Download or read book Novel Ferrocenediyl Ligands Their Transition Metal Complexes and Potential for Catalysis written by Charlotte Katherine Williams and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Novel Ferrocenediyl Ligands Their Transition Metal Complexes and Potential Towards Catalysis written by and published by . This book was released on 2001 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Synthesis and Properties of Novel Ferrocenyl transition Metal Complexes and Other Ferrocenes for Potential Application in Catalysis and Materials Chemistry written by Vincent Onserio Nyamori and published by . This book was released on 2001 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metallocenes in Regio and Stereoselective Synthesis written by Marko Hapke and published by Springer. This book was released on 2024-06-20 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the latest synthetic protocols for the assembly of functionalized Cp ligands and their transition metal complexes. Cyclopentadienyl (Cp) complexes of transition metals belong to the most important classes of transition metal complexes with tightly bound ligands in the coordination sphere since their discovery in the middle of the last century. Even though they have been known for a long time, this field constantly evolves to deliver novel modified Cp ligands and complexes and to blossom into new fields of application. Beside the synthesis of ligands and metal complexes this book concentrates on novel and prospering fields of their application in organic synthesis. In this respect the Cp complexes have been applied to induce and catalyze various significant chemical transformations such as new C-C bond formation involving unsaturated substrates (e.g. cyclotrimerizations, cycloadditions, carbometallations, etc.), C-H bond and C-C bond activations followed by subsequent reactions (e.g. arylation, alkenylations, annulations, etc.), as well as many other processes. This volume also covers the recent development and application of chiral Cp complexes in enantioselective synthesis.
Download or read book Novel N Ligand Stabilized Transition Metal Complexes of the Group IV Triad as Efficient Catalysts for Polymerization and Oligomerization written by Isabelle Haas and published by . This book was released on 2013 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rational Ligand Design for Potential Applications in Transition Metal Catalysis written by Sergey L. Sedinkin and published by . This book was released on 2011 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Strategies to influence the steric and electronic properties of three classes of ligands were investigated. First, a compound class known as amino-dithiaphospholanes was studied. It is structurally related to phosphoramidites, which have been successfully applied in catalysis. The synthesis of amino-dithiaphospholanes was envisaged as an approach to electronically tuned phosphoramidites. General access to a variety of structurally modified amino-dithiaphospholanes from commercially available starting materials was developed. The electron donating properties of the new ligands were characterized by NMR. They were found to be more electron-donating than the corresponding phosphoramidites. The coordination chemistry of amino-dithiaphospholanes was investigated by synthesis of a series of iridium and rhodium complexes. Analysis of the physical data obtained for the complexes confirmed the increase in the electron density at the metal centers as a consequence of the increased basicity of the ligands. Second, a series of new, as well as known, phosphinooxazoline (PHOX) ligands was synthesized. A systematic study of structure-property relationships was performed with the PHOX ligands. It was shown that electronic tuning of the ligands is possible by varying the substituents on the phenyl ring. However, the tuning was seen to have unexpected, and often only minor influence on the electronic properties of the metal complexes. The efficiency of steric tuning was investigated by evaluation of X-ray structure analysis data of new iron PHOX complexes synthesized for the study. It was shown that the presence of substituents in the position a to the nitrogen atom of the oxazoline ring had the most profound impact on the geometries of the corresponding metal complexes. Finally, five new multidentate N, O donating ligands (L) were synthesized and characterized. Their coordination chemistry was investigated by preparation of new iron complexes mimicking naturally occurring non-heme enzymes. The general formulation [Fe(L)2](OTf)2, [Fe(L)(OTf)2] or [Fe(L)(OTf)](OTf) was established for the new complexes, and formation of only one isomer was confirmed for one of the complexes. The catalytic activity of the new compounds was demonstrated in the oxidation of activated methylene groups and alcohols to the corresponding ketones.
Download or read book Syntheses of Novel Cyclopentadienyl and Indenyl Ligands and Their Transition Metal Complexes written by Jayesh Manoj Mehta and published by . This book was released on 1991 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transition Metal Complexes with P N ligands and Silylenes written by Eva Neumann and published by . This book was released on 2006 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Elucidating the Electronic Structure of Transition Metal Complexes Featuring Redox Active Ligands written by Linus Kai Ho Chiang and published by . This book was released on 2014 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis a number of projects involving the design and characterization of complexes bearing redox active ligands are described. Focusing on the phenolate containing ligands, the properties and electronic structure of their corresponding metal complexes were studied by a series of experimental (i.e. electrochemistry, UV-Vis-NIR, EPR, rR etc.) and theoretical (DFT) methods. Specifically, the redox processes of these metal complexes were tuned by varying the para-ring substituents. In one study, nickel-salen (salen is a common abbreviation for N2O2 bis-Schiff-base bis-phenolate ligands) complexes were investigated, where the oxidation potentials of the ligand were predictably decreased as the electron donating ability of the para-ring substituents was increased (NMe2 > OMe > tBu > CF3). Interestingly, the oxidation of these geometrically-symmetric complexes afforded an asymmetric electronic structure in a number of cases, in which the ligand radical was localized on one phenolate rather than delocalized across the ligand framework. This difference in electronic structure was found to be dependent on the electron donating ability of the substituents; a delocalized ligand radical was observed for electron-withdrawing substituents and a localized ligand radical for strongly donating substituents. These studies highlight that para-ring substituents can be used to tune the electronic structure (metal vs. ligand based, localized vs. delocalized radical character) of metallosalen complexes. To evaluate if this electronic tuning can be applied to the metal center, a series of cobalt complexes of these salen ligands were prepared. Indeed, the electronic properties of the metal center were also significantly affected by para-ring substitution. These cobalt-salen complexes were tested as catalysts in organometallic radical-mediated polymerizations, where the most electron rich complexes displayed the best conversion rates. With a firm understanding of the role that the para-ring substituent can play in influencing the electronic structure and reactivity of metallosalen complexes in catalysis, two novel iron complexes, which contain a number of redox active phenolate fragments, were prepared. In addition, these iron-complexes feature a chiral bipyrrolidine backbone. Ligands with this chiral diamine backbone bind metals ions diastereoselectively owing to its increased rigidity, which is critical to stereoselectivity in catalysis. A symmetric (with two phenolates) ligand was prepared by reported methods, and a novel route to synthesize an asymmetric ligand (one phenolate and one pyridine) from symmetric starting materials was established. The neutral iron-complexes were found to be high spin (S = 5/2), and can undergo ligand based oxidation to form an antiferromagnetically-coupled (Stotal = 2) species. The results presented will serve as the basis for catalyst development using complexes of similar ligands.
Download or read book Novel Ferrocenyl Ligands and Their Potential Applications in Catalysis written by and published by . This book was released on 2004 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ferrocenes written by Antonio Togni and published by John Wiley & Sons. This book was released on 2008-07-11 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt: With applications ranging from asymmetric catalysis to magnetic materials, ferrocene is one of the most versatile building blocks in synthesis. This book captures the multidisciplinary nature of ferrocene research, including topics such as ferrocene-containing polymers, ferrocene-containing thermotropic liquid crystals, chiral ferrocene derivatives, and ferrocene-containing charge-transfer materials. In addition, the reader will find * valuable information for planning syntheses * over 70 tables, making relevant data available at a glance * carefully selected references, providing an easy access to the primary literature Up-to-date, and written by leading international experts in the field, among them R. Deschenaux, C. D. Hall, Y. Butsugan, and R. Herrmann, this book is a welcome source of in-depth information for graduate students and professionals in organic, organometallic, and polymer chemistry, as well as in materials science.
Download or read book Interactions of Immobilized Transition Metal Complexes with Electrode Surfaces and Their Implications for Catalysis written by Felix Marc Brunner and published by . This book was released on 2021 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the incorporation of more renewable electricity into the power-grid leads to surplus generation, methods to utilize electricity to drive chemical reactions are becoming more relevant. Immobilizaton of molecular electrocatalysts combines the mechanistic understanding of molecular catalysts with the advantages of heterogeneous catalysts. Electrocatalysts of the type Ni(P2N2)2 are well-understood molecular catalysts that can achieve enzyme-like activity for hydrogen evolution and oxidation in solution. This extraordinary performance is attributed to their unique structure with proton shuttles in the second coordination sphere. Previously this amine substituent was used for surface attachment to immobilize this catalyst onto electrodes. However, the mobility of this substituent is crucial to the activity of the catalyst. We evaluated possible synthetic pathways to incorporate surface attachable functionality on the phosphine substituent of these ligands. Due to the high reactivity of the phosphines involved in the synthesis, incorporation of surface attachable groups through established synthetic protocols was found to be not feasible. A synthesis based on post-synthetic modification of P[superscript ArBr]2N[superscript Ph]2 was identified as the best way to incorporate attachable surface groups. This strategy was subsequently utilized to synthesize complexes of the type Ni(P2N2)2 with unprecedented, highly functionalized, surface attachable phosphine substituents. Phosphonate modified ligands and their corresponding nickel complexes were isolated and characterized. Subsequent deprotection of the phosphonic ester derivatives provided the first Ni(P2N2)2 catalyst that can be covalently attached via pendent phosphonate groups to an electrode without the involvement of hte important pendent amine groups. Mesoporous TiO2 electrodes were surface modified by attachment of the new phosphonate functionalized complexes, and these provided electrocatalytic materials that proved to be competent and stable for sustained hydrogen evolution in aqueous solution at mild pH and low over potential. We directly compared the new ligand to a previously reported complex that utilized the amine moiety for surface attachment. Using HER as the benchmark reaction, the P-attached catalyst showed a marginally (9-14%) higher turnover frequency than its N-attached counterpart. Finally, we report the synthesis of three new iridium piano-stool complexes that are immobilized on gold surfaces through thiol groups. We characterized these molecules using surface-sensitive IR spectroscopy. Further studies with these molecules are geared towards promoting the non-faradaic electrochemical tuning of catalysts using interfacial electric fields.
Download or read book Novel Ferrocenyl Complexes and Their Potential Applications in Catalysis written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Development of Novel Transition Metal Catalysts and Electrochemical Methods for the Formation of Carbon carbon and Carbon heteroatom Bonds written by Mikhaila D.. Ritz and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Transition metal catalysis has revolutionized modern synthetic methodology by enabling the facile activation and generation of sp2 and sp3 (hetero)carbon bonds. Thus, organometallic complexes are ubiquitous in the production of commodity chemicals, synthetic building blocks, and polymers. Although transition metal catalysis has been broadly used, there is still room for improvement in its efficiency, sustainability, and applicability. To this extent this dissertation will focus on employing different strategies to address these challenges. Chapter 2 will discuss the implementation of an electrocatalytic system for the metal catalyzed oxidation of alcohols and amines using benzoquinones as regenerable hydrogen acceptors. Chapter 3 will illustrate the design and development of a novel bisoxazoline-pincer ligated cobalt complex and its catalytic ability to hydrogenate alkenes, followed by discussion of exploratory work of this scaffold's early transition metal analogs and potential further catalytic reactivity. Lastly, chapter 4 will examine a set of trispyrazoylborate metal complexes for their capacity to perform direct arene borylation and compare the resulting reactivity to their heavily studied isoelectronic cyclopentamethyldienyl iridium counterparts. Analysis of the reaction reveals formation of nanoparticles leading to further characterization via XRD and TEM imaging."--Page x.
Download or read book The Synthesis of Novel Transition Metal Complexes Containing Amidinato Ligands written by David John Maloney and published by . This book was released on 1995 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Developments in Late Transition Metal Complexes of Ferrocene Based Ligands and Study of Their Efficiency as Catalysts in Asymmetric Reactions written by Marta Ayerbe Garcia and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Versatile Cooperative Ligand Effects in Group 9 Transition Metal Catalysis written by and published by . This book was released on 2015 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt:
