Main group elements alkaline earths

Main Group Element Carborane Derivatives. Main group element carborane derivatives have been reviewed (231). Only a few alkaline-earth element metaHacarborane derivatives have been characterized. The icosahedral beryUacarborane, /(9j (9-3-[(CH3)3N]-3,l,2-BeC2B H, shown in Figure 24a, has been prepared via the reaction of nido-1 and Be(CH3)2 [0(C2H3)2]2 followed by reaction of the diethyletherate product and... 

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. 

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. 

Experience suggests that d-type functions are required on second-row and heavier main-group elements even though they are not occupied in the free atoms (discussion is provided in Section II). This situation is very much like that found for alkali and alkaline-earth elements where p-type functions, while not occupied in the ground-state atoms, are required for proper description of bonding in molecules. Here, the absence of p functions leads to descriptions... 

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... 

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. 

The results of this procedure for alkaline and alkaline-earth systems were quite good [186,187], at least for atoms, and pseudopotentials of this type were generated [188] and applied [189] for most of the main group elements. However, due to the limited validity of the frozen-core approximation when going from a medium or highly charged one-valence electron ion to a neutral atom or nearly neutral ion, the approach is bound to fail for most other elements. This is especially the case for transition metals, lanthanides and actinides, where small cores are indispensable for accurate pseudopotentials. More recent calibration studies of alkaline and alkaline earth elements exhibited however, that for accu-... 

The occurrence of the binary borides of the alkaline, alkaline earth, aluminum, and transition elements has been collected in Table 1, together with boron compounds of the right main group elements (carbides, etc.). Only relatively well-established phases have been included. Noncorroborated and/or badly characterized borides lacking precise composition and structure data are not included. The reader is referred to other sources for references. There are no binary borides among the Cu, Zn, Ga, and Ge group elements with the exception of a noncorroborated early report on diborides in the Ag-B and Au-B systems. Two silicon borides have been established, namely, SiB3 4 and SiBe. 

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