Phosphole modified pentathienoacene: Synthesis, electronic properties and self-assemblyElectronic supplementary information (ESI) available: The POM, OM and SEM images of gel, 1H NMR spectra. CCDC reference number 822000. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c1ob06584j

A series of new ladder -conjugated materials, phosphole modified pentathienoacene ( PO-PTA ), are synthesized and characterized. Single-crystal X-ray results demonstrate that methyl-disubstituted PO-PTA forms a face-to-face dimer structure driven by interactions. The investigations of optical properties showed that the oxidized phosphole moiety in this ladder system can effectively narrow the band gap. PO-PTA is a promising building block in -conjugated polymers and oligomers for optoelectronic applications. The derivative of PO-PTA , obtained by introducing four long alkyl chains, can self-assemble into one-dimensional (1D) fibers based on intermolecular interactions, dipoledipole interactions and van der Waals interactions. Interestingly, the uniform and well-ordered monolayers were also obtained for PO-PTA derivative on a HOPG (highly oriented pyrolytic graphite) surface. Phosphole modified pentathienoacene with a much lower LUMO level can self-assemble into different supramolecular structures with the aid of long alkyl chains.