Transition metals actinides

Lanthanides Any sixth-period inner transition metal. Actinides Any seventh-period inner transition metal. 

Ion chromatography gained general acceptance as fast and sensitive multielement detection method for the determination of alkali and alkaline earth metals, heavy and transition metals, actinides and lanthanides, as well as selected organic cations, allowing detection limits in the range of microgram per liter and analysis time of less than 20 min. 

Lanthanide and actinide compounds are difficult to model due to the very large number of electrons. However, they are somewhat easier to model than transition metals because the unpaired / electrons are closer to the nucleus than the outermost d shell. Thus, all possible spin combinations do not always have a significant effect on chemical bonding. 

HDPE resias are produced ia industry with several classes of catalysts, ie, catalysts based on chromium oxides (Phillips), catalysts utilising organochromium compounds, catalysts based on titanium or vanadium compounds (Ziegler), and metallocene catalysts (33—35). A large number of additional catalysts have been developed by utilising transition metals such as scandium, cobalt, nickel, niobium, molybdenum, tungsten, palladium, rhodium, mthenium, lanthanides, and actinides (33—35) none of these, however, are commercially significant. 

Carbon monoxide [630-08-0] (qv), CO, the most important 7T-acceptor ligand, forms a host of neutral, anionic, and cationic transition-metal complexes. There is at least one known type of carbonyl derivative for every transition metal, as well as evidence supporting the existence of the carbonyls of some lanthanides (qv) and actinides (1) (see AcTINIDES AND THANSACTINIDES COORDINATION COMPOUNDS). 

The alkaline and rare-earth metals, and positive actinide ions, generally have greater affinity for —0 groups as electron donors. Many transition metals complex preferentially with enoHc —0 and some nitrogen functions. PolarizabiUty of the donor atoms correlates with stabiUty of complexes of the heavier transition metals and the more noble metal ions. 

The reaction is general and has been applied to many transition metals as well as lanthanides and actinides. Variants use metal carbonyls and other complexes to supply the capping unit, e.g. 

Covalent transition metal lanthanide and actinide tetrahydroborate complexes. T. J. Marks and... 

Preparations and reactions of oxide fluorides of the transition metals, the lanthanides and the actinides. J. H. Holloway and D. Laycock, Adv. Inorg. Chem. Radiochem., 1984, 28, 73 (278). 

Because they exhibit interplay of magnetic and superconducting properties, the formation and crystal chemistry of MRgMy4B4 compounds have been examined. Ternary rare-earth and actinide (Th, U, Pu)-transition metal borides of the approxi-... 

Compounds containing group-lIB-transition-metal bonds arc characterized for almost every transition metal. Although there are more derivatives containing Hg than Zn or Cd, there is no difficulty in producing analogous compounds of each of these metals. No compound is known in which Zn, Cd or Hg is bonded to either lanthanide or actinide elements. 

Blasse G (1976) The Influence of Charge-Transfer and Rydberg States on the Luminescence Properties of Lanthanides and Actinides. 26 43-79 Blasse G (1980) The Luminescence of Closed-Shell Transition Metal-Complexes. New Developments. 42 1-41... 

As the computational effort in the LDF approach grows, in the limit, only with the third power in the number of orbitals, it can be expected that fairly large systems with a hundred atoms, including transition metals, rare earth, and actinide elements, will become tractable. 

The elements in Groups 3 through 12 are known as transition metals. The elements in rows 6 and 7 that are normally shown below the rest of the table are the inner transition metals, subdivided into lanthanides (row 6) and actinides (row 7). All other elements are main group elements. 

Between barium (Group 2, element 56) and lutetium (Group 3, element 71), the 4f orbitals fill with electrons, giving rise to the lanthanides, a set of 14 metals named for lanthanum, the first member of the series. The lanthanides are also called the rare earths, although except for promethium they are not particularly rare. Between radium (Group 2, element 88) and lawrenclum (Group 3, element 103), are the 14 actinides, named for the first member of the set, actinium. The lanthanides and actinides are also known as the inner transition metals. 

The structural chemistry of the actinides is often similar to that of lighter transition metals, such as Zr and Hf, and to that of the lanthanides however, the diffuse nature of the 5/ orbitals leads to some differences and specifically to interesting magnetic and electrical properties. The actinide sulfides are generally isostructural with the selenides, but not with the analogous tellurides. The binary chalcogenides of uranium and thorium have been discussed in detail [66], but the structural... 

In terms of gross features of mechanism, a redox reaction between transition metal complexes, having adjacent stable oxidation states, generally takes place in a simple one-equivalent change. For the post-transition and actinide elements, where there is usually a difference of two between the stable oxidation states, both single two-equivalent and consecutive one-equivalent changes are possible. 

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