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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 37 for “"deuteration"”.
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Isotopic labelling applied to the infrared spectra of metal complexes
… nitrates, perchlorates and halides is reported. Deuteration of the imidazole ring provides reliable assignments for the internal vibrations of imidazole. This technique also permits unambiguous assignments of the internal vibrations of nitrate or perchlorate by their lack of deutero-sensitivity. …
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Nondirected C(sp2)–H Activation of (Hetero-)Arenes Through Ligand-Enabled Palladium Catalysis
… establishing useful synthetic methods are deuteration studies. Chapter 3 shows how newly prepared ligands were used to develop a broadly applicable method for the per-deuteration of several classes of heteroarenes. Reaction optimization was performed using a multi-substrate-screening …
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Isotopic labelling applied to the infrared spectra of metal complexes
… to the band shifts induced by ¹⁵N-labelling and deuteration of the pyridine ring and by metal ion substitution. ¹⁵N-Labelling aids in establishing the pyridine ring vibrations, while deuteration and metal substitution are more useful in assigning the νM-L frequencies. Results of the isotopic …
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The Application of Pulsed Electron Paramagnetic Resonance to the Investigation of Protein Structure
… on the signals strength and persistence, with deuteration of both the underlying protein structure and surrounding media found to increase both the signal intensity and persistence. Within this thesis the current use of PELDOR for investigating disordered areas of protein structure along with …
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Isotopic labelling applied to the infrared spectra of metal complexes
… together with metal-ion substitution, deuteration and ¹⁵N isotopic labelling of the amino group in 2-aminomethylpyridine enable reliable band assignments to be made. The study shows that in complexes of the type M(amp)nX₂, metal-to-amino-nitrogen stretches occur at frequencies greater …
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Superelectrophiles and their chemistry
… VII underwent regiospecific hydrogenation (or deuteration) in the 2-position to give pyridinium disalt XIII (or XIV in the case of deuteration). In this case, 2-DMAP disalt VII showed similar reactivity to the substrate CH≡H₄MPT⁺ in the [Fe]-hydrogenase enzyme. This significantly enhanced …
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Asymmetric hydrogenation of unfunctionalized trisubstituted and tetrasubstituted olefins
… increased with increasing pressure. Again, deuteration experiments showed that isomerization processes may occur under the reaction conditions.
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Selective functionalization of azines via phosphonium salts
… pharmaceuticals using azinyl phosphonium salts. Deuteration is commonly used as a means to deter unwanted oxidative metabolism on drugs, and tritium is installed as a radiolabel for metabolic studies in the pharmaceutical industry. The protocol of the reaction is simple, and it functions on a …
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High field dynamic nuclear polarization methods: Microwave sources and mechanisms
… the Overhauser mechanism through selective deuteration of radicals, leading to a relatively simple modification which yielded a significant increase in Overhauser enhancement. Finally, I detail studies of two unexplored DNP mechanisms in trityl: the three-spin solid effect and resonant …
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Low Absorption Liquid Crystal Materials for Midwave Infrared
… approaches have been considered, such as deuteration, fluorination, and chlorination. The fluorine and chlorine not only act as the polar group to provide dipole moment but also helps shift some vibration absorption bands outside the MWIR window. Long phenyl ring compounds, fluorinated …
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Mechanism of the hydropyrolysis of Manvers coal
… to distinguish between direct hydrogenation (deuteration!) of the coal and the products of pyrolysis and the 'shuttling' of hydrogen atoms between different parts of the pyrolysing coal. The addition to the coal of 5% (wt.% of coal) of either tetralin or pyrite was also studied. A variety of …
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Structure, conformational dynamics and formation of large amyloids: the case of alpha-synuclein fibrils
… We first investigated the effect of protein deuteration and 1H decoupling optimization to maximize the resolution and sensitivity of biomolecular solid-state NMR; We then applied state-of-the-art solid-state NMR experiments to do a detailed structural characterization and conformational …
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Diastereoselective Synthesis of Planar Chiral N-Substituted Ferrocenes Derived from Epimeric Imidazolones and their Application to Asymmetric Hydrogenation of Quinolines
… of the base, comparison of enantiomers, deuteration experiments, nOe difference studies and computational modeling of the ground states and lithiation transition states for both substrates. The products are then converted to ligand precursors to make iridium and rhodium complexes. Among …
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Dynamic nuclear polarization of amorphous and crystalline small molecules
… better spectral resolution but requires heavy deuteration to attenuate proton relaxation. Further application of DNP to nanocrystalline acetaminophen embedded in cellulose membrane as an undissolved suspension in organic solvent was less successful due to the fast methyl group motion within the …
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Characterizing Conformational Dynamics and Catalytic Activity of Enzymes by Hydrogen-Deuterium Exchange Mass Spectrometry
… resolved HDX experimentation was used to monitor deuteration events concurrently with catalytic activity on the millisecond to second timescale. Native mass spectrometry enabled studies into binding affinity and monitoring of substrate inactivation on a measured time course. Ion mobility mass …
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Studies towards a total synthesis of Hippeastrine
… by treatment with n-butyllithium. Lithiation and deuteration of 6-bromopiperonylic acid (98) , 2-bromobenzoic acid (136) and of 2-bromo-5-methoxybenzoic acid (140) were investigated by using various reagents such as n-butyllithium, LiHMDS and NaH to find the best route for the arylation of 98 to …
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Supramolecular approaches to cryorelaxors for biological NMR studies
… in T1 at low temperatures with higher levels of deuteration of the system studied, the p-iso-propylcalix[4]arene (2:1) p-xylene complex has been shown to have the best relaxation properties. Synthetic strategies towards calixarene and fullerenes complexes bearing active biological anchors are …
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Gold compact disc appended Tröger’s base scaffolds as MALDI-TOF biodetection probes
… report a new protocol for the mild and efficient deuteration of terminal alkynes and their subsequent use in organic chemistry.
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Short-time interdiffusion at polymer interfaces: A probe to study polymer motion
… end fractions were deuterated. Since, the total deuteration was equal in both the polymers, initially, the concentration of H and D segments was 0.5 at all depths in the HDH/DHD bilayer. Upon interdiffusion, if the polymer chains reptate, i.e., move ends first, a local enrichment of D in the HDH, …
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Spectroscopic investigations on the molecular motions and solution chemistry of the medicinal pigment curcumin.
… of curcumin is the rate limiting step of the deuteration at the α-carbon position (Cα), the rate of tautomerisation is inferred from the rate of deuteration at the Cα of curcumin. The proton resonance peak corresponding to the hydrogen of Cα decays as a function of time, signifying a …
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