Electronic conductance of helicenes

We report calculations of the electronic properties of helicene molecules. By tuning the radius of the helix and the width of the helix ribbon a helic ene can be made semiconducting or metallic. We calculate the I/V characteri stic for representatives of selected helicene classes, and analyse their ba llistic electronic conductance. For a hybrid metal-semiconductor helicene w e show localization of metallic states, and propose the design of a quantum dot based on this phenomenon. (C) 1999 Elsevier Science B.V. All rights re served.