Self-Assembled Molecular Rotor Arrays That Perform Simple Computations

The consistency of rotational patterns of ethyl groups within a self-assembled array is a promising method to produce computations within nanotechnology. When 4-bromo-1-ethyl-flourobenzene is dosed onto a Cu(111) surface and cooled to 5K, the compound remains in an intermediate state of Ullman coupling, in which the bromide atom is released and in its place the benzene ring attached to a copper atom on the catalytic surface. At these conditions, the molecules arrange themselves so that their ethyl groups align in parallel rows and are allowed to switch into one of two states. The two states that an ethyl group will be found are (1) protruding from the surface and (2) facing down towards the surface. In the event that an ethyl group switches from one state to another, a nearby ethyl group within the row will very likely rotate to another state to stabilize. These correlated switching patterns constitute the first time a self-assembled monolayer has performed logic operations. With further development, similar monolayers have the potential to be key components of a computer processor.