Metal-element multiple bonds

Reactions other than Lewis acid-base associations/dissociations are frequently observed wit donor molecules, leading notably to solvolysis, oxygen or sulfur abstraction, insertion reaction and carbon-carbon coupling reactions. The tendency to form metal-element multiple bonds i remarkable in this respect the activation of dinitrogen by tantalum or niobium is unique. Th formation and chemistry of constrained reactive metallacycles open another promisin fast-developing area, on the frontier with organometallic chemistry. 

Complexes with Metal-element Multiple Bonds. 46... 

Silyl and germyl complexes with suitable functionalities were successfully used as precursors for the synthesis of compounds with corresponding transition metal element multiple bonds.137 145 Due to the aforementioned... 

This statement applies to the representative elements. Multiple bonding is also important for some transition elements. For a review of metal-metal multiple bonds, see Cotton, F.A. J. Chem. Educ., 1983, 60, 713. 

Fig. 8.3 Warren R. Roper (born in 1938) studied chemistry at the University of Canterbury in Christchurch, New Zealand, and completed his Ph.D. in 1963 under the supervision of Cuthbert J. Wilkins. He then undertook postdoctoral research with James P. Collman at the University of North Carolina at Chapel Hill in the US, and returned to New Zealand as Lecturer in Chemistry at the University of Auckland in 1966. In 1984, he was appointed Professor of Chemistry at the University of Auckland and became Research Professor of Chemistry at the same institution in 1999. His research interests are widespread with the emphasis on synthetic and structural inorganic and organometallic chemistry. Special topics have been low oxidation state platinum group metal complexes, oxidative addition reactions, migratory insertion reactions, metal-carbon multiple bonds, metallabenzenoids and more recently compounds with bonds between platinum group metals and the main group elements boron, silicon, and tin. His achievements were recognized by the Royal Society of Chemistry through the Organometallic Chemistry Award and the Centenary Lectureship. He was elected a Fellow of the Royal Society of New Zealand and of the Royal Society London, and was awarded the degree Doctor of Science (honoris causa) by the University of Canterbury in 1999 (photo by courtesy from W. R. R.)...

In contrast to the d-block, vhere there are many examples of metal-ligand multiple bonds, f-element-ligand multiple bond chemistry is in its infancy. In part this reflects the entire area of molecular f-element chemistry which is much less developed than that of the transition metals, and, in part, it is the result of difficulties in evaluating the nature of the bonding in heavy metals vhich are highly ionic, do not follow simple electron counting rules (e.g. the 18... 

The list of rare earth-element multiple bonds is still missing terminal metal carbenes. However, CaveU (Apama et al., 2000), Le Hoch (Cantat et al., 2005), and Liddle (Mills et al., 2010 Chart 4) synthesized formal rare earth carbene complexes by incorporating the carbene in the framework of a chelating bis(iminophosphorano)methylene (N2C ) or bis (diphenylthiophosphinoyl)methylene (S2C ) ligand. Also, P. Arnold reported numerous examples of interesting reactivity of f-block complexes supported by A -heterocyclic carbenes (NHCs Chart 4 Arnold and Casely, 2009 Liddle and Arnold, 2005). 

Multiple bonds between transition metals and bare main group elements links between inorganic solid state chemistry and organometallic chemistry. W. A. Herrmann, Angew. Chem., Int. Ed. Engl., 1986, 25,56 (115). 

In addition to Refs, [la-d] there have been several recent reviews that have dealt with various aspects of multiple bonding to the group 13 elements (a) Robinson GH (1999) Acc Chem Res 32 773 (b) Downs AJ (1999) Coord Chem Revs 189 59 (c) Robinson GH (2000) Chem Common 2175. Low-valent heavier group 13 species and their bonding to transition metal moieties have also been reviewed recently (d) Linti G, Schnockel H (2000) Coord Chem Rev 206-207 285... 

In the second chapter, Phil Power continues his remarkable and continuously successful search for new main group metal multiple bonding. The chapter is entitled Multiple Bonding Between Heavier Group 13 Elements, and covers the astounding new developments that have occurred in this area in... 

The addition of metal hydrides to C—C or C—O multiple bonds is a fundamental step in the transition metal catalyzed reactions of many substrates. Both kinetic and thermodynamic effects are important in the success of these reactions, and the rhodium porphyrin chemistry has been important in understanding the thermochemical aspects of these processes, particularly in terms of bond energies. For example, for first-row elements. M—C bond energies arc typically in the range of 2, i-. i() kcal mol. M—H bond energies are usually 25-30 kcal mol. stronger, and as a result, addition of M—CH bonds to CO or simple hydrocarbons is thermodynamically unfavorable. 

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