Joined: 16 Mar 2004
|Posted: Tue Oct 16, 2007 3:53 pm Post subject: Addressable Nanorotors in a network
|Scientists of the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute (Switzerland) in collaboration with colleagues from the University of Heidelberg (Germany) have made a major step forward in the development of addressable and functional supramolecular structures. Their work was published this week in the international science journal Chemical Communications. The team of Meike Stöhr, Lutz Gade and Thomas Jung incorporated single porphyrin molecules into a self-assembled perylene network. The porphyrin molecules can be thought of as tiny gears turning like rotors in the pores of the network. On this network surface, they behave totally different from porphyrin molecules in a solid state body, in solution or in the gas phase. The researchers are able to slow down the molecule movement by bringing the tip of a scanning tunnelling microscope into very close proximity to an individual molecule.
Recently, the same scientists reported about the self-assembly and formation of a stable perylene network by a thermal chemical reaction. Now they have used this network to assemble millions of tiny rotors about one nanometer in size in a periodic arrangement on a surface. With a scanning tunnelling microscope each rotor can individually be addressed, activated or slowed down. With raising temperature the rotors turn faster.
The technique described in the paper opens up many more applications as the network architecture can be readily configured. Different molecules can be incorporated into the combs. Like honeycombs that exhibit different functions according to their specific filling, the combs in the nano-network can receive characteristic properties according to the incorporated molecule. Date storage units can be envisaged as well as new optical, chemical or logical switching elements.
The presented work builds on the pioneering work of Professor Jean-Marie Lehn who suggested and showed supramolecular assemblies in the eighties and was honoured with the Nobel Prize in 1987. The research teams from Basel and Heidelberg have now succeeded in producing well-defined, addressable arrays of supramolecular structures and demonstrated their operation. This work provides the key to manufacturing devices by cheap supramolecular self-assembly which may one day compete with much larger and more expensive techniques to fabricate technological devices. While the complexity of the demonstrated network moves towards similar supramolecular assemblies in biology, the nano-networks are stable without water or other solvents. This makes them especially suitable for technical applications.
The presented research was substantially supported by the interdisciplinary collaboration of physicists from the Institute of Physics from the University of Basel and the Paul Scherrer Institute (Villigen, Switzerland) and chemists from the University of Heidelberg. Interdisciplinary co-operations are the key to innovation and are supported in Basel by the Swiss National Science Foundation.
Source: Swiss Nanoscience Institute press release
Story first posted: 26th March 2007.