Inorganic Chemistry Commons^™

Functionalized Ruthenatricarbadecaborane Via Selective Cage Iodination And Sonogashira Coupling Reactions, Ariane Perez-Gavilan, Larry Sneddon, Patrick J. Carroll

Articles

Selective iodination of the cyclopentadienylruthenium tricarbadecaboranyl complexes 1-(η5-C5H5)–2-Ph–closo-1,2,3,4-RuC3B7H9 (1) and 1-(η5-C5(CH3)5)–2-Ph–closo-1,2,3,4-RuC3B7H8 (2) to form their mono-iodo derivatives, 1-(η5-C5H5)–2-Ph–6-I–closo-1,2,3,4-RuC3B7H9 (3) and 1-(η5-C5(CH3)5)–2-Ph–6-I–closo-1,2,3,4-RuC3B7H8(4), was achieved in 90% yields by their reactions with ICl in CH2Cl2 solutions. Also isolated in trace amounts from the reaction with 2 was the di-iodo 1-(η5-C5(CH3)5)–2-Ph–6,11-I2–closo-1,2,3,4-RuC3B7H7, (5) complex. The sonication-promoted Sonogashira coupling reaction of 3 with terminal acetylenes catalyzed by Pd(dppf)Cl2/CuI yielded the functionalized ruthenatricarbadecaboranyl complexes 1-(η5-C5H5)–2-Ph–6-(Ph-C≡C)–closo-1,2,3,4-RuC3B7H8 (6), 1-(η5-C5H5)–2-Ph–6-[CH3CH2C(O)OCH2-C≡C]–closo-1,2,3,4-RuC3B7H8 (7), …

Relating Dynamic Protein Interactions Of Metallochaperones With Metal Transfer At The Single-Molecule Level, J. J. Benítez, A. M. Keller, D. L. Huffman, Liliya A. Yatsunyk, A. C. Rosenzweig, P. Chen

Chemistry & Biochemistry Faculty Works

Metallochaperones undertake specific interactions with their target proteins to deliver metal ions inside cells. Understanding how these protein interactions are coupled with the underlying metal transfer process is important, but challenging because they are weak and dynamic. Here we use a nanovesicle trapping scheme to enable single-molecule FRET measurements of the weak, dynamic interactions between the copper chaperone Hahl and the fourth metal binding domain (MBD4) of WDP. By monitoring the behaviors of single interacting pairs, we visualize their interactions in real time in both the absence and the presence of various equivalents of Cu(1+). Regardless of the proteins' metallation …

Synthesis Of An Antimicrobial Textile Coating, William M. Morris

Chemistry and Biochemistry

A titania nanosol was synthesized and coated onto nylon/cotton blended textile substrates. The substrates were characterized via SEM for adhesion and nanoparticle formation, then subjected to antimicrobial efficacy tests. The titania nanosol was successfully coated on to textiles samples. Particles were observed to be around 2 by 3 micrometers and formed between the interstitial space of textile fibers. Although larger than typical nanoparticles, the coatings exhibited what seemed to be antimicrobial activity. Titania nanosol coated textile samples were subjected to Kirby Bauer Assay in the presence of S. aureus. The coated textile sample exhibited an inhibition of growth around its …

The Tetrafluoroborate Salt Of 4-Methoxybenzyl N-2-(Dimethylamino)Ethyl-N-Nitrosocarbamate: Synthesis, Crystal Structure And Dft Calculations, Helene Hedian, Vladimir Benin

Chemistry Faculty Publications

The tetrafluoroborate salt of 4-methoxybenzyl N-2-(dimethylamino)ethyl-N-nitrosocarbamate was prepared in two steps, via the corresponding carbamate. Its crystal structure is monoclinic, space group P21/c. The unit cell dimensions are: a = 19.499(8) Å, b = 5.877(3) Å, c = 15.757(7) Å, α = 90°, β = 110.019(7)°, γ = 90°, V = 1696.5(12) Å3, Z = 4. The structure exhibits an unexpected, pseudo-gauche conformation with respect to the C2–C3 bond, due to a stabilizing hydrogen bond between the carbonyl oxygen (O1) and the hydrogen atom at the trialkylammonium center (H3n), with a distance between them of …

Electrochemistry Of Pani/Metal Composites In Basic Solutions, Tamthinhan Quy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Polyaniline (PANI) has been extensively investigated due to its unique conductivity, which is primarily dependent on the oxidation state of the material and the solution pH. PANI is an insulator when it is oxidized, and the solution pH exceeds four. Numerous attempts to extend PANI's conductivity to neutral and alkaline environments have been unsuccessful. However, our previous study has demonstrated that PANI/Pd composite is conductive and catalytically active in a basic solution, pH ∼ 12. Therefore, the conductivity and the electrochemical properties of PANI composites including PANI/Au, PANI/Pd and PANI/Pt were evaluated in basic solutions. The fundamental studies of PANI/metal …

Sweep, Step, Pulse, And Frequency-Based Techniques Applied To Protein Monolayer Electrochemistry At Nanoparticle Interfaces, Debbie S. Campbell-Rance, Tran T. Doan, Michael C. Leopold

Chemistry Faculty Publications

Protein monolayer electrochemistry (PME), a strategy using synthetic platforms to study the electron transfer (ET) properties of adsorbed proteins, has been successfully applied to proteins adsorbed at monolayer-protected gold cluster (MPCs) assembled films, an adsorption interface shown to be an effective alternative, compared to traditional self-assembled monolayer (SAM) films, for the immobilization and study of ET proteins. Within PME studies, cyclic voltammetry (CV) remains the most commonly applied electrochemical technique in spite of several limitations that occur when the sweep technique is used at either platform. In particular, CV for PME at MPC films results in analysis complications stemming from …

Computational Studies Of Ion Transport In Polymer Electrolytes, Hui Wu

Doctoral Dissertations

Improving ionic conductivity and lithium mobility in polymer electrolytes is important for their practical use for battery electrolytes. In this study, a combination of molecular dynamics and Monte Carlo simulations was used to bring insight into lithium ion transport in poly(ethylene oxide) (PEO) with plasticizers and also next to alumina solid surface doped with lithium salt. The simulations were performed using a moderately high molecular weight polymer (Mn = 10,000 g/mol) at an EO:Li ratio of 15. For the plasticized system, the PEO with LiN(CF3SO 2)2 (LiTFSI) was mixed with 10 wt% plasticizers that included either cyclic ethylene carbonate …

Optical And Electrochemical Properties Of Multi-Layer Polyelectrolyte Thin Films Incorporating Spherical, Gold Colloid Nanomaterials, Tran T. Doan, Robert W. Day, Michael C. Leopold

Chemistry Faculty Publications

Polyelectrolyte multilayer (PEM) films incorporating various types of spherical, gold nanomaterials (NMs) were investigated to assess the existence of electrochemical and/or optical signal enhancement effects directly attributable to embedded NMs and the relationship of these effects to film structure and composition. Specifically, electrostatically assembled films of cationic poly-L-lysine (PLL) and anionic poly(4-styrene sulfonate) (PSS) incorporating one of four types of spherical, gold colloid NMs were constructed on 3-(aminopropyl)trimethoxysilane (3-APTMS)-modified glass substrates for optical studies or 11-mercaptoundecanoic (MUA)-modified gold electrodes for electrochemical studies. The NMs inserted into the PEM films include citrate-stabilized gold nanoparticles, thioctic acid-stabilized gold nanoparticles (TAS-NPs), MUA-modified monolayer …

Quenching Of The Fluorescence Of Tris (2 2-Bipyridine) Ruthenium(Ii) [Ru(Bipy)3]2+ By A Dimeric Copper(Ii) Complex., Kevin E. Cummins

Electronic Theses and Dissertations

The quenching of the [Ru(bipy)₃]²⁺ by Cu₂L²⁺ was studied and the data were plotted with the Stern-Volmer equation. The plot showed a break and was divided into 2 regions, <0.5 and >0.5 Cu₂L²⁺: [Ru(bipy)₃]²⁺ molar ratio. Quenching above the 0.5 Cu₂L²⁺: [Ru(bipy)₃]²⁺ molar ratio was slower (330 x 10^-6 M^-1s^-1) than the quenching rate reaction below 0.5 ratio (387 x 10^-6 M^-1s^-1).

With Cu₂L²⁺ being a dimeric complex the …

Select Ruthenium Complexes As Potential Candidates For Thiol Ligation, Adam Blake Reinhart

Student Theses and Dissertations

Hydrodesulfurization is an industrial process used to remove sulfur impurities from fossil fuel feedstocks in order to prevent air pollution and acid deposition. The sulfur impurities are passed over a transition-metal sulfide catalyst producing pure hydrocarbons and usable sulfur byproduct. The current process occurs under high temperature and pressure. Molecular models of the catalyst/substrate interaction have been synthesized in order to study the electron density about the sulfur atom and thus give insight to the HDS activity of the complexes. CpRu(dppe)Cl and Ru(9S3)(dmso)Cl2 were studied for their ability to coordinate thiols. A new preparative method using microwave-assisted synthesis was found …

Vapor Liquid Solid Growths Of Germanium And Gallium Antimonide Nanowires, Ralph Alvarez, Esmeralda Arreola, Michael Oye, Meyya Meyyappan

STAR Program Research Presentations

Determining the optimal growth parameters for germanium (Ge) and gallium antimonide (GaSb) nanowires is the focus of this research. Given the fact that nano materials behave differently from their bulk counterparts we are researching some variables that influence nanowire diameter and length such as temperature, ramp rate, gas flow rate, and catalyst particle size. Based on the nano material size which is typically a few 10s of nanometers wide, these nano materials can be engineered to take advantage of their optical properties. Specifically the infrared (IR) response of Ge and GaSb nanowires are directly controllable based on their geometry. Fine …

Spectroscopic Properties Of Lanthanide (Iii) Compounds In Aqueous And Ionic Media, Orissa A. Burghard, Sayandev Chatterjee, Zheming Wang, Samuel A. Bryan

STAR Program Research Presentations

Lanthanide containing materials are receiving increasing attention due to their wide range of potential applications including bioanalytical imaging, dye-sensitized solar cells, nano-biotechnology and catalysis. The unique spectroscopic properties (intense and sharp emission bands with high color purity and high quantum efficiency) of lanthanides make them strong candidates for use as bio-markers or selective detectors. The attractiveness of lanthanides as future imaging agents as well as recent interest in their potential use in biological media has increased the need to understand the behavior of lanthanides in the presence of other ions or in ionic media.

The complexity of the biological media …

Solid-State Synthesis Of Imide Ligands For The Self-Assembly Of Metal-Organic Materials, Jason Alexander Perman

USF Tampa Graduate Theses and Dissertations

In this research project, reduction or complete elimination of organic solvents is explored in the synthesis of cyclic imides using a technique that brings reagents into favorable position to react. Cocrystal Controlled Solid-State Synthesis (C³S^y3), takes advantage of supramolecular interactions such as hydrogen bonding and π-π stacking to form a cocrystal which can sequential be heated to complete the condensation reaction and produce a desirable product. Twenty-five successful condensation reactions result in high and clean yield.

C³S^y3 of cyclic imides with auxiliary hydrogen bonding moieties like carboxylic acid, carboxylate or pyridyl groups are …

Synthetic And Mechanistic Studies Of Coupling Reactions Involving C-H Bond Activation, Ki Hyeok Kwon

Dissertations (1934 -)

Transition metal-catalyzed C-C bond forming reactions involving C-H bond activation have been shown to be effective methods for functionalization of unreactive compounds. Since Murai's pioneering work on ruthenium-catalyzed regioselective arene-to-alkene coupling reactions, a number of well-defined, late transition metal catalysts have been shown to mediate regioseletive C-C bond forming reaction involving C-H bond activation. Recently, late transition metal complexes have also been found to catalyze the regioselective coupling reaction of nitrogen containing compounds with alkenes as well as sp3 bond insertions and oxidative coupling reaction of aimdes. The catalytic C-C bond forming reaction involving C-H bond activation would provide simple …

Application Of Raman Spectroscopy To Lubricants, Lubricated Surfaces And Lubrication Phenomena, David W. Johnson

Chemistry Faculty Publications

Recent advances in lasers and detector technologies and the development of low-cost instruments and fiber-optic probes have brought about an explosion in the lubrication systems being studied by Raman spectroscopy. This article provides examples of the use of Raman spectroscopy in the study of lubrication phenomena, including the characterization of liquid lubricants, lubricant additives, and solid lubricants; the study of vapor-phase lubrication; and the use of coated nanoparticles as lubricants.

Part A: The Use Of Nonionic Associative Polymers For The Thickening And Emulsifying Of Personal Care Products/ Part B: The Synthesis Of A Manganese Sod Mimetic For Reactive Coatings, Mallory Lynn Mcmahon

Master's Theses

Part A

The use of nonionic associative thickeners was proposed for personal care applications.  Various limitations of current rheology modifiers used in personal care were discussed.  Nonionic associative polymers were examined as both thickeners and emulsifiers.  The structure/property relationship for nonionic polymers and their ability to thicken and emulsify were fully examined.  Results showed an increase in thickening efficiency for nonionic associative polymers with higher log(P) (partition coefficient) values.  This was due to the formation of smaller aggregates and increased bridging between aggregates.  The connection between oil polarity, log(P) of the associative polymer, and emulsion stability showed no relationship however; …

Extraction Chromatographic Studies Of Rutherfordium And Dubnium Homologs, Megan E. Bennett

UNLV Theses, Dissertations, Professional Papers, and Capstones

Studying the chemistry of transactinide elements does not only allow for these elements to be properly placed in the Periodic Table, but it also permits for the extrapolation of the electronic structure based upon the position of the element in the Periodic Table. In addition it enable for the assessment of the role that relativistic effects play in the chemical behavior of the heaviest elements. An improved understanding of the role of relativistic effects in chemistry of the heaviest elements allows for a better understanding of the fundamentals principles that govern the Periodic Table. In order to investigate the chemistry …

Synthesis And Characterization Of Extended Solids Containing Nano-Sized Transition Metal Oxide Lattices, Matthew Williams

All Dissertations

In this research, focus has been placed on the study of magnetic anomalies due to geometric frustration of magnetic ions. The goal of the study presented in this dissertation was to synthesize pseudo&ndashlow&ndashdimensional (PLD) compounds, those structures showing zero (dot), one (chain), and two (sheet) dimensional lattices observed in extended (3D) host frameworks with enhanced anisotropic physical properties, in an attempt to elucidate some structure&ndashproperty correlations arising from magnetic spin confinement. The scope of this research involved 1) exploratory synthesis of novel, low&ndashdimensional transition metal oxide lattices, specifically Mn and V, embedded in non&ndashmagnetic oxyanion frameworks, either Ge, P, or …

Resorbable Polymer-Hydroxyapatite Composites For Bone Trauma Treatment: Synthesis And Properties, Troy E. Wiegand

Department of Chemistry: Dissertations, Theses, and Student Research

Contemporary therapies for hard tissue replacement involve allographs, where the donor and recipient are of the same species, or the use of xenogenic transplants.  Intraspecies materials are often in short supply and interspecies materials are subject to immunological barriers such as disease and tissue rejection.  Synthetic composites are unencumbered by these limitations.  Poly lactic acid (PLLA) and its copolymers have been used in medicine due to their ability to be resorbed by the body without adverse effects.  PLLA’s are currently most commonly used in resorbable sutures and gauzes, but there is increasing interest in using them in conjunction with hydroxyapatite …

Dna-Inks For 3-D Printing: Dna Composites For The Rapid Prototyping Of Scaffold In Bioengineering Applications, Jimena I. Aguirre^, Ryan B. Wicker, Mireya A. Perez, Juan C. Noveron*, Juan M. Sanchez

COURI Symposium Abstracts, Spring 2011

Rapid-prototyping has become an incredible technique that manufactures three-dimensional objects with intricate complexity down to 8µm of resolution. We are developing materials that can be used by rapid-prototyping instruments to make scaffolds for bioengineering applications. Our molecular design involves the polymerization of a  (vinylbenzyl)trimethyl-ammonium chloride and DNA solution. Upon UV illumination, the composite polymerizes and forms DNA-hybrid materials.  The end result becomes a ductile transparent material with a thin cross-section. The synthesis, characterization and application of rapid prototyping will be described. Scanning Electron Microscopy (SEM), Light Scattering Detector (LDS), Nuclear Magnetic Resonance (NMR), and Infrared Spectroscopy indicate the structure, characteristics, …