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Showing 1 to 20 of 201 for “"13C NMR"”.
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In situ High Pressure and Temperature 13C NMR for the Study of Carbonation Reactions of CO2
… using a novel, elevated pressure and temperature 13C NMR probe. Critical observations about reaction rates, chemical exchange, and pH measurements throughout these reactions and the implications of the in situ measurements made during these reactions are discussed. A new method is used to …
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Development and testing of a protocol for computational prediction of 1H and 13C NMR chemical shifts and thermochemistry and reaction analysis of benzyne formation and trapping
… of novel compounds, nuclear magnetic resonance (NMR) is by far the most widely applied. Investigation into new reactions may require any number of techniques to understand the reaction scope, kinetics, optimal conditions, mechanisms, etc. In both cases, the use of computational methods is …
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Synthesis and Characterization of Alkyl Tetra-, Tri-, and Triskaidecazirconates
… was identified as [Zr3O](OPrn) 10 by 13C NMR spectroscopy and elemental analysis. Ethanolysis of [Zr3O](OPrn) 10 yielded the ethoxy derivative of the trizirconate which was characterized by 13C NMR spectroscopy and elemental analysis. Reaction of the trizirconates with the parent …
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Determination of the Magnetic Structure of the Antiferromagnetic State of the Organic Superconductor Kappa-(bedt)(2)copper Dicyanamide Chloride Using Nuclear Magnetic Resonance and Magnetometry
We report 13C NMR and magnetometer measurements on the magnetic state of the organic superconductor kappa-(BEDT-TTF)2Cu[N(CN) 2]Cl. Various other magnetization and NMR studies have suggested that there is antiferromagnetic ordering of the electron spins in the magnetic state, but the detailed …
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Determination of the Magnetic Structure of the Antiferromagnetic State of the Organic Superconductor k-(BEDT)2Cu[N(CN)2]Cl Using Nuclear Magnetic Resonance and Magnetometry
We report 13C NMR and magnetometer measurements on the magnetic state of the organic superconductor k-(BEDT-TTF)2Cu[N(CN)2]Cl. Various other magnetization and NMR studies have suggested that there is antiferromagnetic ordering of the electron spins in the magnetic state, but the detailed ordering …
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An NMR Study of 2-Ethylbutyllithium/Lithium 2-Ethyl-1-butoxide Mixed Aggregates, Lithium Hydride/Lithium 2-Ethyl-1-butoxide Mixed Aggregates, n-Pentyllithium Aggregates, and n-Pentyllithium/Lithium n-Pentoxide Mixed Aggregates
A 13C and 6Li variable temperature NMR study of 2-ethylbutyllithium/lithium 2-ethyl-1-butoxide mixed aggregates formed from reacting 2-ethyl-1-butanol with 2-ethylbutyllithium in two O/Li ratios of 0.2/1 and 0.8/1. The 0.2/1 sample resulted in two 2-ethylbutyllithium/lithium 2-ethyl-1-butoxide …
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The synthesis, characterization and activation of some multinuclear catalyst precursors for olefin polymerization
… using techniques such as FTIR spectroscopy, 1 H NMR and 13C NMR spectroscopy, GC mass spectrometry and microanalysis. All new organometallic compounds produced were characterised using techniques such as 1 H NMR and 13C NMR spectroscopy. The polymers prepared were characterised by Gel Permeation …
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Palladium-Catalyzed Alkenylsilanol Cross -Coupling Reactions: Method Development and Mechanistic Analysis
… was examined through the natural abundance 13C NMR kinetic isotope effect (KIE) studies. This provided evidence for either palladium-olefin complexation or a Heck-type carbometalation as the turnover-limiting step for these cross-coupling reactions.
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An NMR Study of Trimethylsilylmethyllithium Aggregates and Mixed Trimethylsilylmethyllithium/Lithium trimethylsilylmethoxide Aggregates
An NMR spectroscopy study of trimethylsilylmethyllilthium, TMSM-Li, indicates that TMSM-Li exists as two different aggregates in cyclopentane solution. Using previously reported colligative properties of TMSM-Li in different solutions in connection with new 13C and 6Li NMR data collected in this …
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Further investigation of mental tris-quinolates using spectroscopy
… We present a comparative analysis of 1H and 13C NMR of nMeq3M's (n = 0, 2, 4, 5) made from thermal sublimation, in a polar as well as a non-polar solvent to investigate possible evidences for the isomer distribution, stability of the metal chelate in the presence of a polar solvent and …
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Modeling Diiron enzymes for alkanes activation
… complexes have been characterized by IR, 1H and 13C NMR spectroscopy, elemental analysis as well as by mass spectrometry.
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Metabolic flux, transport activity, and subcellular communication in intact hearts from dynamic ¹³C NMR spectroscopy
… metabolism was studied using carbon-13 (13C) nuclear magnetic resonance (NMR) spectroscopy to determine the ratelimiting steps in 13C labeling of glutamate. 13C NMR spectra were acquired from isolated rabbit hearts perfused with either 2.5 mM [2- 13C] acetate or 2.5 mM [2- 13C] butyrate, …
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In-situ 13C CM-MAS NMR study of dilute acid biomass pretreatment on 13C enriched poplar wood
In situ 13C NMR measurements are reported on 13C-enriched powdered poplar wood that is subjected to pretreatment with water and 0.5 M sulfuric acid as a function of time at 150 °C. 13C MAS (magic-angle spinning) spectra were obtained in both the CP (cross polarization) and DP (direct polarization) …
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Metallodendrimers as catalysts for C-C coupling reactions
… They were characterized by FTIR spectroscopy, 1H-NMR spectroscopy, 13C-NMR spectroscopy, micro-analysis and ESImass spectrometry.A reaction of the ligands with PdCl2(COD) or PdCl2(MeCN)2 gave palladium(II) complexes C1 – C4 in good yields of over 70%. The complexes were observed to be stable. …
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Lewis Base Catalyzed Enantioselective Aldol Additions: Preparative and Mechanistic Studies
Kinetic studies using ReactIR and rapid injection NMR (RINMR) spectroscopy have confirmed the existence of dual mechanistic pathways involving either one or two phosphoramides. Determination of Arrhenius activation parameters revealed that aldol addition occurs through the reversible albeit …
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Solid-state NMR (¹³C, ²⁷Al and ²⁹Si) study of the reaction between AlMe₃ and the silica gel surface
… surface after an excess-H2O workup. Solid-state NMR (13C, 27 Al and 29Si) have been used to elucidate the structures of moieties generated on the silica gel surface at each of the stages listed above. Solid-state 13C NMR showed that Al(Me)n is the major type of moieties generated on the surface …
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Theoretical Studies of the Solvation, Dynamics, and Photochemistry of Ethylene, Retinal Protonated Schiff Base, Oligocellulose, and Gd(III) Clusters
… of cellulose oligomers have been studied by 13C NMR relaxation techniques and compared to molecular dynamics (MD) simulations. We found evidence of anisotropic motion across the series, with experimentally determined order parameters (S 2) ranging from 0.30 to 0.52 and computationally …
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Some Aspects of the Chemistry and Petrology of Coking Coals
… were affected differently by solvent extraction. 13C NMR spectra, diffuse reflectance infrared spectra, and elemental analyses were obtained of each maceral group. It was found that chemical characterisation of the inertinite maceral group was not feasible and therefore only the vitrinite and …
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Isolation and characterization of bacterial polyhydroxybutyrate inclusions
… the isolated inclusions were characterized using 13C NMR, western blotting, SDS-PAGE, atomic force microscopy, and fluorescence microscopy. A model for the structure of native PHB inclusions is proposed.
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The polymerization of lactic acid anhydrosulphite by anionic initiators
… and this was identified by means of 1H and 13C NMR, elemental analysis and GC-MS. Since poly-α-esters having hydroxyl-bearing substituents might be expected to have high equilibrium water contents and hence low surface tension characteristics which might aid bio-compatibility, synthesis of …
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