Qualitative Valence Bond Descriptions Of Electron Rich Molecules Pauling 3 Electron Bonds And Increased Valence Theory

Author : R. D. Harcourt
Publisher : Springer Science & Business Media
ISBN 13 : 3642932169
Total Pages : 275 pages
Book Rating : 4.68/5 ( download)

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Download or read book Qualitative Valence-Bond Descriptions of Electron-Rich Molecules: Pauling “3-Electron Bonds” and “Increased-Valence” Theory written by R. D. Harcourt and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides qualitative molecular orbital and valence-bond descriptions of the electronic structures for electron-rich molecules, with strong emphasis given to the valence-bond approach. Electron-rich molecules form an extremely large class of molecules, and the results of quantum mechanical studies from different laboratories indicate that qualitative valence-bond descriptions for many of these molecules are incomplete in so far as they usually omit "long-bond" Lewis structures from elementary descriptions of bonding. For example, the usual representation for the electronic structure of the ground-state for 03 involves resonance between the (+1 o and Until standard Lewis structures ~ ~ (-I . b:'" ~d· . . . . , recently, any contribution to resonance of the "long-bond" (or spin-paired o •• / •• ,. . has been largely ignored. diradica~ Lewis structure However, it :0 . 0. . e-. . . . . ______ " has now been calculated to be a very important structure. For the ground-states of numerous other systems, calculations also indicate that "long-bond" structures are more important than is usually supposed, and therefore they should frequently be included in qualitative valence-bond descriptions of electronic structure. The book describes how this may be done, and some of the resulting consequences for the interpretation of the electronic structure, bond properties and reactivities of various electron-rich molecules. When appropriate, molecular orbital and valence bond descriptions of bonding are compared, and relationships that exist between them are derived.

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Total Pages : pages
Book Rating : 4.00/5 ( download)

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Download or read book Qualitative Valence-bond Descriptions of Electron-rich Molecules written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : R. D. Harcourt
Publisher : Springer Verlag
ISBN 13 : 9780387115559
Total Pages : 0 pages
Book Rating : 4.52/5 ( download)

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Download or read book Qualitative Valence-bond Descriptions of Electron-rich Molecules written by R. D. Harcourt and published by Springer Verlag. This book was released on 1982 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : Richard D. Harcourt
Publisher : Springer
ISBN 13 : 331916676X
Total Pages : 328 pages
Book Rating : 4.66/5 ( download)

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Download or read book Bonding in Electron-Rich Molecules written by Richard D. Harcourt and published by Springer. This book was released on 2015-10-30 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second edition was updated to include some of the recent developments, such as “increased-valence” structures for 3-electron-3-centre bonding, benzene, electron conduction and reaction mechanisms, spiral chain O4 polymers and recoupled-pair bonding. The author provides qualitative molecular orbital and valence-bond descriptions of the electronic structures for primarily electron-rich molecules, with strong emphasis given to the valence-bond approach that uses “increased-valence” structures. He describes how “long-bond” Lewis structures as well as standard Lewis structures are incorporated into “increased-valence” structures for electron-rich molecules. “Increased-valence” structures involve more electrons in bonding than do their component Lewis structures, and are used to provide interpretations for molecular electronic structure, bond properties and reactivities. Attention is also given to Pauling “3-electron bonds”, which are usually diatomic components of “increased-valence” structures for electron-rich molecules.

Author : Sason S. Shaik
Publisher : John Wiley & Sons
ISBN 13 : 0470037350
Total Pages : 332 pages
Book Rating : 4.55/5 ( download)

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Download or read book A Chemist's Guide to Valence Bond Theory written by Sason S. Shaik and published by John Wiley & Sons. This book was released on 2007-12-04 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference on current VB theory and applications presents a practical system that can be applied to a variety of chemical problems in a uniform manner. After explaining basic VB theory, it discusses VB applications to bonding problems, aromaticity and antiaromaticity, the dioxygen molecule, polyradicals, excited states, organic reactions, inorganic/organometallic reactions, photochemical reactions, and catalytic reactions. With a guide for performing VB calculations, exercises and answers, and numerous solved problems, this is the premier reference for practitioners and upper-level students.

Author : Sandor Fliszar
Publisher : Springer Science & Business Media
ISBN 13 : 3642514928
Total Pages : 182 pages
Book Rating : 4.20/5 ( download)

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Download or read book Atoms, Chemical Bonds and Bond Dissociation Energies written by Sandor Fliszar and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical bonds, their intrinsic energies in ground-state molecules and the energies required for their actual cleavage are the subject of this book. The theory, modelled after a description of valence electrons in isolated atoms, explains how intrinsic bond energies depend on the amount of electronic charge carried by the bond-forming atoms. It also explains how bond dissociation depends on these charges. While this theory vividly explains thermochemical stability, future research could benefit from a better understanding of bond dissociation: if we learn how the environment of a molecule affects its charges, we also learn how it modifies bond dissociation in that molecule. This essay is aimed at theoretical and physical-organic chemists who are looking for new perspectives to old problems.

Author : Kenny B. Lipkowitz
Publisher : John Wiley & Sons
ISBN 13 : 0471678848
Total Pages : 485 pages
Book Rating : 4.47/5 ( download)

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Download or read book Reviews in Computational Chemistry, Volume 20 written by Kenny B. Lipkowitz and published by John Wiley & Sons. This book was released on 2004-08-16 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt: THIS VOLUME, LIKE THOSE PRIOR TO IT, FEATURES CHAPTERS BY EXPERTS IN VARIOUS FIELDS OF COMPUTATIONAL CHEMISTRY. TOPICS COVERED IN VOLUME 20 INCLUDE VALENCE THEORY, ITS HISTORY, FUNDAMENTALS, AND APPLICATIONS; MODELING OF SPIN-FORBIDDEN REACTIONS; CALCULATION OF THE ELECTRONIC SPECTRA OF LARGE MOLECULES; SIMULATING CHEMICAL WAVES AND PATTERNS; FUZZY SOFT-COMPUTING METHODS AND THEIR APPLICATIONS IN CHEMISTRY; AND DEVELOPMENT OF COMPUTATIONAL MODELS FOR ENZYMES, TRANSPORTERS, CHANNELS, AND RECEPTORS RELEVANT TO ADME/TOX. FROM REVIEWS OF THE SERIES "Reviews in Computational Chemistry remains the most valuable reference to methods and techniques in computational chemistry." -JOURNAL OF MOLECULAR GRAPHICS AND MODELING "One cannot generally do better than to try to find an appropriate article in the highly successful Reviews in Computational Chemistry. The basic philosophy of the editors seems to be to help the authors produce chapters that are complete, accurate, clear, and accessible to experimentalists (in particular) and other nonspecialists (in general)." -JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

Author : Robert Ponec
Publisher : Springer Science & Business Media
ISBN 13 : 3642468179
Total Pages : 135 pages
Book Rating : 4.79/5 ( download)

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Download or read book Overlap Determinant Method in the Theory of Pericyclic Reactions written by Robert Ponec and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: The author summarizes the development and the applications of overlap determinant method in various fields of pericyclic reactivity. The greatest advantage of this new method lies in its remarkable simplicity and flexibility owing to which it opens an interesting possibility of the systematic investigation of important mechanistic problems of pericyclic reactivity which were so far beyond the scope of other existing techniques.

Author : I. Ugi
Publisher : Springer Science & Business Media
ISBN 13 : 3642932665
Total Pages : 270 pages
Book Rating : 4.63/5 ( download)

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Download or read book Perspectives in Theoretical Stereochemistry written by I. Ugi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stereochemistry is the part of chemistry that relates observable prop erties of chemical compounds to the structure of their molecules, i. e. the relative spatial arrangement of their constituent atoms. In classical stereochemistry, the spatial arrangements relevant for interpreting and predicting a given chemical property are customarily described by geometric features/ symmetries in some suitably chosen rigid model of the molecule The solution of stereochemical problems involving single molecular species is the danain of the geometry based approaches, such as the methods of classical stereochemistry, molecular mechanics and quantum chemistry. The molecules of a pure chemical compound form generally an ensemble of molecular individuals that differ in geometry and energy. Thus it is generally impossible to represent a chemical compund adequately by the geo metry of a rigid molecular model. In modern stereochemistry it is often necessary to analyze molecular relation within ensembles and families of stereoisomers and permutation isomers, including molecules whose geometric features are changing with time. Accordingly, there is definitely a need for new types of ideas, concepts, theories and techniques that are usable beyond the scope of customary methodology. This is why the present text was written.

Author : Pierre Turq
Publisher : Springer Science & Business Media
ISBN 13 : 3642487556
Total Pages : 222 pages
Book Rating : 4.52/5 ( download)

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Download or read book Transport, Relaxation, and Kinetic Processes in Electrolyte Solutions written by Pierre Turq and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: The presence of freely moving charges gives peculiar properties to electrolyte solutions, such as electric conductance, charge transfer, and junction potentials in electrochemical systems. These charges play a dominant role in transport processes, by contrast with classical equilibrium thermodynamics which considers the electrically neutral electrolyte compounds. The present status of transport theory does not permit a first prin ciples analys1s of all transport phenomena with a detailed model of the relevant interactions. Host of the models are still unsufficient for real systems of reasonable complexity. The Liouville equation may be adapted with some Brownian approximations to problems of interact ing solute particles in a continuum (solvent>; however, keeping the Liouville level beyond the limiting laws is an unsolvable task. Some progress was made at the Pokker-Planck level; however, despite a promising start, this theory in its actual form is still unsatis factory for complex systems involving many ions and chemical reac tions. A better approach is provided by the so-called Smoluchowski level in which average velocities are used, but there the hydrodyna mic interactions produce some difficulties. The chemist or chemical engineer, or anyone working with complex electrolyte solutions in applied research wants a general representa tion of the transport phenomena which does not reduce the natural complexity of the multicomponent systems. Reduction of the natural complexity generally is connected with substantial changes of the systems.