My trip to the ACS meeting in Atlanta is fast approaching and so planes and trains have been on my mind lately. Then yesterday, along came the rest of the story (thanks Josh!). First, there was the nanocar (see here too) and now, just rolled off the production line, is the nanotruck. Posted as a web ASAP article in the Journal of the American Chemical Society, Jim Tour and coworkers from Rice University in Texas report on ‘Surface-Rolling Molecules’.
These nanovehicles are comprised of three parts: fullerene ‘wheels’ are connected through alkynyl ‘axles’ to a ‘chassis’ made of either phenylene ethynylene units (the nanocar) or fused aromatic rings (the nanotruck). In the case of the truck, the authors speculate that the planar aromatic surface may act as a platform and be able to accommodate cargo – thereby distinguishing this nanotruck from your everyday nanocar. I wonder if the authors expect some readers to have no truck with their nomenclature, as the introduction to the paper contains a very carefully worded paragraph defending it..?
At the moment, there doesn’t seem to be too much mileage in the nanotruck; it is never loaded with anything, and it didn’t perform very well on a test drive. Contamination of the gold surface, and possible instability of the molecules gave rise to complicated STM results. The fullerene wheels, which complicate the synthesis and purification, might be the first to go. At the end of the paper, the authors suggest alternative molecular ‘wheels’: carboranes seem like an obvious substitute, whereas cyclodextrin-shaft complexes would be an interesting choice. Will we be seeing rotaxane nanovehicles before too long?
What else will come out of the nanogarage? Tour hints that he’s now working on nanotrains as well. Let’s just hope they’re more reliable than the ones I catch.
Stuart Cantrill (Associate Editor, Nature Nanotechnology)