NSF Award
2306982
The PI and her team will investigate the interaction of polyatomic molecules with light. Molecules are the primordial constituents of matter that surrounds us, from the air we breathe to the water we drink or the pharmaceutical drugs we take to cure diseases. Light plays a crucial role in humanity’s livelihood - for example, the rhodopsin molecules found in our eyes undergo an ultrafast transformation when exposed to light allowing us to see. This kind of transformation, which we call isomerization, impacts also technological applications such as molecular motors and re-writable optical memories. Other examples of the effect of light on cyclic molecules are the photo-synthesis of vitamin D3 in the skin or optoelectronic applications in optical switching and nanomechanical motors. These light-induced transformations of molecules hold a central role in physics, chemistry, and biology due to their importance in a wide variety of systems from the building blocks of proteins and antibiotics to industrial applications. Of crucial interest is how such molecules transform or break, after the absorption of light. This project, led by the PI and her team, is to investigate in detail these ultrafast photon-activated fundamental quantum mechanical mechanisms. This interdisciplinary research program integrates education at the undergraduate and graduate levels, strives to produce a diverse workforce and provides a comprehensive training in quantum science, programming, and ultrafast laser technology. This training benefits students and postdocs who are the next generation workforce in the STEM fields in academia and also in various industries. The PI’s research has, and will continue to train students and postdocs for several career tracks. Previous NSF funded students and postdocs trained with quantum mechanic, technical and computational skills in the PI’s research lab are now contributing to several areas of science and technology, in academia, national laboratories, defense, and industries such as financials, developing new laser technology and quantum optics. This research program has additional societal impact through its outreach and national mentoring activities of underrepresented groups. <br/><br/>This NSF research program will investigate time-resolved ultrafast light-induced dynamics in polyatomic molecules in order to advance knowledge and understanding of non-adiabatic molecular dynamics due to their important role in fundamental physical and chemical processes. The PI and her team will contribute to the understanding of the conversion of photon energy from light into chemical energy via the physical and chemical mechanisms they will study. In particular, the PI’s team will examine the coupled electronic and nuclear dynamics during photo-induced chemical reactions with temporal resolution. Specifically, the team’s goal is to investigate, at the femtosecond timescale, how electronic rearrangement in molecules, subsequent to photon absorption, induces and effects nuclear motion and transformation in molecules. The team will examine in detail internal molecular energy conversion, atomic rearrangement in molecules, transformation of molecules through isomerization, molecular bond elongation, roaming molecular fragments that detach from the parent molecules but stay nearby and form new molecules, cyclic molecules opening, bond breaking, bond making and molecular fragmentation. The experiments will be conducted with Ultraviolet or Infrared laser pump-probe techniques. The resulting charged fragments will be detected using the coincidence technique of Cold-Target Recoil Ion Momentum Spectroscopy (COLTRIMS). The underlying photo-induced molecular dynamics will be revealed by ion-momentum imaging. This quasi-background free differential experimental imaging technique will provide new, detailed information on the aforementioned competing physical and chemical processes.<br/><br/>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.
