Chemistry Commons^™

Aldehyde Bromination For Stilbenoid Syntheses, Dhanunjay N. Padal

Student Theses and Dissertations

This thesis will focus on being able to synthesize an alkyne from an aldehyde, forming a dibromoalkene as an intermediate. This alkyne then can be converted to a stilbenoid in the future on reaction with alkyl lithium. Combretastatin A-4 and resveratrol are the stilbenoids, which have biological significance. These compounds have therapeutic value and are extracted from plants or fruits for their production. The chemical synthesis for these compounds from an economic point of view is very important. The Corey-Fuchs reaction was used to synthesize the dibromoalkenes. Literature cites use of triphenylphosphine as a reactant, but triisopropyl phosphite was used …

Magnesium-Based Sacrificial Anode Cathodic Protection Coatings (Mg-Rich Primers) For Aluminum Alloys, Shashi S. Pathak, Sharathmukar K. Mendon, Michael D. Blanton, James W. Rawlins

Faculty Publications

Magnesium is electrochemically the most active metal employed in common structural alloys of iron and aluminum. Mg is widely used as a sacrificial anode to provide cathodic protection of underground and undersea metallic structures, ships, submarines, bridges, decks, aircraft and ground transportation systems. Following the same principle of utilizing Mg characteristics in engineering advantages in a decade-long successful R&D effort, Mg powder is now employed in organic coatings (termed as Mg-rich primers) as a sacrificial anode pigment to protect aerospace grade aluminum alloys against corrosion. Mg-rich primers have performed very well on aluminum alloys when compared against the current chromate …

Effects Of Thiophene Units On Substituted Benzothiadiazole And Benzodithiophene Copolymers For Photovoltaic Applications, Ping Ding, Yingping Zou, Cheng-Che Chu, Dequan Xiao, Chain-Shu Hsu

Chemistry and Chemical Engineering Faculty Publications

Two conjugated copolymers, P1 and P2, comprising of benzodithiophene and 5, 6-dioctyloxy-benzothiadiazole (DOBT) derivatives with/without thiophene unit, were synthesized via Stille cross-coupling polymerization reaction. These copolymers are promising for the applications in BHJ solar cells due to their good solubilities， proper thermal stability and moderate hole mobility as well as low bandgap. The photovoltaic properties of the copolymers were investigated based on the blend of the different polymer/PC71BM weight ratio under AM1.5G illumination, 100 mW/cm2. The device with ITO/PEDOT:PSS/P2: PC71BM (1:2, w/w)/Ca/Al gave relatively better photovoltaic performance, with a power conversion efficiency of 1.55%.

Rnase L Controls Terminal Adipocyte Differentiation, Lipids Storage And Insulin Sensitivity Via Chop10 Mrna Regulation, O. Fabre, T. Salehzada, K. Lambert, Y. Boo Seok, Aimin Zhou, J. Mercier, C. Bisbal

Chemistry Faculty Publications

Adipose tissue structure is altered during obesity, leading to deregulation of whole-body metabolism. Its function depends on its structure, in particular adipocytes number and differentiation stage. To better understand the mechanisms regulating adipogenesis, we have investigated the role of an endoribonuclease, endoribonuclease L (RNase L), using wild-type and RNase L-knockout mouse embryonic fibroblasts (RNase L^−/−-MEFs). Here, we identify C/EBP homologous protein 10 (CHOP10), a dominant negative member of the CCAAT/enhancer-binding protein family, as a specific RNase L target. We show that RNase L is associated with CHOP10 mRNA and regulates its stability. CHOP10 expression is conserved in RNase …

Spectroscopy And Dynamics Of The Predissociated, Quasi-Linear S₂ State Of Chlorocarbene, Chong Tao, Craig A. Richmond, Calvin Mukarakate, Scott H. Kable, George B. Bacskay, Eric C. Brown, Richard Dawes, Phalgun Lolur, Scott A. Reid

Chemistry Faculty Research & Creative Works

In this work, we report on the spectroscopy and dynamics of the quasi-linear S₂ state of chlorocarbene, CHCl, and its deuterated isotopologue using optical-optical double resonance (OODR) spectroscopy through selected rovibronic levels of the S₁ state. This study, which represents the first observation of the S₂ state in CHCl, builds upon our recent examination of the corresponding state in CHF, where pronounced mode specificity was observed in the dynamics, with predissociation rates larger for levels containing bending excitation. In the present work, a total of 14 S₂ state vibrational levels with angular momentum 1 were observed …

Development And Validation Of A Rapid Lc-Ms/Ms Method Fortthe Determination Of Jcc76, A Novel Antitumor Agent For Breast Cancer, In Rat Plasma And Its Application To A Pharmacokinetics Study, Xiaohan Cai, Bo Zhong, Bin Su, Songlin Xu, Baochuan Guo

Chemistry Faculty Publications

JCC76 is a novel nimesulide analog that selectively inhibits the human epidermal growth factor receptor 2 (HER2) overexpressing breast cancer cell proliferation and tumor progression. To support further pharmacological and toxicological studies of JCC76, a novel and rapid method using liquid chromatography and electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) has been developed and validated for the quantification of the compound in rat plasma. A C18 column was used for chromatographic separation, and the mobile phase was aqueous ammonium formate (pH 3.7; 5 mm)–methanol (1:9, v/v) with an isocratic elution. With a simple liquid–liquid extraction procedure using the mixture of methyl …

Identification Of Selective Tubulin Inhibitors As Potential Anti-Trypanosomal Agents, Rati Lama, Ranjodh Sandhu, Bo Zhong, Bibo Li, Bin Su

Chemistry Faculty Publications

The potency of a series of sulfonamide tubulin inhibitors against the growth of Trypanosoma brucei (T. brucei), as well as human cancer and primary fibroblast cells were evaluated with the aim of determining whether compounds that selectively inhibit parasite proliferation could be identified. Several compounds showed excellent selectivity against T. brucei growth, and have the potential to be used for the treatment of Human African trypanosomiasis. A T. brucei tubulin protein homology model was built based on the crystal structure of the bovine tubulin. The colchicine-binding domain, which is also the binding site of the tested sulfonamide tubulin inhibitors, showed …

The Effect Of The Charge-Separating Interface On Exciton Dynamics In Photocatalytic Colloidal Heteronanocrystals, Timothy O’Connor, Maxim S. Panov, Andrey Mereshchenko, Alexander N. Tarnovsky, Ryan Lorek, Dimuthu Perera, Geoffrey Diederich, Scott Lambright, Pavel Moroz, Mikhail Zamkov

Chemistry Faculty Publications

Ultrafast transient absorption spectroscopy was used to investigate the nature of photoinduced charge transfer processes taking place in ZnSe/CdS/Pt colloidal heteronanocrystals. These nanoparticles consist of a dot-in-a-rod semiconductor domain (ZnSe/CdS) coupled to a Pt tip. Together the three components are designed to dissociate an electron-hole pair by pinning the hole in the ZnSe domain while allowing the electron to transfer into the Pt tip. Separated charges can then induce a catalytic reaction, such as the light-driven hydrogen production. Present measurements demonstrate that the internal electron-hole separation is fast and results in the localization of both charges in nonadjacent parts of …

Anti-Corrosion Performance Of Primer And Top Coat Formulations For Metal Substrates, Laural Elizabeth Hargrove

Master's Theses

This project involved the improvement of several properties of the current “universal” primer coating sold by Kelly-Moore Paint Company. This formulation is an all purpose primer used both for interior and exterior applications. However, its corrosion resistance has room for improvement. The addition of sodium nitrite, an aminocarboxylate salt, and a zinc phosphate-based additive were all tested as corrosion inhibitors. In addition, during the project the coating binder was changed to improve adhesion. After a systematic experimental program, a new “universal” primer with increased corrosion resistance and adhesion was formulated.

A direct to metal top coat formulation sold by Kelly-Moore …

Structure To Function: Case Studies Of Hotdog-Fold Superfamily Thioesterases From Escherichia Coli, John A. Latham

Chemistry and Chemical Biology ETDs

My doctoral research primarily focuses on the Escherichia coli hotdog-fold thioesterases ydiI and ybgC. The ydiI gene is colocalized in the operon ydiHIJ. A substrate screen provided evidence that YdiI prefers aryl-CoA substrates and discriminated against the analogous aryl-ACP, unlike the paralog YbdB which works on 2,4-DHB-EntB in the enterobactin synthesis pathway. A bioinformatic approach showed that in some bacteria, ydiI is colocalized with genes from the menaquinone pathway. YdiI was shown to catalyze the hydrolysis of DHNA-CoA with physiological relevance (k_cat/K_M ~ 10⁵). Furthermore, the E. coli YdiI- strain was shown to …

Discharge Curve Fitting Of Lifepo4 Based On Impedance Model, Ming Wang, Jian-Jun Li, Xiang-Ming He, Peng Bai, Gan Wu, Chun-Rong Wan, Guang-Yu Tian

Journal of Electrochemistry

In this paper, an impedance model is developed for simulating the discharge curve of LiFePO₄ cathode material. The voltage drop is divided into three parts: the Ohm voltage drop, the charge transfer voltage drop and the diffusion voltage drop. A theoretical expression has been derived to predict the discharge curves at various discharge rates. The parameters of the equation have been obtained by fitting the results of EIS measurement, and a good agreement between the fitting and the experimental data has been found at all discharge rates.

Poly(Aniline/O-Nitroaniline): A High Capacity Cathode Material For Lithium Ion Batteries, Rui-Rui Zhao, Li-Min Zhu, Jiang-Feng Qian, Han-Xi Yang

Journal of Electrochemistry

Polyaniline can be used as a high capacity cathode material due to the advantages of material abundance and synthetic simplicity. However, its practical application in battery has been hindered by poor electrochemical utilization and cycling instability. To solve these problems, we synthesized the poly(aniline/o-Nitroaniline) (P(AN-oNA)) by introducing the electron-drawing group-nitroaniline onto the polyaniline chains, so as to enhance electrochemical utilization and stability of the polyaniline derivative. The as-prepared Li/P(AN-oNA) copolymer shows a greatly enhanced discharge capacities of 186 mAh·g^-1 at initial cycles, about 37% higher than its parent PAN, and remains 168 mAh·g^-1 after 60th cycle. Also, the …

Influences Of Particle Size And Sulfuric Acid Treatment On The Electrochemical Performance Of Bamboo Charcoal, Yu Yao, Ai-Shui Yu

Journal of Electrochemistry

The bamboo charcoal had been milled and treated by sulfuric acid. The influences of as-prepared material particle size and sulfuric acid treatment on the electrochemical performance had been studied. The result displays that the bamboo charcoal with mean particle size about 5 μm has the best first coulombic efficiency. Sulfuric acid treatment could raise the discharge capacity of bamboo charcoal, and the first discharge capacity of 328.2 mAh·g^-1 was obtained with the bamboo charcoal treated by sulfuric acid for 18 h. Furthermore, the capacity of 302.3 mAh·g^-1 could be maintained for 50 cycles, showing good cycle performance.

Synthesis And Electrochemical Characterization Of Li3V2(Po4)3/C Cathode Material By Ball-Milling Assisted Microwave Method, Zhi-Yuan Tang, Wen-Feng Mao, Ji Yan, Wei Yuan, Xin-He Zhang

Journal of Electrochemistry

The cathode materials of Li₃V₂(PO₄)₃/C were successfully synthesized by ball-milling assisted microwave method and the microwave irradiation time was also optimized. It is found that the Li₃V₂(PO₄)₃/C material obtained at a microwave power of 640 W for 18 min showed the best electrochemical performance with the initial reversible capacity of 101.3 mAh·g^-1 and the remained 100.8 mAh·g^-1 at 5C rate after 300 cycles. This excellent electrochemical capability may be resulted from good crystallinity, smaller and uniform particle size of the material, showing …

Electrochemical Performance Of Yf3-Coated Li(Li0.22Ni0.17Mn0.61)O2 Cathode Material For Li-Ion Batteries, Xin Feng, Guo-Ran Li, Shi-Hai Ye, Xue-Ping Gao

Journal of Electrochemistry

The Li(Li_0.22Ni_0.17Mn_0.61)O₂ was prepared with oxalic co-precipitation and coated with an YF₃ layer by a chemical deposition method. The as-prepared and YF₃-coated Li-rich materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The results demonstrate that the as-prepared and YF₃-coated Li(Li_0.22Ni_0.17Mn_0.61)O₂ materials have a typical layered structure and are composed of sphere-like particles with a diameter of 100~200 nm. Galvanostatic charge-discharge tests show that the discharge capacity of the YF₃-coated Li(Li_{0.22 …}

Preparation And Performance Of Sn-Co-M-C（M = Zn, Fe）Composites As An Anode Material, Guo-Qing Fang, Wei-Wei Liu, Shi-Ci He, Qian Zhang, Jun-Wei Zheng, De-Cheng Li

Journal of Electrochemistry

The anode materials of Sn-Co-M-C (M = Zn, Fe) composites were prepared by carbothermal reduction method from metal oxides and sucrose in N₂ atmosphere. Their structural and electrochemical properties were studied by XRD, SEM and charge-discharge test. Among them, the Sn-Co-Zn-C composite showed higher specific capacity and good cycle performance. The initial specific discharge capacity of 571 mAh·g^-1 could be obtained, while 369 mAh·g^-1 was still kept after 45 cycles.

Experimental Determination Of Pka Values By Use Of Nmr Chemical Shifts, Revisited, Alan D. Gift

Chemistry Faculty Publications

This laboratory experiment, using proton NMR spectroscopy to determine the dissociation constant for heterocyclic bases, has been modified from a previously described experiment. A solution of a substituted pyridine is prepared using deuterium oxide (D2O) as the solvent. The pH of the solution is adjusted and proton NMR spectra are collected for a variety of pH values. The chemical shifts of the peaks in the NMR spectrum change depending on the degree of protonation of the pyridine ring. Analysis of the spectral data is used to calculate the dissociation constant of the substituted pyridine. This experiment is suitable for a …

Alkynal Involved Organocatalytic Reactions, Xinshuai Zhang

Chemistry and Chemical Biology ETDs

During the past twenty years, vast progress has been achieved in the field of organocatalysis. One of the fruitful areas is iminium catalysis using α, β-unsaturated aldehydes as essential reactants. Enals involved enantioselective reactions (including single-step reactions and cascade/tandem reactions) represent an enormous and fruitful research branch. In contrast, the protocols for the corresponding alkynals, even in single-step conjugate addition reactions, are extremely rare. Toward this end, my Ph. D. research work mainly focuses on the development of alkynal involved organocatalytic reactions and expands the scope of organocatalysis by uncovering new activation modes. Unlike enals, ynals with sp hybridized C≡C …

Carbon Nanotubes With Ni2P Nanoparticles As A Counter Electrode In Dye-Sensitized Solar Cells, Yan-Ye Dou, Nan-Fu Yan, Guo-Ran Li, Xue-Ping Gao

Journal of Electrochemistry

Carbon nanotubes (CNTs) supported by Ni₂P nanoparticles are prepared and used as a counter electrode in dye-sensitized solar cells (DSSCs) for the first time. The CNTs-Ni₂P composite was prepared by the heat treatment of a mixed precursor including nickel chloride, sodium hypophosphite and CNTs in argon atmosphere. The X-Ray diffraction (XRD) results indicate that the as-prepared sample consists of hexagonal Ni2P and carbon nanotubes. No peaks of other nickel phosphides are observed in the XRD pattern. Microstructure of the Ni₂P-CNTs composite was investigated using transmission electron microscopy (TEM). It is shown that the Ni …

Electrochemical Sensing Of Guanine And Adenine Based On The Boron-Doped Carbon Nanotubes Modified Electrode, Ya-Lin Xia, Chun-Yan Deng, Juan Xiang

Journal of Electrochemistry

In this work, the boron-doped carbon nanotubes (BCNTs) modified glassy carbon (GC) electrode was simply fabricated, and the electrochemical oxidation behaviors of guanine and adenine at the BCNTs/GC electrode were investigated. Compared with the bare GC and CNTs/GC electrodes, the BCNTs-modified electrode exhibited extraordinary electrocatalytic activity towards the oxidations of guanine and adenine as indicated by the obvious increase in current responses. Moreover, the peak separation between guanine and adenine was large enough for their potential recognition in mixture without any separation or pretreatment. Therefore, the simultaneous determination of guanine and adenine was successfully achieved. The BCNTs/GC electrode showed high …

Electrochemical Immunosensor Based On Polycalconcarboxylic Acid Modified Electrode For The Determination Of Alpha-Fetoprotein, Xiao Lin, Shao-Huang Weng, Jian-Zhang Zhou, Ai-Lin Liu, Xin-Hua Lin, Yong-Ji You

Journal of Electrochemistry

A highly sensitive electrochemical immunosensor based on novel electropolymerized polycalconcarboxylic acid modified electrode (poly-CCA/GC) has been fabricated for the detection of alpha-fetoprotein (AFP). The differences of the poly-CCA/GC electrodes before and after the immobilization of AFP antibody were characterized via scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The immobilization of antibody/antigen/antibody-HRP sandwich was formed on the poly-CCA modified electrode for the determination of special AFP concentrations. The electrochemical signals generated from the HRP which catalyzed the TMB substrate were measured. Experiment results indicated that the developed immunosensor showed a good sensitivity and precision.

Naf-M (M = Fe, Cu) Nanocomposites As Conversion Cathode Materials For Sodium Ion Batteries, Ting Li, Zhong-Xue Chen, Yu-Liang Cao, Han-Xi Yang

Journal of Electrochemistry

The NaF-M (M = Fe, Cu) nanocomposites were prepared by high-energy ball milling using TiN grinding nanoparticles and investigated as cathode materials for sodium ion batteries. The experimental results demonstrated that NaF-Fe and NaF-Cu nanocomposites can go through electrochemical conversion reaction with Na⁺ uptake or removal, delivering a reversible capacity of ~ 150 mAh·g^-1, even through a reversed conversion from initial discharged state to a charged state. These results reveal the possibility to realize a conversion reaction as long as NaF and elemental metal particles are intimately contacted to form active nanocomposites at nanodomain, which suggests a …

Preparation And Electrochemical Performance Of Nanostructured Mno2 Materials, Wen Wu, Dan-Dan Zhou, Meng-Yan Hou, Yong-Yao Xia

Journal of Electrochemistry

Nanostructured MnO₂ materials were prepared in a micro-emulsion medium using sodium dodecyl sulfate (SDS）as a surfactant by a redox reaction between potassium permanganate and aniline. The morphologies of the obtained MnO₂ were critically dependent on the concentrations of SDS. The particle sizes varied with the change in the micro-emulsion medium. The optimized properties of MnO₂ material obtained with the surfactant concentration of 0.2 mol.L^-1 had a specific surface area of 228.2 m².g^-1, and delivered a specific capacitance of 237 F.g ^-1 in 1 mol.L^-1 Li₂SO₄. Additionally, a …

Synthesis And Electrochemical Properties Of High-Capacity Cathode Material 0.08lico0.75Al0.25O2-0.92linio2, Ru-Ying Wang, Tian Qiu, Chong Mao, Wen-Sheng Yang

Journal of Electrochemistry

CoAl-LDH or Co(OH)₂ coated spherical Ni(OH)₂ precursors were obtained via a co-precipitation method at a constant pH. The mixtures of the precursors and LiOH·H₂O were annealed at high temperature in O₂ atmosphere, and then the cathode materials of 0.08LiCo_0.75Al_0.25O₂-0.92LiNiO₂, 0.08LiCoO₂-0.92LiNiO₂ and LiNiO₂ were synthesized. Effects of the coating layer were also studied. The results showed that the 0.08LiCo_0.75Al_0.25O₂-0.92LiNiO₂ material possessed the best rate and cycle life performance. The discharging capacities at 0.1C, 0.5C and 3C were …

A Facile Approach To Prepare Lifepo4/C Composite With High-Rate Performance, Peng Zhang, Ling-Bin Kong, Yong-Chun Luo, Long Kang

Journal of Electrochemistry

The LiFePO₄/C composite electrode material was synthesized by a moderate in situ carbothermal reduction method at 600 °C using FeCl_3·6H₂O, LiOH·H₂O, and NH₄H₂PO₄ as starting materials, soluble starch sol as a carbon source and a reducing agent. This method is readily reproducible and possibly feasible to carry out large-scale synthesis. The structure and morphology of the LiFePO₄/C samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The synthesized LiFePO₄/C composite was in pure phase of olivine-type, …

Preparation And Modification Of Li4Ti5O12 As Anode Materials For Lithium-Ion Batteries, Jin-Long Liu, Zhou-Guang Lu, Yang Ren, Ya-Jie Zhu, Shan-Shan Hu, Zhong Peng, Dong Qian, You-Gen Tang

Journal of Electrochemistry

Anode Material Li₄Ti₅O₁₂ for lithium-ion batteries was successfully prepared using half-solid-state method. Furthermore, carbon coating modification of Li₄Ti₅O₁₂ was also carried out. The phase structure and morphology were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). The electrochemical properties were investigated by constant current discharge-charge tests, cyclic voltammetry and electrochemical impedance techniques. The results indicated that the electrochemical performance of Li₄Ti₅O₁₂ without modification declined seriously due to the aggregation of Li₄Ti …

Electrochemical Performances Of Layered Polypyrrole/Chemically Reduced Graphene Oxide Nanocomposites As Supercapacitor Electrodes, Si-Zhe Xu, Xue-Jiao Zhou, Kun Wu, Yong-Qiang Yang, Hai-Xia Wu

Journal of Electrochemistry

Nanocomposites of polypyrrole (Ppy) and chemically reduced graphene oxide (CRGO), Ppy/CRGO, have been fabricated through in-situ polymerization of pyrrole on graphene oxide (GO) sheets. The as-synthesized Ppy/CRGO composites were characterized complementarily using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier transformed infrared spectroscopy (FT-IR). By controlling the initial ratio of the GO to pyrrole, the layered composites could be obtained and their thickness could be tuned properly. The Ppy/CRGO electrodes were prepared using a mechanical compressing technique and their electrical conductivity and electrochemical properties were characterized systematically. We demonstrated that as electrodes for supercapacitor, the Ppy/CRGO composites with Ppy …

Electrochemical Corrosion And Protection Of Copper Foil Treated By Surface Siloxane Filming, Wei-Jun Miao, Yu-Bao Zhang, Ning-Yu Gu, Feng Liu

Journal of Electrochemistry

Copper foil specimens were immersed in hydro-alcoholic solution of 3-amino-propyl-trimethoxy-silane (γ-APS) to prepare a protective self-assembled siloxane membrane on the surface. Potentiodynamic polarization and electrochemical impedance spectroscopic tests were performed in 0.1 mol.L^-1 NaCl to evaluate the effects of the self-assembled siloxane membranes prepared at different pH of γ-APS on corrosion of copper foil. The surface morphology of siloxane membrane was studied by SEM. Experimental results revealed that the γ-APS self-assembled siloxane membranes effectively inhibited the corrosion of copper foil and the optimum anti-corrosion effect was found when the pH value of the silane solution was 7.

Electrocatalytic Activities Of Mb/Aunps/Mwnts/Gc Electrode For Hydrogen Peroxide Reduction, Zheng-Juan Huang, Hua-Ping Peng, Dai-Jun Cha, Ai-Lin Liu, Wei Chen, Xin-Hua Lin, Yong-Ji You

Journal of Electrochemistry

A novel matrix, multiwalled carbon nanotubes supported Au nanoparticles composite nanomaterial (AuNPs/MWNTs), for immobilization of protein and biosensing was designed using a simple and effective one-step in situ synthesis route. Using myoglobin (Mb) as a model, the direct electrochemistry of the immobilized proteins on the AuNPs/MWNTs composite was studied. The results showed that the AuNPs/MWNTs composite can maintain the bioactivity and facilitate the direct electrochemistry of Mb in the Mb/AuNPs/MWNTs/GC electrode. Based on the direct electron transfer of the immobilized Mb, the protein electrode exhibited excellent electrocatalytic activity to the reduction of H₂O₂ with a linear range …

Magnetic Properties Of The S=1/2 Quasisquare Lattice Antiferromagnet Cuf2(H2o)(2)(Pyz) (Pyz = Pyrazine) Investigated By Neutron Scattering, C H. Wang, M D. Lumsden, R S. Fishman, G Ehlers, T Hong, W Tian, H Cao, A Podlesnyak, C Dunmars, J A. Schlueter, Jamie L. Manson, A D. Christianson

Chemistry and Biochemistry Faculty Publications

We have performed elastic and inelastic neutron scattering experiments on single crystal samples of the coordination polymer compound CuF2(H2O)(2)(pyz) (pyz = pyrazine) to study the magnetic structure and excitations. The elastic neutron diffraction measurements indicate a collinear antiferromagnetic structure with moments oriented along the [0.7 0 1] real-space direction and an ordered moment of 0.60 +/- 0.03 mu(B)/Cu. This value is significantly smaller than the single-ion magnetic moment, reflecting the presence of strong quantum fluctuations. The spin wave dispersion from magnetic zone center to the zone boundary points (0.5 1.5 0) and (0.5 0 1.5) can be described by a …