[4]Cyclofluorene: unexpected influence of alkyl chain length

Abstract : Molecular nanorings have attracted a lot of interest the last ten years. Here we present the study of a new example of [4]cyclofluorene, with ethyl chains on the bridgeheads. Its molecular structure was established by solution NMR spectroscopy and single-crystal X-ray diffraction. Three successive oxidation processes and one reversible reduction were observed via cyclic voltammetry. The optical properties were characterized both in solution and film by UV-visible spectroscopy, stationary and time-resolved fluorescence. It was found that this [4]cyclofluorene displays different characteristics compared to the other [4]cyclofluorenes substituted by methyl or propyl chains: a simple modification of the chain length induces a non-negligible effect on the emission properties which must be linked to the specific arrangement of the fluorene units. Furthermore, single-crystal X-ray diffraction reveals the formation of a pseudo-tubular solid state arrangement of fully symmetrical ring structures, which was not observed for the other members of the [4]cyclofluorenes family. This feature, never discussed to date, could open the way to the modulation of properties of cyclofluorenes through alkyl chain engineering.
Document type :
Journal articles
Complete list of metadatas

Cited literature [32 references]  Display  Hide  Download

https://hal-univ-rennes1.archives-ouvertes.fr/hal-01890153
Contributor : Laurent Jonchère <>
Submitted on : Monday, October 8, 2018 - 2:06:19 PM
Last modification on : Sunday, December 23, 2018 - 7:06:14 PM

File

Sicard_4_Cyclofluorene-Unexpec...
Files produced by the author(s)

Identifiers

Citation

Lambert Sicard, Olivier Jeannin, Joëlle Rault-Berthelot, Cassandre Quinton, Cyril Poriel. [4]Cyclofluorene: unexpected influence of alkyl chain length. ChemPlusChem, Wiley, 2018, 83 (9), pp.874-880. ⟨10.1002/cplu.201800369⟩. ⟨hal-01890153⟩

Share

Metrics

Record views

78

Files downloads

116