A Sodium Salt Of The Dimer Of Boronoterephthalic Acid Anhydride,
2011
University of Dayton
A Sodium Salt Of The Dimer Of Boronoterephthalic Acid Anhydride, Scott Simmons, Albert Fratini, Vladimir Benin
Chemistry Faculty Publications
The title compound, sodium bis(6-carboxy-1-hydroxy-3-oxo-1,3-dihydro-2,1-benzoxaborol-1-yl)oxidanium, Na+·C16H15B2O13-, was prepared in two steps from 2-bromo-p-xylene. Its crystal structure was determined at 140 K and has triclinic (P) symmetry. The compound presents a unique structural motif, including two units of the cyclic anhydride of boronoterephthalic acid, joined by a protonated, and thereby trivalent, oxonium center. Association in the crystal is realized by complementary hydrogen bonding of the carboxyl groups, as well as by coordination of the sodium cations to the oxygen centers on the five-membered rings.
Theoretical Investigation Of A Reported Antibiotic From The 'Miracle Tree' Moringa Oleifera,
2011
University of Dayton
Theoretical Investigation Of A Reported Antibiotic From The 'Miracle Tree' Moringa Oleifera, Michael Horwath, Vladimir Benin
Chemistry Faculty Publications
Moringa oleifera, sometimes called the “Miracle Tree,” has received international attention for its potential to improve health in impoverished tropical areas. In addition to high vitamin content in the leaves and pods, the tree contains compounds with antioxidant and antibacterial properties. This study focused on the theoretical investigation of the suggested structure of one antibacterial compound, “pterygospermin,” whose existence was proposed after some studies of the roots of M. oleifera. The structure of pterygospermin was first proposed by a research group working in the 1950s, but later studies have not found evidence of this compound and have instead …
Electrospinning Fabrication, Structural And Mechanical Characterization Of Rod-Like Virus-Based Composite Nanofibers,
2011
University of South Carolina - Columbia
Electrospinning Fabrication, Structural And Mechanical Characterization Of Rod-Like Virus-Based Composite Nanofibers, Laying Wu, Jianfeng Zang, L. Andrew Lee, Zhongwei Niu, Gary C. Horvatha, Vaughn Braxtona, Arief C. Wibowo, Michael A. Bruckman, Soumitra Ghoshroy, Hans-Conrad Zur Loye, Xiaodong Li, Qian Wang
Faculty Publications
Tobacco mosaic virus (TMV) was electrospun with polyvinyl alcohol (PVA) into continuous TMV–PVA composite nanofibers to form a biodegradable nonwoven fibrous mat as an extracellular matrix (ECM) mimetic. Morphological characterizations by electron microscopyshowed that the addition of varying amounts of TMV resulted in homogeneous nanofibers without phase separation and did not change the diameter of the composite nanofibers. The orientation of TMV in as-spun fibers could be readily controlled and post-processing of the nonwoven TMV–PVA mat significantly improved its water resistance. In addition, tensile tests were performed on individual nanofibers, which revealed that the TMV–PVA composite nanofibers achieved a comparable …
Carboxymethylation Of Kappa-Carrageenan For Intestinal-Targeted Delivery Of Bioactive Macromolecules,
2011
Department of Pharmacy, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur. Malaysia
Carboxymethylation Of Kappa-Carrageenan For Intestinal-Targeted Delivery Of Bioactive Macromolecules, Kok Hoong Leong
Kok Hoong Leong
The work presented herein discusses the carboxymethylation of kappa-carrageenan, a natural linear polysaccharide, to afford a pH-dependent swelling property allowing for intestinal-targeted delivery of bioactive macromolecules. The carboxymethylation conditions with respect to the volume and concentration of sodium hydroxide (VNaOH, CNaOH), weight of monochloroacetic acid (WMCA), and reaction temperature (T) were optimized using a response surface method incorporating a multivariate spline interpolation technique (RSMS). Fluorescein isothiocyanate-labeled dextran (FD-4; 4.4 kDa) was used as a hydrophilic macromolecule model. Beads made from encapsulating FD-4 in the carboxymethylated kappa-carrageenan displayed pH-dependent swelling and encapsulation efficiency of 74%. The release of FD-4 was low …
Low Temperature Growth Of High Purity, Low Resistivity Copper Films By Atomic Layer Deposition,
2011
Wayne State University
Low Temperature Growth Of High Purity, Low Resistivity Copper Films By Atomic Layer Deposition, Thomas J. Knisley
Thomas J Knisley
No abstract provided.
Volatility And High Thermal Stability In Mid To Late First Row Transition Metal Diazadienyl Complexes,
2011
Wayne State University
Volatility And High Thermal Stability In Mid To Late First Row Transition Metal Diazadienyl Complexes, Thomas J. Knisley
Thomas J Knisley
No abstract provided.
Abatement Of Benzyl Alcohol And Methyl Ethyl Ketone (Mek) From Polluted Air Over Nanostructured Mn -Supported Alumina Catalyst,
2011
University of Tabriz
Abatement Of Benzyl Alcohol And Methyl Ethyl Ketone (Mek) From Polluted Air Over Nanostructured Mn -Supported Alumina Catalyst, Hosein Afshary, Aligoli Niaei
Hosein Afshary
Total combustion of methyl ethyl ketone and benzyl alcohol as two models of volatile organic compounds (VOCs) using catalytic method was studied over γ-Al2O3 and Mn/γ- Al2O3 catalysts. Catalyst (Mn/γ-Al2O3) was prepared by wet impregnation and characterized using XRD, BET, ICP-AES and SEM methods and the nanostructure of the catalyst were approved. The activity of the catalysts was measured in a catalytic packed bed reactor under atmospheric pressure and different reaction temperatures at range 150 to 450°C. The studies confirmed that manganese supported on γ-Al2O3 can be suitable for the abatement of the mentioned pollutants from contaminated air and hopefully …
Fabrication And Characterization Of Graphene Hydrogel Via Hydrothermal Approach As A Scaffold For Preliminary Study Of Cell Growth,
2011
University of Malaya
Fabrication And Characterization Of Graphene Hydrogel Via Hydrothermal Approach As A Scaffold For Preliminary Study Of Cell Growth, Huang Nay Ming
Huang Nay Ming
Three-dimensional assembly of graphene hydrogel is rapidly attracting the interest of researchers because of its wide range of applications in energy storage, electronics, electrochemistry, and waste water treatment. Information on the use of graphene hydrogel for biological purposes is lacking, so we conducted a preliminary study to determine the suitability of graphene hydrogel as a substrate for cell growth, which could potentially be used as building blocks for biomolecules and tissue engineering applications. A three-dimensional structure of graphene hydrogel was prepared via a simple hydrothermal method using two-dimensional large-area graphene oxide nanosheets as a precursor. The concentration and lateral size …
Time-Resolved Resonance Raman And Computational Investigation Of The Influence Of 4-Acetamido And 4-N-Methylacetamido Substituents On The Chemistry Of Phenylnitrene,
2011
University of Hong Kong
Time-Resolved Resonance Raman And Computational Investigation Of The Influence Of 4-Acetamido And 4-N-Methylacetamido Substituents On The Chemistry Of Phenylnitrene, Jiaden Xue, Shubham Vyas, Yong Du, Hoi-Ling Luk, Yung-Ping Chuang, Tracy Yuen Sze But, Patrick H. Toy, Jin Wang, Arthur Winter, David Lee Phillips, Christopher M. Hadad, Matthew S. Platz
Arthur Winter
A time-resolved resonance Raman (TR3) and computational investigation of the photochemistry of 4-acetamidophenyl azide and 4-N-methylacetamidophenyl azide in acetonitrile is presented. Photolysis of 4-acetamidophenyl azide appears to initially produce singlet 4-acetamidophenylnitrene which undergoes fast intersystem crossing (ISC) to form triplet 4-acetamidophenylnitrene. The latter species formally produces 4,4′-bisacetamidoazobenzene. RI-CC2/TZVP and TD-B3LYP/TZVP calculations predict the formation of the singlet nitrene from the photogenerated S1 surface of the azide excited state. The triplet 4-acetamidophenylnitrene and 4,4′-bisacetamidoazobenzene species are both clearly observed on the nanosecond to microsecond time-scale in TR3 experiments. In contrast, only one species can be observed in analogous TR3 experiments after …
Rh1−Xpdxnanoparticle Composition Dependence In Co Oxidation By Oxygen: Catalytic Activity Enhancement In Bimetallic Systems,
2011
University of California - Berkeley
Rh1−Xpdxnanoparticle Composition Dependence In Co Oxidation By Oxygen: Catalytic Activity Enhancement In Bimetallic Systems, James Russell Renzas, Wenyu Huang, Yawen Zhang, Michael E. Grass, Dat Tien Hoang, Selim Alayoglu, Derek R. Butcher, Franklin Tao, Zhi Liu, Gabor A. Somorjai
Wenyu Huang
Bimetallic 15 nm Rh1−xPdxnanoparticle catalysts of five different compositions and supported on Si wafers have been synthesized, characterized using TEM, SEM, and XPS, and studied in CO oxidation by O2 in two pressure regimes: atmospheric pressure and 100–200 mTorr. The RhPd bimetallic nanocrystals exhibited similar synergetic effect of increased reaction activity at both atmospheric (760 Torr) and moderate (100–200 mTorr) pressures compared with pure Pd or Rh. The magnitude of the effect depends on the relative pressures of the CO and O2 reactant gases and the reaction temperature. The catalytic activity of the nanocrystals measured at moderate pressure is directly …
2-(3,5-Dinitrophenyl)-1,3-Dithiane Carbanion: A Benzylic Anion With A Low Energy Triplet State,
2011
University of Maryland - College Park
2-(3,5-Dinitrophenyl)-1,3-Dithiane Carbanion: A Benzylic Anion With A Low Energy Triplet State, Raffaele R. Perrotta, Arthur Winter, William H. Coldren, Daniel E. Falvey
Arthur Winter
Calculations at the DFT level predict that benzyl anions with strong π-electron-withdrawing groups in the meta position(s) have low energy diradical or triplet electronic states. Specifically, the 2-(3,5-dinitrophenyl)-1,3-dithiane carbanion is predicted to have nearly degenerate singlet and triplet states at the (U)B3LYP level as a free anion. Its lithium ion pair is predicted to be a ground-state triplet with a substantial (26 kcal/mol) singlet–triplet energy gap. Experiments on this anion using chemical trapping, NMR, and the Evans method strongly suggest that this anion is either a triplet or a ground-state singlet with a very low energy triplet state.
A Pt-Cluster-Based Heterogeneous Catalyst For Homogeneous Catalytic Reactions: X-Ray Absorption Spectroscopy And Reaction Kinetic Studies Of Their Activity And Stability Against Leaching,
2011
University of California - Berkeley
A Pt-Cluster-Based Heterogeneous Catalyst For Homogeneous Catalytic Reactions: X-Ray Absorption Spectroscopy And Reaction Kinetic Studies Of Their Activity And Stability Against Leaching, Yimin Li, Jack Hung Chang Liu, Cole A. Witham, Wenyu Huang, Matthew A. Marcus, Sirine C. Fakra, Pinar Alayoglu, Zhongwei Zhu, Christopher M. Thompson, Arpana Arjun, Kihong Lee, Elad Gross, F. Dean Toste, Gabor A. Somorjai
Wenyu Huang
The design and development of metal-cluster-based heterogeneous catalysts with high activity, selectivity, and stability under solution-phase reaction conditions will enable their applications as recyclable catalysts in large-scale fine chemicals production. To achieve these required catalytic properties, a heterogeneous catalyst must contain specific catalytically active species in high concentration, and the active species must be stabilized on a solid catalyst support under solution-phase reaction conditions. These requirements pose a great challenge for catalysis research to design metal-cluster-based catalysts for solution-phase catalytic processes. Here, we focus on a silica-supported, polymer-encapsulated Pt catalyst for an electrophilic hydroalkoxylation reaction in toluene, which exhibits superior …
Spectroscopic Study Of Platinum And Rhodium Dendrimer (Pamam G4oh) Compounds: Structure And Stability,
2011
University of California - Berkeley
Spectroscopic Study Of Platinum And Rhodium Dendrimer (Pamam G4oh) Compounds: Structure And Stability, Yuri Borodko, Christopher M. Thompson, Wenyu Huang, Huseyin B. Yildiz, Heinz Frei, Gabor A. Somorjai
Wenyu Huang
Hydroxyl-terminated, poly(amidoamine) (PAMAM) dendrimer-capped platinum and rhodium nanoparticles were studied with UV−vis, Fourier transform IR, and UV-Raman spectroscopy. The adsorption bands in the region of 190−900 nm were shown to be sensitive to the electronic structure of Pt compounds in solution and in the solid state. The electron charge-transfer Pt2+ ← N band at 260 nm was attributed to mononuclear Pt2+ compounds, and resonance Raman (244 nm) established that the electron donors are amide nitrogen atoms. Multidentate coordination bonding with Pt2+ causes a strong stabilizing chelate effect, and this entropic factor hinders reduction of Pt2+ by BH4−. UV diffuse-reflectance spectra …
Rh1−X Pd X Nanoparticle Composition Dependence In Co Oxidation By No,
2011
University of California - Berkeley
Rh1−X Pd X Nanoparticle Composition Dependence In Co Oxidation By No, James Russell Renzas, Wenyu Huang, Yawen Zhang, Michael E. Grass, Gabor A. Somorjai
Wenyu Huang
Bimetallic 15 nm Pd-core Rh-shell Rh1−x Pd x nanoparticle catalysts have been synthesized and studied in CO oxidation by NO. The catalysts exhibited composition-dependent activity enhancement (synergy) in CO oxidation in high NO pressures. The observed synergetic effect is attributed to the favorable adsorption of CO on Pd in NO-rich conditions. The Pd-rich bimetallic catalysts deactivated after many hours of oxidation of CO by NO. After catalyst deactivation, product formation was proportional to the Rh molar fraction within the bimetallic nanoparticles. The deactivated catalysts were regenerated by heating the sample in UHV. This regeneration suggests that the deactivation was caused …
Photochemical Heterolysis Of 3,5-Bis(Dimethylamino)Benzyl Alcohols And Esters: Generation Of A Benzyl Cation With A Low-Energy Triplet State,
2011
University of Maryland - College Park
Photochemical Heterolysis Of 3,5-Bis(Dimethylamino)Benzyl Alcohols And Esters: Generation Of A Benzyl Cation With A Low-Energy Triplet State, Raffaele R. Perrotta, Arthur Winter, Daniel E. Falvey
Arthur Winter
An earlier computational study (CASPT2/pVDZ) by Winter et al. predicts the 3,5-bis(dimethylamino)benzyl cation to have nearly degenerate singlet and triplet states. Through product studies it is demonstrated that photolysis of 3,5-bis(dimethylamino)benzyl alcohol and its corresponding acetate and phenylacetate esters in alcoholic solvents produces a solvent incorporated adduct, 3,5-bis(dimethylamino)benzyl ethers, and 3,5-bis(dimethylamino)toluene.
Fabrication And Catalytic Property Of Cerium Oxide Nanomaterials,
2011
University of Nebraska-Lincoln
Fabrication And Catalytic Property Of Cerium Oxide Nanomaterials, Keren Jiang
Student Research Projects, Dissertations, and Theses - Chemistry Department
Cerium oxide, or ceria (CeOx: x = 1.5 to 2), has been widely used as a heterogeneous catalyst. Ceria has several properties make it high catalytic active: the fluctuating valence of cerium, the high oxygen storage capacity and high oxygen mobility in the nonstoichiometric ceria. With the high abundance of cerium on earth crust, ceria is a highly effective alternative of the noble metal catalysts. Research has been focused on designing nanostructured ceria and ceria related materials in recent years. The catalytic activity of ceria can be enhanced by the nanoscale effect which can be applied for various …
Elastic Properties Of Poly(Vinyldene Fluoride) (Pvdf) Crystals: A Density
Functional Theory Study,
2011
University of Nebraska-Lincoln
Elastic Properties Of Poly(Vinyldene Fluoride) (Pvdf) Crystals: A Density Functional Theory Study, Yong Pei, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
We computed structural and elastic properties of totally nine phases of poly(vinyldene fluoride) (PVDF) crystals using the density-functional theory (DFT) method with and without inclusion of the dispersion corrections. In addition to the four known crystalline forms, mechanic properties of five theoretically predicted crystalline forms of PVDF are also investigated. The all-trans form Ip exhibits the largest cohesive energy, bulk, and Young’s modulus among the nine crystalline forms. The DFT calculations suggest that the δ crystalline forms (IIIau, IIIpu, IIIpd, and IIIad) possess poor chain rigidity among the nine PVDF …
Structure Evolution Of Gold Cluster Anions Between The Planar And Cage Structures By Isoelectronic Substitution: AuN− (N = 13–15) And MauN− (N = 12–14; M = Ag, Cu),
2011
University of Nebraska-Lincoln
Structure Evolution Of Gold Cluster Anions Between The Planar And Cage Structures By Isoelectronic Substitution: AuN− (N = 13–15) And MauN− (N = 12–14; M = Ag, Cu), Rhitankar Pal, Lei-Ming Wang, Wei Huang, Lai-Sheng Wang, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
The structural and electronic effects of isoelectronic substitution by Ag and Cu atoms on gold cluster anions in the size range between 13 and 15 atoms are studied using a combination of photoelectron spectroscopy and first-principles density functional calculations. The most stable structures of the doped clusters are compared with those of the undoped Au clusters in the same size range. The joint experimental and theoretical study reveals a new C3v symmetric isomer for Au13 −, which is present in the experiment, but has hitherto not been recognized. The global minima of Au14 − and Au …
Analysis Of Electrodeposited Nickel-Iron Alloy Film Composition Using Particle-Induced X-Ray Emission,
2011
Hope College
Analysis Of Electrodeposited Nickel-Iron Alloy Film Composition Using Particle-Induced X-Ray Emission, Alyssa Frey, Nicholas Wozniak, Timothy Nagi, Matthew Keller, J. Mark Lunderberg, Graham F. Peaslee, Paul Deyoung, Jennifer R. Hampton
Faculty Publications
The elemental composition of electrodeposited NiFe thin films was analyzed with particle-induced X-ray emission (PIXE). The thin films were electrodeposited on polycrystalline Au substrates from a 100mM NiSO4, 10 mM FeSO4, 0.5M H3BO3, and 1M Na2SO4 solution. PIXE spectra of these films were analyzed to obtain relative amounts of Ni and Fe as a function of deposition potential and deposition time. The results show that PIXE can measure the total deposited metal in a sample over at least four orders of magnitude with similar fractional uncertainties. The technique is …
Heat Recovery Mechanism In The Excitation Of Radiative Polaritons By Broadband Infrared Radiation In Thin Oxide Films,
2011
James Madison University
Heat Recovery Mechanism In The Excitation Of Radiative Polaritons By Broadband Infrared Radiation In Thin Oxide Films, Anita J. Vincent-Johnson, Kyle A. Vasquez, John E. Bridstrup, Andrew E. Masters, Xiaofeng Hu, Giovanna Scarel
Department of Physics and Astronomy - Faculty Scholarship
This work probes radiative polaritons in thin oxide layers as a mean to capture and absorb broadband infrared radiation and transform it into heat. A heat recovery mechanism, based on the Seebeck effect, is used as the tool of the investigation. Heat production challenges the current understanding which views the excitation of radiative polaritons as only accompanied by the emission of electromagnetic radiation. The heat recovery mechanism presented here can inspire the design of infrared energy harvesting devices, similar to photovoltaic cells, and other devices to convert energy from a wide range of the electromagnetic radiation spectrum using thermoelectric power …
