Unimolecular rectifiers and prospects for other unimolecular electronic devices.

We briefly review the progress towards useful one-molecule electronic devices, toward the ultimate reduction in integrated circuit sizes, and then describe five unimolecular rectifiers, or one-way conductors of electrical current: gamma-hexadecylquinolinium tricyanoquinodimethanide, an acetyl sulfoxide derivative of this compound, 2,6-di[dibutylamino-phenylvinyl]-1-butylpyridinium iodide, dimethylanilino-aza[C60]fullerene, and a new fullerene derivative.