Concepts of Photoinduced Electron and Energy Transfer Processes Across Molecular Bridges

Abstract

As we have seen in the previous chapter individual molecules or supramolecular assemblies may perform the functions of electronic devices. Using molecular building blocks to develop electronic circuits mandates the design of specific molecular functionalities. The latter are then the inception to imitate components of an electronic circuit. One of the simplest of these components is a wire. Not surprisingly, the design of “molecular wires” has received a great deal of attention [1, 2]. Despite its simplicity, the definition of this term is rather broad. Some relate it to molecular structures mediating the transport of charge between appropriate donor and acceptor moieties. For instance, one can probe the conduction of molecular wires in break-junction experiments, placing the wire between two tiny gold-rods. In the same way of thinking, the electrodes may be replaced by appropriate donor and acceptor molecules. Generally speaking, we should employ the term “molecular wire” on any molecular structure, which mediates charges between donors and acceptors. In this work, photo- or redox-active organic molecules serve as donors and acceptors. π-conjugated bridges referred to as “molecular wires” link these acceptors and donors.