Quantum Chemistry: The Challenge of Transition Metals and Coordination Chemistry

ISBN-13: 9789027722379 / Angielski / Twarda / 1986 / 530 str.

A. Veillard

Opis

Over the last twenty years, developments of the ab initio metho dologies and of the computing capacities have progressively turned quantum chemistry into a predictive tool for molecular systems involving only light elements. The situation appears less advanced for systems containing transition metal elements where specific difficulties arise, like those 1inked to the quasi-degeneracy of the lowest atomic states. Correlation effects, which are important only for quantitative accuracy in the treatment of molecules made of light elements, need sometimes to be considered even for a qualitative des cription of transition metals systems (like the multiple metal-metal bond). The treatment of atoms of a high atomic number has necessited the development of model potential methods. These difficulties ex acerbate for systems containing several trans ition atoms a correct description of the dichromium molecule Crz still represents a challenge to quantum chemists. Yet many advances have been made recently in the theoretical treatment of these systems, despite the fact that our understanding still remains disparate with a variety of models and methodologies used more or less successfully (one-electron models, explicitly correlated ab initio methods, density functional formalisms). For these reasons, a NATO Advanced Research Workshop was organized to review in detail the state-of-the-art techniques and at the same time the most common applications. These encompass many fields including the spectroscopy of diatomics and small aggregates, structure and reactivity problems in organometallic chemistry, the cluster surface analogy with its implications for heterogeneous catalysis and the description of extended structures."

Spis treści

Accurate Studies on the Structure and Reactivity of Transition Metal Complexes and Clusters.- The Importance of Atomic and Molecular Correlation on the Bonding in Transition Metal Compounds.- The Electronic Structure of Transition Metal Atoms and Diatoms Through Pseudopotential Approaches.- Spectroscopic Characterization of Bonding in Diatomics and Small Transition Metal Aggregates.- Low-Lying Electronic States of ScH, tih and VH According to MRD-CI Calculations.- Energy-Adjusted Pseudopotentials For Transition-Metal Elements.- Spectroscopic Studies of Copper Complexes.- Scandium atom Interacting with Diatomic Groups.- The Nature of the Bonding in the Transition Metal Trimers.- Electronic Structure and Reactions of Transition Metal Complexes Using Effective Core Potentials.- Correlation Effects in the Ground and Ionized States of Transition Metal Complexes.- Analysis of ?-Bonding, ?-(Back) Bonding and the Synergic Effect in Cr(Co)6. Comparison of Hartree-Fock and X? Results for Metal-Co Bonding.- Applications of the LCGTO-X? Method to Transition Metal Carbonyls.- Quantitative Results and Qualitative Analysis by the Hartree-Fock-Slater Transition State Method.- X? Electronic Structure of Transition Metal Halides: Calculation of Ligand-Field Multiplet States.- Complementary Spherical Electron Density Model for Coordination and Organometallic Compounds.- Theoretical Analysis of Bonding Properties in Transition Metal Complexes. Ligand Substitution Effects.- Topology of Potential Energy Surfaces: The Complementarity of MO and VB Approaches.- Applied mo Theory: Organometallic Structure and Reactivity Problems.- CO Activation and Reactivity in Organometallic Chemistry: Theoretical Studies.- Structural Distortions and Activation of A C-H Bond in D° Electron Deficient Alkyl Transition Metal Complexes.- Stereochemistry and Metal-Ligand Interaction of Group VIII Low-Valent Transition Metal Complexes. An Ab Initio MO and Energy Decomposition Analysis Study.- Stabilization of Phosphinidene and Phosphirene by Complexation on Phosphorus. Theoretical and Photo-Electron Studies.- Molecular Orbital Calculations on Metallocenes with Unusual Geometries.- Transition State for Carbonyl and Olefin Insertion Reactions.- Theoretical Aspects of the Photochemistry of Organo-Metallics.- Electronic Structure of Metalloporphyrins: Ab Initio CI Calculations.- Multiple Metal-Metal and Metal-Carbon Bonds.- Design of Ferromagnetically Coupled Polymetallic Systems: Toward the Molecular Ferromagnets.- A Spectroscopic and Magnetic Investigation of M4X4 Clusters: Localized or Itinerant Electrons?.- Moving from Discrete Molecules to Extended Structures: A Chemical and Theoretical Approach to the Solid State.- Cluster-Surface Analogy: New Developments.- Cluster Model Calculations of the Interaction of H and CO with Small Pd Clusters.- Theoretical Study on the Catalytic Activities of Palladium for the Hydrogenation Reaction of Acetylene.- Theoretical Study of the Successive Hydrogenation of Small Platinum Clusters.- Participants.