Global ETD Search
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 28 for “"NHCs"”.
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Development of N-Heterocyclic Carbenes as Organic Catalysts and Efficient Ligands in Palladium Mediated Transformations
N-Heterocyclic carbenes (NHCs) have emerged as appropriate replacements for phosphines in transition metal catalyzed cross-coupling chemistry. The advantages of NHCs over phosphines include ease of handling, minimal toxicity, stability and powerful electron donating properties. Improvement of …
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Molecular-level study of N-heterocyclic carbenes: Binding modes and self-assembly on Au(111)
… for thirty years, N-heterocyclic carbenes (NHCs) have recently been used to create SAMs that are more thermally and chemically stable. For example, NHCs based on diisopropyl benzimidazolylidene (NHCiPr) have been integrated into biosensors. The field of NHC-based material science is very new …
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Synthesis of Well-Defined N-Heterocyclic Carbene (NHC) Complexes of Late Transition Metals
N-heterocyclic carbenes (NHCs) have emerged as appropriate replacements for phosphines to synthesized highly active metal complexes in homogeneous catalysis. The advantages of NHCs over phosphines include ease of handling, minimal toxicity and powerful electron donating properties. They bind …
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In support of natural history digitization: assistive tools for the mobilization of biodiversity data
… are preserved in natural history collections (NHCs). Recently, these collections began to make those data digitally available through online portals thereby improving their accessibility and usability. The processes involved in creating digital representations of these physical objects are, as …
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Scanning Probe Study of N-Heterocyclic Carbene Self-Assembly on Coinage Metal Surfaces
… anchor. More recently, N-heterocyclic carbenes (NHCs) have gained interest due to their increased oxidative and thermal robustness relative to the thiol. Since the emergence of NHCs in surface science, several key insights into how their structure relates to their adsorption motif have become …
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Increasing accessibility and enhancing value of two university small vertebrate collections through digitization and online database publication
Natural history collections (NHCs) are widely considered to be an exceptionally valuable resource and a critical foundation for research. Of the thousands of collections maintained today, the majority are considered small with a local or taxonomic focus. Collaboration among smaller NHCs through …
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COMPLEXES OF GROUP 10 METALS WITH NON-CLASSICAL AND THIOETHER-FUNCTIONALIZED N-HETEROCYCLIC CARBENE LIGANDS
… nucleophilicities, and novel pyrazole-derived NHCs and their catalytic activities in direct arylation reactions are presented. The third part is focused on indazolin-3-ylidene ligands, their coordination chemistry with palladium(II), and catalytic applications for the direct arylation of …
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Introduction of a Novel Family of Bitopic N-Heterocyclic Carbenes
… and a decrease in cost. N-heterocyclic carbenes (NHCs) have been recognized as a powerful class of ligands to metals, perhaps most notably in catalysis. This thesis introduces a family of bis-NHC ligands. This family links the N-alkylated benzimidazolium moieties by a bridge providing a rigid …
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A New 2,1,3-Benzothiadiazole-Fused N-Heterocyclic Carbene and Its Metal Complexes
… the last few decades, N-heterocyclic carbenes (NHCs) have emerged as a powerful class of carbon-based ligands. Owing to their unique electronic and steric properties, they have been incorporated in a large variety of catalytically active metal complexes. One of the strategies that have been used …
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Synthesis of Chiral Benzimidazolylidenes from 1,10-Phenathrolines and 1,10-Phenathroline-2,9-dione /
A^-heterocyclic carbenes (NHCs) have become the focus of much interest as ancillary ligands for transition metal catalysts in recent years. Their structural variability and strong cy-donation properties have led to the preparation of demonstrably useful organometallic catalysts. Among the three …
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Self-Assembled Monolayers of N-Heterocyclic Carbenes on Gold and Silver: Applications in Biosensing
… of silver surfaces with a series of NHCs, which might serve as appropriate candidates for use in an SPR sensor. X-ray photoelectron spectroscopy (XPS) data show the NHCs chemisorb intact on the surface, and the stability of the films to oxidation are explored under a range of …
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N-heterocyclic Carbene Synthesis Towards Self-Assembled Monolayers on Gold
… surface stability of n heterocyclic carbenes (NHCs) to a gold substrate. Here in we report the synthesis and modification of gold surfaces with NHCs containing unique functionality. Chemical synthesis was characterized using nuclear magnetic resonance spectroscopy techniques and SAM formation …
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Preparation of Novel Carbenes and their Catalytic Application to the Cross-Benzoin, Aza-Benzoin and Stetter Reactions
N-Heterocyclic carbenes (NHCs) derived from bicyclic triazolium salts possessing a fused 6 membered ring were found to induce chemoselectivity in the cross-benzoin between aromatic and aliphatic aldehydes. Use of these catalysts gave rise to predominantly one cross-benzoin product which could be …
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Fischer and N-heterocyclic carbene complexes of Group (VII) transition metals
… of Fischer- and N-heterocyclic carbene (NHCs) complexes of the group VII transition metals were investigated. By using density function theory calculations, the structural and electronic parameters could be elucidated and the fundamental bonding interactions between the carbene ligands …
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Exploring Photocatalytic and Electrocatalytic Reduction of CO2 with Re(I) and Zn(II) Complexes and Attempts to Employ a Novel Carbene Ligand to this Endeavor
… and popularity of N-heterocyclic carbenes (NHCs) as a class of ligands in the field of organometallic catalysis, six-membered perimidine based carbenes are further explored. Synthesis of a chelating pyridyl-perimidine NHC in addition to potential transition metal catalysts are also attempted.
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NEW GO- AND RGO-BASED MORALS AND CARBENE-FUNCTIONALIZED GOLD NANOPARTICLES FOR HETEROGENEOUSLY CATALYZED REDUCTIONS
… ligands that cap their surface. In recent years, NHCs have emerged as a powerful alternative to traditional thiol based ligands, offering stronger metal-ligand bonds, enhanced robustness under reaction conditions, and the possibility of fine tuning the electronic environment of the metal surface. …
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CERBERUS-TYPE TRISANIONIC TRISNHC AND ITS ZWITTERIONIC GOLD AND SILVER COMPLEXES
… multitopic nonchelating N-heterocyclic carbenes (NHCs), limited progress has been made in the development of their anionic counterparts. This thesis describes the synthesis and characterization of a novel trianionic NHC. The corresponding thione was generated through an NMR experiment of the free …
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Development Towards an Ethylene Sensing Artificial Metalloenzyme
… this end biotinylated N-heterocyclic carbenes (NHCs) were synthesized, which can be appended onto the ruthenium probe. Efforts towards the expression and purification of the protein scaffold are also here reported.</p> <p>Mycofactocin (MFT) is a ribosomally synthesized and post-translationally …
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Toward the Synthesis of Trianionic Cerberus-Type N-Heterocyclic Carbenes and their Zwitterionic Gold and Silver Complexes
… multitopic nonchelating N-heterocyclic carbenes (NHCs), limited progress has been made in the development of their anionic counterparts. This thesis describes the synthesis and characterization of a novel anionic tris(maloNHC) and its corresponding transition metal complexes. The free carbene was …
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Dianionic Janus-Type N-Heterocyclic Carbenes and their Zwitterionic Gold and Silver Metal Complexes
… multitopic nonchelating N-heterocyclic carbenes (NHCs), limited progress has been made in the development of anionic counterparts. This thesis describes the synthesis and characterization of two new dianionic bis(maloNHC). The corresponding thiones were generated by the reaction of the free …
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