快猫短视频

YOU won鈥檛 find it powering a Formula 1 racing car, but it鈥檚 still a world
first: a motor consisting of a single molecule that鈥檚 been designed from
scratch. Almost all life depends on nature鈥檚 molecular motors鈥攃omponents
in cells that turn chemical energy into physical movement to help transport
substances around the cell. But Ross Kelly and his colleagues at the Eugene F.
Merkert Chemistry Center at Boston College, Massachusetts, have invented an
artificial molecular motor.

Their invention is a rotor that turns on a stator鈥攖he static part of
the device鈥攋ust like an electric motor. These two components are linked by
a chemical bond between two carbon atoms. While the stator, called a helicene,
stays still, the rotor spins for one-third of a revolution about its 鈥渁xle鈥�.

Kelly鈥檚 rotor is a three-bladed paddle, with each hexagon-shaped blade
separated from the next by one-third of a revolution. Energy from phosgene,
better known as a chemical warfare gas, drives the rotor. To do this, a tiny
amount of phosgene alters a chemical group
(marked A on the diagram) on the
rotor. The altered grouping reacts with a second group (B) on the stator,
turning the rotor clockwise through about 60掳. Heat absorbed from the
environment takes the rotor a further 60掳. There it stops, although adding a
reagent restores A and B to their original form.

Kelly admits that the motor is unlikely to find a use. 鈥淚t鈥檚 so much smaller
than anything you might want to move,鈥� he says. 鈥淏ut figuring out how a
molecular motor works, from scratch, may help biologists work out how nature鈥檚
motors work,鈥� he adds.