03/19/2024
By Kwok Fan Chow

The Kennedy College of Science, Department of Chemistry, invites you to attend a Ph.D. Dissertation defense by Zhen Yang entitled “Dynamic Chemistry for Enhanced Optical Properties through Fluorochromism and Aggregation.”

Degree: Doctoral
Location: Olsen Room 503
Date: Tuesday, April 2, 2024
Time: 9 a.m.

Committee:

  • Chair Prof. Olof Ramstrom, Department of Chemistry, University of Massachusetts Lowell
  • Prof. Mingdi Yan, Department of Chemistry, University of Massachusetts Lowell
  • Prof. Marina Ruths, Department of Chemistry, University of Massachusetts Lowell
  • Prof. Lawrence Wolf, Department of Chemistry, University of Massachusetts Lowell

Abstract:
Applying dynamic chemistry can promote a deeper understanding of the mechanisms underlying the transformation processes that occur in organic reactions. Various dynamic processes, such as configurational and interactional dynamics, can enhance the intricacy and broaden the scope of chemical reactions within a system. Therefore, it is imperative to design molecules capable of multiple responses and to improve their adaptability within these systems. Molecule switches have been discussed in shifting between different states in response to environmental stimuli, such as changes in pH, temperature, light, and viscosity. The structural transformations of switches such as rotation make their chemical and physical changes simultaneously, allowing them to adapt to more environmental inputs. Herein, versatile strategies of dynamic enamine switches are introduced. Electron-withdrawing groups are strategically added to enamine conjugated systems to minimize their conversion rate to imine isomers. Intramolecular H-bonding increases the possibility that the E-isomers of enamine switches can dominate in neutral/basic conditions, and the structures perform precisely through switching around the enamine C=C bond upon addition of acid/base. This thesis investigates the optical properties and applications of molecular switches in dynamic configurational systems.

All interested students and faculty members are invited to attend.