Clusters to functional molecules, nanomaterials, and molecular devices: Theoretical exploration

This chapter discusses how the insights obtained from theoretical investigations of various cluster systems have enabled a researcher to predict structures and properties of novel functional molecular systems. Clusters are self-assembled structures comprised of a number of monomers under the given condition. Apart from aiding the development of novel materials, clusters are very useful for understanding the intrinsic and fundamental nature of molecular recognition and self-assembling phenomena. This is amply illustrated in a number of publications on a wide variety of atomic and molecular clusters, ranging from H-bonded clusters, p-system-containing clusters, and metal clusters. These investigations not only provide pertinent information useful for nanomaterial design but also highlight some of the important similarities and differences in their physical characteristics. These characteristics include structures, magnitudes of both attractive and repulsive interaction energies, vibrational frequencies, and charge redistributions. Additionally, one also obtains an insight into the contributions of cooperative and competitive forces, both of which govern self-assembly and molecular recognition.