Main Group, Lanthanide and Actinides

1 Main Group, Lanthanide and Actinides - A mixed CpMg/CpTi complex which 

1 Main Group, Lanthanides and Actinides - In the series of papers Studies on Organolanthanide Complexes several topics have been covered the formation of ion-pair complexes of the type [ Na.phenan3 Cp]LnCl phenan] (phenan = 1,10-phenanthroline), the synthesis and structural chemistry of bismethoxylethylcyclopentadienyl complexes, and furan bridged bis-cyclopentadienyl complexes. A number of synthetic papers have also appeared in the area the synthesis of cyclooctatetraenyl-cyclopentadienyl sandwich complexes, the 

Actinide bond disraption enthalpies of the complexes Cp jMR M = actinide, R H, Me have been measured using iodinolysis and alcoholysis titration calorimetry and biallyl-monocyclopentadienyl lanthanum(III) complexes have been prepared for use as butadiene polymerisation catalysts. Finally, the reaction of [ Cp 2LnH 2] Ln = Y, Sm with [CpjWH2] results in the formation of the sigma bonded metathesis products via dehydrocoupling.  

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The Periodic Table of Metalloporphyrins, presented first by Buchler [47] and then by Kadish [2], was expanded in the 1980s to include most of the Main Group, lanthanide, and actinide elements, as well as a number of the Group 15 nonmetals. At the same time, the range of known metal or nonmetal oxidation states that could be accommodated by a given metallopor-phyrin was expanded in part by the use of novel axial ligands or macrocycles, in part by the use of different solvents or solvent conditions (i.e. low temperature), and in part by the application of... 

The application of these methods is described in some detail for recovery of base metals and platinum group metals in Sections 9.17.5-9.17.6 focusing mainly on solution-based hydrometal-lurgical operations, largely those involving solvent extraction, because the nature of the metal complexes formed is usually best understood in such systems. NB. Extraction of lanthanides and actinides is not included as this subject is treated separately in Chapters 3.2 and 3.3. 

Type I momentum densities, characteristic of He, N, Mn, all atoms from groups 1-6, 13, and 14 except Ge, and the lanthanides and actinides, are unimodal and have a maximum at p = 0. A density of this type is shown in Figure 5.5 for the potassium atom. The maximum at p = 0 comes mainly from... 

The main group metals are the most important, given the role of Na+, K+, and Ca + in bioelectrical excitability. The transition metals also have biological relevance. A formal definition of transition metals is that they have partially filled d ox f orbitals in either their free (uncombined) atoms or one or more of their ions. Transition metals may be divided into t/-block and /-block elements the /-block is further divided into the lanthanide and actinide series. Since/-block metals are not of great significance to medicinal... 

Figure 1.1 Principal features of the periodic table. The International Union of Pure and Applied Chemistry (IUPAC) now recommends Arabic group numbers 1-18 in place of the traditional Roman I—VIII (A and B). Group names include alkali metals (1), alkaline earth metals (2), coinage metals (11), chalcogens (16), and halogens (17). The main groups are often called the s,p block, the transition metals the d, block elements, and the lanthanides and actinides the / block elements, reflecting the electronic shell being filled. (See inside front cover for detailed structure of the periodic table.)...

The main drawback of CMPO calixarenes is their low solubility in most of the diluents. Their concentration in the organic phase is not sufficient to allow lanthanides and actinides to be coextracted from HAW. Adamantyl groups improve the solubility of CMPO calixarenes. It would be interesting to continue to study these compounds and possibly to seek other ways to achieve a sufficient solubility (e.g., 0.1 M) of these calixarenes. 

MtfBy, M Bg, M B10, 3, 165 Group 10 complexes, 3, 167 lanthanide and actinide complexes, 3, 137 macropolyhedral metallaboranes, 3, 168 main group complexes, 3, 139 main group and lanthanide metal complexes, 3, 139 monoboron clusters, 3, 146... 

Particular areas of interest are the chemistry early-late metal-metal bonded complexes, main group metal-transition metal dimers, transition metal carborane derivatives, and lanthanide and actinide transition metal complexes. ... 

Complexes with main group metal ions, and with lanthanides and actinides, can be prepared in water or organic solvents. The complexes are probably (but see later) less robust than those of the transition... 

First, only transition metal complexes are considered, thereby excluding bimetallic and trimetallic compounds with a- or 7r-bonded main group metals, for example, (t7 -C5H4ER3)M(CO) X (M = Fe, Mo E = Ge, Sn, Pb X = Me) (30), as well as lanthanides and actinides (3)). 

I Note that these same criticisms apply equally well to scandium (known only as the Sc ", ion). 19 That is. there would be only thirteen lanthanides and actinides, just as elimination of zinc, cadmium, and mercury leaves only nine transition metal groups, and elimination of the noble ga.ses. leaves only five groups to contain the nonmetals and posttransition metals. The main difficulty with any of these suggestions is that they contradict the simple expectations that the j-block should consist of two elements, the p-block should consist of six elements, the d-block should consist of ten elements, and the /-block should consist of fourteen elements. 

One other approach for the activation of alkane C-H bonds is to choose a metal that forms a strong metal-to-carbon bond. Main group and early J-block elements (e.g., AIR3, TaRs, etc.) as well as lanthanide and actinide alkyls fall into this category. 

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