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Campagna Group Published in Environmental Microbiology

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The Campagna Group has published a collaborative piece titled “Nitrogen flux into metabolites and microcystins changes in response to different nitrogen sources in Microcystis aeruginosa NIES-843” in Environmental Biology. 

The over-enrichment of nitrogen (N) in the environment has contributed to severe and recurring harmful cyanobacterial blooms, especially by the non-N2 -fixing Microcystis spp. N chemical speciation influences cyanobacterial growth, persistence and the production of the hepatotoxin microcystin, but the physiological mechanisms to explain these observations remain unresolved.

Stable-labelled isotopes and metabolomics were employed to address the influence of nitrate, ammonium, and urea on cellular physiology and production of microcystins in Microcystis aeruginosa NIES-843. Global metabolic changes were driven by both N speciation and diel cycling. Tracing 15 N-labelled nitrate, ammonium, and urea through the metabolome revealed N uptake, regardless of species, was linked to C assimilation.

The production of amino acids, like arginine, and other N-rich compounds corresponded with greater turnover of microcystins in cells grown on urea compared to nitrate and ammonium. However, 15 N was incorporated into microcystins from all N sources. The differences in N flux were attributed to the energetic efficiency of growth on each N source.

While N in general plays an important role in sustaining biomass, these data show that N-speciation induces physiological changes that culminate in differences in global metabolism, cellular microcystin quotas and congener composition.

 

Honors Day 2020

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Department of Chemistry recognized the achievements among students, faculty and staff members of the department. Below, you will find a complete list of recipients for the Honors Day 2020.

UNDERGRADUATE AWARDS

ACS-Hach Land Grant Scholarship Natalie Parsons
CRC Press General Chemistry Award Kara Holt
C.W. Keenan Outstanding General Chemistry Student Award Marissa Knofczynski
Department of Chemistry Scholarships Maggie Eslinger, Elizabeth Lander and Sean Weiland
Dr. Lucy E. Scroggie Scholarship Ghaeath Abbas
Halbert and Anne Carmichael Scholarship Elijah Hix and Thaddeus Puzdrakiewicz
C.A. Buehler Chemistry Scholarship Nicholas Legaux and Kristopher Reynolds
Melaven-Rhenium Scholarships Catherine Armstrong, Nicholas Legaux and Clayton West

GRADUATE AWARDS

Keenan Teaching Award Amber Gray
Outstanding Teaching Award Alexandria Bone
Second Year Candidacy Award Alexandria Bone
Gleb Mamantov Graduate Chemistry Scholar Jacob Townsend
Jerome Eastham Fellowship in Organic Chemistry Jinchao Lou
Eugene John Barber Fellowship in Physical Chemistry Kevin Smith
Burchfield Burridge Warner Fellowship in Polymer Chemistry Bishnu Prasad Thapaliya

STUDENT RECOGNITIONS

Goldwater Scholarship Kristopher Reynolds
Winners of the Board of Visitor’s Poster Competition Jinchao Lou and Brandon Colon

STAFF AWARDS

Outstanding Service Award Pam Roach and Linda Sherman
Carol Moulton ACGS Service Award Linda C. Sherman
James F. Green ACGS Service Award Noah Hathcock

FACULTY AWARDS

Ziegler Professorship David Jenkins
T. Ffrancon Williams Professorship Konstantinos Vogiatzis
Gleb Mamantov Professorship in Chemistry Brian Long
2020 Max Bredig Award Sheng Dai

FACULTY RECOGNITION

New Faculty Fred Heberle
Retiring Charles Feigerle

Dai Lab Publishes Study on High-Entropy Perovskite Fluorides

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Members of the Dai Lab, a Department of Chemistry lab headed by Professor Sheng Dai, recently published an article titled “High-Entropy Perovskite Fluorides: A New Platform for Oxygen Evolution Catalysis” in the Journal of The American Chemical Society.

Members of the Dai Lab focus their research projects on the synthesis and characterization of functional materials for energy-related applications, including electrical energy storage.

This study highlights oxygen evolution reactions (OERs) and the beneficial uses of high-entropy perovskite fluorides (HEPFs) in oxygen evolution catalysts.

“The oxygen evolution reaction is a critical process for many energy storage options, such as water splitting and metal-air batteries,” said Tao Wang, a post-doc working with the lab.

HEPFs consisting of cost-effective elements can act as excellent catalysts for OREs in an alkaline medium.

“HEPFs can provide a new platform for oxygen evolution catalysis,” Wang said. “Moreover, the flexible synthesis of HEPFs in a boiled solution combining the hydrothermal method with mechano-chemistry, provides a new concept for the low-temperature synthesis of high entropy materials.”

Written by Kelly Alley

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Dai Lab Publishes Study in Nature Communications

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Members of the Dai Lab, a Department of Chemistry lab headed by Professor Sheng Dai, recently published an article titled “Mechanochemical synthesis of pillar[5]quinone derived multi-microporous organic polymers for radioactive organic iodide capture and storage” in the Nature research journal Nature Communications.

Members of the Dai Lab studied porous organic polymers (POPs), high surface area materials with sponge-like qualities. These POPs can be easily designed and constructed at molecular levels.

The incorporation of supramolecular macrocycles with the reservation of their cavities into porous organic polymers may endow the material with enhanced uptake of specific guests through host−guest interactions,” said Kecheng Jie, a post-doctoral research associate working with the lab. “This work demonstrates not only a new synthetic pathway to porous polymers but also the superiority of the incorporation of a supramolecular host into porous polymers for guest uptake.”

Written by Kelly Alley

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Jenkins Group Published in Angewandte Chemie

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The Jenkins Group published their work “A Benchtop Method for Appending Protic Functional Groups to N‐Heterocyclic Carbene Protected Gold Nanoparticles” in the highly-profiled journal Angewandte Chemie. Joseph DeJesus is the first author and recent PhD alumus from the Department of Chemistry’s program. 

This piece explores the resilience of N‐heterocyclic carbene (NHC) gold bonds. They synthesize NHC‐functionalized gold surfaces from gold(I) NHC complexes and aqueous nanoparticles without the need for additional reagents, enabling otherwise difficult functional groups to be appended to the carbene.

The resilience of the NHC−Au bond allows for multi‐step post‐synthetic modification. “Beginning with the nitro‐NHC, we form an amine‐NHC terminated surface, which further undergoes amide coupling with carboxylic acids,” DeJesus said.  “The simplicity of this approach, its compatibility with aqueous nanoparticle solutions, and its ability to yield protic functionality, greatly expands the potential of NHC‐functionalized noble metal surfaces.”

Roy and Long Collaborative Work Published

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Catalysis Science & Technology published a collaborative piece from the Roy and Long groups titled  “A mechanistic study of microstructure modulation in olefin polymerizations using a redox-active Ni(ii) alpha-diimine catalyst.”

Polyolefins are among the world’s most widely produced and utilized classes of polymers, serving as synthetic alternatives to traditional materials such as wood, glass, and metal. While numerous prior research efforts have focused on the development of faster, more efficient, and less expensive catalysts, recent studies have demonstrated that redox-active olefin polymerization catalysts may also be employed to modulate catalytic activity, reactivity, and selectivity in situ.

The group reports a computational study based on density functional theory designed to better understand the structure and underlying olefin polymerization mechanisms of the active catalytic species in two distinct redox states. These findings are further supported through experimental evidence and suggest that upon activation of the reduced catalyst species, the added electron density of the catalyst is transferred from the active metal center to the alpha-diimine ligand.

The observed decrease in polyethylene branching that results from catalyst reduction is believed to stem from changes in the subtle balance of steric, electronic, and entropic effects, primarily perturbing the coordination of subsequent monomer units. This perturbation is expressed not only in the monomer-inserted-product energy differences but also in the catalysts’ deviation from square planarity about the Ni center. Through these studies, we can better understand how the addition of an electron to a Ni(ii) alpha-diimine catalyst perturbs its catalytic behavior, which may influence the design of future generations of redox-active olefin polymerization catalysts.

Kent & Zhao’s Most Read Article

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Shape Changing Brush Polymers Are Receiving Attention. 

Molecular bottlebrushes are complex polymers composed of polymeric side chains densely grafted on a relatively long backbone polymer. These types of polymers are found in our body and show important biological functions, e.g., joint lubrication by lubricin.

In an effort to develop smart polymers mimicking the function of the von Willebrand Factor, a protein important in the blood clotting cascade, Ethan W. Kent, a doctoral graduate student in Bin Zhao’s research laboratory, recently designed and synthesized dually responsive shape-changing star molecular bottlebrushes.

At acidic pH values and lower temperatures, the molecules take on a three-arm star shape with a span size of ~ 180 nm. When the pH is increased to basic or temperature is raised, the molecules undergo dramatic shape changes from stars to spheres with an average dimension of ~ 80 nm. 

“It is really cool to see these molecules change their shapes spontaneously,” Kent said. These brush polymers have potential in drug delivery, molecular actuators, and sensors. Ethan is currently applying his responsive brush polymers in sensors.

This work has been published in Macromolecules, an ACS journal in polymer science. The paper has been on the list of Most Read Articles in Macromolecules for nearly two months. “It is really exciting to see our paper garner a lot of attention” Kent said.        

BOV 2019

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The Department of Chemistry’s Board of Visitors (BOV) is a volunteer advisory body dedicated to helping the Department successfully fulfill its teaching, research and service missions and become one of the preeminent chemistry departments in the nation. The BOV has a vision of enriching the research and teaching endeavors and the intellectual capital of the Department.

This year’s annual meeting was held November 1-2, 2019. Activities included dinner downtown, faculty presentations, 10 year academic program review discussion, student poster session, invited speaker, Shea Kidd Houze, Homecoming Parade, banquet dinner at the Foundry, alumni tailgate, and attending the UAB football game.

Two graduate students were awarded for their posters presentations:

  • Jinchao Lou from the Best group titled”Calcium-triggered release of contents from liposomes for drug delivery applications”
  • Brandon Colon from the Calhoun group titled “Imaging excited-state dynamics of IR-144 with total internal reflection transient absorption microscopy (TIRTAM)”

View Poster Session Program 

The department recognizes and appreciates all of the support and interaction it receives from its engaged board.

Pictures from event

New Instrument in the PCL

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Small Angle X-Ray Scattering

The Xenocs Xeuss 3.0 SAXS instrument is a powerful technique that allows for the determination of size, distribution, shape, and order of nanoparticles and macromolecules. This instrument has 2 radiation sources, Cu and Mo, that can be switched and aligned automatically. It can operate over different configurations that spans a variety of q-ranges; WAXS, SAXS, MSAXS, and USAXS. Accessories include a low-noise flow cell for dilute or low scattering samples, BioCube for low volume samples, capillary holder for liquid samples, gel and powder sample holder, GISAXS sample holder for thin film and surface analysis, heating stage, and humidity stage.