Nanoparticles: Uses and Relationships to Molecular Cluster Compounds

More than a thousand articles on various aspects of nanoparticles and nanoscale chemistry have appeared in the last year. Nanoparticles have attracted so much attention because they are both important and interesting. Important, as nanoparticles can have useful properties not exhibited by either smaller molecular systems or larger particulate matter; interesting, as working on supramolecular scales raises exciting synthetic challenges and allows intimate exploration of the relationships among atoms, molecules, and extended systems. In the first part of this article we briefly discuss a selected few of the useful properties exhibited by nanoparticles and/or nanostructured materials. In the second part of this article we examine a subset of the relationships between molecular and extended systems, especially between binary and ternary inorganic molecular cluster compounds and the smallest nanometer-sized particles, and consider some implications for the synthesis and chemistry of ananoclusterso. In neither part of this article do we attempt a systematic review of the nanoparticle literature, but rather we focus on a few examples from research conducted at DuPont and from the literature. And, while we rely heavily upon experience with inorganic molecular cluster compoundsÐwhere chemistry and detailed structures are often much better understood than they are in larger particlesÐwe caution that overly relying upon cluster experience would be misleading, as there are fundamental differences between molecular-sized clusters and nanometer-sized particles.