Coupling carbon nanomaterials with photochromic molecules for the generation of optically responsive materials

Multifunctional carbon-based nanomaterials offer routes towards the realization of smart and high-performing (opto)electronic (nano)devices, sensors and logic gates. Meanwhile photochromic molecules exhibit reversible transformation between two forms, induced by the absorption of electromagnetic radiation. By combining carbon-based nanomaterials with photochromic molecules, one can achieve reversible changes in geometrical structure, electronic properties and nanoscale mechanics triggering by light. This thus enables a reversible modulation of numerous physical and chemical properties of the carbon-based nanomaterials towards the fabrication of cognitive devices. This review examines the state of the art with respect to these responsive materials, and seeks to identify future directions for investigation.

Assembly of functional molecular nanostructures on surfaces

This tutorial review discusses different techniques for the preparation and deposition on surfaces of organic nanostructures--monolayers, nanowires, nano-dots and other aggregates--with emphasis on the key role that chemical design and non-covalent interactions (between molecules themselves and molecules and surface) play in the definition of the final structure and its properties. The characterisation of the nanostructures and the important effects of post-deposition treatment are also touched upon. The tetrathiafulvalene (TTF) unit is used as the example to demonstrate the general principles that are applicable for these different nanoscale architectures, because of the interest of this family of compounds in molecular electronics.

Expanding Dendrons. The Photoisomerism of Folded Azobenzene Dendrons

Irradiation of a folded azobenzene dendron system triggers a large, reversible structural expansion. The dendrons adopt a compact helical conformation in the stable E form owing to the E geometry of azo linkage and the syn-syn preference of the dendritic branch points. E --> Z photoisomerization disrupts this folded conformation in a manner that decreases the packing efficiency and results in an expansion in hydrodynamic volume.