Various synthetic routes have been compared to access to unsymmetrical 1,2-bisthienylperfluorocyclopentenes having one electro-withdrawing formyl group. The strategy based on key monosusbtituted cyclopentenes appears to be the most reliable and versatile synthetic approach. Applying this controlled sequential synthesis to appropriate thiophenic building blocks leads to the preparation of π-conjugated extended push–pull system where photochromic performance were characterised.

The performance attained by electronic devices incorporating more than a single molecule is in part limited by weak electronic coupling between molecules. By implementing designed supramolecular interactions, chemists have begun taking control of the nanoscale ordering of the active layer in an effort to move beyond the trial and error tuning of the device morphology. This review describes current progress in solid-state devices in which the molecular components possess designed supramolecular interactions – as opposed to non-specific cohesive forces – used to instill or modify functionality. Supramolecular organic devices for applications in solar energy conversion, light-emitting diodes, field-effect transistors, storage and logic functions are covered.

The synthesis and the photochromic performance of a single-molecule system based on the covalent combination of dithienylperfluorocyclopentene and indolino[2,1-b]oxazolidine are described. The photoinduced interconversion between four states was shown to be deeply dependent on solvent and can be selectively controlled by adjusting the irradiation wavelength in chlorobenzene solutions. The color can be switched between colorless, yellow, pink and green on demand. This biphotochromic hybrid compound, despite poor fatigue resistance properties of the most conjugated colored isomer, displays large contrasts in structure, switching between zwitterionic and neutral character, independent chromophores and highly conjugated π systems.