Guest: Abdullah Kahraman
Title: Secrets of the Materials in Femtoseconds
Time: March 20, 2024, 16:00 - 17:00
Zoom: https://sabanciuniv.zoom.us/j/6938110217?omn=91242398195
Abstract: The function of any materials cannot be fully comprehended without knowing its structure first. Yet, function is more accurately represented as a series of events unfolding over time, marked by structural changes. The advent of real-time atomic observation could revolutionize a new era in our comprehension of molecular-level chemical dynamics. This leap forward is made possible through the utilization of large-scale accelerator facilities, such as X-ray Free Electron Lasers (XFELs). The ultrafast x-ray pulses generated by XFELs enable us to closely observe and understand the underlying mechanisms of various fundamental physical, chemical, and biological phenomena.
In this seminar, I aim to highlight the transformative potential of XFEL technology. I will present our groundbreaking findings on the observation of charge-transfer interactions during the carbon-hydrogen (C-H) activation in a rhodium-based complex—a discovery of paramount significance for fields ranging from drug development to the chemical industry. These results, recently published in the journal Science, underscore the vital role of XFEL in advancing our knowledge.
Furthermore, I will delve into our ongoing research on the tracking of protonation events, followed by metal-ligand charge transfer in ruthenium-based complexes. These systems are pivotal for understanding proton-coupled electron transfer (PCET) processes, which are crucial for artificial photosynthesis applications, including water splitting, CO2 reduction, and nitrogen fixation. Through this work, we aim to shed light on the synthetic pathways for producing energy-rich molecules like H2, CH3OH, or NH3 using solar light, thereby contributing to the development of sustainable energy solutions.
Bio: Dr. Abdullah Kahraman is a research associate at the Stanford PULSE Institute within the SLAC National Accelerator Laboratory and the Pacific Northwest National Laboratory (PNNL), where he specializes in ultrafast X-ray - matter interactions. Holding an M.Sc. in Physics from Bilkent University, and a Ph.D. in Materials Science from Koç University, Dr. Kahraman has made contributions to the physics and surface science of semiconductors, with applications in optoelectronics and photoelectrochemical systems. His expertise lies in ultrafast (femtoseconds-to-picoseconds) spectroscopy, aiming to elucidate carrier recombination losses in metal-oxide semiconductors, a critical aspect for enhancing the efficiency of optoelectronic devices.
Dr. Kahraman has conducted extensive core-level spectroscopy experiments at leading synchrotrons across the US and Italy, contributing to the field with his deep understanding of material behaviors under extreme conditions. His transition to working with X-ray free electron laser (XFEL) accelerators was driven by a desire to combine his background in core-level spectroscopy with the unique capabilities of XFELs to provide both core-level and ultrafast time-resolved insights. During his first postdoctoral tenure at the SwissFEL, Paul Scherrer Institute (PSI), he expanded his repertoire to include ultrafast X-ray spectroscopy and the synthesis, characterization, and spectroscopy of colloidal semiconductor quantum dots, further broadening the scope of his research. Currently, Dr. Kahraman's work focuses on investigating metal-to-ligand charge transfer interactions during fundamental chemical reactions such as C-H activation and Hydrogen bonding by metal-complexes using ultrafast X-ray techniques and state-of-art theoretical calculations. While his plan in future involves probing the charge transfer mechanisms through both semiconductors and metal-complexes in parallel, he will focus on the distinct way to experimentally evaluate metal-ligand charge-transfer interactions during C-H activation in this seminar.