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.
Results
Showing 1 to 20 of 35 for “"N-Heterocyclic Carbenes"”.
-
Introduction of a Novel Family of Bitopic N-Heterocyclic Carbenes
… to greener production 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 …
-
Coordination Chemistry of Fe–S Clusters Supported by N-Heterocyclic Carbenes
… on adjacent metal sites (here, monodentate N-heterocyclic carbenes), to obtain [Fe₄S₄] clusters for which subsequent reactivity can be localized to a single Fe site. That is, the steric bulk of di-aryl NHC ligands enables isolation of [Fe₄S₄] clusters in which three of the Fe centers are …
-
Self-Assembled Monolayers of N-Heterocyclic Carbenes on Gold and Silver: Applications in Biosensing
… standard. Our group has described a series of N-heterocyclic carbenes (NHC) which form SAMs on gold. As the carbene is attached to the surface via a metal-carbon bond, the problem of sulfidization may be overcome. Here, I describe the synthesis of a peptide for the application of heavy metal …
-
N-Heterocyclic Carbenes of the Late Transition Metals: A Computational and Structural Database Study
… study of the bonding in late transition metal N-heterocyclic carbene (NHC) complexes is reported. The results illustrate a metal-carbon bond for these complexes, approximately 4% shorter than that of a M-C single bond found in metal alkyl complexes. As a consequence of this result, two hypotheses …
-
Dianionic Janus-Type N-Heterocyclic Carbenes and their Zwitterionic Gold and Silver Metal Complexes
… chemistry of neutral 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 …
-
Molecular-level study of N-heterocyclic carbenes: Binding modes and self-assembly on Au(111)
… have been the gold-standard 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 …
-
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 …
-
Toward the Synthesis of Trianionic Cerberus-Type N-Heterocyclic Carbenes and their Zwitterionic Gold and Silver Complexes
… chemistry of neutral 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 …
-
Robust Nickel Catalysts Supported By Biaryl-Bridged Pyridyl-N-Heterocyclic Carbenes For Carbon Dioxide Reduction To Value-Added Products
… We report a family of biaryl-bridged pyridyl-N-heterocyclic carbene-based ligands and their corresponding nickel complexes. Ligand synthesis, structural characterization of complexes, and their application in electrocatalytic CO2 reduction are discussed.
-
Surface chemistry of N-Heterocyclic carbenes and the self-assembly, structure, and properties of polymer metal-organic cage gels
… as well as persistent and non-persistent carbenes. We synthesize from the reviewed reports a mechanistic understanding of this chemistry and outline the road ahead in this field. Chapter 2. Addressable Carbene Anchors for Gold Surfaces New strategies to access functional monolayers could …
-
Synthesis of Electron Deficient N-heterocyclic-carbenes and Activity of Imidazol-2-imine Thioureate Ligand on Group 10 Transition Metals
Previous work in the Lavoie group has resulted in the synthesis of new imidazol-2-imine ligands that have low activity towards ethylene polymerization due to their electron rich nature. In an attempt to alleviate this an electron poor naphthalene-1,4-dione-IMes imidazol-2-imine ligand (L) was …
-
Study of Bis-Imidazol-2-Ylidines as Ligands for Transition Metal Catalyzed Coupling Reactions
Two bis-imidazol-2-ylidine N-heterocyclic carbenes have been employed as ancillary ligands in an attempt to illustrate their utility in the palladium-mediated preparation of aryl ethers from aryl halides. Ullman-type homo-coupling of the aryl halides persistently occurred instead of ether …
-
Synthesis and characterization of various ruthenium small molecules and metallopolymers for potential use in photovoltaic devices and luminescence properties of N-heterocyclic carbenes and trifluoro methylated tris(pyrazolyl)borate silver (I) acid-base adducts
… photophysical studies of different metallo N-heterocyclic carbenes and acid-base adducts comprising fluorinated tris(pyrazolyl)borate silver(I) complexes coordinated to different solvent and aromatic molecules. These species have been investigated and found to exhibit unusual photophysical …
-
Progress in nucleophilic catalysis and development of nickel-catalyzed cross-couplings of propargylic halides
… a novel umpolung process catalyzed by N-heterocyclic carbenes. The second section discusses the first successful phosphine-catalyzed, y-alkylation reaction of isomerizable allenoates. A highly enantioselective variant of this reaction is described. Chapter 2 discusses nickel-catalyzed …
-
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
… Lastly, with the importance 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 …
-
Synthetic, Structural and Thermochemical Studies of N-Heterocyclic Carbene (NHC) and Tertiary Phosphine Ligands in the Ni(CO)2(L)x (L-PR3, NHC) Systems
Carbonyl complexes of Ni(0) incorporating two N-heterocyclic carbenes of the type Ni(CO)2(NHC)2 (NHC = ICy [N, N'-bis(cyclohexylimidazol)-2-ylidene], IMes [N, N'- bis(2, 4, 6-trimethylphenyl)-imidazol)-2-ylidene]) have been prepared. The complexes Ni(CO)2(ICy)2 (8) and Ni(CO)2(IMes)2 (9) have been …
-
Benign Catalysis and Expansion of Cyclobenzoins
… cyclotetrabenzoin. After testing a series of N-heterocyclic carbene catalysts, a suitable alternative was determined. Initial results indicated a substantial drop in yield, but optimizing conditions brought the production from the N-heterocyclic carbene conditions into line with the …
-
CERBERUS-TYPE TRISANIONIC TRISNHC AND ITS ZWITTERIONIC GOLD AND SILVER COMPLEXES
… chemistry of neutral 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 …
-
A New 2,1,3-Benzothiadiazole-Fused N-Heterocyclic Carbene and Its Metal Complexes
<p>In 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 …
-
Development Towards an Ethylene Sensing Artificial Metalloenzyme
… metalloenzyme. To 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 …
Page 1 of 2