Electron Distributions and the Chemical Bond

Author: Philip Coppens

Publisher: Springer

ISBN:

Category: Science

Page: 479

View: 299

This book represents the proceedings of a symposium held at the Spring 1981 ACS meeting in Atlanta. The symposium brought together Theoretical Chemists, Solid State Physicists, Experimen tal Chemists and Crystallographers. One of its major aims was to increase interaction between these diverse groups which often use very different languages to describe similar concepts. The devel opment of a common language, or at least the acquisition of a multilingual capability, is a necessity if the field is to prosper. Much depends in this field on the interplay between theory and experiment. Accordingly this volume begins with two introduc tory chapters, one theoretical and the other experimental, which contain much of the background material needed for a through under standing of the field. The remaining sections describe a wide variety of applications and illustrate, we believe, the central role of charge densities in the understanding of chemical bonding. We are most indebted to the Divisions of Inorganic and Phy sical Chemistry of the American Chemical Society, which provided the stimulus for the symposium and gave generous financial support. We also gratefully acknowledge financial support from the Special Educational Opportunities Program of the Petroleum Research Fund administered by the American Chemical Society, which made exten sive participation by speakers from abroad possible.

Electron Distributions and the Chemical Bond

Author: P. Coppens

Publisher: Springer

ISBN:

Category: Gardening

Page: 479

View: 298

This book represents the proceedings of a symposium held at the Spring 1981 ACS meeting in Atlanta. The symposium brought together Theoretical Chemists, Solid State Physicists, Experimen tal Chemists and Crystallographers. One of its major aims was to increase interaction between these diverse groups which often use very different languages to describe similar concepts. The devel opment of a common language, or at least the acquisition of a multilingual capability, is a necessity if the field is to prosper. Much depends in this field on the interplay between theory and experiment. Accordingly this volume begins with two introduc tory chapters, one theoretical and the other experimental, which contain much of the background material needed for a through under standing of the field. The remaining sections describe a wide variety of applications and illustrate, we believe, the central role of charge densities in the understanding of chemical bonding. We are most indebted to the Divisions of Inorganic and Phy sical Chemistry of the American Chemical Society, which provided the stimulus for the symposium and gave generous financial support. We also gratefully acknowledge financial support from the Special Educational Opportunities Program of the Petroleum Research Fund administered by the American Chemical Society, which made exten sive participation by speakers from abroad possible.

Electron Distributions and the Chemical Bond

Author: Philip Coppens

Publisher: Springer Science & Business Media

ISBN:

Category: Science

Page: 479

View: 911

This book represents the proceedings of a symposium held at the Spring 1981 ACS meeting in Atlanta. The symposium brought together Theoretical Chemists, Solid State Physicists, Experimen tal Chemists and Crystallographers. One of its major aims was to increase interaction between these diverse groups which often use very different languages to describe similar concepts. The devel opment of a common language, or at least the acquisition of a multilingual capability, is a necessity if the field is to prosper. Much depends in this field on the interplay between theory and experiment. Accordingly this volume begins with two introduc tory chapters, one theoretical and the other experimental, which contain much of the background material needed for a through under standing of the field. The remaining sections describe a wide variety of applications and illustrate, we believe, the central role of charge densities in the understanding of chemical bonding. We are most indebted to the Divisions of Inorganic and Phy sical Chemistry of the American Chemical Society, which provided the stimulus for the symposium and gave generous financial support. We also gratefully acknowledge financial support from the Special Educational Opportunities Program of the Petroleum Research Fund administered by the American Chemical Society, which made exten sive participation by speakers from abroad possible.

Chemical Bonds in Solids

Volume 3: X-Ray and Thermodynamic Investigations

Author: N. N. Sirota

Publisher: Springer Science & Business Media

ISBN:

Category: Science

Page: 200

View: 259

The present four volumes, published under the collective title of "Chemical Bonds in Solids," are the translation of the two Russian books "Chemical Bonds in Crystals" and "Chemical Bonds in Semiconductors." These contain the papers presented at the Conference on Chemical Bonds held in Minsk between May 28 and June 3, 1967, together with a few other papers (denoted by an asterisk) which have been specially incorporated. Earlier collections (also published by the Nauka i Tekhnika Press of the Belorussian Academy of Sciences) were entitled "Chemical Bonds in Semiconductors and Solids" (1965) and "Chemical Bonds in Semiconductors and Thermody namics" (1966) and are available in English editions from Consultants Bureau, New York (pub lished in 1967 and 1968, respectively). The subject of chemical bonds in crystals, including semiconductors, has recently become highly topical and has attracted the interest of a wide circle of physicists, chemists, and engineers. Until recently, the most successful description of the properties of solids (including semi conductors) has been provided by the band theory, which still dominates the physics of solids. Nevertheless, it is clear that the most universal approach is that based on the general theory of chemical bonds in crystals, in which details of the electron distributions between atoms and of the wave functions appear quite expliCitly.

Applications of Environmental Aquatic Chemistry

A Practical Guide, Third Edition

Author: Eugene R. Weiner

Publisher: CRC Press

ISBN:

Category: Science

Page: 618

View: 747

Professionals and students who come from disciplines other than chemistry need a concise yet reliable guide that explains key concepts in environmental chemistry, from the fundamental science to the necessary calculations for applying them. Updated and reorganized, Applications of Environmental Aquatic Chemistry: A Practical Guide, Third Edition provides the essential background for understanding and solving the most frequent environmental chemistry problems. Diverse and self-contained chapters offer a centralized and easily navigable framework for finding useful data tables that are ordinarily scattered throughout the literature. Worked examples provide step-by-step details for frequently used calculations, drawing on case histories from real-world environmental applications. Chapters also offer tools for calculating quick estimates of important quantities and practice problems that apply the principles to different conditions. This practical guide provides an ideal basis for self-study, as well as short courses involving the movement and fate of contaminants in the environment. In addition to extensive reorganization and updating, the Third Edition includes a new chapter, Nutrients and Odors: Nitrogen, Phosphorus, and Sulfur, two new appendices, Solubility of Slightly Soluble Metal Salts and Glossary of Acronyms and Abbreviations Used in this Book, and new material and case studies on remediation, stormwater management, algae growth and treatment, odor control, and radioisotopes.

Chemical Bonds in Solids

Volume 4: Semiconductor Crystals, Glasses, and Liquids

Author: Academician N. N. Sirota

Publisher: Springer Science & Business Media

ISBN:

Category: Science

Page: 165

View: 740

The present four volumes, published under the collective title of "Chemical Bonds in Solids," are the translation of the two Russian books "Chemical Bonds in Crystals" and "Chemical Bonds in Semiconductors." These contain the papers presented at the Conference on Chemical Bonds held in Minsk between May 28 and June 3, 1967, together with a few other papers (denoted by an asterisk) which have been specially incorporated. Earlier collections (also published by the Nauka i Tekhnika Press of the Belorussian Academy of Sciences) were entitled "Chemical Bonds in Semiconductors and Solids" (1965) and "Chemical Bonds in Semiconductors and Thermody namics" (1966) and are available in English editions from Consultants Bureau, New York (pub lished in 1967 and 1968, respectively). The subject of chemical bonds in crystals, including semiconductors, has recently become highly topical and has attracted the interest of a wide circle of physicists, chemists, and engineers. Until recently, the most successful description of the properties of solids (including semi conductors) has been provided by the band theory, which still dominates the physics of solids. Nevertheless, it is clear that the most universal approach is that based on the general theory of chemical bonds in crystals, in which details of the electron distributions between atoms and of the wave functions appear quite explicitly.

Chemical Activation of Molecules by Metals

Experimental Studies of Electron Distributions and Bonding. Technical Progress Report, March 1, 1992--February 28, 1995

Author:

Publisher:

ISBN:

Category:

Page: 36

View: 723

During this period of the project we have (1) accomplished the high-resolution gas phase photoelectron spectra of C60 and C--0, (2) characterized the electronic features of imaging C60 on gold by STM, (3) evaluated the orbital distributions of C60 and the bonding interactions with metals, (4) revealed details of the bonding of phosphines to metals, including the subtleties of a geometrical twist in sterically crowded situations, (5) determined the formal electron distribution in the bonding of?3 -cyclopropenyl with metals, (6) related gas-phase ionization energies to electron transfer kinetics and ion salvation thermochemistry of metallocenes, (7) correlated lone-pair ionization energies with proton affinities for a variety of amino acids and related compounds, (8) examined sigma-pi interactions in non-conjugated polyalkynes, (9) characterized extensive metal-ligand? interactions in metal-acetylide compounds, and (10) continued to develop the experimental and theoretical methods for these studies. All of these studies have contributed significantly to expanding our understanding of the electronic structure and bonding of organic molecules and the ways this electronic structure is altered by interaction with metals. Further developments in the instrumentation and methods of gas phase and surface photoelectron spectroscopy are underway. Most notable is the progress on the new gas phase photoelectron spectrometer that combines improved capabilities for He I/He II UPS, XPS, and Auger investigations of organometallic molecules.

Crystal Structure Analysis for Chemists and Biologists

Author: Jenny P. Glusker

Publisher: John Wiley & Sons

ISBN:

Category: Science

Page: 872

View: 951

The fields of structural chemistry and biochemistry have blossomed in the last seventy years since X-ray diffraction was discovered in 1912. Dorothy Hodgkin, who obtained a Nobel Prize in 1965 for her X-ray diffraction work wrote 'a great advantage of X-ray analysis as a method of chemical structure analysis is its power to show some totally unexpected and surprising structure with, at the same time, complete certainty.' The results of all X-ray diffraction studies are used by chemists and buiochemists but these scientists need to be able to appreciate the significance and extent to which these results may be used. A number of books written for practicing crystallographers cover the theory and applications of X-ray diffraction, but few are of real practical use to non-specialists. In 'Crystal Structure Analysis for Biologists and Chemists', the general principles of crystal structure are presented in a highly readable way. The book of Glusker, who is internationally renowned, provides good coverage of theory, including data and understanding their significance.

Electron Density and Bonding in Crystals

Principles, Theory and X-ray Diffraction Experiments in Solid State Physics and Chemistry

Author: V.G Tsirelson

Publisher: CRC Press

ISBN:

Category: Science

Page: 532

View: 714

Electron Density and Bonding in Crystals: Principles, Theory and X-Ray Diffraction Experiments in Solid State Physics and Chemistry provides a comprehensive, unified account of the use of diffraction techniques to determine the distribution of electrons in crystals. The book discusses theoretical and practical techniques, the application of electron density studies to chemical bonding, and the determination of the physical properties of condensed matter. The book features the authors' own key contributions to the subject as well a thorough, critical summary of the extensive literature on electron density and bonding. Logically organized, coverage ranges from the theoretical and experimental basis of electron density determination to its impact on investigations of the nature of the chemical bond and its uses in determining electromagnetic and optical properties of crystals. The main text is supplemented by appendices that provide clear, concise guidance on aspects such as systems of units, quantum theory of atomic vibrations, atomic orbitals, and creation and annihilation operators. The result is a valuable compendium of modern knowledge on electron density distributions, making this reference a standard for crystallographers, condensed matter physicists, theoretical chemists, and materials scientists.

Chemical Bonds in Solids

Volume 4: Semiconductor Crystals, Glasses, and Liquids

Author: Academician N. N. Sirota

Publisher: Springer

ISBN:

Category: Science

Page: 165

View: 142

The present four volumes, published under the collective title of "Chemical Bonds in Solids," are the translation of the two Russian books "Chemical Bonds in Crystals" and "Chemical Bonds in Semiconductors." These contain the papers presented at the Conference on Chemical Bonds held in Minsk between May 28 and June 3, 1967, together with a few other papers (denoted by an asterisk) which have been specially incorporated. Earlier collections (also published by the Nauka i Tekhnika Press of the Belorussian Academy of Sciences) were entitled "Chemical Bonds in Semiconductors and Solids" (1965) and "Chemical Bonds in Semiconductors and Thermody namics" (1966) and are available in English editions from Consultants Bureau, New York (pub lished in 1967 and 1968, respectively). The subject of chemical bonds in crystals, including semiconductors, has recently become highly topical and has attracted the interest of a wide circle of physicists, chemists, and engineers. Until recently, the most successful description of the properties of solids (including semi conductors) has been provided by the band theory, which still dominates the physics of solids. Nevertheless, it is clear that the most universal approach is that based on the general theory of chemical bonds in crystals, in which details of the electron distributions between atoms and of the wave functions appear quite explicitly.

Chemical Bonds in Solids

Proceedings of the International Symposium on Chemical Bonds in Semiconducting Crystals Held in Minsk, USSR, in 1967

Author:

Publisher:

ISBN:

Category: Chemical bonds

Page:

View: 435

Quantum Chemistry

A Unified Approach Second Edition

Author: David B Cook

Publisher: World Scientific Publishing Company

ISBN:

Category: Science

Page: 332

View: 370

This book is a presentation of a qualitative theory of chemical bonding, stressing the physical processes which occur on bond formation. It differs from most (if not all) other books in that it does not seek to “rationalise” the phenomena of bonding by a series of mnemonic rules. A principal feature is a unified and consistent treatment across all types of bonding in organic, inorganic, and physical chemistry. Each chapter has an Assignment Section containing “problems” which might be usefully attempted to improve the understanding of the new material in that chapter. The new edition has had several appendices added which give support to concepts which, if included in the main text, would have hindered the main thrust of the presentation. These new appendices are an attempt to clarify oversights and errors which have been tacitly ignored and which have now become part of the conventional wisdom.

The Application of Charge Density Research to Chemistry and Drug Design

Author: G.A. Jeffrey

Publisher: Springer Science & Business Media

ISBN:

Category: Science

Page: 409

View: 571

In the past twenty years, the X-ray crystallography of organic molecules has expanded rapidly in two opposite directions. One is towards larger and larger biological macromolecules and the other is towards the fine details of the electronic structure of small molecules. Both advances required the development of more sophisticated methodologies. Both were made possible by the rapid development of computer technology. X-ray diffraction equipment has responded to these demands, in the one case by the ability to measure quickly many thousands of diffraction spectra, in the other by providing instruments capable of very high precision. Molecules interact through their electrostatic potentials and therefore their experimental and theoretical measurement and calculation is an essential component to understanding the electronic structure of chemical and biochemical reactions. In this ASI, we have brought together experts and their students from both the experimental and theoretical sides of this field, in order that they better understand the philosophy and complexity of these two complementary approaches. George A. Jeffrey Department of Crystallography University of Pittsburgh Pittsburgh, Pennsylvania 15260 USA vii CONTENTS LECTURES General Considerations on Methods for Studying Molecular Structures and Electron Density Distributions ..

Modelling of Minerals and Silicated Materials

Author: B. Silvi

Publisher: Springer Science & Business Media

ISBN:

Category: Science

Page: 341

View: 329

The modeling of minerals and silicated materials is a. difficult challenge faced by Solid StatePhysics, Quantum Chemistry and Molecular Dynamics communities. The difficulty of such a modeling is due to the wide diversity of elements, including heavy atoms,and types of bonding involved in such systems. Moreover, one has to consider infinite systems: either perfect cr- tals or glasses and melts. In the solid state a given chemical composition gives rise to numerous polymorphs, geometricallycloselyrelated. These polymorphs have very similar energies and related thermodynamical pr- erties which explain the complexity of their phase diagrams. The modeling of silicates and minerals covers a wide field of applications ranging from basic research to technology, from Solid State Physics to Earth and Planetary science. The use of modeling techniques yields information of different nature. In the case of chemical studies, we can mention inv- tigations on catalytic processes occurring on surfaces and in zeolite cages. These calculations find possible applications in chemical engineering, in particular in the oil industry.

Chemical Activation of Molecules by Metals

Experimental Studies of Electron Distributions and Bonding

Author:

Publisher:

ISBN:

Category:

Page: 7

View: 208

Purpose of this research program is to obtain experimental information on the different fundamental ways metals bond and activate organic molecules. Our approach has been to directly probe the electronic interactions between metals and molecules through a wide variety of ionization spectroscopies and other techniques, and to investigate the relationships with bonding modes, structures, and chemical behavior. During this period, we have (1) characterized the electronic features of diphosphines and monophosphines in their coordination to metals, (2) carried out theoretical and experimental investigations of the bonding capabilities of C[sub 60] to transition metals, (3) developed techniques for the imaging of single molecules on gold substrates that emphasizes the electronic backbonding from the metal to the molecule, (4) obtained the high resolution photoelectron spectrum of pure C[sub 70] in the gas phase, (5) compared the bonding of [eta][sup 3]- acetylide ligands to the bonding of other small organic molecules with metals, and (6) reported the photoelectron spectra and bonding of [eta][sup 3]-cyclopropenyl groups to metals.

Information Theory of Molecular Systems

Author: Roman F. Nalewajski

Publisher: Elsevier

ISBN:

Category: Computers

Page: 462

View: 663

As well as providing a unified outlook on physics, Information Theory (IT) has numerous applications in chemistry and biology owing to its ability to provide a measure of the entropy/information contained within probability distributions and criteria of their information "distance" (similarity) and independence. Information Theory of Molecular Systems applies standard IT to classical problems in the theory of electronic structure and chemical reactivity. The book starts by introducing the basic concepts of modern electronic structure/reactivity theory based upon the Density Functional Theory (DFT), followed by an outline of the main ideas and techniques of IT, including several illustrative applications to molecular systems. Coverage includes information origins of the chemical bond, unbiased definition of molecular fragments, adequate entropic measures of their internal (intra-fragment) and external (inter-fragment) bond-orders and valence-numbers, descriptors of their chemical reactivity, and information criteria of their similarity and independence. Information Theory of Molecular Systems is recommended to graduate students and researchers interested in fresh ideas in the theory of electronic structure and chemical reactivity. ·Provides powerful tools for tackling both classical and new problems in the theory of the molecular electronic structure and chemical reactivity ·Introduces basic concepts of the modern electronic structure/reactivity theory based upon the Density Functional Theory (DFT) ·Outlines main ideas and techniques of Information Theory

Perspectives in Electronic Structure Theory

Author: Roman F. Nalewajski

Publisher: Springer Science & Business Media

ISBN:

Category: Science

Page: 720

View: 621

The understanding in science implies insights from several different points of view. Alternative modern outlooks on electronic structure of atoms and molecules, all rooted in quantum mechanics, are presented in a single text. Together these complementary perspectives provide a deeper understanding of the localization of electrons and bonds, the origins of chemical interaction and reactivity behavior, the interaction between the geometric and electronic structure of molecules, etc. In the opening two parts the basic principles and techniques of the contemporary computational and conceptual quantum chemistry are presented, within both the wave-function and electron-density theories. This background material is followed by a discussion of chemical concepts, including stages of the bond-formation processes, chemical valence and bond-multiplicity indices, the hardness/softness descriptors of molecules and reactants, and general chemical reactivity/stability principles. The insights from Information Theory, the basic elements of which are briefly introduced, including the entropic origins and Orbital Communication Theory of the chemical bond, are the subject of Part IV. The importance of the non-additive (interference) information tools in exploring patterns of chemical bonds and their covalent and ionic components will be emphasized.

Chemical Bonding and Spectroscopy in Mineral Chemistry

Author: F. J. Berry

Publisher: Springer Science & Business Media

ISBN:

Category: Science

Page: 326

View: 749

In recent years mineralogy has developed even stronger links with solid-state chemistry and physics and these developments have been accompanied by a trend towards further quantification in the theoretical as well as the experimental aspects of the subject. The importance of solid-state chemistry to mineralogy was reflected in a symposium held at the 1982 Annual Congress of The Royal Society of Chemistry at which the original versions of most of the contributions to this book were presented. The meeting brought together chemists, geologists and mineralogists all of whom were interested in the application of modern spectroscopic techniques to the study of bonding in minerals. The interdisci plinary nature of the symposium enabled a beneficial exchange of information from the various fields and it was felt that a book presenting reviews of the key areas of the subject would be a useful addition to both the chemical and mineralogical literature. The field of study which is commonly termed the 'physics and chemistry of minerals' has itself developed very rapidly over recent years. Such rapid development has resulted in many chemists, geologists, geochemists and mineralogists being less familiar than they might wish with the techniques currently available. Central to this field is an understanding of chemical bonding or 'electronic structure' in minerals which has been developed both theoretically and by the use of spectroscopic techniques.