Physics Magazine talks with faculty Paul Kempler about the Oregon Center for Electrochemistry’s Master’s Internship Program that provides students with hands-on experience working with industry partners.
Author: Leah O'Brien
OCE Solid-State Battery Workshop – April 29th
Oregon Center for Electrochemistry
Solid-State Battery Workshop
April 29th 10 am – 12 pm
Allen Hall 141
Electrochemical stability and transport optimization in sulfide and halide based solid-state batteries.
Introduction by Mathias Agne
Guest speakers: Yannik Rudel, Tim Bernges and Caro Rosenbach
Organic-Inorganic-Materials Seminar – David A. Leigh, April 26th
Organic-Inorganic-Materials Chemistry Seminar Series
Department of Chemistry and Biochemistry
Professor David A. Leigh, University of Manchester, UK
April 26, 2024
3:00 pm, 110 Willamette Hall
Hosted by Mike Haley and Darren Johnson
Much Ado About Knotting
Knots are important structural features in DNA and some proteins, and play a significant role in the physical properties of both natural and synthetic polymers.1 Although billions of prime knots are known to mathematics, few have been realized through chemical synthesis.2 Here we will discuss the latest progress from our laboratory, including the synthesis of some of the most complex molecular knots and links (catenanes) to date3-9 and the introduction of 2D molecular weaving.10
References
[1] “Molecular knots”, Angew. Chem. Int. Ed. 56, 11166 (2017).
[2] “Knotting matters: orderly molecular entanglements”, Chem. Soc. Rev. 51, 7779 (2022).
[3] “A synthetic molecular pentafoil knot”, Nat. Chem. 4, 15 (2012).
[4] “A Star of David catenane”, Nat. Chem. 6, 978 (2014).
[5] “Allosteric initiation and regulation of catalysis with a molecular knot”, Science 352, 1555 (2016).
[6] “Braiding a molecular knot with eight crossings”, Science 355, 159 (2017).
[7] “Stereoselective synthesis of a composite knot with nine crossings”, Nat. Chem. 10, 1083 (2018).
[8] “A molecular endless (74) knot”, Nat. Chem. 13, 117 (2021).
[9] “Vernier template synthesis of molecular knots”, Science 375, 1035 (2022). [10] “Self-assembly of a layered two-dimensional molecularly woven fabric”, Nature 588, 429 (2020).
Organic-Inorganic-Materials Seminar – David A. Leigh, April 24th
Organic-Inorganic-Materials Chemistry Seminar Series
Department of Chemistry and Biochemistry
Professor David A. Leigh, University of Manchester, UK
April 24, 2024
4:00 pm, 182 Lillis Hall
Hosted by Mike Haley and Darren Johnson
Giving Chemistry Direction
In recent years examples of synthetic molecular machines and motors1 have been developed,2 all be they primitive by biological standards. Such molecules are best designed to work through statistical mechanisms. In a manner reminiscent of Maxwell’s Demon,3 random thermal motion is rectified through ratchet mechanisms,3-8 giving chemistry direction.
It is increasingly being recognised that similar concepts can be applied to other chemical exchange processes9. Ratchet mechanisms—effectively chemical engines10 in which atalysis4,6,7 of ‘fuel’ to ‘waste’ is used to drive another chemical process—can cause directional impetus in what are otherwise stochastic systems, including reversible chemical reactions. This is ushering in a new era of non-equilibrium chemistry, providing fundamental advances in functional molecule design and the first examples of molecular robotics,11,12 overturning existing dogma and offering fresh insights into biology and molecular nanotechnology.
For a musical introduction, see ‘Nanobot’
[1] The Nobel Prize in Chemistry 2016–Advanced Information. Nobelprize.org. Nobel Media AB 2014. Web. 6 Oct, 2016, http://www.nobelprize.org/nobel_prizes/chemistry/laureates/2016/advanced.html.
[2] “Rise of the molecular machines”, Angew. Chem. Int. Ed. 54, 10080 (2015).
[3] “A molecular information ratchet”, Nature 445, 523 (2007).
[4] “An autonomous chemically fuelled small molecule motor”, Nature 534, 235 (2016).
[5] “Rotary and linear molecular motors driven by pulses of a chemical fuel”, Science 358, 340 (2017).
[6] “A catalysis-driven artificial molecular pump”, Nature 594, 529 (2021).
[7] “Autonomous fuelled directional rotation about a covalent single bond”, Nature 604, 80 (2022). [8] “A tape-reading molecular ratchet”, Nature 612, 78 (2022).
[9] “Design, synthesis and operation of small molecules that walk along tracks”, J. Am. Chem. Soc. 132, 16134 (2010).
[10] “Chemical engines: Driving systems away from equilibrium through catalyst reaction cycles”, Nat. Nanotechnol. 16, 1057 (2021).
[11] “Sequence-specific peptide synthesis by an artificial small-molecule machine”, Science 339, 189 (2013).
[12] “Stereodivergent synthesis with a programmable molecular machine”, Nature 549, 374 (2017).
Physical Chemistry Seminar – Anatoly Kolomeisky, April 22nd
Department of Chemistry and Biochemistry
Physical Chemistry Seminar Series
Professor Anatoly Kolomeisky, Rice University
April 22, 2024—2:00pm
Tykeson 140
Hosted by: Marina Guenza
How To Find Targets That Are Always Hidden:
The Story of Nucleosome-Covered DNA and Pioneer Transcription Factors
All major biological processes start after transcription factors detect specific regulatory sequences on DNA and initiate genetic expression by associating to them. But in eukaryotic cells, much of the DNA is covered by nucleosomes, preventing the transcription factors from binding to their targets. At the same time, experiments show that there are several classes of proteins, called “pioneer transcription factors”, that can penetrate chromatin structures. However, the underlying microscopic mechanisms remain not well understood. We propose a new theoretical approach that might explain these observations. It is argued that due to structural similarity with linker histones, pioneer transcription factors might weaken the interactions between the DNA and the nucleosome by substituting them with similar interactions between pioneer transcription factors and DNA. Using this idea, we develop a discrete-state stochastic framework that allows for explicit calculations of target search dynamics on nucleosomal DNA. It is found that finding specific sequences on nucleosomal DNA for pioneer transcription factors might be significantly accelerated while the search is slower on naked DNA segments in comparison with normal transcription factors. In addition, it is shown that nucleosome breathing makes the target search by pioneer transcription factors even faster, and theoretical arguments to explain these observations are presented. Our theoretical predictions are supported by Monte Carlo computer simulations, and they also agree with available experimental observations, providing new microscopic insights on complex nature of protein-DNA interactions.
Organic-Inorganic-Materials Seminar – Kayode D. Oshin, April 19th
Organic-Inorganic-Materials Chemistry Seminar Series
Department of Chemistry and Biochemistry
Professor Kayode D. Oshin, Creighton University
April 19, 2024
3:00pm in Willamette Hall, Room 110
Hosted by Darren Johnson
Catalyst Development & Kinetic Investigation of ATRA Reactions: Integrating Undergraduate Research and Chemical Education
Atom Transfer Radical Addition (ATRA) of haloalkanes and halocarbonyls to α-olefins is one of the most atom economical methods to simultaneously form C–C and C–X bonds, providing synthetic access to functionalized monoadducts. Studies that attempt to improve this reaction model are important as developing efficient methods to convert olefins into monoadducts for use in subsequent transformation reactions (reductions, displacements, making Grignards) are highly desirable. This presentation will highlight; (i) our research work designing copper and iron complexes for use as catalysts in ATRA, (ii) development of an experimental technique to measure kinetic parameters (activation rate constant values) for ideal ATRA reactions, and (iii) transformation of our results into effective laboratory modules, guided by important academic learning objectives and assessments, so they can be incorporated in the chemistry curriculum. This effort provides faculty at other academic institutions with current and effective modules that can be used in their courses and contributes to the important field of chemical education.
UO Summer REU students present at Spring 2024 ACS Meeting
REU in Chemistry, Physics, and Materials Science
Six Chemistry and Biochemistry 2023 Research Experience for Undergraduates (REU) students presented their UO research at the Spring American Chemical Society Meeting held in New Orleans, Louisiana, March 17-22, 2024.
Fernanda Siordia
“Investigating Cell Viability With Pt (II) Clickable Compounds”
Vickie DeRose Lab
Mentor: Katelyn Alley
Home institution: Southwestern College
Sawyer Lazar
“Mechanistic Study of Charge Separation in Faceted nanoparticle Photocatalysis”
Shannon Boettcher Lab
Mentor: Aaron Kaufman
Home institution: University of Southern California
Sam Jarvis
“Compression & Supporting Mesh Characteristics as Factors in the Performance of a Bipolar Membrane”
Shannon Boettcher Lab
Mentor: Olivia Traenkle
Home institution: University of Colorado, Boulder
Natalie Lakanen
“Supramolecular Anion Recognition: MOF Integrated ChemFET Sensors and HBeXB Anion Receptors”
Darren Johnson Lab
Mentor: Doug Banning & Shiva Moaven
Home institution: Indiana Wesleyan University
George Piepgras
“Converting Terminal Carboxylic Acids to Internal Alkenes Using Orthogonal Tandem Catalysis”
Amanda Cook-Sneathen Lab
Mentor: Melanie Kascoutas
Home institution: Fort Lewis College
Andrew Jenkins
“Harnessing Energy with Controllable Chaos by Designing and Investigating Thermocell Redox Entropy”
Carl Brozek Lab
Mentor: Jaiwei Huang
Home institution: University of New Hampshire
Organic-Inorganic-Materials Seminar – Maxwell Robb, April 12th
Organic-Inorganic-Materials Chemistry Seminar Series
Department of Chemistry and Biochemistry
Maxwell J. Robb, California Institute of Technology
April 12, 2024
3:00pm in Willamette Hall, Room 110
Hosted by Ramesh Jasti
MOLECULAR DESIGN STRATEGIES FOR MECHANOCHEMICALLY ACTIVE POLYMERS
The use of mechanical force to selectively activate covalent bond transformations presents unique opportunities for the design of stimuli-responsive polymers for applications ranging from sensing to drug delivery. By incorporating stress-sensitive molecules called mechanophores into polymer chains, force is transduced selectively to weak bonds in the mechanophore to elicit a productive chemical reaction. Mechanochromic mechanophores that produce a change in color are particularly useful and have been widely developed as molecular force probes, empowering the visualization of critical stress and/or strain in materials. These same attributes also make force-induced color changes in polymeric materials appealing for patterning and encryption. The mechanically triggered release of small molecules is also a powerful approach for sensing and delivery. This presentation will highlight some of our recent research on the development of molecular design strategies and structure–activity relationships for several different mechanophore platforms enabling visual stress reporting and mechanically triggered molecular release as well as some unusual reactivity.