Molecular Optoelectronic Gates

In this paper we describe molecular devices where an electronic energy transfer process is selectively gated by one-electron alteration of the redox state of one spatially isolated pigment in a multipigment array. We demonstrate gating of a photonic signal in a molecular device via a spatially isolated redox switch. This gating process can be used for wires that involve energy migration as the basis for signal transmission, is particularly attractive as it does not involve changes in molecular conformation, and in principle also can be achieved by photochemical means. These molecular gates complement molecular sensors or switches where the luminescent readout of one chromophore is altered by conformational changes or the availability of photoinduced electron transfer processes to an adjacent site. Access to these gates is made possible by a modular approach that enables incorporation of a wide variety of metalloporphyrin building blocks with desired redox and photophysical properties. We anticipate that these types of gates could be used to transmit signals across lipid bilayers and other interfaces, could provide the basis for various types of sensors, and may be useful in future molecular-scale information processing systems. 12 refs., 1 fig.