Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023)

Stimuli-responsive and electroactive organic compounds are integral to technological developments in materials and device manufacturing, respectively. Despite the current interest in these areas, significant gaps remain in our fundamental knowledge about them, which continue to drive research in molecular engineering. The proposed research program has two streams involving the synthesis of small, highly functionalized molecules: one dedicated to solving problems in organic electronics, and the other to controlling switching dynamics and addressing multi-state switching in responsive molecules.

A better understanding of organic device operation has led to the production of increasingly efficient conjugated polymers (CPs) and small molecules/oligomers for use as components of organic electronic devices. Despite our increasing knowledge, the effectiveness of organic devices is still low. Advances in organic electronics will rely heavily on the ability to access molecular units that can be combined to program the physical and electronic features required to produce an efficient material. However, the majority of current CP and small molecule designs rely on a surprisingly limited range of molecular building blocks. The proposed research program focuses on the design and synthesis of a range of highly functionalizable and tunable molecular units that will be used to investigate novel systems with extended pi-conjugation, and to produce better organic materials for device applications.

Molecular switches are used extensively to create complex molecules and architectures. While a number of bistable switches are known, only a few of these are synthetically accessible enough to be useful for the desired range of materials applications. The result is that virtually all attempts to regulate structure and function in materials are limited to a small number of available switchable motifs. Most of these switches are bistable, interconverting between two stable states. Multi-stable switches, on the other hand, are very rare, but are desirable for their ability to precisely access a number of molecular orientations, and for their applications in fields such as information storage. The proposed research plan focuses on the development of new and underexplored responsive functionalities. They will be utilized in combination with more traditional molecular switches to create multi-stable molecular switches with novel switching motifs. Specific objectives include determining how to synthesize what are necessarily complex molecules; how to use orthogonal stimuli to maximize control over molecular movements; and how to transform between different states in high yields. Ultimately, exploring these objectives will allow us to fulfill our long-term goals of building light responsive sensors with remote tunable activity, and constructing the next generation of molecular machines.