Synthese bifunktionaler Cyclooctine zur Schichtsynthese auf Silizium und ein Beitrag zur Synthese von Azapentacenen mit alternierendem Stickstoff-Substitutionsmuster

Im ersten Teil der vorliegenden Arbeit wurde eine additivfreie Schichtsynthese in Lösung erprobt. Dazu konnte das Enolether-funktionalisierte Cyclooctin mit dem Azid-haltigen Tetrazin selektiv, schnell, bei Raumtemperatur und in hohen Ausbeuten umgesetzt werden. Auf einer Azid-bedeckten, molekula...

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Bibliographic Details
Main Author: Meinecke, Jannick
Contributors: Koert, U. (Prof. Dr.) (Thesis advisor)
Format: Doctoral Thesis
Language:German
Published: Philipps-Universität Marburg 2021
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By employing a bifunctional, strained cyclooctyne and an azide-incorporated tetrazine an additive-free, sequential layer-by-layer synthesis was demonstrated. The conversion was selective, fast, high-yielding and running at room temperature. The ligation steps in means of SpAAC and IEDDA were first exhibited on a cholic acid derived triazide.Subsequently the synthesis was examined on silicon(001) in cooperation with AG DÜRR. After the selective [2+2]- reaction of the strained triple bond with silicon dimers, a tetrazine reacted within IEDDA to the corresponding pyridazine and a second layer was built for the first time in UHV. Since in a previous work a terminal alkyne did not react in UHV within a 1,3-dipolar cycloaddition, a new strategy in order to synthesize a second layer for this bifunctional cyclooctyne was established. By diving the organic-semiconductor interface into a stain solution of azide and CuX(PPh3)3 (X = Br,I) in acetonitrile, a second layer was successfully achieved in cooperation with AG DÜRR. To facilitate the reaction, suitable conditions were investigated on a test system with particular requirements. In addition to enol ether and bisalkyne different cyclooctynes and 8-membered-ring-vinyl bromides were investigated towards their applicability for an additive-free layer-by-layer synthesis. SuFEx, hydrazone-formation, esterification and 1,3-dipolar cycloaddition were inferior to SpAAC & IEDDA.