College

Buchtel College of Arts and Sciences

Date of Last Revision

2025-05-06 06:38:30

Major

Biochemistry

Honors Course

CHEM 497

Number of Credits

2

Degree Name

Bachelor of Science

Date of Expected Graduation

Spring 2025

Abstract

Chalcones are a class of naturally occurring compounds found in plants, which have a general structure of Ar–CO–CH=CH–Ar’. They have shown significant potential as tunable organic fluorophores due to their extended π-conjugation and structural simplicity. In this study, a 2-hydroxy-substituted chalcone featuring a terminal dimethylamino group was synthesized via a pyrrolidine-catalyzed aldol condensation and characterized for its photophysical properties. The electron-donating and -accepting ends of the molecule establish an intramolecular charge transfer (ICT) pathway, while the hydroxyl group enables excited state intramolecular proton transfer (ESIPT), leading to complex emission behavior. Room temperature fluorescence analysis revealed broad, featureless emission, while low-temperature studies unveiled a well resolved vibronic structure consistent with distinct tautomeric states. Selective excitation at specific wave lengths could give two different emission bands, attributable to either enol or keto forms. The observation highlighted the role of excited-state proton dynamics and molecular geometry in modulating fluorescence. These findings suggest that this chalcone derivative serves as a valuable model compound for exploring vibronic coupling, ICT, and ESIPT processes in small-molecule organic fluorophores.

Research Sponsor

Yi Pang

First Reader

David Modarelli

Second Reader

Yilin Liu

Honors Faculty Advisor

Yi Pang

Proprietary and/or Confidential Information

No

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