Actinoid metals compounds

Chemistry of lanthanoid metal compounds Reactivity of actinoid metals... 

Compounds with Sc, Y, lanthanoids and actinoids are of three types. Those with composition ME have the (6-coordinated) NaCl structure, whereas M3E4 (and sometimes M4E3) adopt the body-centred thorium phosphide structure (Th3P4) with 8-coordinated M, and ME2 are like ThAsi in which each Th has 9 As neighbours. Most of these compounds are metallic and those of uranium are magnetically ordered. Full details of the structures and properties of the several hundred other transition metal-Group 15 element compounds fall outside the scope of this treatment, but three particularly important structure types should be mentioned because of their widespread occurrence and relation to other structure types, namely C0AS3,... 

Numerous compounds adopt the PbFCl structure. These include, apart from fluoride chlorides, oxide halides MOX (M = Bi, lanthanoids, actinoids X = Cl, Br, I), hydride halides like CaHCl and many compounds with metallic properties like ZrSiS or NbSiAs. 

The rules above gave maximum and minimum oxidation numbers, but those might not be the only oxidation numbers or even the most important oxidation numbers for an element. Elements of the last six groups of the periodic table for example may have several oxidation numbers in their compounds, most of which vary from each other in steps of 2. For example, the major oxidation states of chlorine in its compounds are -1, +1, +3, +5, and +7. The transition metals have oxidation numbers that may vary from each other in steps of 1. The inner transition elements mostly form oxidation states of + 3, but the first part of the actinoid series acts more like transition elements and the elements have... 

To the best of our knowledge there are no structure reports on species with Au-Group 3 metals (Sc, Y, La, Ac) as well as Au-lanthanoids and Au-actinoids bonds, or compounds with Au-Hf, Au-Zr or Au-Ta bonds or interactions. 

Clear interseparation of the lanthanoids or actinoids by gas chromatography of inorganic compounds is a challenge to experimental techniques. Thermochromatography does not have adequate resolving power for the separations, but the method proved very useful for adsorption studies of tracer metals. Hiibener [77] was the first to realize the difficult experiments with some lanthanoids and the actinoids... 

In this chapter we look at /-block metals and their compounds. There are two series of metals the lanthanoids (the 14 elements that follow lanthanum in the periodic table) and the actinoids (the 14 elements following actinium). The lanthanoids and actinoids (Table 24.1) are collectively known as the inner transition metals, while scandium, yttrium, lanthanum and the lanthanoids are together called the rare earth metals. Although La and Ac are strictly group 3 metals, the chemical similarity of La to the elements... 

Give a short account of aspects of the organometallic compounds formed by the lanthanoids and actinoids and highlight major differences between families of organometallic complexes of the d- and /-block metals. 

Organometallic compounds of the early transition elements, especially of the lanthanoides and actinoides, are among the very newest organometallic compounds. The electronically unsaturated character of these elements originally made it very difficult to synthesize satisfactorily stable compounds with metal-to carbon bonds. 

Although organometallic complexes are known for all the early actinoids, compounds of Th and U far exceed those of the other metals. In addition to radioactive properties, organoactinoids are air-sensitive and inert atmosphere techniques are required for their handling. 

The position of the refined a-hydrogen atoms is noteworthy. Both are pointed towards the metal (CeC(12)H(17) 93° and CeC(ll)H(16) 90°), and this results in short Ce-H distances (Ce-H(17) 2.82 and Ce H(16) 2.71 A). Similar a-CH agostic interactions have been observed for a number of lanthanoid and actinoid carbyls and reflect the high electron deficiency of those compounds [58]. 

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