Chemistry Commons^™

Iron Speciation In Pm2.5 From Urban, Agriculture, And Mixed Environments In Colorado, Usa, Joseph R. Salazar, David J. Pfotenhauer, Frank Leresche, Fernando L. Rosario-Ortiz, Michael P. Hannigan, Sirine C. Fakra, Brian Majestic

Chemistry and Biochemistry: Faculty Scholarship

Atmospheric iron solubility varies depending on whether the particles are collected in rural or urban areas, with urban areas showing increased iron solubility. In this study, we investigate if the iron species present in different environments affects its ultimate solubility. Field data are presented from the Platte River Air Pollution and Photochemistry Experiment (PRAPPE), aimed at understanding the interactions between organic carbon and trace elements in atmospheric particulate matter (PM). 24-hr PM2.5 samples were collected during the summer and winter (2016–2017), at three different sites on the Eastern Colorado plains: an urban, agricultural, and a mixed site. Downtown Denver had …

Two Forms Of Tyrosyl-Trna Synthetase From Pseudomonas Aeruginosa: Characterization And Discovery Of Inhibitory Compounds, Casey Anne Hughes, Varesh Gorabi, Yaritza Escamilla, Frank B. Dean, James M. Bullard

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Pseudomonas aeruginosa is a multidrug-resistant (MDR) pathogen and a causative agent of both nosocomial and community-acquired infections. The genes (tyrS and tyrZ) encoding both forms of P. aeruginosa tyrosyl-tRNA synthetase (TyrRS-S and TyrRS-Z) were cloned and the resulting proteins purified. TyrRS-S and TyrRS-Z were kinetically evaluated and the Km values for interaction with Tyr, ATP, and tRNATyr were 172, 204, and 1.5 μM and 29, 496, and 1.9 μM, respectively. The kcatobs values for interaction with Tyr, ATP, and tRNATyr were calculated to be 3.8, 1.0, and 0.2 s–1 and 3.1, 3.8, and 1.9 s–1, …

A Novel Analytical Method For Studying Pharmacological Treatments For Affective Disorders In Neuroscience, Shane N. Berger

Theses and Dissertations

Histamine and serotonin are important neurochemicals that maintain crucial brain functions. Both are thought to be altered in affective and neurodegenerative disorders such as depression and Parkinson’s disease. Histamine and serotonin are thought to modulate one another but the exact relationship remains unknown and this gap in knowledge makes diagnosing and treating disorders involving the transmitters difficult. The Hashemi lab studies serotonin neurochemistry to understand serotonin’s role in psychiatric disorders. However, histamine has remained an understudied neurotransmitter due to a lack of analytical tools. In 2015 and 2016, the Hashemi lab pioneered a novel detection method utilizing fast-scan cyclic voltammetry …

Unravelling A Long-Lived Ligand-To-Metal Cluster Charge Transfer State In Ce–Tcpp Metal Organic Frameworks, Sizhou Yang, Wenhui Hu, James Nayakuchena, Christian Fiankor, Cunming Liu, Eli Diego Kinigstein, Jian Zhang, Xiaoyi Zhang, Jier Huang

Chemistry Faculty Research and Publications

Metal organic frameworks (MOFs) have emerged as promising photocatalytic materials for solar energy conversion. However, a fundamental understanding of light harvesting and charge separation (CS) dynamics in MOFs remains underexplored, yet they are key factors that determine the efficiency of photocatalysis. Herein, we report the design and CS dynamics of the Ce–TCPP MOF using ultrafast spectroscopic methods.

Pharmacologic Ire1/Xbp1s Activation Confers Targeted Er Proteostasis Reprogramming, J. M. D. Grandjean, A. Madhavan, L. Cech, B. O. Seguinot, R. J. Paxman, E. Smith, L. Scampavia, E. T. Powers, Christina B. Cooley, L. Plate, T. P. Spicer, J. W. Kelly, R. L. Wiseman

Chemistry Faculty Research

Activation of the IRE1/XBP1s signaling arm of the unfolded protein response (UPR) is a promising strategy to correct defects in endoplasmic reticulum (ER) proteostasis implicated in diverse diseases. However, no pharmacologic activators of this pathway identified to date are suitable for ER proteostasis remodeling through selective activation of IRE1/XBP1s signaling. Here, we use high-throughput screening to identify non-toxic compounds that induce ER proteostasis remodeling through IRE1/XBP1s activation. We employ transcriptional profiling to stringently confirm that our prioritized compounds selectively activate IRE1/XBP1s signaling without activating other cellular stress-responsive signaling pathways. Furthermore, we demonstrate that our compounds improve ER proteostasis of destabilized …

Distance Dependent Energy Transfer Dynamics From A Molecular Donor To A Zeolitic Imidazolate Framework Acceptor, Wenhui Hu, Fan Yang, Nick Pietraszak, Jing Gu, Jier Huang

Chemistry Faculty Research and Publications

Zeolitic Imidazolate frameworks (ZIFs) have been demonstrated as promising light harvesting and photocatalytic materials for solar energy conversion. To facilitate their application in photocatalysis, it is essential to develop a fundamental understanding of their light absorption properties and energy transfer dynamics. In this work, we report distance-dependent energy transfer dynamics from a molecular photosensitizer (RuN3) to ZIF-67, where the distance between RuN3 and ZIF-67 is finely tuned by depositing an ultrathin Al₂O₃ layer on the ZIF-67 surface using an atomic layer deposition (ALD) method. We show that energy transfer time decreases with increasing distance between RuN3 and …

Versatility Of The Cyano Group In Intermolecular Interactions, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Several cyano groups are added to an alkane, alkene, and alkyne group so as to construct a Lewis acid molecule with a positive region of electrostatic potential in the area adjoining these substituents. Although each individual cyano group produces only a weak π-hole, when two or more such groups are properly situated, they can pool their π-holes into one much more intense positive region that is located midway between them. A NH₃ base is attracted to this site, where it forms a strong noncovalent bond to the Lewis acid, amounting to as much as 13.6 kcal/mol. The precise nature …

Synthesis Of Novel Thiazole And Pyrazole Derivatives As Antimicrobial And Anticancer Agents, Md Mahbub Kabir Khan

Student Theses and Dissertations

This thesis contains two chapters. In chapter one, I report the synthesis of new pyrazole derivatives from dicarboxylic acid containing phenyl-derived, monotrifluoromethyl phenyl-derived, and acetovanillone-derived pyrazole aldehydes using Hantzsch ester. All of our pyrazole compounds have been synthesized efficiently using Hantzsch ester without any catalyst. Most of our pyrazole and thiazole compounds have been effectively recrystallized with acetonitrile and methanol respectively. We have synthesized 99 different pyrazole, 17 fused-thiazole ethisterone, and D-(-) norgestrel derivatives in good yield. In the present research, it has been shown possible to synthesize novel pyrazoles and thiazoles by using readily available starting materials and benign …

Aqueous Kinetics Of Α-Hydroxyhippuric Acid Derivatives Bearing Electron-Withdrawing Groups As A Function Of Ph And Buffer Catalysts, Mohamad Imad Rafie

Theses and Dissertations

It has been shown that carbinolamides are intermediates in the enzyme-catalyzed synthesis of -amidated peptides. Although carbinolamides are important intermediates in the production of these hormones and have roles in other biological venues, little attention has been given to their mechanisms of reaction in water, and, thus, it is difficult to speculate how their reaction would be enzymatically catalyzed. The purpose of the work presented here was to synthesize structural analogs of the biological intermediates and study their mechanism of breakdown in water. -Hydroxyhippuric acid, a substrate for the enzymatic system, provides an easily modified template for the study of …

Single‐Molecule 3d Orientation Imaging Reveals Nanoscale Compositional Heterogeneity In Lipid Membranes, Jin Lu, Hesam Mazidi, Tianben Ding, Oumeng Zhang, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

In soft matter, thermal energy causes molecules to continuously translate and rotate, even in crowded environments, thereby impacting the spatial organization and function of most molecular assemblies, such as lipid membranes. Directly measuring the orientation and spatial organization of large collections (>3000 molecules μm⁻²) of single molecules with nanoscale resolution remains elusive. In this paper, we utilize SMOLM, single‐molecule orientation localization microscopy, to directly measure the orientation spectra (3D orientation plus “wobble”) of lipophilic probes transiently bound to lipid membranes, revealing that Nile red's (NR) orientation spectra are extremely sensitive to membrane chemical composition. SMOLM images resolve …

Hexacyanoferrate-Based Nanocomposites For The Electrochemical Sensing Of Hydrogen Peroxide And Nicotine, Lee Pui Kee

Student Works (2020-2029)

Metal hexacyanoferrate (MeHCF) is a unique material that not only acquired immense research interest in electrochemical sensing field but also possesses potential as energy storage material. As such, the present thesis sought to investigate the facile method to synthesis MeHCF-based nanocomposites and explore its possible applications. First, comparative research on the synthesis of Prussian blue-polypyrrole (PB-PPy) nanocomposite by novel self-assembly (SA) method and conventional electrodeposition technique was performed. PB-PPy nanocomposites were prepared by the novel self-assembly method and via the electrodeposition approach. The nanocomposites were compared in term of surface morphology and its electrochemical and electrocatalytic characteristics. The results indicated …

Kras Ubiquitination At Lysine 104 Retains Exchange Factor Regulation By Dynamically Modulating The Conformation Of The Interface, Guowei Yin, Jerry Zhang, Vinay Nair, Vinh Truong, Angelo Chaia, Johnny Petela, Joseph S. Harrison, Alemayehu A. Gorfe, Sharon L. Campbell

College of the Pacific Faculty Articles

RAS proteins function as highly regulated molecular switches that control cellular growth. In addition to regulatory proteins, RAS undergoes a number of posttranslational modifications (PTMs) that regulate its activity. Lysine 104, a hot spot for multiple PTMs, is a highly conserved residue that forms key interactions that stabilize the RAS helix-2(H2)/helix-3(H3) interface. Mutation at 104 attenuates interaction with guanine nucleotide exchange factors (GEFs), whereas ubiquitination at lysine 104 retains GEF regulation. To elucidate how ubiquitination modulates RAS function, we generated monoubiquitinated KRAS at 104 using chemical biology approaches and conducted biochemical, NMR, and computational analyses. We find that ubiquitination promotes …

Ruggedized Color Measurement For Beer, Wort, And Malt, Roger Barth, Randall H. Reiger, Yuki Kim

Chemistry Faculty Publications

The standard instrument for measuring malt, wort, and beer color is the spectrophotometer. Spectrophotometers are not rugged; they have critically aligned collimators, monochromators, lenses, slits, and mirrors that make them difficult to use and maintain in a production environment. Our research shows that wort and beer color can be measured accurately with rugged equipment based on light emitting diodes (LEDs) with results in agreement with those of a spectrophotometer. Two or more colored diodes were used. LED-based apparatus does not require critical alignment, is not highly sensitive to environmental conditions such as temperature, moisture, dust, and vibration, and can be …

Thionated Organic Compounds As Emerging Heavy-Atom-Free Photodynamic Therapy Agents, Luis A. Ortiz-Rodríguez, Carlos E. Crespo-Hernández

Faculty Scholarship

This minireview focuses on recent progress in developing heavy-atom-free photosensitizers based on the thionation of nucleic acid derivatives and other biocompatible organic compounds for prospective applications in photodynamic therapy. Particular attention is given to the use of thionated nucleobase derivatives as "one-two punch"photodynamic agents. These versatile photosensitizers can act as "Trojan horses"upon metabolization into DNA and exposure to activating light. Their incorporation into cellular DNA increases their selectivity and photodynamic efficacy against highly proliferating skin cancer tumor cells, while simultaneously enabling the use of low irradiation doses both in the presence and in the absence of molecular oxygen. Also reviewed …

Self-Supported Nanocolumnar Pt And Pt-Ni Alloy Electrocatalysts For Polymer Electrolyte Membrane Fuel Cells, Busra Ergul

Theses and Dissertations

Polymer electrolyte membrane fuel cell (PEMFC) technology has gained significant attention as an alternative power source, especially for automotive applications due to PEMFCs’ high energy conversion efficiency, low operating temperature and being environment-friendly compared to the other types of fuel cells. However, sluggish kinetics of oxygen reduction reaction (ORR) on the cathode requires a high loading of platinum (Pt), which increases the cost of the fuel cell. In addition, dissolution and agglomeration of Pt nanoparticles and oxidation of the carbon support are among the major factors that cause electrode degradation and performance loss. Therefore, it is essential to develop a …

Molten Salt Synthesized Submicron Perovskite La1–Xsrxcoo3 Particles As Efficient Electrocatalyst For Water Electrolysis, Swati Mohan, Yuanbing Mao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Perovskite oxides are an important and effective class of mixed oxides which play a significant role in the fields of energy storage and conversion systems. Here we present a series of cobaltite perovskite LaCoO3 particles which have been doped with 0, 5, 10, 20, and 30% of Sr2C and have been synthesized by a combined sol– gel and molten-salt synthesis procedure, which provides a regular morphology of the particles. These Sr2C-doped LaCoO3 particles have been characterized by powder X-ray diffraction, Raman spectroscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Moreover, these Sr2C doped LaCoO3 particles have been demonstrated …

Nanoscale Battery Cathode Materials Induce Dna Damage In Bacteria, Tian A. Qiu, Valeria Guidolin, Khoi Nguyen L. Hoang, Thomas Pho, Andrea Carra, Peter W. Villalta, Jiayi He, Xiaoxiao Yao, Robert J. Hamers, Silvia Balbo, Z Vivian Feng, Christy L. Haynes

Faculty Authored Articles

The increasing use of nanoscale lithium nickel manganese cobalt oxide (LixNiyMnzCo1−y−zO2, NMC) as a cathode material in lithium-ion batteries poses risk to the environment. Learning toxicity mechanisms on molecular levels is critical to promote proactive risk assessment of these complex nanomaterials and inform their sustainable development. We focused on DNA damage as a toxicity mechanism and profiled in depth chemical and biological changes linked to DNA damage in two environmentally relevant bacteria upon nano-NMC exposure. DNA damage occurred in both bacteria, characterized by double-strand breakage and increased levels of many putative chemical modifications on bacterial DNA bases related to direct …

Protective Spinel Coating For Li1.17ni0.17mn0.50co0.17o2 Cathode For Li-Ion Batteries Through Single-Source Precursor Approach, Evgney V. Dikarev, Jesse C. Carozza, Andrey Shevtsov, Haixiang Han, Anatolii Morozov, Aleksandra A. Savina, Iaroslava Shakhova, Nellie R. Khasanova, Evgeny V. Antipov, Artem M. Abakumov

Chemistry Department Faculty Scholarship

The Li_1.17Ni_0.17Mn_0.50Co_0.17O₂ Li-rich NMC positive electrode (cathode) for lithium-ion batteries has been coated with nanocrystals of the LiMn_1.5Co_0.5O₄ high-voltage spinel cathode material. The coating was applied through a single-source precursor approach by a deposition of the molecular precursor LiMn_1.5Co_0.5(thd)₅ (thd = 2,2,6,6-tetramethyl-3,5-heptanedionate) dissolved in diethyl ether, followed by thermal decomposition at 400 °C inair resulting in a chemically homogeneous cubic spinel. The structure and chemical composition of the coatings, deposited on the model SiO₂ spheres and Li-rich NMC crystallites, were …

Development Of Ultrasonic-Based Ambient Desorption Ionization Mass Spectrometry, Linxia Song

USF Tampa Graduate Theses and Dissertations

Ambient desorption/ionization techniques (ADI) have drawn significant attention in mass spectrometric instrumentation development. The analyte classes that are successfully studied by any ADI mass spectrometry (MS) method strongly depends on how gas-phase ions are generated. Spray-based techniques may ionize molecules across a wide range of mass-to-charge ratios, but are commonly used for polar analyte, however, suffers from severe matrix effect. Contrastingly, methods employing electric (or laser) plasmas are capable of ionization of polar and nonpolar analytes suffering from less matrix effect, but primarily targeting those with low molecular masses. Thus far, developments of universal ionization methods, which do not depend …

Trapping Conformational States Of A Flavin-Dependent N-Monooxygenase In Crystallo Reveals Protein And Flavin Dynamics, Ashley C. Campbell, Kyle M. Stiers, Julia S. Martin Del Campo, Ritcha Mehra-Chaudhary, Pablo Sobrado, John J. Tanner

Chemistry Faculty Research & Creative Works

The siderophore biosynthetic enzyme A (SidA) ornithine hydroxylase from Aspergillus fumigatus is a fungal disease drug target involved in the production of hydroxamate-containing siderophores, which are used by the pathogen to sequester iron. SidA is an N-monooxygenase that catalyzes the NADPH-dependent hydroxylation of L-ornithine through a multistep oxidative mechanism, utilizing a C4a-hydroperoxyflavin intermediate. Here we present four new crystal structures of SidA in various redox and ligation states, including the first structure of oxidized SidA without NADP(H) or L-ornithine bound (resting state). The resting state structure reveals a new out active site conformation characterized by large rotations of the FAD …

Surface Modification Of Biomaterials To Reduce Polyethylene Wear In Metal-Polymer Contact / Tan Mean Yee, Tan Mean Yee

Student Works (2020-2029)

This research focus on studying different surface modification (Texturing and DLC coating) on the metal part of TKR (Total knee replacement) in improving UHMWPE (Ultra-high molecular weight polyethylene) wear. TKR was widely being used to relieve knee pain due to osteoarthritis and further restore knee function of patients. Generally, TKR consists of metal femoral component, metal tibial component, and UHMWPE tibial insert. TKR will fail due to various factors over time, however, this study will be focusing on failure cause by loosening. Loosening failure of TKR was mainly caused by wear debris generated during articulation motion, where UHMWPE wear was …

Effect Of Oxidation Level On The Interfacial Water At The Graphene Oxide-Water Interface: From Spectroscopic Signatures To Hydrogen-Bonding Environment, Rolf David, Aashish Tuladhar, Le Zhang, Christopher Arges, Revati Kumar

Faculty Publications

The interfacial region of the graphene oxide (GO)-water system is nonhomogenous due to the presence of two distinct domains: an oxygen-rich surface and a graphene-like region. The experimental vibrational sum-frequency generation (vSFG) spectra are distinctly different for the fully oxidized GO-water interface as compared to the reduced GO-water case. Computational investigations using ab initio molecular dynamics were performed to determine the molecular origins of the different spectroscopic features. The simulations were first validated by comparing the simulated vSFG spectra to those from the experiment, and the contributions to the spectra from different hydrogen bonding environments and interfacial water orientations were …

A Review Of The Preclinical And Clinical Efficacy Of Remdesivir, Hydroxychloroquine, And Lopinavir-Ritonavir Treatments Against Covid-19, Dawid Maciorowski, Samir Z. El Idrissi, Yash Gupta, Brian J. Medernach, Michael B. Burns, Daniel P. Becker Ph.D., Ravi Durvasula, Prakasha Kempaiah

Chemistry: Faculty Publications and Other Works

In December of 2019, an outbreak of a novel coronavirus flared in Wuhan, the capital city of the Hubei Province, China. The pathogen has been identified as a novel enveloped RNA beta-coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The virus SARS-CoV-2 is associated with a disease characterized by severe atypical pneumonia known as coronavirus 2019 (COVID-19). Typical symptoms of this disease include cough, fever, malaise, shortness of breath, gastrointestinal symptoms, anosmia, and, in severe cases, pneumonia.¹ The high-risk group of COVID-19 patients includes people over the age of 60 years as well as people with existing cardiovascular …

Algal Biomarkers As A Proxy For Pco2: Constraints From Late Quaternary Sapropels In The Eastern Mediterranean, Caitlyn R. Witkowski, Marcel T.J. Van Der Meer, Brian Blais, Jaap S. Sinninghe Damsté, Stefan Schouten

Science and Technology Department Faculty Journal Articles

Records of carbon dioxide concentrations (partial pressure expressed as pCO2) over Earth’s history provide trends that are critical to understand our changing world. To better constrain pCO2 estimations, here we test organic pCO2 proxies against the direct measurements of pCO2 recorded in ice cores. Based on the concept of stable carbon isotopic fractionation due to photosynthetic CO2 fixation (Ɛp), we use the stable carbon isotopic composition (δ13C) of the recently proposed biomarker phytol (from all photoautotrophs), as well as the conventionally used alkenone biomarkers (from specific species) for comparison, to reconstruct pCO2 over several Quaternary …

Synthesis And Characterization Of Water-Soluble Polyaniline For Hydrazine Detection / Hazira Hussin, Hazira Hussin

Student Works (2020-2029)

In this study, polyaniline (PAni) was synthesized through the chemical oxidation method using aniline (Ani) as a monomer, hydrochloric acid (HCl) as a dopant, and ammonium persulphate (APS) as an initiator. PAni was rendered water soluble through treating with cellulose derivatives. Cellulose derivatives such as methylcellulose (MC), hydroxypropyl cellulose (HPC), and hydroxypropyl methylcellulose (HPMC) were used as a stabilizer to improve the solubility of PAni in an aqueous medium. The water-soluble PAni-cellulose derivative was applied as a chemical sensor for hydrazine detection. The chemical structures and electrical conducting behaviours of PAni-cellulose derivatives were investigated using Fourier transform infrared (FTIR) and …

Ru(Ii)-Diimine Complexes And Cytochrome P450 Working Hand-In-Hand, Celine Eidenschenk, Lionel Cheruzel

Faculty Publications, Chemistry

With a growing interest in utilizing visible light to drive biocatalytic processes, several light-harvesting units and approaches have been employed to harness the synthetic potential of heme monooxygenases and carry out selective oxyfunctionalization of a wide range of substrates. While the fields of cytochrome P450 and Ru(II) photochemistry have separately been prolific, it is not until the turn of the 21st century that they converged. Non-covalent and subsequently covalently attached Ru(II) complexes were used to promote rapid intramolecular electron transfer in bacterial P450 enzymes. Photocatalytic activity with Ru(II)-modified P450 enzymes was achieved under reductive conditions with a judicious choice of …

Nucleic Acid Delivery With Α-Tocopherol-Polyethyleneimine-Polyethylene Glycol Nanocarrier System., A K M Nawshad Hossian, Seetharama D Jois, Subash C. Jonnalagadda, George Mattheolabakis

College of Science & Mathematics Departmental Research

Purpose: Nucleic acid-based therapies are a promising therapeutic tool. The major obstacle in their clinical translation is their efficient delivery to the desired tissue. We developed a novel nanosized delivery system composed of conjugates of α-tocopherol, polyethyleneimine, and polyethylene glycol (TPP) to deliver nucleic acids.

Methods: We synthesized a panel of TPP molecules using different molecular weights of PEG and PEI and analyzed with various analytical approaches. The optimized version of TPP (TPP

Results: Through a panel of synthesized molecules, TPP

Conclusion: These results indicate that we successfully synthesized the TPP

Feasibility Of Modifying Existing Chemistry Demonstrations By Using Substitute Materials, Dane Mykel M. Quiambao, Armando M. Guidote Jr, Rhodora F. Nicdao

Chemistry Faculty Publications

This study aimed to reiterate the use of Chemistry demonstrations as effective teaching tools to students while addressing some of its drawbacks, which discourages teachers from doing them such as cost and safety. Four chosen existing Chemistry demonstrations (Blue Bottle Experiment, Copper Sulfate Experiment, Blown Away, Dancing Flames) were modified by using substitute reagents, which are more accessible, relatively safer, and at lower cost. These demonstrations were chosen based on how easily the substitute reagents will be obtained. Afterwards, with the permission of a private junior high school, they were presented to a group of Grade 9 students of their …

Mechanism And Chemoselectivity For Hocl-Mediated Oxidation Of Zinc-Bound Thiolates, Lindsay Zumwalt, Arden Perkins, O. Maduka Ogba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Quantum mechanical calculations reveal the preferred mechanism and origins of chemoselectivity for HOCl‐mediated oxidation of zinc‐bound thiolates implicated in bacterial redox sensing. Distortion/interaction models show that minimizing geometric distortion at the zinc complex during the rate‐limiting nucleophilic substitution step controls the mechanistic preference for OH over Cl transfer with HOCl and the chemoselectivity for HOCl over H2O2.

Mechanism And Chemoselectivity For Hocl-Mediated Oxidation Of Zinc-Bound Thiolates, Lindsay Zumwalt, Arden Perkins, O. Maduka Ogba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Quantum mechanical calculations reveal the preferred mechanism and origins of chemoselectivity for HOCl‐mediated oxidation of zinc‐bound thiolates implicated in bacterial redox sensing. Distortion/interaction models show that minimizing geometric distortion at the zinc complex during the rate‐limiting nucleophilic substitution step controls the mechanistic preference for OH over Cl transfer with HOCl and the chemoselectivity for HOCl over H₂O₂.