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Showing 1 to 20 of 22 for “"Ammonium salt"”.
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Synthesis of Crown Ether/Ammonium Salt for Electron Transfer Study
… in this study are a series of crown ether/ammonium salt, which incorporate a redox partner on each component of the complex. The dimethoxynaphthalene redox donor was attached to the crown ether and a series of ammonium salts was synthesized which bear substituted quinone and naphthoquinone …
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The constitution of lead salts dissolved in ammonium salt solutions
Thesis: B.S., Massachusetts Institute of Technology, Department of Chemistry, 1903
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Direct oxidative Ammonia-Ammonium salt leaching of sphalerite concentrate from the Gamsberg Mine and study of the catalytic effect of Cu(II) on Zinc extraction
The feasibility of using ammonia-ammonium salts to selectively leach Zn over Fe from Gamsberg sphalerite flotation concentrate under moderate temperatures and atmospheric pressure was investigated in stirred tank reactors. This approach is suggested as an alternative primary method for extracting …
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Zur asymmetrischen Synthese von C-Azanucleosiden und 2-Amino-1,3-diolen
… removal of the acetonid protecting group the ammonium salt of the 2-amino-1,3-diols could be isolated. Using the methodology previously developed, the ammonium salt of D-erythro-sphinganine was synthesized starting from the Dioxanone-RAMP-hydrazone in a seven-step procedure. The desired …
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Disposal Methods for Diluted Herbicide Rinsates
… alachlor, metolachlor, 2,4-D DMA {dimethyl amine salt}, chloramben (ammonium salt). These compounds are the principal herbicides used in Illinois soybean and corn fields.
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A carbon-13 nuclear magnetic resonance study of a series of cyclohexanol amines
… alcohols, amines, and ammonium salts was undertaken and the resultant correlations were extended to a series of eight b-butylcyclohexanol amines and their hydrochloride salts. Among the effects examined were the substituent parameters of the mono- and difunctionalized …
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Design, synthesis, and biological evaluation of selective sphingosine kinase inhibitors
… of a SphK inhibitor containing a quaternary ammonium salt. We developed highly potent and moderately selective inhibitors that were cell permeable and interfered with S1P signaling inside the cell. In an effort to improve the selectivity of our inhibitors and enhance their in vivo stability, …
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Organocatalytic asymmetric mannich-type reactions: an easy approach to optically active amine derivatives
… by Cinchona alkaloid phase-transfer quaternary ammonium salt derivatives, using acetone cyanohydrin, a relatively harmless cyanide source (Scheme IV). The reaction proceeded very well providing the corresponding α-amino nitriles in good yields and enantiomeric excesses. Finally, we developed two …
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An Exploration of Ion Pairing Interactions as a Tool to Control Regioselectivity in Iridium-Catalysed C–H Borylation
… group on the ligand and cationic quaternary ammonium salt substrates, good to excellent meta selectivity was obtained with four classes of substrates, with various tether lengths between the arene and the ammonium functionality. Further functionalisation of the products was demonstrated and a …
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Synthesis and Characterization of Multiphase, Highly Branched Polymers
… Highly branched ionenes, which have a quaternary ammonium salt in the main chain, were synthesized with a modified Menshutkin reaction. The oligomeric A2 was comprised of well-defined telechelic tertiary amine endcapped poly(tetramethylene oxide). Reduced mechanical properties were observed for …
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Producing Enantiopure Secondary Alcohols via a Silylation based Kinetic Resolution and a One-Pot Polishing Sequence
… catalysts and fluoride sources including: ammonium salt catalysts with potassium fluoride, nucleophilic catalysts with benzoyl fluoride, and an ammonium fluoride salt complex. While desilylation was achieved with the catalysts and fluoride sources, none of the reactions were …
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Dimensional Stability and Properties of Thermoplastics Reinforced with Particulate and Fiber Fillers
… nano-clays surface modified with a quaternary ammonium salt that contained two hydroxyl groups as opposed to fine talc particles, the level of particle reinforcement could be reduced from 6 to 1 wt% without sacrificing the modulus of the reinforced PC/PBT composites. Further benefits included a …
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Investigation of a hydrometallurgical process route to recover metals from waste printed circuit boards
… liquid to solid ratio and choice of ammonium salt used in the buffer system, were investigated in the copper leaching optimisation stage of this thesis. Using ammonium carbonate resulted in lower recoveries compared to ammonium sulphate in the diagnostic leach test. Increasing the …
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Development of Electrolyte Salts for Multivalent Ion Batteries
… and electrochemical testing of new electrolyte salts for rechargeable multivalent ion batteries. In chapters 2 and 3 the synthesis of Mg and Ca hexafluoropnictogenate salts as well as the electrochemical behaviour of Mg(PF6)2 is presented. Pure samples of Mg(EF6)2 (E = P, As, and Sb) can be …
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Pseudorotaxanes and Supramolecular Polypseudorotaxanes Based on the Dibenzo-24-Crown-8/Paraquat Recognition Motif
… as examples. While the bis(hexafluorophosphate) salts of paraquat derivatives are predominantly ion paired in acetone (and other low dielectric constant solvents presumably) the complex based on dibenzo-24-crown-8 and paraquat is not ion paired in solution, resulting in concentration dependence …
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Chemical modification of smectite clays
… Wyoming bentonite with a long chain quaternary ammonium salt using the `dry' process affords a partially exchanged, 69-78%, organoclay, with a monolayer formation of ammonium ions in the interlayer. Excess ion pairs are sorbed on the silicate surfaces of both the clay mineral and the quartz …
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Structural and kinetic studies of surfactant and phospholipid monolayers at the air/liquid interface using sum-frequency generation spectroscopy
… of a fatty alcohol and a long chain quaternary ammonium salt, self-assembled from solution onto a silica surface (which serves as a very approximate model of the hair surface). SFG was used to investigate and the effects of temperature and ionic strength on the conformational ordering of the …
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Analogues of bredinin: Synthesis of 5-hydroxyimidazoles from acyclic precursors
… 3 of the imidazole ring, to form the quaternary ammonium salt, confirms that this is the most nucleophilic atom within the imidazole ring system.A novel linear synthetic strategy using acyclic precursors was developed which enabled the addition of substituents in positions 1, 2, 4 and 5 of the …
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Design and fabrication of ceramic beads and laminated composites for the study of stress wave mitigation
… powder dispersed in 17.3 wt% water using 0.8 wt% ammonium salt dispersant with 0.2 wt% polyvinyl alcohol (PVA) binder was used. After the drying of the alumina slurry, the mixture becomes a paste and it is fairly solid when left at rest, but will begin to flow under applied stress. With the …
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