Bonding metal suboxides

Simon, A. Structure and Bonding with Alkali Metal Suboxides. Vol. 36, pp. 81-127. 

Even the extremely electron-deficient alkali metals can form clusters when interstitial atoms contribute to their stabilization. Compounds of this kind are the alkali metal suboxides such as Rb902 it has two octahedra sharing a common face, and each is occupied by one O atom (Fig. 13.16). Flowever, the electron deficiency is so severe that metallic bonding is needed between the clusters. In a way, these compounds are metals, but not with single metal ions as in the pure metal Rb+e-, but with a constitution [Rb902]5+(e )5, essentially with ionic bonding in the cluster. 

The structural principle of combining salt-like bonded units with stoichiometric amounts of alkali metal in the structure of Ba2ONa is equivalent to that which characterizes the alkali metal suboxides as well as the subnitrides of alkaline earth metals, such that a variation at least according to a general formula [Ba20 Na% can be expected. Indeed, there are indications of the existence of further suboxides in... 

All suboxides and subnitrides described in the preceding sections are metallic. In the case of the alkali metal suboxides this property has been demonstrated by measurements of the electrical conductivity [58], CS7O, for example, exhibits a free electron like behavior in the temperature dependence of its resistivity rather similar to the element Cs itself. The characteristic colors of the alkali metal suboxides have been mentioned before, and spectroscopic investigations to be discussed in the following provide a more quantitative access to the metallic properties and the underlying chemical bonding. 

A Simon Structure and Bonding with Alkali Metal Suboxides... 

The bonding within the alkali metal suboxides is illustrated by comparing the interatomic distances in the compounds Rb9C>2 and CS11O3 with those in... 

The chemistry of the alkali metals suboxides such as RbeO, CS7O, Rb902, and CS11O3 has been reviewed by Simon and will not be discussed here. Rather, this section will concentrate on transition metal compounds where d electrons are utilized in bonding. 

IV. Chemical Bonding in the Stable Alkali Metal Suboxides.100... 

Preparative aspects of the investigations of alkali metal suboxides, e.g. synthesis, analysis and crystal growth have been described in detail earlier. (11,12) The emphasis of this paper lies on structural aspects, measurements of some important physical properties and their discussion in terms of the chemical bonding within these compounds. Some attention is paid to the structure and bonding in metastable and amorphous states of alkali metal suboxides, too. 

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