Grant: Discovery Grants Program - Individual

The properties of materials depend not only on the nature of the constituent molecules, but also on the way that these molecules are organized and interact with each other. Therefore, the design of new materials with specific desired properties requires control of both molecular structure and the self-assembly of these molecules. Through synthetic chemistry, we can prepare new molecules and control molecular properties by making specific structural modifications. We can also control the organization of these molecules by incorporating units that direct molecular self-assembly. The proposed research focuses on the design and synthesis of new materials by making rigid molecular building blocks based on polycyclic aromatic hydrocarbons that will assemble themselves in predictable ways, ultimately allowing us to control the properties of the material. The research will focus on two areas. The first goal of the research is to make new polycyclic aromatic hydrocarbons with several flexible chains. These flat, disk-shaped molecules have a tendency to stack into columns and form liquid crystalline phases. These liquid crystalline phases are states of matter that are intermediate between a solid and a liquid - they are ordered fluids. Although there are numerous examples of liquid crystalline materials, the relationship between molecular structure and the ability to form a liquid crystalline phase is not well understood. By preparing new disk-shaped liquid crystalline compounds with systematic structural variations, we aim to better understand the factors that control liquid crystalline behavior. Materials such as these can exhibit semiconducting or photoconducting properties that make them potentially useful in devices such as photovoltaic solar cells, light emitting diodes (LEDs) for displays, and thin film transistors for organic electronics. The second area of the research program is to use aromatic compounds as building blocks for the preparation of macrocycles (large rings) or extended open networks. Both of these types of materials are expected to have small channels and pores and can potentially be used to aid in the separation of compounds based on size or to capture small molecules.