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Actinide elements organometallic compounds

A77. C. Keller, The Chemistry of the Transuranium Elements. Verlag Chemie, Weinheim, 1971. Chapter 8, Organometallic compounds of the actinides, pp. 187-193 (36). Not as comprehensive as reference 4.39. [Pg.449]

Among the natural and artificial radioactive elements (Tc, Pm, Po, Fr, Ra, Ac, and actinides), coordination and organometallic compounds of only technetium and the actinide series (An) are well represented at the present time. The interest in their metal complexes has been motivated by the extended use of Tc, available in kilogram amounts, for medical and technical purposes, meanwhile actinides are important on their own for the nuclear industry. A lot of original papers, reviews, and chapters of some books are dedicated to Tc and An complexes [263-281], In the present section, dedicated to the coordination and organometallic chemistry of the actinides and Tc, we intend to present the synthetic techniques for these compounds according to their ligand nature. [Pg.428]

Actinide organometallic complexes are compounds containing an actinide-carbon 7i-bond, an actinide-carbon a-bond, or a combination of both. Actinide organometallic complexes are known for all of the early actinide elements (An)... [Pg.428]

Not every actinide element has known or well-developed organometallic chemistry. By far the most research has been done on thorium and uranium compounds, a consequence of favorable isotope-specific nuclear properties and, at least until recently, the commercial availability of key starting materials such as Th metal, anhydrous ThCLi, U metal, and anhydrous UCL. Thorium chemistry is dominated by the -F4 oxidation state and has some similarities to the chemistry of the heavier group 4 metals. For uranium, one can access oxidation states from d-3 to 4-6 in organic media. Although there are some similarities to the chemistry of the heavier group 6 elements, for example, tungsten, there are also some remarkable differences made possible by the availability of the 5f valence orbitals. [Pg.33]

Not every actinide element has known or well-developed organometallic chemistry. By far the most research has been done on thorium and uranium compounds, a consequence of favorable isotope-specific nuclear properties and, at least until recently, the commercial availability of key starting materials such as Th metal, anhydrous ThCH, U metal, and anhydrous Thorium chemistry is dominated... [Pg.32]

Compounds of the stoichiometry MCp 2X2 provide an opportunity to compare actinides with block elements. Several such species have been studied both by gas phase PE experiments as well as by theoretical approaches. Thus, the first comparative study of the PE spectra of a series of transition metal and actinide organometallic compounds with exacdy the same ligand array was carried out on MCp 2X2 (M = Zr, Th, U, and X = CH3 and Cl) complexes. Comparable bonding was found along the series with smaller differences than encountered in the parent series involving transition elements. The major differences between Zr and the actinides are due to the involvement of yin the bonding. [Pg.403]

The actinide elements begin with actinium. Actinium serves as a starting point for the other actinide series elements, which span 14 spaces across the periodic table from actinium to lawrencium. Actinides are more reactive than lanthanides. They form covalent compounds and organometallic complexes. Most of the actinide elements were discovered during development of the nuclear bomb. The set of actinides is represented by the symbol An. [Pg.227]

The past decade has witnessed a dramatic expansion in what we know about the organometallic compounds of the 5f elements. It is now evident that the actinides have a very rich, intricate, and instructive organo-metallic chemistry, and that we have much to learn about the basic principles governing structure, bonding, and reactivity. Nowhere is this situation more obvious than in the area of metal hydrocarbyls (i.e., alkyls, aryls, alkenyls, etc.) and hydrides, and the growth in this area since our last ASI review in 1978 [ll has been phenomenal. [Pg.115]

E)espite substantial recent advances in the organometallic chemistry of other actinide elements, progress with curium has been slow. This lack of progress apparently is due to the nuclear properties of the element rather tlm to an inherent chemical instability of the organometallic compounds. For more detailed discussion of this topic, especially comparison with organometallics containing other actinide metals, the reader is directed to Chapters 22 and 23 of this volume. [Pg.104]

Actinide elements and their compounds have become the subject of intensive research in recent years (see the reviews [1-3]). In technology, interest is stimulated by the role of these elements in nuclear fuel and waste products, as well as the development of the actinide-organometallic chemical industry. In basic physics, actinide ions are prime candidates for observing parity non-conservation effects, which may reveal possible inconsistencies of the Standard Model [4]. It is interesting to note that actinides may have been involved in the creation of life on our planet [5], In spite of recent progress, many spectroscopic and other physical properties of actinides are still unknown, or known with very low accuracy, due in part to the relative scarcity, toxicity, and radioactivity of these elements. [Pg.23]

The T -bonding of the CO and RNC insertion products is characteristic of these actinide compounds, but has some parallels in the organometallic chemistry of the d-block elements. There are similar insertions into An—NR2 bonds to give products with rf ligands, namely,... [Pg.1156]

Although lacking 7T-bonded compounds in low oxidation states that characterize the d-block elements, the actinides have a rich organometallic chemistry. Their compounds frequently exhibit considerable thermal stability, but like the lanthanide compounds are usually intensely air- and moisture-sensitive. They are often soluble in aromatic hydrocarbons such as toluene and in ethers (e.g., THF) but are generally destroyed by water. Sometimes they are pyrophoric on exposure to air. Most of the synthetic work has been carried out with Th and U this is partly due to the ready availability of MCI4 (M = Th, U) and also because of the precautions that have to be taken in handling compounds of other metals, especially Pu and Np. [Pg.209]

Although the elements of the lanthanide and actinide series have long been known to exhibit a quite extensive organometallic chemistry, it is only within the last decade that typical sandwich species have been prepared and studied. These systems however, although resembling the familiar metallocene and bis-arene compounds of the d-block elements, are not strictly their analogues since in both f-orbital series the known sandwich complexes are derived only from the cyclooctatetraenyl dianion. [Pg.98]


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See also in sourсe #XX -- [ Pg.1278 , Pg.1279 ]




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