CAREER:Correlated Exciton Fluctuations in Natural and Artificial Light Harvesting Antennae

University Of North Carolina At Chapel Hill, Chapel Hill NC

Investigators

Abstract

In this project supported by the Chemical Structure, Dynamics, and Mechanisms Program of the Division of Chemistry, Professor Andrew Moran and his research group at the University of North Carolina at Chapel Hill will study how large assemblies of molecules absorb light, and transfer the energy from one part of the assembly to another. They will focus specifically on the role of spatially correlated nuclear motion in light harvesting mechanisms. The study will obtain information about atomic and molecular motions on very short time scales using a femtosecond laser technique called two-dimensional photon echo spectroscopy (2D-PES). In addition, Prof. Moran and his team will develop a new technique called intraband electronic coherence spectroscopy (IECS), which will provide more detailed information about the mechanisms controlling energy transfer processes. The systems to be studied include light harvesting phycobilisomes, which are protein structures in cyanobacteria, as well as artificial cyanine dye aggregates, whose readily controlled shapes make them excellent models for exploring structure-function relationships. This research project will advance our fundamental understanding of photochemical processes, and also have implications for the biological sciences (e.g., photosynthesis) and sustainable energy technology. The research program will be fertile ground for undergraduate and graduate students. Many of the optical components used in the experiments are/will be built by graduate students. This hands-on experience represents a unique opportunity for chemists to obtain an interdisciplinary expertise in advanced methods of ultrafast science. Undergraduates will contribute by preparing the nanostructured aggregates that will be studied using 2D-PES and IECS. As part of the Project Seed Program, high school students will participate in the research program. For example, they will use computer simulations to design pigment complexes and simulate their absorption spectra. In addition, Prof. Moran and his team will conduct laboratory demonstrations for a Pre-College program administered by the School of Education at the University of North Carolina. The goal of the Pre-College program is to broaden the pool of students pursuing mathematics and science based majors and careers.