Substituted [10]Cycloparaphenylenes : Synthesis and their Supramolecular Behavior

Datum

2023

Betreuer/Gutachter

Weitere Beteiligte

Herausgeber

Zeitschriftentitel

ISSN der Zeitschrift

Bandtitel

Verlag

Zusammenfassung

Cycloparaphenylenes (CPPs), the shortest section of armchair carbon nanotubes, are a class of organic compounds with exceptional structural characteristics and potential applications across various scientific and technological domains. Their potential application in carbon-based functional materials derives from the radially oriented π system and the inherent strain of these nanohoops. The former not only confers unusual optoelectronic properties of CPPs, but also makes them excellent hosts for fullerenes. In this thesis, a new strategy for the synthesis of a substituted [10]CPP derivative was developed. The [2+2+2] cycloaddition reaction was used as key step to introduce substituents in this synthesis to obtain a diethyl phthalane-containing [10]CPP in seven steps and with 8% overall yield. This efficient synthesis allowed additional studies on the behavior of these nanohoop in supramolecular assemblies. The diethyl phthalane-containing CPP was used together with di- and tetra-tert-butyl ester-substituted [10]CPP to investigate the substitution effect in supramolecular fullerene (C60 and C70) architectures. Experimental analysis, supported by theoretical investigations, revealed that in complexes of the ellipsoidal C70 the attractive substituent-fullerene interactions are enhanced with respect to C60. Furthermore, a systematic study of the substituent-substituent interactions in such supramolecular motifs was conducted with di-tert-butyl ester-substituted [10]CPP and a series of methano-fullerenes. These Bingel adducts of fullerene C60 were functionalized with different linear or branched alkyl esters and the interaction between these and the tert-butyl ester substituted CPP was evaluated. While all alkyl ester derivatives showed a stabilizing effect – based on a double mutant cycle – these effects were enhanced with longer chain length, while the steric demand plays a significant role in the branched alkyl derivatives. As an exception, the adamantyl substitution on the fullerene shows an increased stabilizing effect being rationalized with the increased London dispersion ability.

Beschreibung

Inhaltsverzeichnis

Anmerkungen

Erstpublikation in

Sammelband

URI der Erstpublikation

Forschungsdaten

Schriftenreihe

Erstpublikation in

Zitierform