Chemistry of Transition Metals

Because several of the superalloys contain very little iron, they are closely related to some of the non-ferrous alloys. Some of the second- and third-row transition metals possess many of the desirable properties of superalloys. They maintain their strength at high temperatures, but they may be somewhat reactive with oxygen under these conditions. These metals are known as refractory metals, and they include niobium, molybdenum, tantalum, tungsten, and rhenium. 

Although much of the chemistry of transition metals is associated with coordination compounds, there are some important aspects of their behavior that are related to other types of compounds. In this section, a brief overview of the chemistry of transition metals will be given with emphasis on the first-row metals. 

The reaction between a transition metal and oxygen frequendy yields a product that may not be stricdy stoichiometric. Part of the reason for this was shown in Chapter 8 when the dynamic nature of the reaction of a metal with a gas was considered. Moreover, it is frequendy found that transition metals can exist in more than one oxidation state, so mixed oxides are possible. The product that is in contact with oxygen is normally that in which the higher oxidation state is found. 

There are several ways in which titanium can be produced. For example, reduction of Ti02 gives the metal, 

It can also be produced from ilmenite, FeTi03( by the reaction 

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W. A. Nugent and J. M. Mayer, Metal-Eigand Multiple Bonds The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Jilkylidene, orJilkylidyne Eigands,Jolm. Wiley Sons, Inc., New York, 1988. Contains electronic and molecular stmcture, nmr, and ir spectroscopy, reactions, and catalysis. 

Chemistry of transition metal complexes supported by hydrotris(pyrazolyl) borates and chemistry of dioxygen complexes based on these ligands 99YGK619. 

The unique importance of the cyclopentadienyl ligand in the coordination chemistry of transition metals is mainly based on following three features ... 

The application of diffuse reflectance spectroscopy to the chemistry of transition metal coordination compounds. E. L. Simmons, Coord. Chem. Rev., 1974,14,181-196 (81). 

Recent results in the chemistry of transition metal clusters with organic ligands. H. Vahrenkamp, Struct. Bonding (Berlin), 1977, 32, 2-56 (408). 

Some recent developments in the chemistry of transition metal oxo-cations. J. Selbin, Angew. Chem., Int. Ed. Engl., 1966,5,712-722 (184). 

One of the commonest reactions in the chemistry of transition-metal complexes is the replacement of one ligand by another ligand (Fig. 9-3) - a so-called substitution reaction. These reactions proceed at a variety of rates, the half-lives of which may vary from several days for complexes of rhodium(iii) or cobalt(m) to about a microsecond with complexes of titanium(iii). 

Brothers, Penelope J., Organometallic Chemistry of Transition Metal Porphyrin... 

The literature concerning the chemistry of transition-metal complexes containing 1,1-dithiolato ligands was extensively reviewed, up to 1968, by Coucouvanis (1). We attempt here to update that excellent account. 

Vahrenkamp H (1977) Recent Results in the Chemistry of Transition Metal Clusters with Organic Ligands. 32 1-56... 

Gaussian-type orbitals, the computational requirements grow, in the limit, with the fourth power in the number of basis functions on the SCF level and with even a higher power for methods including correlation. Both the conceptual and the computational aspects prevent the computational study of important problems such as the chemistry of transition metal surfaces, interfaces, bulk compounds, and large molecular systems. 

Ames Laboratory (Iowa State University, USA) investigating new solid state phases based on reduced rare earth halides. Since 1993, she has held a position at the University Jaume 1 of Castello (Spain) and became Associate Professor of Physical Chemistry in 1995. During the second semester of 2005, she held a visiting professor position at the Laboratory of Chemistry, Molecular Engineering and Materials of the CNRS-Universtity of Angers (France). Her research has been focussed on the chemistry of transition metal clusters with special interest in multifunctional molecular materials and the relationship between the molecular and electronic structures of these systems with their properties. She is currently coauthor of around 80 research papers on this and related topics. 

J. S. Bradley, in G. Schmid (ed.) The Chemistry of Transition Metal Colloids, Wiley-VCH, Weinheim, 1994, 459. 

McQuillin, F. J., Parker, D. G., Stephenson, G. R., Transition Metal Organometallics for Organic Synthesis. Cambridge Press, 1991 Crabtree, R. H The Organometallic Chemistry of Transition Metals, 2nd ed. John Wiley Sons, New York, 1994. 

The ability of transition metal ions, and especially chromium (as Cr3+), to form very stable metal complexes may be used to produce dyeings on protein fibres with superior fastness properties, especially towards washing and light. The chemistry of transition metal complex formation with azo dyes is discussed in some detail in Chapter 3. There are two application classes of dyes in which this feature is utilised, mordant dyes and premetallised dyes, which differ significantly in application technology but involve similar chemistry. 

Although there are a lot of publications on the chemistry of technetium [2-4] and transition-metal clusters [1,5-8], the chemistry of technetium clusters was insufficiently studied until the early eighties [1,2]. Nevertheless, the available scanty data on the compounds with Tc-Tc bonds inspired hope that interesting results would be obtained in the chemistry of technetium in general, in radiochemistry, and in the chemistry of transition-metal cluster compounds. The anticipated results were actually obtained [9-15] and the conclusion was drawn that technetium had a number of anomalous cluster-forming properties [9]. This review looks at the detailed studies of these properties and their interpretation in terms of electronic structure theory. 

The chemistry of transition metal-carbyne complexes is rather less developed than the chemistry of carbene complexes. This is almost certainly because reactions which form new carbyne complexes are relatively rare when compared with those forming metal carbenes. The few theoretical studies of carbyne complexes which are available indicate that close parallels exist between the bonding in carbene and carbyne compounds. These parallels also extend to chemical reactivity, and studies of Group 8 complexes again prove instructive. 

Dunbar, K. R. Heintz, R. A. Chemistry of Transition Metal Cyanide Compounds Modern Perspectives. In Progress in Inorganic Chemistry, Karlin, K. D., Ed. J. Wiley New York, 1997, Vol. 45, pp 283-391. 

Brooks, H., in Electronic Structure and Alloy Chemistry of Transition Metals (P. A. Beck, ed.). Wiley, New York, 1963. [Russian transl. p. 9.]... 

Livage, J., Henry, M. and Sanchez, C. (1988) Sol-gel chemistry of transition-metal oxides. Progress in Solid State Chemistry, 18,... 

Coordination compounds have been produced by a variety of techniques for at least two centuries. Zeise s salt, K[Pt(C2H4)Cl3], dates from the early 1800s, and Werner s classic syntheses of cobalt complexes were described over a century ago. Synthetic techniques used to prepare coordination compounds range from simply mixing the reactants to employing nonaqueous solvent chemistry. In this section, a brief overview of some types of general synthetic procedures will be presented. In Chapter 21, a survey of the organometallic chemistry of transition metals will be presented, and additional preparative methods for complexes of that type will be described there. 

Cotton, F. A., Wilkinson, G., Murillo, C. A., and Bochmann, M. (1999). Advanced Inorganic Chemistry, 6th ed. Chapter 5. Wiley, New York. A 1300-page book that covers a great deal of organometallic chemistry of transition metals. 

Leclercq, L., Almazouari, A., Dufour, M., and Leclercq, G. 1996. Carbide-oxide interactions in bulk and supported tungsten carbide catalysts for alcohol synthesis. In Chemistry of transition metal carbides and nitrides, ed. S. T. Oyama, 345-61. Glasgow Blackie. 

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