Chemistry Commons^™

Root Exudates: The Rhizospheric Frontier For Advancing Sustainable Plant Protection, Muhammad Rahil Afzal, Misbah Naz, Youbo Yu, Lisha Yan, Peiyi Wang, Janaki Mohotti, Gefei Hao, Jing-Jiang Zhou, Zhou Chen, Libo Zhang, Qian Wang

Faculty Publications

Root exudates (REs), a diverse array of bioactive metabolites secreted by plant roots in response to environmental stimuli, serve as key mediators of rhizosphere ecology and plant defense responses, offering a promising avenue for sustainable pest management and eco-friendly plant protection. While earlier reviews primarily focus on root exudates in the context of general rhizosphere dynamics and plant-microbial interactions, critical knowledge gaps persist in REs-plant-pest tripartite interactions, the mechanistic basis of REs-mediated plant defense, and their practical integration with integrated pest management (IPM) frameworks. This review provides a synthesis of the latest literature on the biochemical diversity and functions of …

Growth Of Cylindrical Micelles And Their Use To Prepare Porous Materials With Tailored Dimensions And Alignment, Mengxue Zhang, Xiaomeng Li, Chuanbing Tang, Morgan Stefik

Faculty Publications

Materials with cylindrical pores are optimal for electrochemical devices and filtration due to their straight paths with minimal tortuosity when aligned. Polymer templates have led to many individual cylindrical architectures however the independent tailoring of pore and wall dimensions has remained elusive. Here short cylindrical micelle templates (PEO-b-PS) with glassy cores enabled the fabrication of sample series with constant cylindrical pore diameter (∼63 nm) and tailored wall thickness (TiO₂, ∼45–100 nm). This ShortCyl series (aspect ratio 4.25) had modest alignment that was attributed to the low free-energy cost for misalignment. Though the plasticized micelles (DCM present) …

Non-Spectator Behavior Of A Neutral Phosphine Ligand Driven By A Redox-Active Boron Cluster, Jared R. Riffle, Cash L. Jowers, Sarah Luna, Mark D. Smith, Dmitry V. Peryshkov

Faculty Publications

A new concept of ligand ambiphilicity that relies on the redox behavior of the indirectly coordinated boron cluster scaffold instead of the direct involvement of a single center in a ligand is introduced. A copper(I) complex of a carboranyl-based triphosphine, [t^BuP-closo-{C₂B₁₀}-^PhP-closo-{C₂B₁₀}-t^BuP]CuPF₆, in acetonitrile solution coordinates an exogenous X− anion (X− = Cl− or N3−) at the phosphorus center of the ligand and not at the cationic metal site to form [t^BuP(X)-nido-{C₂B …

Recent Insights Into Electrochemical Sensing Of Per- And Polyfluoroalkyl Substances, Christopher T. Lebarron, Pavithra Hosseini, Seyyedamirhossein Hosseini

Faculty Publications

Per- and polyfluoroalkyl substances (PFAS) are widely studied due to their persistence, prevalence, and harmful effects on human and environmental health. Key challenges include improving detection methodologies, such as lowering detection limits, and developing more sensitive and selective approaches. Given the ubiquity of PFAS, effective sensing must be paired with remediation strategies that transform these pollutants into value-added or less toxic products. This perspective explores recent advances in electrochemical PFAS detection, highlighting challenges and future opportunities.

Recent Insights Into Electrochemical Sensing Of Per- And Polyfluoroalkyl Substances, Christopher T. Lebarron, Pavithra Hosseini, Seyyedamirhossein Hosseini

Faculty Publications

Per- and polyfluoroalkyl substances (PFAS) are widely studied due to their persistence, prevalence, and harmful effects on human and environmental health. Key challenges include improving detection methodologies, such as lowering detection limits, and developing more sensitive and selective approaches. Given the ubiquity of PFAS, effective sensing must be paired with remediation strategies that transform these pollutants into value-added or less toxic products. This perspective explores recent advances in electrochemical PFAS detection, highlighting challenges and future opportunities.

Purification Of Uranium Tetrafluoride Using Ammonium Bifluoride, Kyle R. Foster, Juliano Schorne-Pinto, Ronald E. Booth, Annabelle Husek, Mina Aziziha, Hunter B. Tisdale, Bernie W.N. Fitzpatrick, Hans Conrad Zur Loye, Markus H.A. Piro, Theodore M. Besmann

Faculty Publications

A method of purification for UF₄ utilizing NH₄HF₂ was investigated to remove oxygen and hydrate impurities from the salt. The original salt exhibited a melting point at 915–920 °C, which corresponds to the eutectic temperature of the UF4-UO2 system, showing clear signs of oxygen contamination. To purify the salt, an air-tight reaction vessel inside an argon glovebox was used to react UF4/NH4HF2 mixtures at elevated temperatures under a continuous flow of inert gas. The process yielded a significantly purer UF4 salt as confirmed via inert gas fusion, X-ray diffraction, differential scanning calorimetry and inductively coupled plasma-optical …

Crystal Growth, Thermal, Optical, Magnetic And Electrochemical Properties Of Mo2Ta2O11, Md Abdullah Al Muhit, Alevtina A. Maksimova, Sean C. Wechsler, Habiba Binte Kashem, Gopabandhu Panigrahi, Gregory Morrison, Morgan Stefik, Hans Conrad Zur Loye

Faculty Publications

Single crystals of the transition metal oxide Mo2Ta2O11 were grown for the first time using molten flux synthesis. The compound crystalizes in the trigonal space group R 3‾m (no. 166) with lattice parameters a = b = 5.6267(1) Å and c = 25.1424(6) Å and a unit cell volume of 689.36(3) ų. The structure of Mo2Ta2O11 is composed of alternating layers of TaO6 octahedra and MoO4 tetrahedra connected via corner-sharing. CaH2 was used to achieve a partial low temperature reduction of Mo2Ta2O11. The electrochemical lithiation of polycrystalline Mo2Ta2O11 was also investigated for the first time. Mo2Ta2O11 underwent a …

Photo-Crosslinked Persistent Micelle Templates With Near Universal Solvent Compatibility, Coby S. Collins, Mengxue Zhang, Cj Strurgill, Christian X. Ruff, Bryce Melton, Morgan Stefik

Faculty Publications

The controlled preparation of porous nanomaterials from block polymer templates is important for diverse applications from energy devices to optical coatings and sorbents. The architectural dimensions determine the overall performance for many of these applications, however the independent control of these dimensions has remained limited to a narrow range of solvent conditions for kinetically trapped (“persistent”) micelle templates. Polymers with a photo-reactive chemistry are shown to enable cross-linked micelle templates that universally remain persistent under diverse solvent conditions. Specifically, poly(poly(ethylene glycol methacrylate))-b-poly(butyl methacrylate-co-coumarin methacrylate) (OBC) was prepared by RAFT polymerization and the resulting micelles were crosslinked …

Human Gut Commensal Alistipes Timonensis Modulates The Host Lipidome And Delivers Anti-Inflammatory Outer Membrane Vesicles To Suppress Colitis In An Il10-Deficient Mouse Model, Ethan Older, Mary K. Mitchell, Andrew Campbell, Xiaoying Lian, Michael Madden, Yuzhen Wang, Lauren E. Van De Wal, Thelma Zaw, Brandon N. Vanderveen, Rodney Tatum, E. Angela Murphy, Yan-Hua Chen, Daping Fang, Melissa Ellermann, Jie Li

Faculty Publications

Correlative studies have linked human gut microbes to specific health conditions. Alistipes is one such microbial genus negatively linked to inflammatory bowel disease (IBD). However, the protective role of Alistipes in IBD is understudied, and the underlying molecular mechanisms remain unknown. In this study, colonization of Il10-deficient mice with Alistipes timonensis DSM 27924 delays colitis development. Colonization does not significantly alter the gut microbiome composition, but instead shifts the host plasma lipidome, increasing phosphatidic acids while decreasing triglycerides. Outer membrane vesicles (OMVs) derived from Alistipes are detected in the plasma of colonized mice, carrying potentially immunomodulatory metabolites into the …

A New Transition Metal Borate, Co6(B24O39(Oh)6(H2O) 6·2.21h2O, Synthesized Via A Mild Hydrothermal Synthesis, Alevtina Maksimova, Patrick Belt, Nilah Whitfield, Mark D. Smith, Gopabandhu Panigrahi, Gregory Morrison, Hans Conrad Zur Loye

Faculty Publications

A new transition metal borate hydrate, Co₆B₂₄O₃₉(OH)₆(H₂O)₆·2.21H₂O, was synthesized via a mild hydrothermal method using boric acid as the melt. The compound crystallizes in the trigonal space group P 3‾ with lattice parameters a = b = 13.17840(10) Å, c = 12.3287(2) Å, and a unit cell volume of 1854.27(4) ų (Z = 2). This borate hydrate crystallizes in a new structure type comprised of layers containing [BO3] trigonal planar units and [BO4] tetrahedra that are linked by CoO6 and Co(OH)2(H2O)4 octahedra via corner-sharing. The …

Ai-Based Detection Of Optical Microscopic Images Of Pseudomonas Aeruginosa In Planktonic And Biofilm States, Bidisha Roy Sengupta, Esther Mallet, Angel Torres, Ravyn Solis

Faculty Publications

No abstract provided.

Kinetic Control And Trapping In The Supramolecular Polymerization Of M-Terphenyl Bis-Urea Macrocycles, Sophya V. Garashchuk, Gamage Isuri P. Wijesekera, Isabella G. Rushton, Vaibhavi A. Samant, Fahidat A. Gbadamosi, Dr. Md Faizul Islam, Sophya V. Garashchuk, Prof. Dr. Linda S. Shimizu

Faculty Publications

Herein, we examine pathway complexity in the supramolecular polymerization of a novel m-terphenyl bis-urea macrocycle. Designed to induce kinetically metastable states, the macrocycle‘s concentration-dependent aggregation was studied via 1H NMR and IR spectroscopy in THF and CHCl₃. Temperature-dependent UV-Vis spectroscopy in water/THF revealed a cooperative nucleation-growth mechanism, indicated by a shift in λmax to longer wavelengths upon cooling. Morphological studies using DLS, AFM, and SEM demonstrated fibrous aggregate formation. Thermal hysteresis observed in assembly-disassembly cycles indicated kinetically trapped species, with cooling governed by kinetic control and heating by thermodynamic processes. Deviations in ΔH values during cooling, compared to van′t …

Synthesis Of A Series Of Rare-Earth-Based Multi-Anion Chalcogenide Iodides Re3Si2SeXS8-XI (Re = La, Ce, Pr, And Nd) Using The Flux-Assisted Boron-Chalcogen Mixture Method, Gopabandhu Panigrahi, Habiba Binte Kashem, Gregory Morrison, Hans Conrad Zur Loye

Faculty Publications

Single crystals and polycrystalline powders of rare earth mixed chalcogenide iodides La3Si2Se1.21S6.79I, Ce3Si2Se1.39S6.61I, Pr3Si2Se1.22S6.78I, and Nd3Si2Se1.18S6.82I were prepared using the reactive flux-assisted boron-chalcogen mixture (BCM) method at 850 °C. All compounds crystallized in the monoclinic crystal system, space group C2/c (space group number 15). The series adopts the La3Si2O8Cl structure type, containing isolated SiQ4 tetrahedra connected by REQ8 (RE = La, Ce, Pr and Nd) polyhedra; this arrangement creates tunnels that are filled by I atoms. The partial substitution of S by Se was carried out to modulate the optical properties. Phase pure samples and uniform solid solutions were obtained …

Nanostructure Retention To 1100 °C In Soft-Templated Niobium Tungstates Using Dual-Carbon Strategy, Sean C. Wechsler, Alexander Gregg, Coby S. Collins, Santosh Kiran Balijepalli, Morgan Stefik

Faculty Publications

Mesoporous metal oxides (MMOs) have diverse applications including energy storage, catalysis, and separation membranes. Block polymer structure directing agents enable the control of morphology and pore size, however preservation of the nanostructure is often limited to a narrow range of heat treatment temperatures which constrains the tailoring of defect chemistries. High temperature treatments typically lead to collapse of the porous structure as surface area is reduced during crystal growth. Here, using a mesoporous niobium tungstate it is shown that neither in situ carbon generation nor ex situ carbon infiltration alone enable preservation of the ordered mesostructure at temperatures high enough …

Associations Between Social Determinants Of Health And Mental Health Disorders Among U.S. Population: A Cross-Sectional Study, S. Tanarsuwongkul

Faculty Publications

Aims

The impact of social determinants of health (SDOH) on mental health is increasingly realized. A comprehensive study examining the associations of SDOH with mental health disorders has yet to be accomplished. This study evaluated the associations between five domains of SDOH and the SDOH summary score and mental health disorders in the United States.

Methods

We analyzed data from a diverse group of participants enrolled in the All of Us research programme, a research programme to gather data from one million people living in the United States, in a cross-sectional design. The primary exposure was SDOH based on Healthy …

Analysis Of Phytochemicals In Watercress Leaves Using Chromatographic, Spectroscopic And In-Vitro Approaches, Bidisha Roy Sengupta

Faculty Publications

No abstract provided.

Biofilm-Based Biomonitoring Of Treated Wastewater Using Bacillus Thuringiensis: Toward Sustainable Water Reuse, Bidisha Roy Sengupta, Kefa K. Onchoke, Olabisi O. Ogunlewe, Robert Friedfeld

Faculty Publications

No abstract provided.

Durable Oxyfluoride Waste Forms For Salt Wastes From Molten Salt Reactors, Alevtina A. Maksimova, Jake W. Amoroso, Matthew Page, Gregory Morrison, Hans Conrad Zur Loye

Faculty Publications

Molten salt reactors (MSRs) are promising technology to replace traditional light and heavy water reactors in the near future. Waste management for MSRs, however, remains a pressing concern that needs to be resolved prior to realizing deployment of MSRs. Specifically, the generated salt waste needs to be safely sequestered, a task made difficult by the high solubility of the salt waste that can cause the release of radionuclides into the environment. This work demonstrates a new approach to immobilize multiple fluoride salts into a single waste form by converting highly-soluble fluorides to durable and stable oxyfluorides. Notably, we report a …

Molten Flux Synthesis Of Plutonium (Iv) Silicates K2Pusi2O7 And Rb2Pusi6O15, Travis K. Deason, Gregory Morrison, Amir Mofrad, Jake Amoroso, David Diprete, Theodore M. Besmann, Shanna L. Estes, Hans Conrad Zur Loye

Faculty Publications

Few plutonium containing silicates have been reported in the literature and only one other tetravalent plutonium silicate structure has been reported using the flux growth method. With the goal of understanding actinide incorporation into silicates, we describe herein two new plutonium (IV) silicates, Rb2PuSi6O15 and K2PuSi2O7, synthesized using a mixed alkali chloride/alkali fluoride flux growth. Both structures crystallize in the C2/c space group with lattice parameters a=24.2980(10) Å, b=7.1466(3) Å, c=17.2025(8) Å and 96.6560(10)° for Rb2PuSi6O15, and a=9.9478(2) Å, b=5.59820 (10) Å, c=13.1848(2) Å, and 105.7400(10)° for K2PuSi2O7. Comparisons to the synthesis of other reported alkali actinide silicates (Ce, U, …

Capacity-Weighted Figures-Of-Merit For Battery Transport Metrics, Cj Sturgill, Christopher Sutton, Julian Schwenzel, Morgan Stefik

Faculty Publications

New battery materials with improved transport are needed. Typical measurements yield widely varying voltage-dependent diffusivities and reporting practices are diverse. Some materials (e.g. first-order phase change) have most redox occur at a specific voltage and may be sufficiently represented by singular transport metrics. Many rapid intercalation materials, however, exhibit second-order phase transitions with redox over a broad voltage range. How should such cases be compared? The use of capacity-weighted average values is suggested where voltage-dependent metrics are consolidated into representative descriptors as figures-of-merit. Examples are elaborated where differential capacity (dQ/dV) is used to derive a …

Organic Alkalinity Distributions, Characteristics, And Application To Carbonate System Calculations In Estuarine And Coastal Systems, Christopher W. Hunt, Joseph Salisbury, Xuewu Liu, Robert H. Byrne

Faculty Publications

The capacity of aquatic systems to buffer acidification depends on the sum contributions of various chemical species to total alkalinity (TA). Major TA contributors are inorganic, with carbonate and bicarbonate considered the most important. However, growing evidence shows that many rivers, estuaries, and coastal waters contain dissolved organic molecules with charge sites that create organic alkalinity (OrgAlk). This study describes the first comparison of (1) OrgAlk distributions and (2) acid–base properties in contrasting estuary-plume systems: the Pleasant (Maine, USA) and the St. John (New Brunswick, CA). The substantial concentrations of OrgAlk in each estuary were sometimes not conservative with salinity …

Na2B12Si6Se18: A Novel B12-Cluster-Containing Quaternary Selenoborate Framework Material, Gopabandhu Panigrahi, Hunter B. Tisdale, Gregory Morrison, Hans Conrad Zur Loye

Faculty Publications

We report the successful synthesis of the new quaternary, three-dimensional Na₂B₁₂Si₆Se₁₈ material using a solid-state synthesis route. This compound is characterized by a unique framework structure that features the rare icosahedral [B₁₂]¹⁰⁺ cation which is connected via Si2Se6 polyhedral units into a 3D framework structure with Na+ ions located inside the channels. The Na₂B₁₂Si₆Se₁₈ compound crystallizes in the cubic crystal system in the space group Im, with lattice parameter a = 11.91110(10) Å and unit cell volume of 1689.88(4) ų. …

Investigation Of Magnesium-Potassium Phosphates As Potential Nuclear Waste Form For The Immobilization Of Minor Actinides, Hans Conrad Zur Loye, Petr Vecernik, Monika Kiselova, Vlastislav Kašpar, Hana Korenkova, Vlastimil Miller, Petr Bezdicka, Jan Šubrt, Natalija Murafa, Volodymyr Shkuropatenko, Sergey Sayenko

Faculty Publications

Several recent studies have evaluated technologies of spent nuclear fuel processing specifically for solidifying transuranic (TRU) waste as a by-product of fission. Of the TRU group, plutonium and the minor actinides will be responsible for the bulk of the radiotoxicity and heat generation of spent nuclear fuel in the long term (300 to 20,000 years). In this study, we investigated magnesium potassium phosphate (MKP)-based compounds as host waste forms for the encapsulation of inactive trivalent Nd and Sm as analogues of the minor trivalent actinides, Am and Cm. Waste forms were fabricated under ambient atmospheric conditions by adding 5 wt.% …

Examination Of Photoinduced Radicals In Two Crystal Forms Of Triphenylamine Bis-Urea Macrocycles, Md Faizul Islam, Gamage Isuri P. Wijesekera, Anmon J. Sindt, Mark D. Smith, Linda S. Shimizu

Faculty Publications

This study probes two solvates of triphenylamine (TPA) bis-urea macrocycle 1 and their activated structures to evaluate their maximum photoinduced radicals (PIRs), the subsequent decay of the radicals, and their regeneration. The hierarchical assembly of TPAs shows promise in stabilizing less substituted derivatives, potentially expanding the utility of TPAs that lack stabilizing para-substituents. Single crystal structure analysis reveals that host 1 adopts a planar conformation with the two ureas pointing in opposite directions when dimethoxyethane (DME) is encapsulated within the channel. Whereas previously, 1 adopted a bowl-shaped conformation with the two ureas pointing in the same direction (syn …

Examination Of Photoinduced Radicals In Two Crystal Forms Of Triphenylamine Bis-Urea Macrocycles, Md Faizul Islam, Gamage Isuri P. Wijesekera, Ammon J. Sindt, Mark D. Smith, Linda S. Shimizu

Faculty Publications

This study probes two solvates of triphenylamine (TPA) bis-urea macrocycle 1 and their activated structures to evaluate their maximum photoinduced radicals (PIRs), the subsequent decay of the radicals, and their regeneration. The hierarchical assembly of TPAs shows promise in stabilizing less substituted derivatives, potentially expanding the utility of TPAs that lack stabilizing para-substituents. Single crystal structure analysis reveals that host 1 adopts a planar conformation with the two ureas pointing in opposite directions when dimethoxyethane (DME) is encapsulated within the channel. Whereas previously, 1 adopted a bowl-shaped conformation with the two ureas pointing in the same direction (syn …

Accurate Crystal Structure Prediction Of New 2d Hybrid Organic–Inorganic Perovskites, Nima Karimitari, William J. Baldwin, Evan W. Muller, Zachary J.L. Bare, W. Joshua Kennedy, Gábor Csányi, Christopher Sutton

Faculty Publications

Low-dimensional hybrid organic–inorganic perovskites (HOIPs) are promising electronically active materials for light absorption and emission. The design space of HOIPs is extremely large, as a variety of organic cations can be combined with different inorganic frameworks. This not only allows for tunable electronic and mechanical properties but also necessitates the development of new tools for in silico high throughput analysis of candidate materials. In this work, we present an accurate, efficient, and widely applicable machine learning interatomic potential (MLIP) trained on 86 diverse experimentally reported HOIP materials. This MLIP was tested on 73 experimentally reported perovskite compositions and achieves a …

Improvement Of Single-Crystal Structures Of Very Heavy Element Compounds By Refining Anomalous Dispersion Parameters, Florian Meurer, Gregory Morrison, Birgit Hischa, Hans Conrad Zur Loye, Christoph Hennig, Michael Bodensteiner

Faculty Publications

Refining the anomalous dispersion parameters of the four uranium compounds NaUF5, NaU2F9, Cs2(UO2)TiO4, and Cs2(UO2)Ti2O6 gave insights into the crystallographic model improvement of very heavy atoms. We found that the values for the dispersive and absorptive parts, f′ and f″, closely followed the X-ray absorption spectra on their L3, L2, and L1 edges. The obtained values are sensitive to the chemical environment at each crystallographically independent position. An incorrect treatment of the anomalous dispersion correction can lead to a wrong crystallographic model. The above-mentioned, already published structures were improved by this process. General guidelines were given for the crystal structure …

Syntheses, Characterizations And Reactions Of Acene-2,3-Dicarbaldehydes, Glen Miller, Qian Liu

Faculty Publications

Here, we report improved syntheses, detailed characterizations and reactions of a series of acene-2,3- dicarbaldehydes including tetracene-2,3-dicarbaldehyde. DFT calculations corroborate and complement the experimental results. Tetracene-2,3-dicarbaldehyde and the benchmark organic semiconductor pentacene have isoelectronic p-systems and similar HOMO–LUMO gaps. Tetracene-2,3-dicarbaldehyde is soluble in a host of organic solvents (e.g., DMF, toluene, THF, chloroform, dichloromethane) and shows excellent photooxidative resistance in solution phases exposed to light and air. Further, it is readily sublimed from the solid-state without decomposition, and can be functionalized using different chemistries. We have demonstrated the utility of acene-2,3-dicarbaldehydes as reactants in the syntheses of novel diaryl-2,3-acenedimethanols and …

Impact Of Aureobasidium Species Strain Improvement On The Production Of The Polysaccharide Pullulan, Thomas P. West

Faculty Publications

This review explores the production of the fungal polysaccharide pullulan by mutants and natural isolates of Aureobasidium species using strain improvement. Pullulan is a neutral polysaccharide gum whose structure is a maltotriose-containing glucan. This polysaccharide gum has applications in the fields of food, pharmaceuticals, biomedical and wastewater treatment. The strain improvement of Aureobasidium species has focused on the pullulan production process, including the isolation of strains exhibiting reduced pigmentation, polysaccharide overproduction, the production of pullulan with variable molecular weight, and increased osmotolerant strains promoting pullulan production at high carbon source concentrations and pullulan production on hemicellulosic substrates. The majority of …

Incorporating Oxygen Isotopes Of Oxidized Reactive Nitrogen In The Regional Atmospheric Chemistry Mechanism, Version 2 (Icoin-Racm2), Wendell W. Walter, Masayuki Takeuchi, Nga L. Ng, Meredith G. Hastings

Faculty Publications

The oxygen isotope anomaly (Δ¹⁷O = δ¹⁷O − 0.52 × δ¹⁸O > 0) has proven to be a robust tool for probing photochemical cycling and atmospheric formation pathways of oxidized reactive nitrogen (NO_y). Several studies have developed modeling techniques to implicitly model Δ¹⁷O of NO_y molecules based on numerous assumptions that may not always be valid. Thus, these models may be oversimplified and limit our ability to compare model Δ¹⁷O values of NO_y with observations. In this work, we introduce a novel method for explicitly tracking Δ …