The major focus of this research is the "Nanoengineering of Physical Properties of Materials". The goal is to learn to use molecular and nanoparticle building blocks to predictively design specific, highly controllable properties into materials that are not necessarily available in naturally occurring condensed-matter systems. The optical properties of composite nanoparticles called metal nanoshells are of particular interest in this context. Metal nanoshells are a new and unique type of composite nanoparticle that possesses physical properties of clear technological and defense-related importance. These properties include an extremely strong structure-dependent optical resonance that can be shifted across a remarkably broad range of the visible and the infrared regions of the spectrum. Our immediate objective is to extend our knowledge of the growth chemistry, molecular control, and optical properties of metal nanoshells and associated nanoparticle assemblies, both in dilute matrices and in nanoscale proximity to each other and to other optically active materials. This is a coordinated effort consisting of nanoparticle synthesis, molecular based assembly methods, optical characterization techniques, scanning probe microscopy, theory, and the demonstration of new functional materials and simple device structures.