Three-State pH Driven Biaryl Lactone Molecular Switches with Amine Donors

Aaron Bruckbauer, and Dr. Bart Dahl, Department of Chemistry, University of Wisconsin – Eau Claire, 105 Garfield Ave, Eau Claire, WI 54701

Our research group is focused on the synthesis of four new biphenyl molecules with amine donor groups and nitro or cyano acceptors. These molecules should be great candidates for becoming three-state pH-driven electronic switches which could be useful in molecular-based electronics and sensing applications. Research by our group previously demonstrated that that it is possible to create a two-state molecular switch using a weaker methoxy donor group on these biphenyl lactones via lactone cleavage at high pH and reformation at low pH. The cleavage and reformation of the lactone leads to dramatic changes in the dihedral angle of the biphenyl unit and thus affects the optical properties of these switches. It is now being studied if it is possible to further enhance the optical properties of these biphenyl molecules by incorporating dimethylamine or diphenylamine donor groups. This will allow for a third switch state on the molecular switch which increases its usefulness as a pH sensor by creating a narrow range of pH available for the ON state. Like switches previously studied by our group, the biaryl switches should become non-planar at high pH (OFF state – lactone cleavage) and planar at low pH (ON state – lactone formation). However, a third OFF state exists via amine protonation at very low pH which will cause a third OFF state for the molecule. The ON state is associated with absorption in the visible region of the electromagnetic spectrum and the strength of the amine donor should result in a large bathochromic shift in the absorbance of visible light, leading to visibly colorful switches. The OFF state attenuates the optical properties leading to visible changes in appearance. Progress toward the synthesis of these new three-state switches will be reported. 

Additional Abstract Information

Presenter: Aaron Bruckbauer

Institution: University of Wisconsin - Eau Claire

Type: Poster

Subject: Chemistry

Status: Approved

Time and Location

Session: Poster 4
Date/Time: Tue 11:00am-12:00pm
Session Number: 3617