Chemistry Commons^™

Progress Toward Red And Near-Infrared (Nir) Emitting Saccharide Sensors, Martha Sibrian-Vazquez, Jorge O. Escobedo, Mark Lowry, Robert M. Strongin

Chemistry Faculty Publications and Presentations

Red-shifted and near-infrared (NIR)-active rhodamine analogs and their boronic acid derivatives were synthesized and studied. These latter compounds function as fluorogenic NIR active substrates for sugar sensing. The effects of benzannulation and boronic acid functionalization on fluorophore optical and sensing properties are described.

Titanium Dioxide Nanofibers And Microparticles Containing Nickel Nanoparticles, Faheem A. Sheikh, Javier Macossay-Torres, M. A. Kanjwal, Abdalla Abdal-Hay, Mudasir A. Tantry, Hern Kim

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

The present study reports on the introduction of various nanocatalysts containing nickel (Ni) nanoparticles (NPs) embedded within TiO2 nanofibers and TiO2 microparticles. Typically, a sol-gel consisting of titanium isopropoxide and Ni NPs was prepared to produce TiO2 nanofibers by the electrospinning process. Similarly, TiO2 microparticles containing Ni were prepared using a sol-gel syntheses process. The resultant structures were studied by SEM analyses, which confirmed well-obtained nanofibers and microparticles. Further, the XRD results demonstrated the crystalline feature of both TiO2 and Ni in the obtained composites. Internal morphology of prepared nanofibers and microparticles containing Ni NPs was characterized by TEM, which …

On Pi-Stacking, Ch/Pi, And Halogen Bonding In Halobenzene Clusters: Resonant 2-Photon Ionization Studies Of Chlorobenzene, Lloyd Muzangwa, Silver Nyambo, Brandon Uhler, Scott A. Reid

Chemistry Faculty Research and Publications

Noncovalent interactions such as hydrogen bonding, π-π stacking, CH/π interactions, and halogen bonding play crucial roles in a broad spectrum of chemical and biochemical processes, and can exist in cooperation or competition. Here we report studies of the homoclusters of chlorobenzene, a prototypical system where π-π stacking, CH/π interactions, and halogen bonding interactions may all be present. The electronic spectra of chlorobenzene monomer and clusters (Clbz)_n with n = 1-4 were obtained using resonant 2-photon ionization in the origin region of the S₀–S₁ (ππ*) state of the monomer. The cluster spectra show in all cases a …

On The Electronic Spectroscopy Of The Iso-Polyhalomethanes, Aimable Kalume, Lisa George, Scott A. Reid

Chemistry Faculty Research and Publications

The iso-polyhalomethanes are important reactive intermediates, displaying intense near-UV absorption bands that have been assigned to the S₀ → S₃ transition on the basis of Time-Dependent Density Functional Theory (TDDFT) calculations. In this work, theory and multi-dimensional Franck–Condon (FC) analysis are used to model the electronic spectra of selected iso-polyhalomethanes. The S₀ → S₃ transition approximately corresponds to a π–π^∗ transition on the halocarbocation subunit, which induces significant geometry changes. The calculated multimode FC profiles capture features of the experimental spectra of the matrix-isolated species, and are compared with the results of previous Resonance Raman …

Electronic Communication Across Diamagnetic Metal Bridges: A Homoleptic Gallium(Iii) Complex Of A Redox-Active Diarylamido-Based Ligand And Its Oxidized Derivatives, Brendan J Liddle, Sarath Wanniarachchi, Jeewantha S. Hewage, Sergey Lindeman, Sergey V. Lindeman, James R. Gardinier

Chemistry Faculty Research and Publications

Complexes with cations of the type [Ga(L)₂]ⁿ⁺ where L = bis(4-methyl-2-(1H-pyrazol-1-yl)phenyl)amido and n = 1, 2, 3 have been prepared and structurally characterized. The electronic properties of each were probed by electrochemical and spectroscopic means and were interpreted with the aid of density functional theory (DFT) calculations. The dication, best described as [Ga(L^–)(L⁰)]²⁺, is a Robin-Day class II mixed-valence species. As such, a broad, weak, solvent-dependent intervalence charge transfer (IVCT) band was found in the NIR spectrum in the range 6390–6925 cm^–1, depending on the solvent. Band shape …

Identification Of The Nad(P)H Binding Site Of Eukaryotic Udp-Galactopyranose Mutase, Richa Dhatwalia, Harkewal Singh, Luis M. Solano, Michelle Oppenheimer, Reeder M. Robinson, Jacob F. Ellerbrock, Pablo Sobrado, John J. Tanner

Chemistry Faculty Research & Creative Works

UDP-galactopyranose mutase (UGM) plays an essential role in galactofuranose biosynthesis in microorganisms by catalyzing the conversion of UDP-galactopyranose to UDP-galactofuranose. The enzyme has gained attention recently as a promising target for the design of new antifungal, antitrypanosomal, and antileishmanial agents. Here we report the first crystal structure of UGM complexed with its redox partner NAD(P)H. Kinetic protein crystallography was used to obtain structures of oxidized Aspergillus fumigatus UGM (AfUGM) complexed with NADPH and NADH, as well as reduced AfUGM after dissociation of NADP+. NAD(P)H binds with the nicotinamide near the FAD isoalloxazine and the ADP moiety extending toward the mobile …

The Electrochemical Properties Of 1-Pyrenebutyric Acid/Graphene Composites And Their Application In Glucose Biosensors, Min Wang, Jiong Wang, Fengbin Wang, Xinghua Xia

Journal of Electrochemistry

The electrochemical properties of 1-pyrenebutyric acid/graphene composites (PBA/G) obtained by one-step synthesis via π-π stacking was investigated. The electrochemical impedance titration curve shows the surface charge changes as function of solution pH by using ferricyanide/ferrocyanide redox couple as the probe. An apparent pK_a value is estimated as 6.2 according to the impedance titration curve. In addition, a glucose biosensor was constructed by immobilizing glucose oxidase (GOD) on the surface of PBA/G via covalent interaction. This biosensor shows a linear response to glucose within the concentration up to 5 mmol L^-1 with a detection limit of 0.085 mmol L …

The Oxidation Of Hydrogen Peroxide On Nanostructured Rhodium Microelectrodes, N. Bartlett Philip, F. Esterle Thomas

Journal of Electrochemistry

Mesoporous Rh films were deposited onto platinum microelectrodes from the H₁ lyotropic liquid crystalline phase of C₁₂EO₈ (octaethyleneglycol monododecyl ether). The electrodes show well defined voltammetry for the oxidation and the reduction of hydrogen peroxide at low concentrations (<10 mmol•L-1) with excellent stability for operation at neutral pH. Based on the hysteresis in the current and the potential dependence the oxidation of hydrogen peroxide occurs through a CEE mechanism involving Rh(OH)₃ on the mesoporous Rh electrode surface. At higher hydrogen peroxide concentrations the current reaches a plateau that is due to either saturation of the binding sites for hydrogen peroxide or limitation of the reaction due to acidification of the solution within the pores. For the thin films (below 200 nm) the hydrogen peroxide calibration curves we …

Foreword, Bin Ren

Journal of Electrochemistry

On the request of Prof. Shi-Gang Sun, Editor-in-Chief of Journal of Electrochemistry, I served as the guest editor for this International Special Issue on Current Electrochemistry. The Journal of Electrochemistry was founded in 1995 associated to the Chinese Chemical Society just before the 46^th Annual meeting of the International Society of Electrochemistry (ISE). Prof. Zhao-Wu Tian was the founder of the journal and had been serving as the Editor-in-Chief until 2010. The journal is known for high quality scientific papers related to the electrochemical science, techniques and engineering, and is well-known in Electrochemistry Community in China. However, the journal …

In Situ Pm-Irras Studies Of A Floating Bilayer Lipid Membrane At Au(111) Electrode Surface, Su Zhangfei, Kycia Annia, Jay Leitch J., Lipkowski Jacek

Journal of Electrochemistry

In situ Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) was used to study the structure of a DMPC + cholesterol + GM1 floating bilayer lipid membrane (fBLM) at a Au(111) surface. 1-thio-beta-D-glucose (beta-Tg) was self-assembled onto the Au electrode to increase the overall hydrophilicity of the surface. The fBLM was deposited on the beta-Tg self-assembled monolayer (SAM) using a combination of Langmuir-Blodgett/Langmuir-Schaefer (LB/LS) techniques. The carbohydrate headgroups of the GM1 molecules were physically adsorbed to the beta-Tg SAM forming a water rich cushion between the fBLM and the modified gold substrate. The PM-IRRAS spectra indicate that the DMPC molecules within …

Electrochemical Synthesis Of Silver-Tetracyanoquinodimethane Nanorods At Agar Supported Water/1,2-Dichloroethane Interface, Li Huang, Yixian Wang, Michael V. Mirkin, Bin Ren, Dongping Zhan

Journal of Electrochemistry

Silver-tetracyanoquinodimethane (AgTCNQ) is an important charge transfer salt due to its high conductivity and other electronic properties. In this communication, we report the synthesis of AgTCNQ at the liquid/liquid interface. Agar was used as a gelling agent to support water/1,2-dichloroethane (DCE) interface. Silver ions were transferred from the hydrogel into DCE phase, where they combined with TCNQ^- to form AgTCNQ nanorods. The developed method can provide a new route for synthesis of functional materials based on the electrochemistry at the liquid/liquid interface.

Underpotential Deposition Of Copper On Pt(S)[N(100)X(110)] Stepped Surfaces, Gisbert Rubn, Climent Vctor, Herrero Enrique, M. Feliu Juan

Journal of Electrochemistry

The underpotential deposition of Cu on platinum stepped surfaces composed of (100) terraces and (110) monoatomic steps has been studied in different acidic solutions. It has been found that the initial stage of copper deposition on the surface takes place simultaneously on terrace and step sites, irrespective of the nature of the adsorbing anion. During the voltammetric deposition of a full monolayer, several peaks can be observed. The analysis of the dependence of the peak charge with the step density allows assigning the different peaks to different deposition sites. The peak appearing at most positive potentials corresponds to the deposition …

A New Random Walk Simulation Model For Study Of Diffusion Behavior Of Single Particle Within Two-Dimensional Space, Jianwei Zhao, Lili Chen, Yingqiang Fu, Shaohong Li, Tiannan Chen, Shijie Zhang

Journal of Electrochemistry

Research on diffusion behaviors is of significant value in that it is closely related to transport phenomena in micro-chemistry. However, the effects of variables on diffusion are still unclear. Here, we developed and programmed a simulation methodology along with data analysis, which was capable to simulate the diffusion of a particle within twodimensional heterogeneous space in large timescale; the effects of periodically arranged impenetrable barriers of specific shape and lateral drifting velocity on diffusion behavior were studied. As well as standard mean square displacement analysis, a new method, the appearance probability distribution method, was introduced, which revealed whether the particle …

Electrochemical Detection Of Ammonia In Aqueous Solution Using Fluorescamine: A Comparison Of Fluorometric Versus Voltammetric Analysis, Panchompoo Janjira, G. Compton Richard

Journal of Electrochemistry

Fluorescamine is a non-fluorescent reagent widely used for the quantitative determination of primary amines by fluorescence spectroscopy as it reacts readily with primary amines to form a fluorescent product. In this work, a new sensitive voltammetric method for the detection of ammonia in aqueous solution by the reaction with fluorescamine has been developed. First, the electrochemical behaviour of fluorescamine in the absence and presence of ammonia was investigated in 0.1 mol L^-1 borate buffer solution (pH 9.0) by cyclic voltammetry using a glassy carbon (GC) electrode. As for fluorescamine itself, a well-defined irreversible oxidation peak could be observed at …

Host–Guest Complex Of Β-Cyclodextrin And Disulfide Form Of 4-Aminothiophenol, Taylor A. Cappadona, Lee M. Daniels, Tasneem A. Siddiquee

Chemistry Faculty Research

An inclusion complex of β-cyclodextrin and 4-aminothiophenol was assembled by hydrophobic interaction of the host (β-cyclodextrin) and guest (4-aminothiophenol). The complex was isolated as crystalline solid and studied by single crystal X-ray diffraction method along with NMR and IR spectroscopy. Two cyclodextrin rings each containing one disulfide form of 4-aminothiophenol were found to pair up by hydrogen bonding of the outer rim -OH groups. The phenyl disulfide moiety of 4-aminophenyl disulfide molecule was found in the core of β-cyclodextrin, while the amino functional groups were positioned to the exterior of the cyclodextrin ring. Phenyl rings of the guest molecule from …

Organics In Environmental Ices: Sources, Chemistry, And Impacts, V. F. Mcneill, A. M. Grannas, J. P. D. Abbatt, M. Ammann, P. Ariya, T. Bartels-Rausch, F. Domine, D. J. Donaldson, Marcelo I. Guzman, D. Heger, T. F. Kahan, P. Klán, S. Masclin, C. Toubin, D. Voisin

Chemistry Faculty Publications

The physical, chemical, and biological processes involving organics in ice in the environment impact a number of atmospheric and biogeochemical cycles. Organic material in snow or ice may be biological in origin, deposited from aerosols or atmospheric gases, or formed chemically in situ. In this manuscript, we review the current state of knowledge regarding the sources, properties, and chemistry of organic materials in environmental ices. Several outstanding questions remain to be resolved and fundamental data gathered before an accurate model of transformations and transport of organic species in the cryosphere will be possible. For example, more information is needed regarding …

Control Of The Polytypes And Line Defects In Radiation Detector Materials, Narsingh Bahadur R. Singh, Walter M.B. Duval, Richard H. Hopkins, Robert Mazelsky, Donald K. Fox, Milton S. Gottlieb, T. Henningsen, Sam R. Coriell, Martin E. Glicksman

Chemistry and Chemical Engineering Faculty Publications

Experiments were performed with pure and doped lead halides to investigate growth conditions for large crystals. Direct observations during the growth of 25 mm diameter crystal growing at high velocities showed that torodial type instability is formed at the solid/liquid interface during the growth. These instabilities translate into point defects and line defects. We report the results of extensive experiments on Lead bromide doped with silver bromide to study double diffusive transport. Control of instability at the interface provides a great improvement in the quality of crystal more specifically point defects and line defects. The controlled doping controls the defects …

One-Pot Synthesis Of (Z)-B-Sulfonyl Enoates From Ethyl Propiolate, C. Wade Downey, Smaranda Craciun, Ana M. Neferu, Christina A. Vivelo, Carly J. Mueller, Brian C. Southall, Stephanie Corsi, Eric W. Etchill, Ryan J. Sault

Chemistry Faculty Publications

B-Sulfonyl enoates may be synthesized through a one-pot two-step sequence from ethyl propiolate with good to excellent selectivity for the Z isomer. Trialkylamines catalyze thioconjugate additions of aryl thiols, and alkoxides catalyze the addition of aliphatic thiols. Addition of meta-chloroperbenzoic acid (mCPBA) and LiClO₄ to the reaction mixture provides rapid access to the sulfonyl enoates. Yields of the pure Z isomer range from 51 – 90%.

One-Pot Three-Step Thioconjugate Addition-Oxidation-Diels–Alder Reactions Of Ethyl Propiolate, C. Wade Downey, Smaranda Craciun, Christina A. Vivelo, Ana M. Neferu, Carly J. Mueller, Stephanie Corsi

Chemistry Faculty Publications

Ethyl propiolate undergoes one-pot three-step thioconjugate addition-oxidation-Diels–Alder cycloaddition when treated with a variety of thiols in the presence of catalytic base, meta-chloroperbenzoic acid, lithium perchlorate, and cyclopentadiene. The reaction of S‑aryl thiols is catalyzed by trialkylamines, and the reaction of aliphatic thiols requires catalytic alkoxide base. Yields of the major diastereomer of the conveniently functionalized bicyclic products range from 47 to 81% depending upon the thiol reactant, which compares favorably to yields observed when the entire synthesis is performed step by step.

Synthesis Of Di- And Trisubstituted Azulenes Using A Danheiser Annulation As The Key Step: An Advanced Organic Laboratory Experiment, Rebecca M. Thomas, Kevin M. Shea

Chemistry: Faculty Publications

This three-week advanced-level organic experiment provides students with an inquiry-based approach focused on learning traditional skills such as primary literature interpretation, reaction design, flash column chromatography, and NMR analysis. Additionally, students address higher-order concepts such as the origin of azulene’s blue color, the mechanism of the Danheiser annulation (step 1), identification of an unknown reaction byproduct, and rationalization of a selective electrophilic aromatic substitution reaction (step 2). Students are initially drawn in by the fascinating color of azulene and remain engaged by the intriguing questions that naturally occur during this investigation.

Nitrogen And Copper Doped Solar Light Active Tio2 Photocatalysts For Water Decontamination, Mike Fisher, Donal Keane, Pilar Fernandez-Ibanez, John Colreavy, Stephen Hinder, Kevin Mcguigan, Suresh Pillai

Articles

A novel class of photocatalytic coating capable of degrading bacterial and chemical contaminants in the presence of visible sunlight wavelengths was produced by depositing a stable photocatalytic TiO

2 film on the internal lumen of glass bottles via a sol–gel method. This coating was prepared in either undoped form or doped with nitrogen and/or copper to produce visible light-active TiO2 films which were annealed at 600 ◦C and were characterized by Raman and X-ray photoelectron spectroscopy. The presence of doped and undoped TiO2 films was found to accelerate the degradation of methylene blue in the presence of natural sunlight, while …

Spectroscopic And Computational Studies Of Matrix-Isolated Iso-Cxbr3 (X=F,Cl,Br): Structure, Properties, And Photochemistry Of Substituted Iso-Tribromomethanes, Lisa George, Aimable Kalume, Scott A. Reid, Brian J. Esselman, Robert J. Mcmahon

Chemistry Faculty Research and Publications

Iso-polyhalomethanes are important reactive intermediates in the condensed and gas-phase chemistry of halomethanes. Building upon our recent study of iso-bromoform, in this work the substituted iso-tribromomethanes (iso-CXBr₃; X = F, Cl, Br) were characterized by matrix isolation infrared and UV/Vis spectroscopy, supported by ab initio calculations, to further probe the structure, spectroscopy, properties, and photochemistry of these important intermediates. Selected wavelength laser irradiation of CXBr₃ samples in an inert rare gas (typically Ar; mixing ratio 1:500) held at ∼5 K yielded iso-CXBr₃ (XBrC–Br–Br or Br₂C–Br–X). The observed infrared and UV/Vis absorptions are in excellent …

Chemometric Analysis Of Comprehensive Two-Dimensional Liquid Chromatographic-Diode Array Detection Data: Peak Resolution, Quantification And Rapid Screening, Hope P. Bailey

Theses and Dissertations

This research project sought to explore, compare and develop chemometric methods with the goal of resolving chromatographically overlapped peaks though the use of spectral information gained from the four-way data sets associated with comprehensive two-dimensional liquid chromatography with diode array detection (LC ´ LC-DAD). A chemometric method combining iterative key set factor analysis (IKSFA) and multivariate curve resolution-alternating least squares (MCR-ALS) was developed. In the section of urine data analyzed, over 50 peaks were found, with 18 visually observable and 32 additional compounds found only after application of the chemometric method. Upon successful chemometric resolution of chromatographically overlapped peaks, accurate …

Using Slow-Release Permanganate Candles To Remove Tce From A Low Permeable Aquifer At A Former Landfill, Mark D. Christenson, Ann Kambhu, Steve D. Comfort

School of Natural Resources: Faculty Publications

Past disposal of industrial solvents into unregulated landfills is a significant source of groundwater contamination. In 2009, we began investigating a former unregulated landfill with known trichloroethene (TCE) contamination. Our objective was to pinpoint the location of the plume and treat the TCE using in situ chemical oxidation (ISCO). We accomplished this by using electrical resistivity imaging (ERI) to survey the landfill and map the subsurface lithology. We then used the ERI survey maps to guide direct push groundwater sampling. A TCE plume (100-600 µg L^-1) was identified in a low permeable silty-clay aquifer (K_h = 0.5 …

Chemistry & Biochemistry Newsletter, Department Of Chemistry & Biochemistry, South Dakota State University

Chemistry & Biochemistry Newsletter: 2002-2015

Inside:

Page 2 Jing wins Avera/SDSU Collaborative Research Funding; Teaching Assistants complete Certification of Excellence Program; Ron Utecht Issued Two Patents

Page 3 Tille is 2012 Education and Research Grant Recipient; Biochem Student Summit League Male Cross Country Athlete of the Year

Page 4 Zhang receives Board of Regents Grant

Page 5 MLS Receives National Clinical Pathology Scholarship

Page 6 Alumni Updates; Faculty Updates; Recent Publications

Chemical Properties Of Forest Soils In The Catskills Region, Chris E. Johnson

Civil and Environmental Engineering - All Scholarship

No abstract provided.

Photochemical Eilmination Reactions Via Zwitterionic Intermediates Generated By Electrocyclic Ring Closures, Majher Ibna Mannan Sarker

Dissertations (1934 -)

The research focuses on the design of photoremovable protecting groups that can be used to deprotect biological substrates of an organic compound by photolysis. The deprotection of the protecting group via photolysis requires heterolysis of a bond to the substrate. Heterolysis of a C-O or C-S σ-bonds in a zwitterionic intermediate is proposed. The photochemical electrocyclic reactions studied involve acrylanilides, benzothiophene carboxanilides, and N-(9-oxothioxanthenyl) benzothiophene carboxamides. α,β-Unsaturated anilides bearing leaving groups at the allylic position of the α-methylacrylamide group undergo photochemical electrocyclic ring closure with release of leaving group which could occur directly from a photochemically produced zwitterionic intermediate or …

A Novel Microfluidic Enrichment Technique For Carbonylated Proteins, Bryant C. Hollins

Doctoral Dissertations

Proteins are the building blocks of cells in living organisms, and are composed of amino acids. The expression of proteins is regulated by the processes of transcription and translation. Proteins undergo post-translational modifications in order to dictate their role physiologically within a cell.

Not all post-translational modifications are beneficial for the protein or the cell. One type of post-translational modification, called carbonylation, irreversibly places a carbonyl group onto an amino acid residue, most commonly proline, lysine, arginine, and threonine. This modification can have severe consequences physiologically, including loss of solubility, loss of function, and protein aggregation.

Carbonylated proteins have commonly …

Spectral Characterization Of Cytochromes P450 Active Site And Catalytic Intermediates, Daniel Kaluka

Dissertations (1934 -)

Cytochromes P450 (P450s) have been the subject of intense research for over six decades. Though it is widely accepted that a highly reactive Fe(IV)=O π-cation radical, or the so called compound I, facilitates the oxidation of relatively inert hydrocarbons, spectroscopic characterization of this putative intermediate has eluded detection under turnover conditions, presumably due to its very short lifetime. In this work, chemically inert substrates of P450s have been utilized in a new approach to capture and stabilize this transient intermediate and characterize it with resonance Raman (RR) spectroscopy, which is a well established tool for studying heme proteins. Specifically, perfluorodecanoic …

The Association Of Elevated 2′,5′-Oligoadenylate-Dependent Rnase L With Lung Cancer Correlated With Deficient Enzymatic Activity And Decreased Capacity Of Rnase L Dimerization, Huijing Yin, Aimin Zhou, Yalei Dai

Chemistry Faculty Publications

RNase L mediates critical cellular functions including antiviral, proapoptotic, antiproliferative and tumor suppressive activities. In this study, the expression and function of RNase L in lung cancer cells were examined. Interestingly we have found that the expression of RNase L in lung cancer cells was 3- and 9-fold higher in its mRNA and protein levels, but a significant decrease of its enzymatic activity when compared to that in corresponding normal lung cells. Further investigation revealed that 2-5A-induced dimerization of the RNase L protein, a necessary prerequisite for activation of RNase L, was inhibited, as a result of that RLI, a …