Our next webinar will take place via the internet on Tuesday June 10th at 7 PM EDT/12 AM BST. Sign up on our mailing list to receive the Zoom link!
We hope to see/hear from you all at one of our sessions or as one of the next speakers. If you are an early career scientist and would like to present your research, don't hesitate to submit an abstract today! For now, please learn more about our current speakers and their research below. We also thank the generous support from Cell Reports Physical Science, Merck, Janssen, and the Royal Society of Chemistry.
Our featured speakers this week are Alexandra Barth (Graduate Student, California Institute of Technology, USA), and Dr Ernesto Cortes Morales (Postdoctoral Researcher, University of Minnesota, USA).
LEARN MORE ABOUT THE SPEAKERS AND THEIR TALKS BELOW
ALEXANDRA BARTH (on Twitter @AlexTBarth)
Biography: Alex Barth is a graduate student at Caltech studying inorganic spectroscopy (transition metal electronic structure and reactivity) under Prof. Harry Gray. Alex is an NSF-GRFP fellow and received the DOE SCGSR fellowship towards an upcoming research internship at SLAC using x-ray spectroscopy methods. Outside of research, she has completed the Caltech teaching certificate program and received an outstanding mentorship award from Caltech Diversity.
Title of Talk: "Photoredox catalysis mediated by tungsten(0) arylisocyanides in 1,2-difluorobenzene"
Abstract: We have studied the photochemical cyclization of 1-(2-iodobenzyl)-pyrrole (IBP) and 1-(2-bromobenzyl)-pyrrole (BBP) to 5H-pyrrolo[2,1-a]isoindol catalyzed by W(CNDipp)6 (CNDipp = 2,6-diisopropylphenylisocyanide) in 1,2-difluorobenzene (DFB). Irradiation (445 nm) of W(CNDipp)6 (5 mol%) in DFB solution converted 78% of IBP (50 mM) to product after 1 h (16 turnovers). Addition of tetra-n-butyl ammoni-um hexafluorophosphate (TBAPF6) (0.2 M) to the DFB solution led to rapid photoinduced disappearance of W(CNDipp)6 but, remarkably, did not inhibit photochemical cyclization of IBP, indicating that IBP cyclization was driven by a nonluminescent photocatalyst.
DR ERNESTO CORTES MORALES (on Twitter @ernie2k)
Biography: Ernesto Cortes-Morales obtained his PhD in Physics from the University of San Luis Potosi, Mexico. He then moved to the University of Notre Dame to work as a postdoctoral assistant at the research group of Prof. Jonathan Whitmer until September 2021. Currently, he is a postdoctoral researcher at the research group of Prof. Sapna Sarupria at the University of Minnesota. His research interests include enhanced sampling methods on molecular simulations, theoretical insights of the glass transition, and molecular simulations of the ice nucleation phenomena.
Title of Talk: "Molecular view of the plasticization process of poly(vinyl) alcohol"
Abstract: Atomistic simulations are useful to address local interaction processes in a variety of materials, examples of this include self-assembly phenomena in polymers and host-guest binding applied to drug delivery and design. When designing simulations while incorporating advanced sampling methods in order to bias the potential energy surface towards pre-set slow collective variables, the simulation improves its efficiency thus allowing the treatment of realistic complex systems. In this work, we will follow the analysis of free energies governing the interactions of complex systems by employing the Artificial Neural Network (ANN) sampling method developed by Sidky and Whitmer. The discussion will highlight the configurational sampling using atomistic simulations of a polymer chain model interacting with different small-weight molecules, representing here the well-known plasticization process. We will focus on conformational and hydrogen-bond structure changes induced in polymer chain globules by the plasticizer molecules, while hypothesizing that hydrogen bonding plays an important role in the incorporation into polymer materials and thus, in the observed mechanical properties. The findings derived from this study showcase physical features relevant to the design of tailored materials, and the methods developed here are intended to be the first part of a robust framework applicable to an assortment of experimental materials designed for industrial purposes.