Motorizing the nanocar

James M. Tour made nanoautomotive history last year, when his lab at Rice University built the world's first single-molecule car (C&EN, Oct. 24, 2005, page 13). But without an engine, this so-called nanocar couldn't go anywhere without being pushed. Now Tour, along with colleagues Jean-François Morin and Yasuhiro Shirai, have taken a light-powered unidirectional molecular motor and attached it to the chassis of a newer model nanocar (shown, Org. Lett. 2006, 8, 1713). The motor should propel the car forward with a paddle-wheel motion. The Rice team also replaced the fullerene wheels they used in the earlier model of the nanocar with p-carborane tires. The motor, they say, was completely inoperative in the presence of fullerenes, probably because of rapid energy transfer from the motor's excited state to the fullerenes. The p-carboranes are spherical enough to operate as wheels, and kinetic studies in solution demonstrate that the motor rotates when irradiated with light. Next, the group hopes to drive the nanocar across a flat surface.