Main group elements alkali metals

In each representation, the alkali metal is black, the rare-earth element is shaded medium grey, the main group element is dark grey, and selenium is light grey (a) NagEu2(Si2Se6)2,... 

Two principle strategies have been employed for the synthesis of siloxide-containing molecular precursors. The first involves a silanolysis, or condensation, reaction of the Si - OH groups with a metal amido, alkyl, hahde, or alkoxide complex. The second method involves salt metathesis reactions of an alkali metal siloxide with a metal hahde. Much of our work has been focused on formation of tris(tert-butoxy)siloxide derivatives of the early transition metals and main group elements. The largely imexplored regions of the periodic table include the lanthanides and later transition metals. 

King, R. B. (1995). Inorganic Chemistry of the Main Group Elements. VCH Publishers, New York. An excellent introduction to the descriptive chemistry of many elements. Chapter 10 deals with the alkali and alkaline earth metals. 

Mixed alkali-metal chalcogenolates have been synthesized for main group elements, such as aluminium,54,55 germanium, and tin as (6) (Scheme 2),56 or transition metals such as zirconium,57 60 iron,61,62 vanadium,63 nickel,64 rhenium,65 and cobalt,66 or lanthanide metals.67,68... 

The polyhedral boranes and carboranes discussed above may be regarded as boron clusters in which the single external orbital of each vertex atom helps to bind an external hydrogen or other monovalent atom or group. Post-transition main group elements are known to form clusters without external ligands bound to the vertex atoms. Such species are called bare metal clusters for convenience. Anionic bare metal clusters were first observed by Zintl and co-workers in the 1930s [2-5], The first evidence for anionic clusters of post-transition metals such as tin, lead, antimony, and bismuth was obtained by potentiometric titrations with alkali metals in liquid ammonia. Consequently, such anionic post-transition metal clusters are often called Zintl phases. 

Zintl phases remarks on their definition. We have seen that the Zintl phases may be considered as a group of compounds formed by an electropositive (cationic) component (alkali, alkaline earth metal, lanthanide) and an anionic component (for instance a main group element of moderate electronegativity). The anionic part of the structure may be described in terms of normal valence combination. 

This chapter discusses the coordination chemistry of selected main group and transition metal complexes with dipicolinic acid, its analogues, and derivatives as ligands. Selected elements will be presented in terms of increasing atomic number. Out of all of the alkali metals, there has been a report of the crystal structure of sodium coordinated to dipicolinic acid. Calcium, magnesium, and strontium, three alkaline earth metals, are popular metal centers, which have been reported in the literature to be coordinated to dipicolinic acid or its analogues. ... 

One of the classical properties of the main group elements is that the stability of the lower oxidation states increases with atomic number, and the chemistry of thallium is a good example of this effect. In aqueous solution, the Tl+ ion is stable with respect to oxidation by the solvent and there is accordingly an extensive chemistry of this oxidation state. The similarities between Tl+ and the corresponding alkali metal cations have resulted in much interest in the use of this ion as a probe in biochemical systems, and the ease with which 205T1 NMR spectra can be recorded has also had an impact on such studies.277,278... 

For carbides and nitrides containing more than one transition metal, or a transition metal and another element, the compositions and structures are more varied and complex. Plate 1.3 shows examples where the secondary component is a metal or main group element. Figure 1.2 shows examples where one of the secondary components is an alkali or alkaline earth... 

While not strictly metal xanthates, it is apposite to summarize the structural features of the alkali and alkaline metal xanthates, and other salts for at least one crucial reason. On the basis of these structural studies, it will be demonstrated that there is no inherent chemical reason associated with the nature of the xanthate anion that explains the fascinating structural diversity observed for closely related metal xanthate structures to be described in this chapter, particularly for the main group element species. 

A. Simon, Alkali and alkaline earth metal suboxides and subnitrides. In M. Driess and H. Noth (eds.), Molecular Clusters of the Main Group Elements, Wiley-VCH, Weinheim, 2004, pp. 246-66. 

An unusual system involves the incorporation of a main group element, that is, germanium, within the macrocycle side chain. This is shown in Figure 17. The compounds were prepared in order to assess alkali metal cation transport. This was done but the results proved equivocal <2001JOM108>. 

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