Heteronuclear Metal-Metal Bonds


Book Description

The number of organometallic compounds containing heteronuclear metal-metal bonds has grown tremendously in the last ten years. Also known as cluster compounds, these compounds have been found to exhibit a rich diversity of molecular structures and reactivities. Descriptions of the structures and transformations of the complexes are central features. Separate chapters have been prepared for compounds containing bonds between transition metals and the metals of the copper and zinc subgroups. Unlike COMC, this volume contains an entire chapter devoted to studies of heteronuclear metal compounds in catalysis.










Compounds Containing Heteronuclear Metal-Metal Bonds


Book Description

This Report describes the synthesis and structural characterisation of several gold-ruthenium cluster compounds, as well as the discovery of the first trimetallic complexes containing the hexanuclear core structures MM'Ru4 (M = Ag, M' = Cu; M = Au, M' =Cu; M = Au, M' = Ag). Using variable temperature 31P-1H nuclear magnetic resonance spectroscopy we have observed polytopal rearrangements of these clusters in solution. Also described are new heteronuclear cluster compounds containing bonds between iridium and osmium or platinum. In a further study the first mixed-metal clusters involving osmium and platinum with interstitial carbido ligands are reported. Rational synthetic routes have been developed for preparing cluster compounds containing chains and rings of metal atoms in which the metal-metal bonds are bridged by alkylidyne groups. This work has led to the characterisation, via X-ray diffraction and n.m.r. studies, of novel compounds with core structures having eight metal atoms (Pt4W4 or Ni2Pt2W4) in a ring in the shape of a 'star'.




Metal-Metal Bonding


Book Description

John Berry: Metal-Metal Bonds in Chains of Three or More Metal Atoms: From Homometallic to Heterometallic Chains.- Malcolm Chisholm: Electronically Coupled MM Quadruple Bonded Complexes of Molybdenum and Tungsten.- Philip Power: Transition Metal Complexes Stabilized by Bulky Terphenyl Ligands: Applications to Metal–Metal Bonded Compounds.- Gerard Parkin: Metal–Metal Bonding in Bridging Hydride and Alkyl Compounds.- Roland Fischer and Gernot Frenking: Structure and Bonding of Metal Rich Coordination Compounds Containing Low Valent Ga(I) and Zn(I) Ligands.- Mike Hill: Homocatenation of Metal and Metalloid Main Group Elements.- Constandinos A. Tsipis: Aromaticity/Antiaromaticity in "Bare" and ‘‘Ligand-Stabilized’’ Rings of Metal Atoms.- Alexander Boldyrev: All-Transition Metal Aromaticity and Antiaromaticity.




Metal-Metal Bonds and Clusters in Chemistry and Catalysis


Book Description

This book contains a series of papers and abstracts from the 7th Industry-University Cooperative Chemistry Program symposium held in the spring of 1989 at Texas A&M University. The symposium was larger than previous IUCCP symposia since it also celebrated the 25 years that had elapsed since the initial discovery by F. A. Cotton and his co-workers of the existence of metal-metal quadruple bonds. Cotton's discovery demonstrated that multiple bonding in inorganic systems is not governed by the same constraints observed in organic chemistry regarding s and p orbital involvement. The d orbitals are involved in the multiple bonding description. The quadruple bond involves considerable d orbital overlap between adjacent metal centers. Part I of this series of papers focuses upon the impact of this discovery and describes further contributions to the development of the field. Multiple metal-metal bonding now is known to permeate broad areas of transition metal chemistry. The understanding of metal-metal bonding that developed as a result of the discovery of multiple metal-metal bonding awakened a new chemistry involving metal clusters. Clusters were defined by Cotton to be species containing metal-metal bonding. Clusters in catalysis therefore seemed a logical grouping of papers in this symposium. Clusters play an every increasing role in the control of chemical reactions. Part II of this book describes some of the interesting new developments in this field. In Part III the papers examine the role clusters play in describing and understanding solid state materials.




Molecular Metal-Metal Bonds


Book Description

Systematically covering all the latest developments in the field, this is a comprehensive and handy introduction to metal-metal bonding. The chapters follow a uniform, coherent structure for a clear overview, allowing readers easy access to the information. The text covers such topics as synthesis, properties, structures, notable features, reactivity and examples of applications of the most important compounds in each group with metal-metal bonding throughout the periodic table. With its general remarks at the beginning of each chapter, this is a must-have reference for all molecular inorganic chemists, including PhD students and postdocs, as well as more experienced researchers.










Heteronuclear Metal Cluster Compounds Synthesis and Reactivity


Book Description

This Final Report describes the synthesis and characterisation of compounds containing metal-metal bonds between dissimilar transition elements. The new compounds reported included species with chains or rings of metal atoms, involving tungsten or molybdenum bonded to the elements nickel, platinum, rhodium, or iridium. The Report also describes numerous mixed-metal compounds in which the metal-metal bonds are bridged by the carbaborane group C2B9H9R2 (R = H or Me). A variety of unprecedented molecular structures have been identified by X-ray crystallographic studies. Keywords: Cluster compounds of platinum, Nickel, Molybdenum, Tungsten, Rhodium, Iridium, Iron, Ruthenium, Gold. (Js).