Functional Molecules and Assemblies in Controlled Environments: Formation and Measurements

The local environment of a functional molecule or nanoscale assembly has tremendous impact on it and thus can be used for functional control. In addition, the local environment is critical in the interface to the physical, chemical, and biological worlds beyond the assemblies that are the most common applications targeted. Functional measurements without local structural information lack key insight into both the details and the roles of the environment. This Account focuses on progress toward and challenges in the controlled assembly and measurements of functional nanostructures; in well-defined environments. The study of single precise supramolecular assemblies in well-defined environments offers unique insights into both interactions and function. By designing interactions between molecules and controlling assembly conditions, we can create and place atomically precise nanostructures. The tools to test the structures targeted and to measure the function of these assemblies are just now being developed and becoming available. Advances in this field have depended on gaining access to measurements at this scale. In particular, we recognize but do not yet understand the critical role of the chemical and physical environment of the assemblies. Likewise, we are just now realizing the important role that the substrates to which the assemblies are attached play in these processes. In order to develop a predictive understanding and the ability to design and to optimize functional assemblies, we must elucidate the physical, chemical, and electronic couplings among the molecules in the assemblies and with their substrates. With a suite of atomic- and molecular-resolution analytical tools, we are able both to ascertain whether the targeted structures have been formed and to measure their function. One of the keys to our ability to determine structure and measure function has been the development and application of methods for the automated acquisition, analysis, and associations of thousands or tens of thousands of single-molecule/particle/assembly structural, dynamic, spectroscopic, and functional data points.