Discovery of Energetic Materials by Multi-Photon Enabled Synthesis
Abstract
The project ÒDiscovery of Energetic Materials by Multi-Photon Enabled SynthesisÓ explores the synthesis of highly energetic materials using a novel photochemical method employing multiple photons from one or several ultrashort laser pulses. A new multi-photon reactor is assembled to implement the method. Applications relating to the creation of highly energetic organic bi-radicals and to polymers of nitrogen and carbon monoxide are explored. Energetic materials have a wide range of applications in defense areas, for example in rocket fuels. They also find uses in medical applications because energetic molecules can be targeted to interact with specific biochemical systems. More generally, energetic substances are important reagents for chemical reactions that, without the inherent energy of these reagents, would not clear an activation barrier. Energetic materials are inherently metastable, and their creation can be difficult. The premise of the multi-photon reactor is that photons have sizeable energy, on the order of a typical chemical bond. Traditional photochemistry has applied that photon energy toward a large variety of reactions, but almost always only a single photon interacts with a molecule. Largely unexplored is the regime where a molecule absorbs two, or multiple, photons. This can lift the system to much higher energy and therefore can enable reactions that would not proceed at lesser energy. The multi-photon reactor is interfaced with a high-power, ultrafast-pulsed laser, which provides control over the photon parameters. Reaction outcomes are continuously monitored and the desired products are maximized by iteratively changing the photon parameters. By focusing on specific molecular systems of energetic materials, the project will advance our knowledge of molecules in excited electronic states, their chemical reaction dynamics, and the effect of solvent environments. Successful outcome of the proposed research will result in new, highly energetic compounds. The molecular systems will be prepared in their ground electronic states and their properties will be characterized. The research will result in publications that inform the scientific community. The project involves graduate students and undergraduate students in an experimental laboratory using advanced instrumentation. Because of the wide applicability of the methods, the project is an ideal medium to train young scientists in experimental techniques, and, more broadly, in critical thinking and the conduct of scientific research. Numerous collaborations, both domestic and international, provide students with opportunities to interact with scientists worldwide. The projectÕs educational component will have a broad impact by training scientists for the next generation workforce. Particular emphasis is placed on developing a pipeline of students from underrepresented minority groups. The PI works closely with the Leadership Alliance, a national consortium headquartered at Brown University, to expand broadening impact activities that so far have focused on the life and medical sciences. Undergraduate students recruited through the Leadership Alliance will be included in the research. The Leadership Alliance records show that such inclusion at an early stage enables the participants to succeed in college, in graduate school, and in their careers.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 01, 2019
- Source ID
- W911NF1910178
Entities
People
- Peter M. Weber
Organizations
- Army Contracting Command
- Brown University
- United States Army