Dissertation (Metadaten)
Titel:Konkave Phenylethinylpyridine zur Anwendung als Sensoren
 
Autor:Ole Storm
 
URN:NBN:urn:nbn:de:gbv:8-diss-5173
 
Fakultät:Mathematisch-Naturwissenschaftliche Fakultät
DDC Sachgebiet:540 Chemie
 
Datum der mdl. Prüfung:19.12.2001
 
Referent(in):Prof. Dr. Ulrich Lüning
Korreferent(en) Korreferentin:Prof. Dr. Thisbe K. Lindhorst
 
Beschreibung (original):(Keine Zusammenfassung in deutscher Sprache vorhanden.) (No summary in German language.)
 
(übersetzt):Several convergent synthetic approaches of concave pyridines have been examined. These concave pyridines were designed to signal an interaction at the pyridine nitrogen by changing its UV-absorbance. A number of concave arylethinyl pyridines and arylethinyl pyridine diesters have been synthesized and characterized. The spectrometric examination of these sensors show absorption at longer wave lengths. The relative basicities have been determined by titration with trifluoro-acetic acid in two solvents of different polarity (dichloromethane and methanol). The basicities depend on the substituents of the conjugated p-system. This relation is stronger in the polar solvent (rho-value of -0.6, respectively -0.2). The absorbance of the protonation of concave arylethinyl pyridines differs from the solvation in a polar solvent. In any observed case there is a small solvatochromic effect (2 to 6 nm for unprotonated and approximately 10 nm for protonated forms) when the solvent is changed from dichloromethane to methanol. For two sensors, phenyl and naphthyl substituted concave arylethinyl pyridines a nonlinear shift of the absorption maxima by the change of solvent from dichloromethane to methanol occurred. Perhaps this can be interpreted as a hydrogen bond. A route to concave arylethenyl pyridines could be shown employing the new synthesized building blocks in a Stille coupling of halogensubstituted concave pyridines with tinalkenyl compounds. The templated synthesis of diimine macrocycles is part of the synthesis of arylethinyl pyridines. This reaction was used to select several different macrocycles from the same reaction mixture derived from several similar building blocks which are in dynamic equilibrium (VCL, virtual combinatorial library) with each other by addition of different template ions. The parallel synthesis of several discrete macrocycles is possible, too. The reversibility of this thermo-dynamically controlled reaction acts as an repair mechanism for the resulting molecules leading to very good yields in macrocycle synthesis. The Pd(0)catalyzed coupling (so called Sonogashira reaction) of substituted ethinyl arenes to a concave iodopyridine provides access to the class of substituted concave arylethinyl pyridines 1 (yields 70 to 80%). A number of concave arylethinyl pyridines and arylethinyl pyridine diesters have been synthesized and characterized. The spectrometric examination of these sensors show absorption at longer wave lengths. The relative basicities have been determined by titration with trifluoro-acetic acid in two solvents of different polarity (dichloromethane and methanol).
 
Schlagworte:Pyridinderivate ; Konkaves Reagenz ; Solvatochrome Verbindungen ; Chemischer Sensor ; Template Synthesis, Concave Reagents, Virtual Combinatorial Library, Sonogashira Coupling, UV-Titration, Basicity, Molecular Sensor, Hydrogen Bond, Solvent Polarity
 
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