Chemical and constitutional influences in the self-assembly of functional supramolecular hydrogen-bonded nanoscopic fibres

Josep Puigmartí-Luis, Andrea Minoia, Ángel Pérez Del Pino, Gregori Ujaque, Concepció Rovira, Agustí Lledós, Roberto Lazzaroni, David B. Amabilino

Research output: Contribution to journalArticleResearchpeer-review

47 Citations (Scopus)

Abstract

A new series of secondary amides bearing long alkyl chains with π-electron-donor cores has been synthesized and characterised, and their self-assembly upon casting at surfaces has been studied. The different supramolecular assemblies of the materials have been visualized by using atomic force microscopy (AFM) and transmission electron microscopy (TEM). It is possible to obtain well-defined fibres of these aromatic core molecules as a result of the hydrogen bonds between the amide groups. Indeed, by altering the alkyl-chain lengths, constitutions, concentrations and solvent, it is possible to form different rodlike aggregates on graphite. Aggregate sizes with a lower limit of 6-8 nm width have been reached for different amide derivatives, while others show larger aggregates with rodlike morphologies which are several micrometers in length. For one compound that forms nanofibres, doping was 'performed by using a chemical oxidant, and the resulting layer on graphite was shown to exhibit metallic-like spectroscopy curves when probed with current-sensing AFM. This technique also revealed current maps of the surface of the molecular material. Fibre formation not only takes place on the graphite surface: nanometre scale rods have been imaged by using TEM on a grid after evaporation of solutions of the compounds in chloroform. Molecular modelling proves the importance of the hydrogen bonds in the generation of the fibres, and indicates that the constitution of the molecules is vital for the formation of the desired columnar stacks, results that are consistent with the images obtained by microscopic techniques. The results show the power of noncovalent bonds in self-assembly processes that can lead to electrically conducting nanoscale supramolecular wires. © 2006 Wiley-VCH Verlag GmbH & Co. KGaA.
Original languageEnglish
Pages (from-to)9161-9175
JournalChemistry - A European Journal
Volume12
Issue number36
DOIs
Publication statusPublished - 13 Dec 2006

Keywords

  • Hydrogen bonds
  • Isomers
  • pi interactions
  • Supramolecular assembly
  • Tetrathiafulvalene

Fingerprint Dive into the research topics of 'Chemical and constitutional influences in the self-assembly of functional supramolecular hydrogen-bonded nanoscopic fibres'. Together they form a unique fingerprint.

Cite this