Download or read book The Hueckel Model for Small Metal Clusters 3 Anion Structures and HMO Hueckel Molecular Orbital Electron Affinities written by D. M. Lindsay and published by . This book was released on 1987 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most stable structures for the alkali-like clusters M3-Mg- are calculated within the framework of the simple Huckel model. The Huckel geometries are, on average, slightly less compact than those of the neutral and cation clusters, a phenomenon which may be related to the additional electronic kinetic energy of the anions. Cluster compactness is quantified by an estimation of 'soft sphere' volumes, which also allows for a comparison of classical and experimental polarizabilities. The Huckel model gives electron affinities which compare favorably with the experimental results for Cu2-Cug. To our knowledge, the Huckel results in this paper represent the first systematic search for the stable structures of small alkali-like anion clusters. Keywords: Alkali, Metal clusters, Anions, Huckel model, Magnesium, Electron affinities, Experiments, Copper, Clusters.
Download or read book H ckel Molecular Orbital Theory written by Keith Yates and published by Elsevier. This book was released on 2012-12-02 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: Huckel Molecular Orbital Theory aims to be a simple, descriptive, and non-mathematical introduction to the Huckel molecular orbital theory and its applications in organic chemistry, thus the more basic text found in the book. The book, after an introduction to related concepts such as quantum mechanics and chemical bonding, discusses the Huckel molecular orbital theory and its basic assumptions; the variation principle and the basic Huckel method; and the use of symmetry properties in simplifying Huckel method orbital calculations. The book also covers other related topics such as the extensions and improvements of the simple Huckel method; the quantitative significance Huckel molecular orbital results; and the principle of conservation of orbital symmetry. The text is recommended for undergraduate students of organic chemistry who wish to be acquainted with the basics of the Huckel molecular orbital theory.
Download or read book Physics Briefs written by and published by . This book was released on 1987 with total page 1656 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1987 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics and Chemistry of Metal Cluster Compounds written by L.J. de Jongh and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: On Friday, February 20, 1980, I had the pleasure to be present at the inaugural lecture of my colleague Jan Reedijk, who had just been named at the Chair of Inorganic Chemistry of Leiden University. According to tradition, the ceremony took place in the impressive Hall of the old University Academy Building. In the course of his lecture, Jan mentioned a number of recent developments in chemistry which had struck him as particularly important or interesting. Among those was the synthesis of large metal cluster compounds, and, to my luck, he showed a slide ofthe molecular structure of [PtI9(C)b]4-. (To my luck, since at traditional Leiden University it is quite unusual to show slides at such ceremonies.) This constituted my first acquaintance with this exciting new class of materials. I became immediately fascinated by this molecule, partly because of the esthetic beauty of its fivefold symmetry, partly because as a physicist it struck me that it could be visualized as an "embryonically small" metal particle, embedded in a shell of CO ligands.
Download or read book Metal Clusters at Surfaces written by Karl-Heinz Meiwes-Broer and published by Springer Science & Business Media. This book was released on 2000-04-05 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerous experiments and calculations have shown that isolated metal clusters possess many interesting features, quite different from those known from surface and solid- state physics or from atomic and molecular physics. The technological exploitation of these new properties, e.g. in miniature electronic or mechanical components, requires the cluster to be brought into an environment such as an encapsulating matrix or a surface. Due to the interaction with the contact medium, the properties of the clusters may change or even disappear. Thus the physics of cluster-on-surface systems -- the main subject of this book -- is of fundamental importance. The book addresses a wide audience, from the newcomer to the expert. Starting from fundamental concepts of adsorbate-surface interactions, the modification of electronic properties through electron confinement, and concepts of cluster production, it elucidates the distinct properties of the new metallic nanostructures.
Download or read book Molecular Orbital Studies of Transition and Noble Metal Clusters by the SCF X alpha Scattered Wave Method written by K. H. Johnson and published by . This book was released on 1975 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: The electronic structures of small copper, nickel, palladium, and platinum clusters having simple-cubic and cubo-octahedral geometries have been calculated, using the self-consistent-field X-alpha scattered-wave approach to molecular-orbital (MO) theory. As the cluster size and coordination number are increased, the MO results show increasing similarity to the electronic structures of the corresponding crystalline metals. The calculated ionization potentials decrease gradually with increasing cluster size and for the 13-atom cubo-octahedral clusters are approximately 2 eV greater than the corresponding average bulk work functions. Localized d-electron states are also observed for the cubo-octahedral transition-metal clusters. They appear to be cluster analogs of the 'surface states' postulated for crystalline transition metals and probably play an important role in the chemisorption and catalytic activities of small metal aggregates of the type utilized as the active centers of heterogeneous catalysts. The SCF-Xalpha-SW MO results for transition-metal clusters are critically compared with those obtained for similar clusters by the extended-Huckel (EH) and complete-neglect-of-differential-overlap (CNDO) methods. The implications of these results in surface-cluster studies of chemisorption on transition metals are discussed.
Download or read book H ckel Molecular Orbital Theory written by and published by . This book was released on 1978 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book H ckel Theory for Organic Chemists written by Charles Alfred Coulson and published by . This book was released on 1978 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Huckel molecular orbitals HMO written by Edgar Heilbronner and published by . This book was released on with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book HMO H ckel Molecular Orbitals written by Edgar Heilbronner and published by Springer. This book was released on 2014-11-28 with total page 824 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Huckel molecular orbital theory Keith Yates written by Keith Yates and published by . This book was released on 1978 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The HMO Model and Its Application written by and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Orbital Interaction Theory of Organic Chemistry written by Arvi Rauk and published by John Wiley & Sons. This book was released on 2004-04-07 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: A practical introduction to orbital interaction theory and its applications in modern organic chemistry Orbital interaction theory is a conceptual construct that lies at the very heart of modern organic chemistry. Comprising a comprehensive set of principles for explaining chemical reactivity, orbital interaction theory originates in a rigorous theory of electronic structure that also provides the basis for the powerful computational models and techniques with which chemists seek to describe and exploit the structures and thermodynamic and kinetic stabilities of molecules. Orbital Interaction Theory of Organic Chemistry, Second Edition introduces students to the fascinating world of organic chemistry at the mechanistic level with a thoroughly self-contained, well-integrated exposition of orbital interaction theory and its applications in modern organic chemistry. Professor Rauk reviews the concepts of symmetry and orbital theory, and explains reactivity in common functional groups and reactive intermediates in terms of orbital interaction theory. Aided by numerous examples and worked problems, he guides readers through basic chemistry concepts, such as acid and base strength, nucleophilicity, electrophilicity, and thermal stability (in terms of orbital interactions), and describes various computational models for describing those interactions. Updated and expanded, this latest edition of Orbital Interaction Theory of Organic Chemistry includes a completely new chapter on organometallics, increased coverage of density functional theory, many new application examples, and worked problems. The text is complemented by an interactive computer program that displays orbitals graphically and is available through a link to a Web site. Orbital Interaction Theory of Organic Chemistry, Second Edition is an excellent text for advanced-level undergraduate and graduate students in organic chemistry. It is also a valuable working resource for professional chemists seeking guidance on interpreting the quantitative data produced by modern computational chemists.
Download or read book Graph Theoretical Approaches to Chemical Reactivity written by Danail D. Bonchev and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: The progress in computer technology during the last 10-15 years has enabled the performance of ever more precise quantum mechanical calculations related to structure and interactions of chemical compounds. However, the qualitative models relating electronic structure to molecular geometry have not progressed at the same pace. There is a continuing need in chemistry for simple concepts and qualitatively clear pictures that are also quantitatively comparable to ab initio quantum chemical calculations. Topological methods and, more specifically, graph theory as a fixed-point topology, provide in principle a chance to fill this gap. With its more than 100 years of applications to chemistry, graph theory has proven to be of vital importance as the most natural language of chemistry. The explosive development of chemical graph theory during the last 20 years has increasingly overlapped with quantum chemistry. Besides contributing to the solution of various problems in theoretical chemistry, this development indicates that topology is an underlying principle that explains the success of quantum mechanics and goes beyond it, thus promising to bear more fruit in the future.
Download or read book Quantities Units and Symbols in Physical Chemistry written by International Union of Pure and Applied Chemistry. Physical and Biophysical Chemistry Division and published by Royal Society of Chemistry. This book was released on 2007 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prepared by the IUPAC Physical Chemistry Division this definitive manual, now in its third edition, is designed to improve the exchange of scientific information among the readers in different disciplines and across different nations. This book has been systematically brought up to date and new sections added to reflect the increasing volume of scientific literature and terminology and expressions being used. The Third Edition reflects the experience of the contributors with the previous editions and the comments and feedback have been integrated into this essential resource. This edition has been compiled in machine-readable form and will be available online.
Download or read book The Vocabulary and Concepts of Organic Chemistry written by Milton Orchin and published by John Wiley & Sons. This book was released on 2005-07-08 with total page 904 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a basic reference providing concise, accurate definitions of the key terms and concepts of organic chemistry. Not simply a listing of organic compounds, structures, and nomenclatures, the book is organized into topical chapters in which related terms and concepts appear in close proximity to one another, giving context to the information and helping to make fine distinctions more understandable. Areas covered include: bonding, symmetry, stereochemistry, types of organic compounds, reactions, mechansims, spectroscopy, and photochemistry.
