synthesis, Functionalization and Photophysical Properties

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Stable Lanthanide Cryptates As Building Blocks for Solid Phase Peptide Synthesis - Synthesis, Functionalization and Photophysical Properties Stable Lanthanide Cryptates as Building Blocks for Solid Phase Peptide Synthesis - Synthesis, Functionalization and Photophysical Properties Dissertation zur Erlangung des Grades eines Doktors der Naturwissenschaften der Fakultät für Chemie und Biochemie der Ruhr-Universität Bochum vorgelegt von M.Sc. Nicola Alzakhem Bochum, Dezember, 2012 Die vorliegende Arbeit wurde von Dezember 2008 bis Dezember 2012 am Lehrstuhl für Anorganische Chemie I der Ruhr-Universität Bochum angefertigt. Referent: Dr. Michael Seitz Korreferent: Prof. Dr. Martin Feigel To my parents Danksagung Ich danke allen, die mich durch ihre Hilfsbereitschaft und Interesse unterstützt haben, insbesonders: Dr. Michael Seitz für die Vergabe des interessanten Themas und die Einführung in die „Lanthanide Chemistry“. Ich danke ihm für sein entgegengebrachtes Vertrauen und jede wissenschaftliche Diskussion. Jede Phase dieser Arbeit wurde von ihm professionell und motiviert begleitet. Herrn Prof. Metzler-Nolte für die Aufnahme in seine Gruppe, seine Freundlichkeit und sein Bereitstellen von Analysemöglichkeiten in seinem Arbeitskreis. Herrn Prof. Martin Feigel für seine freundliche Übernahme des Korreferates. Herrn Dr. Klaus Merz und Mariusz Molon für die Messungen der Röntgenstrukturanalysen. Frau Andrea Ewald für das Messen zahlreicher ESI-Massenspektren. Jessica Wahsner, Tuba Güden-Silber und Christine Doffek für die außerordentlich tolle Zusammenarbeit und für das Korrekturlesen. Ein besonderer Dank geht an Jessica für ihr Dasein und für ihr offenes Ohr bei Problemen und ihren guten Rat. Mit Jessica habe ich problemlos den Arbeitsplatz geteilt und sie war eine wunderbare Nachbarin. Desweitern möchte ich mich bedanken bei dem gesamten jetzigen und vorherigen Team der ACI für die freundliche Arbeitsatmosphäre. Besonderer Dank geht an David Köster, Lukasz Raszeja, Johanna Niesel, Nina Hüsken und Jan Dittrich für die besondere Zeit am Lehrstuhl und außerhalb der Uni. Ein ganz besonderer Dank geht an meine Eltern für alles was sie für mich und meine Zukunft getan haben. Ohne euch wäre diese Arbeit unmöglich. Zum Schluss will ich mich aus ganzem Herzen bei Caroline Bischof bedanken. Mit Caro habe ich zusammen gearbeitet, zusammen gesungen und zusammen gelacht. Jede schlechte und gute Phase habe ich mit ihr geteilt. Sie war nicht nur eine besondere Freundin, sondern ist Teil meiner Familie geworden. PREFACE................................................................................................I 1 INTRODUCTION ..............................................................................1 1.1 Lanthanides............................................................................................................................................. 1 1.2 Applications of lanthanide complexes................................................................................................... 2 1.2.1 Luminescent lanthanide complexes ..................................................................................................... 2 1.2.2 Magnetism: Lanthanides in NMR spectroscopy .................................................................................. 3 1.2.3 Lanthanides as mass tags ..................................................................................................................... 4 1.2.4 Other applications ................................................................................................................................ 4 1.3 Typical ligands for lanthanide ions ....................................................................................................... 5 1.3.1 Polyamino carboxylates ....................................................................................................................... 5 1.3.2 Crown ethers and cryptands................................................................................................................. 7 1.4 Multinuclear lanthanide complexes ...................................................................................................... 9 1.4.1 Homo-polymetallic lanthanide complexes........................................................................................... 9 1.4.2 Hetero-polymetallic lanthanide complexes........................................................................................ 11 2 THE AIM OF THE WORK ...............................................................15 3 RESULTS AND DISCUSSION........................................................18 3.1 Cryptand Design-General Considerations.......................................................................................... 18 3.2 Synthesis of anionic cryptands............................................................................................................. 20 3.2.1 Cryptands based on bis(thiazole) ....................................................................................................... 20 3.2.2 BINOL-based cryptates...................................................................................................................... 23 3.2.3 2,2 ′-Biphenol-based cryptates............................................................................................................ 24 3.2.4 Stability.............................................................................................................................................. 27 3.2.5 Structural aspects ............................................................................................................................... 29 3.3 Functionalization of cryptates ............................................................................................................. 32 3.3.1 Approach I ......................................................................................................................................... 33 3.3.2 Approach II ........................................................................................................................................ 44 3.3.3 Synthesis of lysine cryptate conjugates.............................................................................................. 52 3.4 Photophysical properties of the cryptates........................................................................................... 56 3.5 Influence of the number of bipyridine on the photophysical properties of bpy-based cryptates: . 60 3.5.1 Synthesis of the sodium and lanthanide cryptates.............................................................................. 60 3.5.2 Triplet state determinations................................................................................................................ 63 3.5.3 Absorption and emission spectra ....................................................................................................... 64 3.5.4 Determination of the quantum yields and lifetimes ........................................................................... 65 3.6 A new kind of chiral cryptate .............................................................................................................. 68 3.6.1 Synthesis of the cryptates................................................................................................................... 69 4 SUMMARY......................................................................................73 5 EXPERIMENTAL SECTION:...........................................................78 6 LITERATURE................................................................................127 7 APPENDIX....................................................................................132 List of abbreviations and units Å angstrom [10-10 m] AA any amino acid BINOL 1,1 ′-Bi-2-naphthol δ chemical shift DCM Dichloromethane DMF Dimethylformamide DMSO Dimethylsulfoxide EDC 1-Ethyl-3-(3-dimethyllaminopropyl)carbodiimide ESI-MS electro-spray ionisation mass spectrometry Fmoc 9-fluorenylmethyloxycarbonyl GC gas chromatography H hour HOSu N-Hydroxysuccinimid HPLC high-pressure liquid chromatography Hz Hertz [s -1] ICP-MS inductively coupled plasma mass spectrometry J coupling constant λ wavelenght [nm] ACN Acetonitrile MRI magnetic resonance imaging m/z mass to charge ratio ν wavenumber [cm -1] NBS N-bromosuccinimide NIS N-iodosuccinimide Nm Nanometer NMR nuclear magnetic resonance o.n. overnight r.t. room temperature SPPS solid phase peptide synthesis TFAA trifluoroacetic acid THF tetrahydrofurane TLC thin layer chromatography TMEDA N,N,N ′,N ′-tetramethylethylenediamine UHP Urea hydrogen peroxide UV Ultraviolet Vis Visible Vs. Versus Preface Preface In our childhood, we played with LEGO bricks and have enjoyed the possibility to build various figures from the same building blocks. These colorful bricks with different shapes can be assembled in many ways to construct different objects such as houses, trees, etc. Similarly, letters are used to build words or texts and musical notes are used to compose beautiful melodies (Figure 0.1). Figure 0.1. Examples of building blocks from everyday life (adopted from internet). (http://www.amazon.de/LEGO-5539-Steine-Steinebox-Starter/dp/B001CQRVVM) Last access: 20.12.2012 (http://en.wikipedia.org/wiki/File:Chopin_Prelude_7.svg) Last access: 20.12.2012 While all of this is going on at the macroscopic level, similar operations are occurring inside us. At the microscopic level, the chemical processes in our body use various sets of small molecules (e.g. amino acids, nucleic acids, monosaccharides, etc.) as building blocks to construct macrobiomolecules such as peptides, proteins,
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