Introduction to Ligand Field Theory


Book Description

"I have tried to give an introduction to that field of chemistry which deals wit the spectral and magnetic features of inorganic complexes. It has been my intention not to follow the theory in all its manifestations, but merely to describe the basic ideas and applications. This has been done with an eye constantly aimed at the practical and experimental features of the chemistry of the complex ions. The book is thus primarily intended for the inorganic chemist, but it is true that, in order to follow the exposition, a course in basic quantum mechanics is needed"--Preface.







Ligand Field Theory and Its Applications


Book Description

A complete, up-to-date treatment of ligand field theory and its applications Ligand Field Theory and Its Applications presents an up-to-date account of ligand field theory, the model currently used to describe the metal-ligand interactions in transition metal compounds, and the way it is used to interpret the physical properties of the complexes. It examines the traditional electrostatic crystal field model, still widely used by physicists, as well as covalent approaches such as the angular overlap model, which interprets the metal ligand interactions using parameters relating directly to chemical behavior. Written by internationally recognized experts in the field, this book provides a comparison between ligand field theory and more sophisticated treatments as well as an account of the methods used to calculate the energy levels in compounds of the transition metals. It also covers physical properties such as stereochemistry, light absorption, and magnetic behavior. An emphasis on the interpretation of experimental results broadens the book's field of interest beyond transition metal chemistry into the many other areas where these metal ions play an important role. As clear and accessible as Brian Figgis's 1966 classic Introduction to Ligand Fields, this new book provides inorganic and bioinorganic chemists as well as physical chemists, chemical physicists, and spectroscopists with a much-needed overview of the many significant changes that have taken place in ligand field theory over the past 30 years.




Ligand Field


Book Description

Twenty years ago Tanabe and Sugano published the first ligand field energy diagrarns which are applicable to dN electronic configurations. These diagrams are limited in scope in that they can be used only for octahedral symmetry and for a limited number of terms. The present volume is an attempt to fill the gap by providing a reasonable nurober of complete and accurate ligand field energy diagrarns for dN configurations in the most commonly encountered symmetries. Despite their limited nature, the diagrarns of Tanabe and Sugano were exten sively used in the past in order to rationalize optical and luminescence spectra and to discuss various electronic properties of transition metal ions, their coordination compounds and solids. Moreover, Tanabe-Sugano diagrams have an established place in the theory of transition metal compounds and are included in most textbooks of inorganic and coordination chemistry. It is expected that the present diagrarns will be found useful for a similar purpose.




Practical Approaches to Biological Inorganic Chemistry


Book Description

Practical Approaches to Biological Inorganic Chemistry, Second Edition, reviews the use of spectroscopic and related analytical techniques to investigate the complex structures and mechanisms of biological inorganic systems that contain metals. Each chapter presents an overview of the technique, including relevant theory, a clear explanation of what it is, how it works, and how the technique is actually used to evaluate biological structures. New chapters cover Raman Spectroscopy and Molecular Magnetochemistry, but all chapters have been updated to reflect the latest developments in discussed techniques. Practical examples, problems and many color figures are also included to illustrate key concepts. The book is designed for researchers and students who want to learn both the basics and more advanced aspects of key methods in biological inorganic chemistry. - Presents new chapters on Raman Spectroscopy and Molecular Magnetochemistry, as well as updated figures and content throughout - Includes color images throughout to enable easier visualization of molecular mechanisms and structures - Provides worked examples and problems to help illustrate and test the reader's understanding of each technique - Written by leading experts who use and teach the most important techniques used today to analyze complex biological structures




Introduction to Coordination Chemistry


Book Description

At the heart of coordination chemistry lies the coordinate bond, in its simplest sense arising from donation of a pair of electrons from a donor atom to an empty orbital on a central metalloid or metal. Metals overwhelmingly exist as their cations, but these are rarely met ‘naked’ – they are clothed in an array of other atoms, molecules or ions that involve coordinate covalent bonds (hence the name coordination compounds). These metal ion complexes are ubiquitous in nature, and are central to an array of natural and synthetic reactions. Written in a highly readable, descriptive and accessible style Introduction to Coordination Chemistry describes properties of coordination compounds such as colour, magnetism and reactivity as well as the logic in their assembly and nomenclature. It is illustrated with many examples of the importance of coordination chemistry in real life, and includes extensive references and a bibliography. Introduction to Coordination Chemistry is a comprehensive and insightful discussion of one of the primary fields of study in Inorganic Chemistry for both undergraduate and non-specialist readers.




Multiplets of Transition-Metal Ions in Crystals


Book Description

Multiplets of Transition-Metal Ions in Crystals provides information pertinent to ligand field theory. This book discusses the fundamentals of quantum mechanics and the theory of atomic spectra. Comprised of 10 chapters, this book starts with an overview of the qualitative nature of the splitting of the energy level as well as the angular behavior of the wavefunctions. This text then examines the problem of obtaining the energy eigenvalues and eigenstates of the two-electron systems, in which two electrons are accommodated in the t2g and eg shells in a variety of ways. Other chapters discuss the ligand-field potential, which is invariant to any symmetry operation in the group to which symmetry of the system belongs. This book discusses as well the approximate method of expressing molecular orbitals (MO) by a suitable linear combination of atomic orbitals (AO). The final chapter discusses the MO in molecules and the self-consistent field theory of Hartree–Fock. This book is a valuable resource for research physicists, chemists, electronic engineers, and graduate students.




The Effective Crystal Field Potential


Book Description

As it results from the very nature of things, the spherical symmetry of the surrounding of a site in a crystal lattice or an atom in a molecule can never occur. Therefore, the eigenfunctions and eigenvalues of any bound ion or atom have to differ from those of spherically symmetric respective free ions. In this way, the most simplified concept of the crystal field effect or ligand field effect in the case of individual molecules can be introduced. The conventional notion of the crystal field potential is narrowed to its non-spherical part only through ignoring the dominating spherical part which produces only a uniform energy shift of gravity centres of the free ion terms. It is well understood that the non-spherical part of the effective potential "seen" by open-shell electrons localized on a metal ion plays an essential role in most observed properties. Light adsorption, electron paramagnetic resonance, inelastic neutron scattering and basic characteristics derived from magnetic and thermal measurements, are only examples of a much wider class of experimental results dependent on it. The influence is discerned in all kinds of materials containing unpaired localized electrons: ionic crystals, semiconductors and metallic compounds including materials as intriguing as high-Tc superconductors, or heavy fermion systems. It is evident from the above that we deal with a widespread effect relative to all free ion terms except those which can stand the lowered symmetry, e.g. S-terms. Despite the universality of the phenomenon, the available handbooks on solid state physics pay only marginal attention to it, merely making mention of its occurrence. Present understanding of the origins of the crystal field potential differs essentially from the pioneering electrostatic picture postulated in the twenties. The considerable development of the theory that has been put forward since then can be traced in many regular articles scattered throughout the literature. The last two decades have left their impression as well but, to the authors' best knowledge, this period has not been closed with a more extended review. This has also motivated us to compile the main achievements in the field in the form of a book.




A Textbook of Inorganic Chemistry – Volume 1


Book Description

An advanced-level textbook of inorganic chemistry for the graduate (B.Sc) and postgraduate (M.Sc) students of Indian and foreign universities. This book is a part of four volume series, entitled "A Textbook of Inorganic Chemistry – Volume I, II, III, IV". CONTENTS: Chapter 1. Stereochemistry and Bonding in Main Group Compounds: VSEPR theory; dπ -pπ bonds; Bent rule and energetic of hybridization. Chapter 2. Metal-Ligand Equilibria in Solution: Stepwise and overall formation constants and their interactions; Trends in stepwise constants; Factors affecting stability of metal complexes with reference to the nature of metal ion and ligand; Chelate effect and its thermodynamic origin; Determination of binary formation constants by pH-metry and spectrophotometry. Chapter 3. Reaction Mechanism of Transition Metal Complexes – I: Inert and labile complexes; Mechanisms for ligand replacement reactions; Formation of complexes from aquo ions; Ligand displacement reactions in octahedral complexes- acid hydrolysis, base hydrolysis; Racemization of tris chelate complexes; Electrophilic attack on ligands. Chapter 4. Reaction Mechanism of Transition Metal Complexes – II: Mechanism of ligand displacement reactions in square planar complexes; The trans effect; Theories of trans effect; Mechanism of electron transfer reactions – types; outer sphere electron transfer mechanism and inner sphere electron transfer mechanism; Electron exchange. Chapter 5. Isopoly and Heteropoly Acids and Salts: Isopoly and Heteropoly acids and salts of Mo and W: structures of isopoly and heteropoly anions. Chapter 6. Crystal Structures: Structures of some binary and ternary compounds such as fluorite, antifluorite, rutile, antirutile, crystobalite, layer lattices- CdI2, BiI3; ReO3, Mn2O3, corundum, pervoskite, Ilmenite and Calcite. Chapter 7. Metal-Ligand Bonding: Limitation of crystal field theory; Molecular orbital theory: octahedral, tetrahedral or square planar complexes; π-bonding and molecular orbital theory. Chapter 8. Electronic Spectra of Transition Metal Complexes: Spectroscopic ground states, Correlation and spin-orbit coupling in free ions for Ist series of transition metals; Orgel and Tanabe-Sugano diagrams for transition metal complexes (d1 – d9 states); Calculation of Dq, B and β parameters; Effect of distortion on the d-orbital energy levels; Structural evidence from electronic spectrum; John-Tellar effect; Spectrochemical and nephalauxetic series; Charge transfer spectra; Electronic spectra of molecular addition compounds. Chapter 9. Magantic Properties of Transition Metal Complexes: Elementary theory of magneto - chemistry; Guoy’s method for determination of magnetic susceptibility; Calculation of magnetic moments; Magnetic properties of free ions; Orbital contribution, effect of ligand-field; Application of magneto-chemistry in structure determination; Magnetic exchange coupling and spin state cross over. Chapter 10. Metal Clusters: Structure and bonding in higher boranes; Wade’s rules; Carboranes; Metal carbonyl clusters - low nuclearity carbonyl clusters; Total electron count (TEC). Chapter 11. Metal-π Complexes: Metal carbonyls: structure and bonding; Vibrational spectra of metal carbonyls for bonding and structure elucidation; Important reactions of metal carbonyls; Preparation, bonding, structure and important reactions of transition metal nitrosyl, dinitrogen and dioxygen complexes; Tertiary phosphine as ligand.




Ligand Design in Medicinal Inorganic Chemistry


Book Description

Increasing the potency of therapeutic compounds, while limiting side-effects, is a common goal in medicinal chemistry. Ligands that effectively bind metal ions and also include specific features to enhance targeting, reporting, and overall efficacy are driving innovation in areas of disease diagnosis and therapy. Ligand Design in Medicinal Inorganic Chemistry presents the state-of-the-art in ligand design for medicinal inorganic chemistry applications. Each individual chapter describes and explores the application of compounds that either target a disease site, or are activated by a disease-specific biological process. Ligand design is discussed in the following areas: Platinum, Ruthenium, and Gold-containing anticancer agents Emissive metal-based optical probes Metal-based antimalarial agents Metal overload disorders Modulation of metal-protein interactions in neurodegenerative diseases Photoactivatable metal complexes and their use in biology and medicine Radiodiagnostic agents and Magnetic Resonance Imaging (MRI) agents Carbohydrate-containing ligands and Schiff-base ligands in Medicinal Inorganic Chemistry Metalloprotein inhibitors Ligand Design in Medicinal Inorganic Chemistry provides graduate students, industrial chemists and academic researchers with a launching pad for new research in medicinal chemistry.