Join LiveMove for a coffee shop chat with Senior Instructor Nick Kohler (Geography) and Professor Gordon Sayre (English/Folklore). Drop in and chat about car cultures, Geographic Information Systems (GIS), human-environment interactions, automobility, car-centrism, the future of transportation, ecocriticism, and more.

There will be free pastries and coffee while supplies lasts! Open to all.

Department of Chemistry and Biochemistry Physical Chemistry Seminar Series

Professor James Prell, University of Oregon

Measuring Energy Landscapes for Biomolecules  with Native Mass Spectrometry

Advances in instrumentation for structural biology and bioanalytical chemistry have enabled the study of ever larger and more dynamic biomolecules and biomolecular complexes. Native ion mobility-mass spectrometry offers advantages for interrogating small, heterogeneous, and dynamic samples while preserving much high-order structure even as analytes are transferred from buffered aqueous solution into the gas phase. Deliberate, precisely controlled heating of the resulting ions inside the mass spectrometer can result in collision-induced dissociation and/or unfolding (CID/U) of non-covalent complexes, revealing structural information that can be exceptionally difficult to access with conventional techniques. However, to date, a quantitative understanding of CID and CIU as a function of acceleration potentials, gas pressure and identity, and other factors has been lacking.

Our recently introduced software suite (IonSPA) can quantitatively predict ion heating, cooling, and motion in such experiments and be used to determine dissociation and unfolding barriers, which are crucial information for interpreting experimental data in terms of structures and chemical properties of the solution-phase biomolecules. We further show that this model can be used to reconcile data acquired using very different instrumentation from a variety of vendors, a key step in tethering these readily available experiments to a universal physical chemistry framework.

Students taking WR 121z, 122z, or 123 are invited to drop by the Tykeson 3rd floor Writing Lab (glass room, 351) for candy and quick writing support. Our GE Writing Support Specialists (tutors) are available to help you with any part of a WR assignment, from coming up with ideas to reading to revising to polishing up a final draft. Join us!

Mondays 3-4 and Thursdays 2-3, beginning week 4, for the rest of Winter quarter 2025.

Department of Chemistry and Biochemistry Organic/Inorganic/Materials Seminar Series

Professor Holger Bettinger, University of Tübingen Hosted by Mike Haley

A Journey from Long Acenes to Cyclacenes

Acenes are a fundamentally and technologically important class of polycyclic aromatic hydrocarbons. Their small HOMO-LUMO gap is a blessing for materials properties but a curse for synthesis, characterization, and handling. My research group has achieved acenes of unprecedented lengths under the stabilizing conditions of matrix isolation and on-surface synthesis that allowed gaining an understanding of acene properties up to pentadecacene (15acene).[1] The key to success is the application of a protection group strategy that enables the release of acenes under these extreme conditions. The cyclic versions of acenes, cyclacenes, are unknown despite significant synthetic efforts since Edgar Heilbronner’s 1954 proposal. I will address expected properties of these zig-zag nanohoops and discuss strategies of their experimental realization using the low-temperature high-vacuum techniques in our laboratory.[2]

1. a) C. Tönshoff, H. F. Bettinger, Photogeneration of Octacene and Nonacene, Angew. Chem., Int. Ed. 2010, 49, 4125, 10.1002/anie.200906355; b) B. Shen, J. Tatchen, E. Sanchez-Garcia, H. F. Bettinger, Evolution of the Optical Gap in the Acene Series: Undecacene, Angew. Chem. Int. Ed. 2018, 57, 10506, 10.1002/anie.201802197; c) Z. Ruan, J. Schramm, J. B. Bauer, T. Naumann, H. F. Bettinger, R. Tonner-Zech, J. M. Gottfried, Synthesis of Tridecacene by Multistep Single-Molecule Manipulation, J. Am. Chem. Soc. 2024, 146, 3700, 10.1021/jacs.3c09392; d) Z. Ruan, J. Schramm, J. B. Bauer, T. Naumann, L. V. Müller, F. Sättele, H. F. Bettinger, R. Tonner-Zech, J. M. Gottfried, On-surface Synthesis and Characterization of Pentadecacene and its Gold Complexes, submitted for publication 2024. 2.  a) D. Gupta, A. Omont, H. F. Bettinger, Energetics of Formation of Cyclacenes from 2,3-Didehydroacenes and Implications for Astrochemistry, Chem. Eur. J. 2021, 27, 4605, https://doi.org/10.1002/chem.202003045; b) J. B. Bauer, F. Diab, C. Maichle-Moessmer, H. Schubert, H. F. Bettinger, Synthesis of the [11]cyclacene framework by repetitive Diels-Alder cycloadditions, Molecules 2021, 26, 3047, 10.3390/molecules26103047; c) A. Somani, D. Gupta, H. F. Bettinger, Computational Studies of Dimerization of [n]-Cyclacenes, J. Phys. Chem. A 2024, 128, 6847, 10.1021/acs.jpca.4c02833.