Download or read book Syntheses and Structures of Iron II and Cobalt II Complexes of Substituted Tetra pyrazolyl lutidine Derivatives written by Heidi Marie Tatlock and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Pentadentate ligands provide stability to metal complexes as well as a binding site for substrates that make them exceptionally useful for studying reactions. They have been used in biomimetic studies, water splitting, and small molecule activation studies. A series of six pentadentate ligands derived from a, a, a', a'-tetra(pyrazolyl)lutidine, pz4lut, with methyl substituents decorating the ligand periphery has been synthesized. These ligands were coordinated to FeIICl, and the electronic and structural properties of the resulting complexes were studied in order to deduce the effects of methyl substitution at the 3-, 4-, and 5-positions of the pyrazolyl groups and at the methine positions. When analyzed via cyclic voltammetry, the resulting complexes exhibited oxidation waves between 0.95 V and 0.75 V. It was determined that the 4-pyrazole position controls electronic effects, and the 3-pyrazolyl position controls steric effects. Substitution at the methine positions favors a low-spin FeII complex. It is thought that adding bulkier groups to the methine positions may change the coordination environment of the resulting complex. An [FeIII(OH)(pz4depy)] complex (pz4depy = a, a, a', a'-tetra(pyrazolyl)diethylpyridine) could be capable of oxidizing hydrocarbons with BDE (bond dissociation enthalpy) values less than 93 kcal/mol. A [CoII(H2O)(pz4depy)]2+ complex was shown to be capable of water oxidation via a concerted proton-electron transfer (PCET) mechanism. This complex was compared to a similar WOC, [CoII(H2O)(PY5)]2+, and found to react with water via a more favorable pathway. The BDFE(OH) (bond dissociation free energy of the OH bond) was also calculated via DFT calculations to be 76.7 kcal/mol, which is higher than that of [CoII(H2O)(PY5)]2+ by 5 kcal/mol. Further studies are needed to make sure that the catalytically active species is not CoOx nanoparticles that may have formed in solution. The [CoII(H2O)(pz4depy)]2+ complex is also thought to be capable of CH-activation reactions. This thesis demonstrates the versatility of a new pentadentate ligand family for controlling the electronic and structural properties of transition metal complexes. The data reported herein may be used to select the appropriate complex to participate in CH-activation reactions.
Download or read book Complexes of Iron II Cobalt II and Copper II with New Tetradentate Ligands written by James Leroy Petrofsky and published by . This book was released on 1962 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Complexes of Iron II Cobalt II Nickel II and Copper II with 2 alpha pyridylmethyleneaminomethyl pyridine written by James Leroy Petrofsky and published by . This book was released on 1964 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cobalt II Halide Complexes of Pyridine and alpha substituted Pyridines written by Jon T. Dumler and published by . This book was released on 1970 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Complexes of the Dimethine and Trimethine Class written by P. E. Figgins and published by . This book was released on 1958 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Syntheses Structures and Magnetic Properties of Heterometallic Cobalt II lanthanide Complexes written by 林羽珊 and published by . This book was released on 2017 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spin crossover and Mesogenic Properties of Cobalt II and Iron II Complexes with Ligands Derived from 2 6 Pyridinedicarboxaldehtde and 1 Aminiakanes written by Nur Linahafizza Mohd Noor and published by . This book was released on 2015 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bis imino pyridine Iron and Cobalt Complexes written by Amanda Catherine Bowman and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The synthesis, reactivity and electronic structures of a series of bis(imino)pyridine iron and cobalt complexes was investigated. A series of monomeric bis(imino)pyridine cobalt dinitrogen complexes was investigated using a combination of 1H NMR and infrared spectroscopies, X-ray crystallography, EPR spectroscopy, solution and solid state magnetic measurements and density functional theory. The neutral bis(imino)pyridine cobalt dinitrogen complexes have doublet ground states and are best described as low-spin cobalt(I) centers with an unpaired electron on the singly reduced chelate, while the anionic bis(imino)pyridine cobalt dinitrogen complexes are also best described as low-spin cobalt(I) centers with dianionic chelates. These investigations established that reduction of monochloride precursors occurs at the metal center, in contrast to the related bis(imino)pyridine iron bis(dinitrogen) complex, (iPrPDI)Fe(N2)2, where reduction of the chelate is observed. A series of bis(imino)pyridine iron imide complexes was also investigated. A combination of Xray crystallography, variable temperature SQUID magnetization data and Mössbauer spectroscopy was used to elucidate the electronic structures of these complexes. In contrast to the previously reported N-aryl substituted bis(imino)pyridine iron imide complexes, where an iron(III) metal center and a singly reduced chelate was observed, an iron(IV) metal center and a triplet diradical chelate was observed for N-alkyl substituted bis(imino)pyridine iron imide complexes. For (iPrPDI)FeN(2Ad) (iPrPDI = 2,6-(2,6-iPr2-C6H3-N=CMe)2C5H3N), thermal spin crossover from S = 0 to S = 1 was observed when warming from 15 K to 200 K. (ArPDI)FeNR compounds with an S = 0 ground state promoted C-H bond activation of both imine methyl groups of the bis(imino)pyridine ligand. The C-H bond activation with (iPrPDI)FeN(CyOct) was firstorder in iron with a rate constant of k = 3.4(2)x10-5 s-1 at 25 °C and a primary kinetic isotope effect of 3.3(2), consistent with a rate-determining step of intramolecular C-H bond activation. In contrast, no C-H bond activation of the ligand was observed for the iron imide complexes that are S = 1 at 23 °C. The reactivity of bis(imino)pyridine iron imide compounds with hydrogen, silanes, terminal alkynes and organic azides, and the electronic structures of the resulting iron complexes, was also investigated.
Download or read book A Study of the Monensin Complexes of Cobalt II Iron II Iron III and Chromium III written by Wayne E. Evans and published by . This book was released on 1973 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low spin Cobalt II Complexes with Macrocyclic Tetraaza Ligands written by Gerald Wayne Roberts and published by . This book was released on 1974 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Syntheses Structures and Properties of Metal Complexes of Bis 2 pyridylmethyl Derivatives of O M and P phenylenediamine and Aniline written by and published by . This book was released on 2008 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Investigation of Hexacarboxamide Cryptands as Anionic Binucleating Ligands written by Glen Edward Alliger and published by . This book was released on 2010 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have investigated the use of hexacarboxamide cryptands as sextuply anionic binucleating ligands. Two homobimetallic complexes of a t-butyl-substituted cryptand, featuring manganese(II) ion and cobalt(II) ions, have been synthesized. The manganese species features a bridging hydroxide ligand; both of these species have been structurally characterized, though complete characterization was not possible due to the compounds' impurity. A highly soluble hexacarboxamide cryptand, featuring dipropoxyphenoxyl substituents, was synthesized for the first time, and has been structurally characterized. The structure features a two-dimensional hydrogen bonding network, resulting in infinite sheets of cryptand units. We have synthesized a dicobalt(II) complex of this ligand. This compound features the metal centers in cofacial trigonal monopyramidal geometries, with an intermetallic distance in excess of 6 A. This marks the first time that such a species has been fully characterized. Despite the void between the metal centers, elucidation of constructive reactivity was a challenge, though insertion of cyanide under forcing conditions was achieved. This dicobalt(II) p-cyano complex was also structurally characterized. Using the methodology set forth for the synthesis of the dicobalt(II) complex of the soluble cryptand, we have synthesized a series of complexes of this ligand, featuring manganese(II), iron(II), nickel(II), and zinc(II). These compounds were structurally characterized, and were found to be isomorphous with the dicobalt(II) complex. A comparison of the structures is drawn. These compounds have also been characterized by a variety of methods, including SQuID magnetometry, cyclic voltammetry, EPR, and, in the case of the diiron complex, Mbssbauer spectroscopy. Also reported is work toward a diiron(III) complex; the M6ssbauer spectrum of this species is reported. In analogy to the pt-cyano complex of the dicobalt complex above, a p-cyano complex of the diiron(II) was synthesized and structurally characterized. Investigations into the utility of the initial t-butyl substituted cryptand as a ligand have also been made. Initial results indicate that monometalation of this ligand is possible, and treatment of a putative monocobalt(II) complex with tetrabutylammonium cyanide suggests that the cyanide-bound product is in equilibrium with the free complex.
Download or read book Pandex Current Index to Scientific and Technical Literature written by and published by . This book was released on 1969 with total page 1778 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gold Chemistry written by Fabian Mohr and published by John Wiley & Sons. This book was released on 2009-04-20 with total page 425 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by world-class authors, this most recent major book on the topic highlights new and current trends as well as future directions. It is comprehensive in its scope, covering all aspects of gold chemistry -- from homogeneous to heterogeneous catalysis, from supramolecular assemblies to sensors and medicinal applications. The result is an invaluable work for both organic and inorganic chemists working in universities and industry, as well as material scientists.
Download or read book Side Reactions in Organic Synthesis written by Florencio Zaragoza Dörwald and published by John Wiley & Sons. This book was released on 2006-03-06 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most syntheses in the chemical research laboratory fail and usually require several attempts before proceeding satisfactorily. Failed syntheses are not only discouraging and frustrating, but also cost a lot of time and money. Many failures may, however, be avoided by understanding the structure-reactivity relationship of organic compounds. This textbook highlights the competing processes and limitations of the most important reactions used in organic synthesis. By allowing chemists to quickly recognize potential problems this book will help to improve their efficiency and success-rate. A must for every graduate student but also for every chemist in industry and academia. Contents: 1 Organic Synthesis: General Remarks 2 Stereoelectronic Effects and Reactivity 3 The Stability of Organic Compounds 4 Aliphatic Nucleophilic Substitutions: Problematic Electrophiles 5 The Alkylation of Carbanions 6 The Alkylation of Heteroatoms 7 The Acylation of Heteroatoms 8 Palladium-Catalyzed C-C Bond Formation 9 Cyclizations 10 Monofunctionalization of Symmetric Difunctional Substrates
Download or read book Inorganic Syntheses Volume 33 written by and published by John Wiley & Sons. This book was released on 2004-08-04 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Inorganic Syntheses series provides inorganic chemists with detailed and foolproof procedures for the preparation of important and timely compounds. Volume 33 includes provocative contributions on syntheses of selected supramolecules, useful reagents/ligands, solid state materials/clusters, and other compounds of general interest.
Download or read book Inorganic Syntheses Volume 36 written by and published by John Wiley & Sons. This book was released on 2014-03-18 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume of Inorganic Syntheses spans the preparations of wide range of important inorganic, organometallic and solid-state compounds. The volume is divided into 6 chapters. The first chapter contains the syntheses of some key early transition metal halide clusters and the very useful mononuclear molybdenum(III) synthon, MoCl3(THF)3. Chapter 2 covers the synthesis of a number of cyclopentadienyl compounds, including a novel route to sodium and potassium cyclopentadienide, MC5H5. Chapter 3 details synthetic procedures for a range of metal-metal bonded compounds, including several with metal-metal multiple bonds. Chapter 4 contains procedures for a range of early and late transition metal compounds, each a useful synthon for further synthetic elaboration. Chapter 5 deals with the synthesis of a number of main group compounds and ligands, while Chapter 6 covers teaching laboratory experiments.
