Download or read book Electron Transfer Reactions of Bis 1 4 7 Trithiacyclononane palladium III II platinum III II and gold III II Complexes in Aqueous Solution and in Acetonitrile written by and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Canadian Journal of Chemistry written by and published by . This book was released on 1999 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Palladium IV in Directed C H Bond Oxidations written by Allison Renae Dick and published by . This book was released on 2006 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigations of the Reactivity of Palladium and Platinum Complexes with Molecular Oxygen and Characterization of a Gold III alkene Complex written by Margaret Louise Scheuermann and published by . This book was released on 2013 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the reactivity of metal complexes with molecular oxygen will facilitate the development of catalysts that can enable the widespread use of molecular oxygen as an oxidant for organic synthesis. This thesis presents two new classes of reactions between metal complexes and molecular oxygen. Neutral five-coordinate Pt complexes were tested for reactivity in the presence of molecular oxygen. In arene solution, the complexes (t̳B̳u̳̳M̳e̳2̳ nacnac)PtMe3 (1, t̳̳B̳u̳M̳e̳2̳ nacnac- = [((4-tBu-2,6-Me2C6H2)NC(CH3))2CH]-), (M̳e̳3̳ Me-nacnac)PtMe3 (2, M̳e̳3̳ Me-nacnac- = [((2,4,6-Me3C6H2)NC(CH3))2CCH3]-), and (t̳B̳u̳2̳ PyPyr)PtMe3 (3, t̳B̳u̳2̳ PyPyr- = 3,5-di-tert-butyl-2-(2-pyridyl)pyrrolide) reacted immediately with oxygen to form peroxo species in which two oxygen atoms bridge between the metal center and a carbon atom in the ligand backbone. In contrast, no reaction between ( i̳P̳r̳2̳ AnIm)PtMe3 (4a, i̳P̳r̳2̳ AnIm− = [o- C66H4-{N(C6H3 i Pr2)}(CH=NC6H3 i Pr2)]−) or (M̳e̳3̳ AnIm)PtMe3 (4b, M̳e̳̳3̳ AnIm− = [o-C6H4- {N(C6H2Me3)}(CH=NC6H2Me3)]−) and oxygen was observed. As activation of oxygen by five- coordinate PtIV species was found to involve cooperation between the metal center and the ligand, the ability of the ligand to participate in the oxygen binding appears to be a vital component. Oxygen atom transfer reactions of the novel peroxo species are also presented. In a separate study, an unusual reaction involving the activation of both molecular oxygen and a C-H bond at the same metal center was investigated. Pd(P(Ar)(tBu)2)2 (15, Ar = naphthyl) was found to react with molecular oxygen at room temperature in arene solvent to form a hydroxide dimer in which one equivalent of phosphine per Pd was lost and the remaining phosphine was cyclometalated through the naphthyl ring. At low temperature, two intermediates were observed. The nature of these intermediates suggests a mechanism involving initial reaction of Pd(P(Ar) (tBu)2)2 with O2 followed by the C-H activation step. In a final chapter unrelated to oxygen reactivity, the generation and characterization of a gold III̳-alkene complex by NMR and X-ray crystallography is presented. Such species have been proposed as intermediates in catalytic reactions but until recently none had been observed.
Download or read book The Chemistry of Platinum and Palladium with Particular Reference to Complexes of the Elements written by F. R. Hartley and published by . This book was released on 1973 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comprehensive Organometallic Chemistry II written by Richard J. Puddephatt and published by Elsevier. This book was released on 1995 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photoinduced Electron Transfer Photoinduced electron transfer reactions organic substrates written by Marye Anne Fox and published by . This book was released on 1988 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electron Transfer Reactions written by Roderick David Cannon and published by Butterworth-Heinemann. This book was released on 1980 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Inorganic Syntheses Volume 32 written by and published by John Wiley & Sons. This book was released on 2009-09-22 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Inorganic Synthesis Series provides all users of inorganic substances with detailed and foolproof procedures for the preparation of important and timely compounds. This new volume includes information on water-solubilizing ligands for organometallics, labile ligand complexes, and the syntheses of cluster compounds and hydrides.
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 Electron transfer Reactions of Encapsulated Transition Metal Complexes written by Michael D. Johnson and published by . This book was released on 1992 with total page 1087 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Intramolecular Electron transfer Reactions in Binuclear Ru II Co III Complexes written by Lauge J. Schäffer and published by . This book was released on 1984 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Light Induced Electron Transfer Reactions of Metal Complexes written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Properties of the excited states of tris(2,2'-bipyridine) and tris(1,10-phenanthroline) complexes of chromium(III), iron(II), ruthenium(II), osmium(II), rhodium(III), and iridium(III) are described. The electron transfer reactions of the ground and excited states are discussed and interpreted in terms of the driving force for the reaction and the distortions of the excited states relative to the corresponding ground states. General considerations relevant to the conversion of light into chemical energy are presented and progress in the use of polypyridine complexes to effect the light decomposition of water into hydrogen and oxygen is reviewed.
Download or read book Electron Transfer Reactions of Excited Dyes with Metal Complexes Progress Report May 1 1976 January 31 1977 Fe III thionine Reaction written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A study was initiated of the factors which determine quantum efficiency of transfer of reducing equivalents between excited dye molecules and metal complexes in their ground state and composition and dynamics of formation and decay of related photostationary states. A ruby laser capable of delivering a 3.6 J, 19 nsec flash was acquired and assembly of an apparatus for laser flash photolysis begun. At the same time, conventional flash photolysis was used to pursue investigation of the dependence upon solvent, anions, pH, and ionic strength of the kinetics of the spontaneous dark reaction of Fe(H2O)/sup 3 +/6 with leucothionine and with semithionine, reactions which contribute to the composition and dynamics of formation and decay of the photostationary state of the iron-thionine photoredox reaction. Results are consistent with formation of an intermediate complex between leucothionine and Fe(III), K/sub A/ = 380 M−1 and k(elec. transfer) = 0.88 s−1 at approximately 22° in water solution at pH2, with sulfate as anion and .mu. = .05 - 1 M. Under similar conditions in 50 v/v percent aqueous CH3CN, K/sub A/ = 780 M−1, k(elec. transfer) = 0.55 s−1. In both solvents, sulfate produces a large positive salt effect. Intermediacy of a complex was not established for the faster reaction of Fe(III) with semithionine under similar conditions: K/sub A/ . k(elec. transfer) approximately 3.5 x 105 M−1s−1 in H2O, approximately 1.0 x 104 in 50 v/v percent aqueous CH3CN.
Download or read book Electron Transfer Reactions of Excited Dyes with Metal Complexes Progress Report March 1 1978 February 28 1979 Iron methylene Blue written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An intense absorption band of 3MBH/sup 2 +/ at 700nm was characterized in several media and its pK/sub A/ was measured to be 7.17 +- 1 in water. Flash photolysis show that semiethylene blue, MBH, formed by quenching 3MBH/sup 2 +/ with Fe/sub II/(H2O)6/sup 2 +/, decays by disproportionation at a diffusion-controlled rate. Rates of decay of the photostationary state of solutions of MB+ and Fe/sup II/(H2O)6/sup 2 +/ in acidic media were measured using crossed beams to yield specific rates of oxidation of leucomethylene blue (MBH3/sup 2 +/) by MB+ (synproportionation) and by Fe(III). Laser flash-photolysis shows that quenching of MB+(S1) by Fe(H2O)6/sup 2 +/ can result in electron transfer to give MBH+. Profound differences between processes initiated by quenching triplet methylene blue with Fe(H2O)6/sup 2 +/ and with stable coordination complexes of Fe(II) were found. Quenchers included (Fe/sup II/(CN)6)/sup 4 -/, (Fe/sup II/(CN)4(bpy)2)/sup 2 -/, (Fe/sup II/(CN)2(bpy))°, and (Fe/sup II/(bpy)3)/sup 2 +/. Measurements were made in aqueous and aqueous-alcoholic solutions at pH 2, 4.4, and 8.2. Quenching of 3MBH/sup 2 +/ or 3MB+ by a stable complex of Fe(II) is diffusion-controlled and 102 to 103 times the rate at which Fe(H2O)6/sup 2 +/ quenches 3MBH/sup 2 +/. Net electron transfer accounts for less than 1/3 of total quenching by complexed Fe(II). In contrast, quenching by Fe(H2O)6/sup 2 +/ goes essentially entirely with net electron transfer. It is concluded that quenching of triplet methylene blue by complexes proceeds via electron transfer which is reversible in the encounter complex. The MBH/sup +/ which results from net electron transfer from complexes of Fe(II) decays essentially entirely to MB/sup +/ via oxidation by complexed Fe(III); no disproportionation has been observed.
Download or read book Self quenching and Cross quenching Reactions of Platinum II Dimine Complexes written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutral square planar platinum(II) diimine complexes undergo self-quenching in fluid solution, characterized by an increase in the emission decay rate with concentration. The corresponding quenching rates (10 9 -10 10 -1 s -1) are nearly diffusion limited. The accumulated evidence suggests that an excited platinum complex, (M*) reacts with a ground-state complex, (M), to form an excimer, (M2*), which rapidly relaxes to give two ground-state complexes. These complexes possess many attractive properties for use in application such as DNA recognition and chemical sensing. However, because the self-quenching rates are nearly diffusional, this behavior presents serious problems for applications demanding a long-lived excited state. As a result, there is great interest in learning to control the self-quenching behavior. Three possible interactions have been proposed to stabilize the excimer: (i) diimine-diimine interactions, (ii) metal-metal interactions, and (iii) a combination of these interactions. Efforts to distinguish between these possibilities have been hampered by short lifetimes and low quantum yields of the excimers. Consequently, we have turned our efforts toward cross-quenching reactions which are similar to self-quenching with the distinction that the excited monomer, M*, reacts with a different ground-state complex, Q, presumably to form an exciplex, MQ*. Through steady-state and time-resolved cross-quenching studies of Pt(tmphen)(tdt) with quenchers having various steric and electronic properties, we were able to investigate the mechanism of quenching. Rapid rates of cross-quenching (10 9 10 10 M -1 s -1) were only observed when the quencher was another platinum(II) diimine complex. Energy transfer and outer-sphere electron transfer were ruled out as possible quenching mechanisms based on the driving forces for these reactions. The effects of both steric and electronic properties of the platinum(II) diimine quenchers on the observed rate constants have been examined in detail. The accumulated data are consistent with metal-metal interactions playing a critical role in cross-quenching.
Download or read book Emerging Trends in Computational Biology Bioinformatics and Systems Biology written by Hamid R Arabnia and published by Morgan Kaufmann. This book was released on 2015-08-11 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emerging Trends in Computational Biology, Bioinformatics, and Systems Biology discusses the latest developments in all aspects of computational biology, bioinformatics, and systems biology and the application of data-analytics and algorithms, mathematical modeling, and simu- lation techniques. • Discusses the development and application of data-analytical and theoretical methods, mathematical modeling, and computational simulation techniques to the study of biological and behavioral systems, including applications in cancer research, computational intelligence and drug design, high-performance computing, and biology, as well as cloud and grid computing for the storage and access of big data sets. • Presents a systematic approach for storing, retrieving, organizing, and analyzing biological data using software tools with applications to general principles of DNA/RNA structure, bioinformatics and applications, genomes, protein structure, and modeling and classification, as well as microarray analysis. • Provides a systems biology perspective, including general guidelines and techniques for obtaining, integrating, and analyzing complex data sets from multiple experimental sources using computational tools and software. Topics covered include phenomics, genomics, epigenomics/epigenetics, metabolomics, cell cycle and checkpoint control, and systems biology and vaccination research. • Explains how to effectively harness the power of Big Data tools when data sets are so large and complex that it is difficult to process them using conventional database management systems or traditional data processing applications. Discusses the development and application of data-analytical and theoretical methods, mathematical modeling and computational simulation techniques to the study of biological and behavioral systems. Presents a systematic approach for storing, retrieving, organizing and analyzing biological data using software tools with applications. Provides a systems biology perspective including general guidelines and techniques for obtaining, integrating and analyzing complex data sets from multiple experimental sources using computational tools and software.
