"Recent developments in molecular electronics and nanotechnology, in general, offer the promise of devices, of great relevance to information technologies, with unprecedented capabilities including memory devices with extraordinary storage capacity as well as circuit elements of vanishing size and superlative speed. Some of the molecular entities that have shown particular promise, to date, include donor/acceptor (D/A) assemblies, transition metal complexes and others. Of particular importance has been our ability to encode information and/or achieve electronic functionality by the storage or movement of charges. This proposal addresses two separate projects which are part of general investigations of nanoscale materials chemistry. The first project will focus on the development of molecular architectures at the nano-scale level toward molecular electronics applications. Molecular switching systems will be investigated and their capability to act as molecular wire allowing the electrons flow through the conjugated system will be tested. Upon establishment of their photoelectrochromic properties, binuclear metallic complexes will be synthesized to study of intramolecular electron transfer through mixed-valence species. By precisely modulating the spacing in between the redox units, we will investigate, with unprecedented control, self-exchange rates in redox reactions, the distance dependence of electron transfer, and photoinduced electron transfer. Subsequently, we will proceed to immobilize the binuclear compounds connected through the corresponding switch on gold or platinum surfaces by taking the advantage of the ability of thiol or nitrile functional groups to bind properly on such surfaces. We thus propose a seed project where we will explore the two areas described above and assess their potential utility as a means of reversibly and reproducibly making contact to nanostructures, for information encoding and as conduction modulators."