Photoexplosive Crystals

University Of Cincinnati Main Campus, Cincinnati OH

Investigators

Abstract

With support from the Chemical Mechanism, Function, and Properties Program of the Chemistry Division, Professor Anna D. Gudmundsdottir of the Department of Chemistry at the University of Cincinnati will analyze how crystals respond to external stimuli. Her research team will investigate the photodynamic and mechanical properties of crystalline benzoyl peroxide, alkyl- and aryl-azide derivatives. Upon exposure to light, the crystalline compounds dissociate vividly, as they burst, coil, fracture and change color, while resulting in the production of either CO2 or N2 gas, along with photoproducts. Because the crystals respond vigorously to light, they have potential use in various applications, such smart materials for sensors, actuators and photopatterning. Professor Gudmundsdottir and her research team will organize outreach and training activities that will benefit diverse group of high school students participating in the ACS Project SEED Program, and undergraduates pursuing research in chemistry and materials science. The mechanism of the photoreactivity of the benzol peroxide and organic azido derivatives will be elucidated in solution and the solid state, by performing laser flash photolysis, matrix isolation, Electron Spin Resonance spectroscopy, and product studies. The reaction mechanisms and the characterization of excited states and reactive intermediates will be further supported by theoretical calculations. In addition, Raman confocal microscopy will be used to determine the chemical compositions of crystal surfaces before and after irradiation, to determine accurately the surface reactivity, and how it affects the photodynamic behavior. The proposed research will provide intensive training opportunity for graduate students in the interdisciplinary of photochemistry and material sciences. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.