Study presents self-organising nanostructures with conductive properties
Japanese-German research team synthesises thiophene-fused nanobelts / Analysis reveals structure and behaviour of the molecules
In the search for useful materials, it is worth taking a closer look at the smallest structures: materials at the nanoscale often exhibit unique properties, e.g. electrical conductivity. These include nanocarbons such as the spherical C60 molecule, nanotubes and two-dimensional graphene. Theoretical considerations also predict interesting properties for belt-shaped compounds made of carbon rings. For example, such compounds could be used as optoelectronic components or in “self-healing materials” whose molecules self-assemble into regular structures. A Japanese-German research team, including scientists from the Institute of Organic Chemistry and the Institute of Physics at the University of Münster, has now produced and analysed such carbon nanobelts.
The molecules formed are neutrally charged but strongly polarised, as are all the sulphur atoms on the same side of the belt. This causes the molecules to attract each other very strongly in the crystalline structure and stack in a columnar shape, making them ideal for creating large, ordered structures on surfaces. “The results on gold and copper were surprisingly different,” says physicist Dr Harry Mönig. “On gold surfaces, the molecules gather at atomic step edges, with the sulphur atoms pointing towards the surface. On copper, by contrast, the molecules gather in large islands on the flat crystal planes. In this case, the sulphur atoms point away from the surface.”
This project received funding from the Japan Society for the Promotion of Science, the Ministry of Education, Culture, Sports, Science and Technology in Japan and the German Research Foundation (DFG).
