Synthesis and Physical Properties of Polyfluorinated Cycloparaphenylenes

Abstract

Fluorinated [6]- and [9]cycloparaphenylene (CPP) derivatives, 8F-[6]CPP and 12F-[9]CPP, were synthesized based on the previous synthesis of the parent CPPs. While the reductive aromatization conditions used in the final step of the synthesis of the parent CPPs did not work for the fluorinated compounds, the use of PBr and SnCl in acetonitrile successfully accomplished the desired transformation. The structures of F-CPPs were determined by single-crystal X-ray analysis. Photo- and electrochemical analyses and host-guest chemistry revealed the effects of the introduction of fluorine atoms.

The Supramolecular Chemistry of Strained Carbon Nanohoops

“…aza- [8]CPP) [26] and halogen-substituted (e.g. 8F- [6]CPP,F igure 1) [27] CPP derivatives were reported, thus indicating that the above-described synthetic routes are broadly applicable.F or more detailed information on the syntheses and optoelectronic properties of [n]CPPs,t he reader is referred to several recent review articles. [28][29][30][31][32] Strained nanohoops of an entirely different design comprise meso-substituted porphyrins instead of the phenylene units found in CPPAs and CPPs.A nderson and coworkers have successfully used oligopyridine templates [33,34] to prepare porphyrin nanorings such as c-P5 (Figure 1) by oxidative Glaser reactions.S ince even at emplated ringclosing step is typically not suitable for the generation of very high strain energies, c-P5 may represent the limit of this approach.…”

“…Equipping nanohoops such as the CPPs with polar functionalities is a promising strategy to enhance their intermolecular interactions in solution and the solid state. To this end, Yamago and co‐workers have successfully prepared 8F‐[6]CPP and 12F‐[9]CPP , which represent the first fluorinated CPP derivatives . Starting from tetrafluoro‐1,4‐benzoquinone, the authors developed both a route based on a Yamamoto coupling step ( 8F‐[6]CPP and 12F‐[9]CPP ) and an unusual combination of the platinum metallacycle and 1,4‐dihydroxy‐2,5‐cyclohexadiene approaches.…”

“…aza‐[8]CPP ) and halogen‐substituted (e.g. 8F‐[6]CPP , Figure ) CPP derivatives were reported, thus indicating that the above‐described synthetic routes are broadly applicable. For more detailed information on the syntheses and optoelectronic properties of [ n ]CPPs , the reader is referred to several recent review articles …”

Supramolekulare Chemie von gespannten Kohlenstoffnanoreifen

“…Nanoreifen wie die CPPs mit polaren Gruppen auszustatten, ist eine vielversprechende Strategie zur Verbesserung ihrer intermolekularen Wechselwirkungen sowohl in Lösung als auch im Festkörper. Zu diesem Zweck haben Yamago und Mitarbeiter 8F‐[6]CPP und 12F‐[9]CPP als die ersten fluorierten CPP ‐Derivate hergestellt . Ausgehend von Tetrafluor‐1,4‐benzochinon entwickelten die Autoren sowohl einen Weg basierend auf einem Yamamoto‐Kupplungsschritt ( 8F‐[6]CPP und 12F‐[9]CPP ) als auch eine ungewöhnliche Kombination aus dem Platin‐Metallazyklus und dem 1,4‐Dihydroxy‐2,5‐cyclohexadien‐Ansatz.…”

“…B. 8F‐[6]CPP ; Abbildung ) CPP ‐Derivate publiziert, was noch einmal die breite Anwendbarkeit der oben beschriebenen Syntheserouten zeigt. Für detailliertere Informationen über die Synthesen und optoelektronischen Eigenschaften von [ n ]CPPs seien den Lesern mehrere aktuelle Übersichtsartikel empfohlen …”