Start: January 30, 2025 3:30 p.m.
End: January 30, 2025 4:30 p.m.
Photodynamic Behavior of Organic Azide Crystals
Dr. Anna D. Gudmundsdottir
Professor of Chemistry, Department of Chemistry, University of Cincinnati
Thursday, January 30th @ 3:30 PM
FB 253
Recent findings highlight that organic crystals can be flexible and when subjected to external stimuli, such light or heat, they can bend, curl, hop, or fragment.1 Thus, photodynamic crystals can convert light into mechanical energy, and therefore have a potential role in the fabrication of mechanically-tunable components for actuation, energy harvesting, flexible electronics, and switchable reflectors. In addition, such crystals can be used as sensors and probes. Irradiation of crystalline azido compounds results in release of N2 gas, that can cause photodynamic response of the azido crystals.2 Herein, we present that the photolysis of azido crystals (1) that only undergo only a surface reaction to from azo dimers, and the azido crystals are remarkable stable and can therefore be used for photolithography applications, as demonstrated with confocal and digital microscopy and SEM. The surface reactivity of the crystals was characterized by confocal Raman microscopy. Similarly, irradiation of crystals of azide 2 also results in only surface reaction, to form 3 and release of N2 gas. Digital microscopy shows that the crystals of 2 crack in specific directions, but the crystals stay intact. In contrast, mixed crystals of 2 and 4 display different photodynamic behavior, as the mixed crystals do not crack in a specific direction, whereas crystals of 4 do not show any photoreactivity or photodynamic behavior. We will discuss what factors render azido crystals photodynamic.
