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Showing 1 to 15 of 15 for “"ligand effects"”.
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Systematic Studies on the Chelating Ligand Effects of Novel Borafluoronium Ions
… characterization of borafluoronium ions via a ligand-based strategy using bidentate amine and phosphine bases as chelating agents to cationic boronium ions.The borafluoronium complexes A–C were synthesized in high yields (80%–95%) and characterized using NMR spectroscopy and single crystal …
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Exploiting imidate ligand effects in transition metal-mediated C-C bond forming processes
The effects of substituting (pseudo)halide for imidate ligands in Au(I) and Au(III) ([AuBr(NHC)] and [AuBr3(NHC)]), Ru(II) ([RuCl2(CHR)(L2)]) and Pd(II) ([Pd(OAc)2]) complexes has been investigated. The activity of these complexes as (pre)catalysts in enyne cycloisomerisation and propargylic …
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Gold Nanomolecules : Developing Synthetic Protocols, Characterization And Investigation Of Ligand Effects On Structure And Properties
… a fixed number of gold atoms and organo-thiolate ligands. They are of the form Aux(SR)y and possess molecule-like properties as a result of distinctive quantum confinement effects occurring at the nanoscale size. The optical and electronic properties of these molecules change as a function of "x" …
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Study of the ligand effects on the metal-ligand bond in some new organometallic complexes using FT-Raman and -IR spectroscopy, isotopic substitution and density functional theory techniques
… containing the isoelectronic ligands 13C=13CH2 and CO, which have the same reduced mass, indicated that the Rh-C bond is stronger in the carbonyl than in the vinylidene complex. Besides, the n(RhF) stretching mode, which has been observed at higher wavenumbers in the FT-Raman …
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Electrocatalysis in Alkaline Media: Mechanistic Studies of Fuel Cell Reactions on Well-Defined Model Catalysts
… methanol dehydrogenation through two distinct ligand effects: it increases the intrinsic dehydrogenation activity of adjacent Pt sites, and it causes CO to diffuse away from these active sites, decreasing the CO poisoning effect. A Ru ligand effect also enhances CO oxidation by weakening the …
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A Theoretical and Experimental Investigation of the Physical and Chemical Properties of Solid Nanoscale Interfaces
… and (ii) deconvoluting the intrinsic (size effects) and extrinsic (ligand effects) physical and electronic properties of Au NPs encapsulated by polystyrene 2-vinylpiridine ligands.
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Enantioselective nickel-catalyzed reductive coupling reactions of alkynes and aldehydes. Synthesis of amphidinolides T1 and T4 via catalytic, stereoselective macrocyclizations
… alkynes and aldehydes was studied for ligand effects with respect to the regioselectivity and enantioselectivity of the coupling process. A class of P-chiral, ferrocenyl phosphines was designed, synthesized, and evaluated for efficacy. Ultimately, these phosphines were found to be the …
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Steric and kinetic measurements at well-defined surface sites
… surface allow for the decoupling of individual ligand properties from surface-solution ligand dynamics, a phenomenon on semiconductor and metal nanoparticles that inhibits the rational study of ligand effects on those materials. The covalent linkage to carbon is exploited in two different ways. …
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Investigation of catalyst effects in enantioselective copper- and rhodium-mediated transformations of α-diazocarbonyl compounds
… at the site of insertion), the copper source, ligand, counterion, additive and solvent was undertaken to provide an insight into the mechanistic basis for enantiocontrol in the synthetically powerful C–H insertion process and to enable optimisation of enantiocontrol and ligand design. Perhaps …
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Rapid Synthesis, Characterization, and Catalytic Function of Rhodium(III) and Iridium(III) Chloro-bridged Dimers
… 3 examples). Reaction of the Me4CpHR ligands with [M(COD)](μ2-Cl)2 (M = Rh, Ir; COD = 1,5-cyclooctadiene) produced the dimeric complexes [Cp*RMCl]2(μ2-Cl)2 in moderate to excellent yield. The resulting dimers were characterized by nuclear magnetic resonance (NMR) spectroscopy, …
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Enantioselective synthesis and reactivity of bicyclobutanes: strained molecular platforms for 4-, 5-, and 6-membered ring synthesis and rhodium(II)-catalyzed reactions of diazoesters with organozinc reagents
… undesired pathway by studying temperature and ligand effects has further extended the powerful chemistry of diazocompounds. Rhodium(II)-catalyzed intermolecular cyclopropanation of diazoesters and alkenes has been widely studied and applied to complex synthesis; however, reports of …
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Electrocatalytic dioxygen reduction with copper complexes
… electrophilicity. Attempts at understanding the ligand effects on the ORR are studied in Chapter 3. Many ligands based on the CuTPA motif were studied. A series of ligands that raise the CuI/II couple potential are found to have no effect on the overpotential for the ORR. Similarly, addition of …
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Direct oxidation of methane to methanol
… is explored. CO has a considerable effect as a ligand, explaining the experimental requirement for CO to have a trace presence in the system. Despite water also being required experimentally, a minimal ligand effect is found. However, water is found to be crucial as a hydrogen source for a key …
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Materials with engineered mesoporosity for programmed mass transport
… to reach this goal, is the surface chemistry/ligand effects on Ni2+. Cation exchange was performed in order to obtain CuS MHS; however, it proved an unsuccessful route to PbS, S and HgS. CdS-ZnS, Bi2S3 and Ag2S MHS were obtained only with significant defects. A novel hierarchically structured …