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 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 Energy Research Abstracts written by and published by . This book was released on 1980 with total page 592 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 One and Two Electron Transfer Reactions Progress Report March 1 1970 February 28 1971 written by and published by . This book was released on 1970 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book One and Two Electron Transfer Reactions Final Progress Report March 1 1971 February 28 1972 written by and published by . This book was released on 1972 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photochemical Activation and Reactivity of Polynuclear Transition Metal Complex Molecules Progress Report June 1980 May 31 1981 written by and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Progress on this project during the past year has proceeded in three different but complementary directions. The first involves a continuing effort to synthesize new and unusual polynuclear transition metal complexes that (1) exhibit multi-electron transfer reactions, (2) can be expected to have long-lived excited states, and/or (3) will undergo photochemically initiated intramolecular energy transfer to produce reactive species. The second involves the electrochemical investigation of multi-electron transfer reactions of polynuclear transition metal complexes. The third is concerned with the study of the photophysics of binuclear complexes in which electron transfer could take place between a photochemically excited metal ion and the metal ion in the same molecule thereby producing two new reactive sites.
Download or read book Excited state Electron transfer Reactions of Transition Metal Complexes written by David Gordon Taylor and published by . This book was released on 1979 with total page 232 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 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electron Transfer Reactions of Mixed Ammmine pyridine Ruthenium and Polypyridine Iron Complexes as a Test of Marcus Theory and Organometallic Metal metal Bond Electron Transfer Studies written by Jeffrey L. Cramer and published by . This book was released on 1975 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book March s Advanced Organic Chemistry written by Michael B. Smith and published by John Wiley & Sons. This book was released on 2007-01-29 with total page 2379 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Sixth Edition of a classic in organic chemistry continues its tradition of excellence Now in its sixth edition, March's Advanced Organic Chemistry remains the gold standard in organic chemistry. Throughout its six editions, students and chemists from around the world have relied on it as an essential resource for planning and executing synthetic reactions. The Sixth Edition brings the text completely current with the most recent organic reactions. In addition, the references have been updated to enable readers to find the latest primary and review literature with ease. New features include: More than 25,000 references to the literature to facilitate further research Revised mechanisms, where required, that explain concepts in clear modern terms Revisions and updates to each chapter to bring them all fully up to date with the latest reactions and discoveries A revised Appendix B to facilitate correlating chapter sections with synthetic transformations
Download or read book Standard Methods for the Examination of Water and Wastewater written by American Public Health Association and published by . This book was released on 1981 with total page 1254 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Toxicological Profile for Polycyclic Aromatic Hydrocarbons written by and published by . This book was released on 1995 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Fingerprint written by U. S. Department Justice and published by Createspace Independent Publishing Platform. This book was released on 2014-08-02 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The idea of The Fingerprint Sourcebook originated during a meeting in April 2002. Individuals representing the fingerprint, academic, and scientific communities met in Chicago, Illinois, for a day and a half to discuss the state of fingerprint identification with a view toward the challenges raised by Daubert issues. The meeting was a joint project between the International Association for Identification (IAI) and West Virginia University (WVU). One recommendation that came out of that meeting was a suggestion to create a sourcebook for friction ridge examiners, that is, a single source of researched information regarding the subject. This sourcebook would provide educational, training, and research information for the international scientific community.
Download or read book Accelerated Aging written by Robert L. Feller and published by Getty Publications. This book was released on 1995-03-02 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accelerated Aging: Photochemical and Thermal Aspects represents the culmination of more than 40 years of research by noted scientist Robert L. Feller. The book focuses on the long-term performance of materials such as wool, dyes, and organic compounds; their resistance to change when exposed to environmental factors such as oxygen, ozone, moisture, heat, and light; and their physical durability with handling and use over time. Processes of deterioration are discussed based on speeded-up laboratory studies designed to clarify the chemical reactions involved and their physical consequences.
Download or read book Copper and Bronze in Art written by David A. Scott and published by Getty Publications. This book was released on 2002 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a review of 190 years of literature on copper and its alloys. It integrates information on pigments, corrosion and minerals, and discusses environmental conditions, conservation methods, ancient and historical technologies.
Download or read book Onsite Wastewater Treatment Systems Manual written by and published by . This book was released on 2002 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This manual contains overview information on treatment technologies, installation practices, and past performance."--Introduction.
