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Albert and Suoma Tuinman’s Passing

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It is with deep sorrow we announce the death of Albert Andrew Tuinman and Suoma Annikki Tuinman.  The couple passed away in their home on March 16, 2020.  Albert came to the University Of Tennessee Department of Chemistry from the Cancer Research Institute in Tempe, AZ serving in the position of Director of Mass Spectrometry and Research Associate Professor from March 1987 until his retirement in April 2006.  A Celebration of Life ceremony will be held May 29, 2021 at the Norris United Methodist Church, 62 Ridgeway Road, Norris, TN 37828, at 10:45 AM.  The hybrid event will include friends and family throughout Europe and South Africa.  Friends of the Tuinmans are invited to attend either in person or on Zoom. For those interested in attending the event through Zoom, please send Linda Lewis (lewisla7755@gmail.com) your desire to participate.

Bone Selected to Attend NX School

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Alex Bone, graduate student in the Xue Group, has been selected to attend the Twenty-Third National School on Neutron and X-ray Scattering to be held virtually from Oak Ridge National Laboratory and Argonne National Laboratory.

Due to the COVID-19 pandemic, the National School on Neutron and X-ray Scattering (NX School) will be held virtually from July 12-30, 2021. The first week of the program will consist of half day lecture sessions, the second and third week will be lectures, remote experiments and data analysis tutorials.

The main purpose of the National School on Neutron and X-ray Scattering is to educate graduate students in the use of major neutron and x-ray facilities. Lectures, presented by researchers from academia, industry, and national laboratories, include basic tutorials on the principles of scattering theory and the characteristics of the sources, as well as seminars on the application of scattering methods to a variety of scientific subjects. Students will conduct short remote experiments at Argonne’s Advanced Photon Source and at Oak Ridge National Laboratory’s Spallation Neutron Source and High Flux Isotope Reactor, which provides hands-on experience using neutron and synchrotron sources.

This year’s NX School will be three weeks in length. The first week will consist of half day lecture sessions. The second two weeks will be full-time consisting of lectures and remote experiments.

Jointly Conducted by: Argonne National Laboratory’s, Advanced Photon Source and Materials Science Division, and Oak Ridge National Laboratory’s Neutron Sciences Directorate and Materials Science and Technology Division.

The School is supported by the U. S. Department of Energy, Office of Science, Basic Energy Sciences, and Materials Sciences and Engineering Division.

Tin Awarded Shull Wollan Center Graduate Research Fellowship

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Pagnareach (Reach) Tin, graduate student in the Xue Group, has been awarded the Shull Wollan Center Graduate Research Fellowship for Spring 2021.

The Shull Wollan Center Graduate Research Fellowship Program has been designed to recognize and support outstanding graduate students in neutron science disciplines who are pursuing research-based doctoral degrees at the University of Tennessee, Knoxville. 

The Shull Wollan Center Graduate Research Fellowship will be awarded to two UTK doctoral students with majors in physics, chemistry, materials science and engineering, biology, or a related area who are engaged in active research as part of their PhD thesis.  Successful applicants will be awarded a monthly stipend for January through June 2021.

Sharma Announced Winner of 2021 Emerging Leader in Molecular Spectroscopy

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Bhavya Sharma, assistant professor, has been named the winner of the 2021 Emerging Leader in Molecular Spectroscopy Award. The award will be presented to Sharma at the SciX 2021 conference this fall, where she will give a plenary lecture and be honored in an award symposium.

“We would like to extend congratulations to Professor Sharma for winning the 2021 Emerging Leader in Molecular Spectroscopy Award,” said Mike Hennessy Jr., president and CEO of MJH Life Sciences™, the parent company of Spectroscopy®. “Sharma is well deserving of this recognition for all of her excellent work as a molecular spectroscopist. We are proud to honor her with this award at the SciX conference this fall.”

Sharma received her Ph.D. from the University of Pittsburgh in 2011. She has become a leader in the area of neurochemical detection with various forms of Raman spectroscopy, including surface-enhanced Raman spectroscopy (SERS) and spatially offset Raman spectroscopy. Sharma has developed novel Raman spectroscopy methods for neurological detection, including surface-enhanced spatially offset Raman spectroscopy. Additionally, she is developing methods to demonstrate direct detection of molecules for the first time by combining SERS and multivariate analysis.

Sharma has published 26 papers and has given more than 40 oral and poster presentations at scientific conferences. She is a reviewer for multiple journals and received an Outstanding Reviewer award for the journal Analyst in 2018. As an active member of the Coblentz Society, Sharma has served on multiple award committees and was also a member of the program committee for the OSA Optical Sensors Conference for 2018 and 2019. Sharma has also been active in organizing sessions at various scientific conferences, including Pittcon, the SPIE Defense + Commercial Sensing Symposium, and SciX. 

Selected by an independent scientific committee, the Emerging Leader in Molecular Spectroscopy Award recognizes the achievements and aspirations of a talented young molecular spectroscopist who has made strides early in his or her career toward the advancement of molecular spectroscopy techniques and applications. The winner must be within 10 years of receiving his or her PhD. 

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Doerr Selected for Prestigious Symposium

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Alicia Doerr, graduate student in the Long Group, has been selected to take part in the ACS national meeting’s symposium entitled “Excellence in Graduate Polymer Research.” This annual symposium is organized by the POLY division and held at Spring national meetings of the ACS to recognize outstanding graduate students in polymer science and engineering, foster networking and exposure, and help develop the careers of future leaders in the field of polymers. This symposium was started in 2004 and includes both oral and poster sessions with presentations exclusively from graduate students.

Due to this meeting’s hybrid nature, the ACS POLY division created an independent web page to highlight the accomplishments of these graduate scientists. 

Doerr’s research explores the field of redox-switchable catalysis which has gained considerable interest in recent years, enabling catalytic reactivity/selectivity to be oscillated based on the redox-state of the ligand or active metal center. Unfortunately, though a myriad of redox-switchable catalysts have been developed for the ring opening polymerization of cyclic esters, very few fundamental structure-catalytic performance studies have been conducted that ascertain how systematic changes in ligand structure affect the catalytic performance.

This work describes studies used to determine how changes in the placement and number of redox-active moieties, ligand denticity, and active metal center identity impacts the catalytic performance.

The results of these studies reveal that the proximity of the redox-active moiety to the active metal center may influence both catalyst activity and redoxswitchability. Conversely, the number of redox-active moieties present within the ligand scaffold may not play a crucial role in the catalysts’ switchability. Lastly, when Ti-/ Zr-centered analogues of these catalysts were compared it was revealed that the choice of metal center may dramatically influence both catalyst activity and redox-switchable.

Do Lab Published in Chemical Science

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The Do Lab recently published their work “α-CGRP disrupts amylin fibrillization and regulates insulin secretion: implications on diabetes and migraine” in Chemical Science.

Amber Gray and Aleksandra Antevska, graduate students, share first authorship on this piece.

Despite being relatively benign and not an indicative signature of toxicity, fibril formation and fibrillar structures continue to be key factors in assessing the structure–function relationship in protein aggregation diseases. The inability to capture molecular cross-talk among key players at the tissue level before fibril formation greatly accounts for the missing link toward the development of an efficacious therapeutic intervention for Type II diabetes mellitus (T2DM).

This research shows that human α-calcitonin gene-related peptide (α-CGRP) remodeled amylin fibrillization. Furthermore, while CGRP and/or amylin monomers reduce the secretion of both mouse Ins1 and Ins2 proteins, CGRP oligomers have a reverse effect on Ins1. Genetically reduced Ins2, the orthologous version of human insulin, has been shown to enhance insulin sensitivity and extend the life-span in old female mice.

Beyond the mechanistic insights, their data suggest that CGRP regulates insulin secretion and lowers the risk of T2DM. Our result rationalizes how migraine might be protective against T2DM. They envision the new paradigm of CGRP : amylin interactions as a pivotal aspect for T2DM diagnostics and therapeutics. Maintaining a low level of amylin while increasing the level of CGRP could become a viable approach toward T2DM prevention and treatment.

Hix in Bailey Lab Named Goldwater Scholar

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As the result of a partnership with the Department of Defense National Defense Education Programs (NDEP), Mrs. Peggy Goldwater Clay, Chair of the Board of Trustees of the Barry Goldwater Scholarship and Excellence in Education Foundation, announced that the Trustees of the Goldwater Board have increased the number of Goldwater scholarships it has awarded for the 2021-2022 academic year to 410 college students from across the United States.

“As it is vitally important that the Nation ensures that it has the scientific talent it needs to maintain its global competitiveness and security, we saw partnering with the Goldwater Foundation as a way to help ensure the U.S. is developing this talent,” said Dr. Jagadeesh Pamulapati, Director of the NDEP program, as he explained the partnership. With the 2021 awards, this brings the number of scholarships awarded since 1989 by the Goldwater Foundation to 9457.

From an estimated pool of over 5,000 college sophomores and juniors, 1256 natural science, engineering and mathematics students were nominated by 438 academic institutions to compete for the 2021 Goldwater scholarships. Of students who reported, 198 of the Scholars are men, 207 are women, and virtually all intend to obtain a Ph.D. as their highest degree objective. Fifty-one Scholars are mathematics and computer science majors, 291 are majoring in the natural sciences, and 68 are majoring in engineering. Many of the Scholars have published their research in leading professional journals and have presented their work at professional society conferences.

Goldwater Scholars have impressive academic and research credentials that have garnered the attention of prestigious post-graduate fellowship programs. Goldwater Scholars have been awarded 94 Rhodes Scholarships, 150 Marshall Scholarships, 170 Churchill Scholarships, 109 Hertz Fellowships, and numerous other distinguished awards like the National Science Foundation Graduate Research Fellowships.

Elijah Hix, of Cookeville, Tennessee, is a College Scholar whose major focuses on quantum chemical biology. Hix has pursued research at UT, Tennessee Tech, and Oak Ridge National Laboratory. Currently he is conducting research at UT under Constance Bailey, assistant professor of chemistry. He subsequently plans to pursue a PhD in biophysics to study the intersection of enzymatic synthesis and cellular networking to develop more adaptable antibiotics. “I am honored to be selected as a 2021 Goldwater Scholar,” Hix said. “It is the culmination of years of work with my two mentors, and I look forward to using this opportunity to propel enzyme modeling and engineering to new heights.”

Hix anticipates graduating May 2022. “After obtaining my degree in Quantum Chemical Biology, I plan to earn a Ph.D. in Biophysics in order to continue my research and teach on the molecular dynamics of enzymes,” Hix said.

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Sokolov Group Published in Energy Storage Mater. and ACS Macro Lett.

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The Sokolov Group recently published their work “Anomalously high elastic modulus of a poly(ethylene oxide)-based composite electrolyte” in Energy Storage Materials.

The practical use of lithium metal anodes in solid-state batteries requires a polymer membrane with high lithium-ion conductivity, thermal/electrochemical stability, and mechanical strength. The primary challenge is to effectively decouple the ionic conductivity and mechanical strength of the polymer electrolytes.

They report a remarkably facile single step synthetic strategy based on in-situ crosslinking of poly(ethylene oxide) (xPEO) in the presence of a woven glass fiber (GF). Such a simple method yields composite polymer electrolytes (CPE) of anomalously high elastic modulus up to 2.5 GPa over a broad temperature range (20 °C – 245 °C) that has never been previously documented.

An unsupervised machine learning algorithm, K-mean clustering analysis, was implemented on the hyperspectral Raman mapping at the xPEO/GF interface. Using such a unique means, we show for the first time that the promoted mechanical strength originates from xPEO and GF interactions through dynamic hydrogen and ionic bonding. High ionic conductivity is achieved by the addition plasticizer (e.g. tetraglyme), where trifluoromethanesulfonate anions are tethered to the xPEO matrix and Li+ cations are favorably transported through coordination with the plasticizer.

Further, stringent galvanostatic cycling tests indicates the CPE can be stably cycled for >3000 h in a Li-metal symmetric cell at a moderate temperature (nearly 1500 Coulombs/cm2 Li equivalents), outperforming most of the PEO-based electrolytes. The GF reinforced CPE reported here has multifunctional uses, such as solid electrolytes for all solid-state batteries and membranes for redox-flow batteries.

Although the focus of this study is on lithium-based batteries, the results are equally promising for other alkali metal based batteries such as sodium and potassium.

The Sokolov Group also had their work “Turning Rubber into a Glass: Mechanical Reinforcement by Microphase Separation” published in ACS Macro Letters.

Supramolecular associations provide a promising route to functional materials with properties such as self-healing, easy recyclability or extraordinary mechanical strength and toughness. The latter benefit especially from the transient character of the formed network, which enables dissipation of energy as well as regeneration of the internal structures. However, recent investigations revealed intrinsic limitations in the achievable mechanical enhancement.

This manuscript presents studies of a set of telechelic polymers with hydrogen-bonding chain ends exhibiting an extraordinarily high, almost glass-like, rubbery plateau. This is ascribed to the segregation of the associative ends into clusters and formation of an interfacial layer surrounding these clusters. An approach adopted from the field of polymer nanocomposites provides a quantitative description of the data and reveals the strongly altered mechanical properties of the polymer in the interfacial layer. These results demonstrate how employing phase separating dynamic bonds can lead to the creation of high-performance materials.

Vogiatzis Group’s Recent Publications

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Research in the Vogiatzis Group centers on the development of computational methods based on electronic structure theory and machine learning algorithms for describing chemical systems relevant to clean, green technologies. They are particularly interested in new methods for non-covalent interactions and bond-breaking reactions of small molecules with transition metals. Their overall objectives are to elucidate the fundamental physical principles underlying the magnetic, catalytic, and sorption properties of polynuclear systems, as well as to assist in the interpretation of experimental data.

Recent work in Coordination Chemistry Reviews “Computational catalysis for metal-organic frameworks: An overview” explores Metal-organic frameworks (MOFs), a family of porous hybrid organic/inorganic materials, have shown great promise for many challenging chemical applications including gas separations, catalysis, and sensors.

“This review highlights recent work performed on catalytic reactions promoted by MOFs from a computational and theoretical standpoint. Computational modeling includes the elucidation of reaction mechanisms, the characterization of electronic structure effects of key intermediates and transition states, and the interpretation of experimental data.” said Gavin McCarver, graduate student.

Vogiatzis also published a paper with his undergraduate advisor, Dimitris Georgiadis. “Professor Georgiadis is the person who taught me first how to do research and follow my scientific goals” said Vogiatzis. Their work  “A Carbodiimide-Mediated P-C Bond-Forming Reaction: Mild Amidoalkylation of P-Nucleophiles by Boc-Aminals” in Organic Letters shares the first example of a carbodiimide-mediated P–C bond-forming reaction. 

The reaction involves activation of β-carboxyethylphosphinic acids and subsequent reaction with Boc-aminals using acid-catalysis. Mechanistic experiments using 31P NMR spectroscopy and DFT calculations support the contribution of unusually reactive cyclic phosphinic/carboxylic mixed anhydrides in a reaction pathway involving ion-pair “swapping”. The utility of this protocol is highlighted by the direct synthesis of Boc-protected phosphinic dipeptides, as precursors to potent Zn-aminopeptidase inhibitors.

Inorganic Chemistry published their work “Electrocatalytic Dechlorination of Dichloromethane in Water Using a Heterogenized Molecular Copper Complex.” 

The remediation of organohalides from water is a challenging process in environment protection and water treatment. They report a molecular copper(I) complex with two triazole units, CuT2, in a heterogeneous aqueous system that is capable of dechlorinating dichloromethane (CH2Cl2) to afford hydrocarbons (methane, ethane, and ethylene). Computational studies provided additional insight into the reaction mechanism and the selectivity toward the CH4 formation. The findings in this study demonstrate that complex CuT2 is an efficient and stable catalyst for the dehalogenation of CH2Cl2 and could potentially be used for the exploration of the removal of halogenated species from aqueous systems.

Dai Group Published in Nano Energy and Chem. Commun.

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The Dai Group published their work “Room temperature synthesis of high-entropy Prussian blue analogues” in Nano Energy.

High-entropy Prussian blue analogues (HEPBAs) integrating the highly dispersed active sites of high-entropy materials with intrinsic 3D diffusion channels and the redox-active sites of Prussian blue analogues have great potential in electrochemical applications but have not been realized. In this work, a series of HEPBAs were successfully synthesized under room temperature combining mechanochemistry with wet chemistry for the first time.

High-entropy Prussian blue analogues (HEPBAs) were fabricated by combining mechanochemistry with wet chemistry. As an optimal element combination, high-entropy K(MgMnFeNiCu)Fe(CN)6 exhibited enhanced higher capacitances than all the single-component PBAs.

The group also published their work “Overcoming the phase separation within high-entropy metal carbide by poly(ionic liquid)s†” in Chemical Communications. 

High-entropy crystalline materials are attracting more attention. In principle, high-entropy metal carbides (HMCs) that contain five or more metal ions, possess more negative free energy value during catalysis. But its preparation is challenging because of the immiscibility of multi metal cations in a single carbide solid solution.

Here, a rational strategy for preparing HMC is proposed via a coordination-assisted crystallization process in the presence of Br-based poly(ionic liquids). Through this method, Mo0.2W0.2V0.2Cr0.2Nb0.2C nanoparticles, with a single cubic phase structure, incorporated on porous carbon, are obtained (HMC@NC). By combination of well dispersed small particle size (∼4 nm), high surface area (∼270 m2 g−1), and high-entropy phase, HMC@NC can function as a promising catalyst for the dehydrogenation of ethylbenzene. Unexpected activity (EB conv.: 73%) and thermal stability (>100 h on steam) at 450 °C are observed. Such a facile synthetic strategy may inspire the fabrication of other types of HMCs for more specific tasks.