Fall 2023 Seminar Series 

All presentations take place on Fridays in the Byker Auditorium at 3:10 pm unless noted otherwise. 

Friday, August 25 

Ms. Olivia Duletski will present a graduate student seminar in Chemistry titled "Development of Cr Complexes Bearing Anionic Pincer Ligands for N2 Reduction Activation of Small Molecules."   

Abstract: Dinitrogen (N2) is an inexpensive feedstock for producing valuable chemical fuels, such as hydrazine and ammonia (NH3). Due to its “carbon free” nature ammonia serves as an attractive  energy vector to generate H2 through NH3 decomposition, or for direct use in ammonia fuel cells.  Large scale ammonia production is reliant on the energy intensive Haber-Bosch process generating CO2 emissions. Molecular systems have displayed catalytic efficiency for ammonia production while eliminating environmentally harmful byproducts. We are developing molecular catalysts for N2 reduction and NH3 oxidation and aim to understand N-H bond energies of M-NxHy intermediates formed during catalysis. The current research is focused on the use of anionic pincer ligated Group 6 metal complexes, primarily chromium, with N2 and N-containing ligands for coordination, activation, and the formation and/or cleavage of N⎯H bonds. Photochemical reactions have been applied to prepare Cr-N2 complexes that are not accessible by typical synthetic routes using chemical reductants. This work will describe the development and interconversion of Cr aryl- or alkylamido and imido complexes and our efforts to prepare Cr complexes to catalyze NH3 oxidation and N2 reduction.

Research Advisor: Mike Mock

Friday, September 8

Mr. Steven Montoya, a 5th year PhD candidate in Chemistry will present a seminar titled “Novel Ion Conducting Materials for Next Generation Solid-State Batteries.” 

Abstract: The rapid expansion of battery-driven applications has spurred the need for new technologies, including high energy density batteries having solid-state electrolytes.  Lithium lanthanum zirconate – Li7La3Zr2O12 or LLZO – is a lithium ion conducting ceramic that promises high energy-density batteries that are significantly safer than current lithium-ion batteries that use liquid organic electrolytes.  Before such promise can be realized, however, challenges associated with LLZO’s chemical, phase, and mechanical stability must be overcome.  Recent work in our research program has developed new strategies to remove carbonate contaminants from LLZO after sintering and – in collaboration with colleagues in engineering – we have begun characterizing how fracture toughening changes the distribution of cubic and tetragonal phases of LLZO. This work draws upon results from high temperature Raman spectroscopy to monitor the effects of conditioning both cubic and tetragonal LLZO at 800˚C as well as Raman microscopy to identify the spatial distribution of phases following micro-indentation of sintered cubic zirconia samples. 

Research Advisor: Rob Walker

Friday, September 15

Mr. Oliver Jackson, a 5th year chemistry graduate student will present a seminar titled "Palladium-catalyzed Regioselective Rearrangements and Cross-couplings."

Abstract: Palladium catalysts were used to control selectivity in two different classes of reaction. The first reaction, developed in the Cook lab, aims to tackle the limited methods available towards the asymmetric synthesis of all-carbon quaternary stereocenters, which are a common motif in natural products and high-value pharmaceuticals. We developed an auto-tandem, branched-selective rearrangement of substituted N-alloc-N-allyl ynamides that proceeds through two separate and distinct catalytic cycles using the same catalytic entity. This reaction provides ready access to complex quaternary nitrile products with vinylogous stereocenters in excellent diastereoselectivity (>20:1 d.r.), including contiguous all-carbon quaternary centers. The stereochemical outcome is determined via a Pd(0)-catalyzed dipolar ketenimine aza-Claisen rearrangement and computational studies exemplify the key role ligand geometry plays. The second reaction, developed in the Neufeldt lab, aims to disrupt the inherent reactivity trends of 2,4-dihalogenated pyrimidines. 2,4-Disubsituted pyrimidines appear frequently in bioactive small molecules; however, strategies to elaborate the pyrimidine core through divergent synthesis (e.g., to prepare a library) are limited because 2,4-dihalopyrimidines tend to react only at C4 in both cross-couplings and nucleophilic aromatic substitutions. Substrate-controlled approaches can enable C2-selective functionalization, but a catalyst-controlled strategy to invert the conventional selectivity of cross-coupling would be more step-economical and general. Here we report that (η3-1-tBu- indenyl)Pd(IPent)(Cl) uniquely effects C2-selective cross-coupling of 2,4-dichloropyrimidines with thiols. Preliminary information suggests against a conventional oxidative addition mechanism for C—Cl cleavage.

Research Advisor: Sharon Neufeldt

Friday, September 22 

Mr. Rhys Trousdale, a 4th year graduate student in Chemistry will present his research in a seminar titled "Solute Partitioning into Model Biological Membranes: The Origins of Bioconcentration."

Abstract: Solutes in the presence of biological membranes can choose either to remain in solution or accumulate in the membrane.  Membranes themselves present solutes with dramatically asymmetric solvation environments where the local surroundings change from aqueous to polar organic to nonpolar and back, all over the span of ~4 nanometers.  Quantifying the tendency of solutes to partition into membranes and identifying where those solutes accumulate are the first steps to understanding bioconcentration.  This seminar will focus on how we have used time resolved fluorescence emission to examine solute partitioning into model biological membranes consisting of dipalmitoyl phosphocholine (DPPC) vesicle bilayers.  In addition to the fluorescence measurements, we also perform differential scanning calorimetry and dynamic light scattering experiments to learn how partitioned solutes affect a membrane’s thermodynamic properties and vesicle size.  My studies have focused on three specific topics:

  1. Amino acid partitioning into DPPC bilayers and learning how membrane hydration affects L‑phenylalanine’s photophysical properties.
  2. Perfluorooctanoic acid (PFOA) affinity for DPPC bilayers and PFOA’s effects on solute partitioning
  3. Herbicide and pesticide partitioning into DPPC bilayers and the challenges associated with understanding bioconcentration in reactive systems.

This seminar will focus on the first two topics and also highlight a new collaboration that considers PFOA effects on protein structure and stability using both fluorescence and mass spectrometry.

Research Advisor: Rob Walker

Friday, September 29

Ms. Hope Welhaven, a 4th year graduate student in Biochemistry will present her research in a seminar titled "Phenotypes Reflect Patient Sex and Injury Status: A Cross-Sectional Analysis."

Abstract: Post-traumatic osteoarthritis (PTOA) is caused by knee injury such as ACL and meniscal injuries. Both injuries are known to cause PTOA but the underlying cellular mechanisms driving disease remain unknown. Aside from injury, patient sex is a prevalent risk factor associated with PTOA where females are at a higher risk for knee injury and development of post-traumatic osteoarthritis (PTOA) compared to males. Although sex differences exist and knee injury is known to cause PTOA, the underlying cellular mechanisms driving disease remain unknown. Metabolomics offers the potential to improve current understanding of the effects of these two factors on knee structures. Therefore, the goal of this study was to perform a cross-sectional analysis of synovial fluid (SF) metabolomic phenotypes comparing different knee injury pathologies between males and females.

Research Advisors: Ron June and Brian Bothner

October 6

Bryce Hughes (Dept. of Education, MSU)

Host: Christopher Lemon

October 13

Ophelia Venturelli 

Host: Roland Hatzenpichler

October 20 

David Fialho (Chemistry, MSU).

Host: Christopher Lemon

October 27 - 

Nicholas Strange (SLAC)

Host: Nick Stadie

November 3 

Asst. Prof. Heather Callaway (Biochemistry, MSU)

Host: Christopher Lemon

November 17 - (9 am Virtual Seminar)

Dr. Fatima Pereira, Lecturer, University of Southampton, England will present a virtual seminar titled "Linking Microbiome Function to Identity using Next-generation Raman Stable Isotope Probing Approaches."

Host: Roland Hatzenpichler

December 1 

Nadja Zeltner (University of Georgia)

Host: Valérie Copié

December 8 

Mary Cloninger (Chemistry, MSU)

Host: Nick Stadie