Octahedra geometry

Capped argon stirring (CAS), 23 264 Capped octahedron, geometry for metal coordination numbers, 7 574, 575t Capped square antiprismatic, geometry for metal coordination numbers, 7 574, 575t... 

In the families of heptanuclear clusters, two geometries are found the capped octahedron that is typical for 98-valence electrons, and the vertex-sharing open tetrahedral (butterfly) stmctures typical for 106-valence electrons. An example of the former is Osy(CO)22 (51) an example of the latter is [H2AuOsg(CO)2Q] (52). In the AuOs cluster anion, the gold atom is at the vertex-sharing position. 

We saw in Chapter 7 that octahedral geometry is characteristic of many molecules (e.g., SF6) in which a central atom is surrounded by six other atoms. (Remember, an octahedron has eight sides, which is irrelevant here it has six comers, which is important) All complex ions... 

The structure theory of inorganic chemistry may be said to have been bom only fifty years ago, when Werner, Nobel Laureate in Chemistry in 1913, found that the chemical composition and properties of complex inorganic substances could be explained by assuming that metal atoms often coordinate about themselves a number of atoms different from their valence, usually four atoms at the comers either of a tetrahedron or of a square coplanar with the central atom, or six atoms at the comers of an octahedron. His ideas about the geometry of inorganic complexes were completely verified twenty years later, through the application of the technique of x-ray diffraction. 

The Lewis stmeture of SFg, shown in Figure 9-24a. indicates that sulfur has six S—F bonds and no lone pairs. The molecular geometry that keeps the six fluorine atoms as far apart as possible is octahedral in shape, as Figure 9-24Z) shows. Figure 9-24c shows that an octahedron has eight triangular faces. 

C09-0129. Tellurium compounds, which are toxic and have a hideous stench, must be handled with extreme care. Predict the formula of the tellurium-fluorine molecule or ion that has the following molecular geometry (a) bent (b) T-shaped (c) square pyramid (d) trigonal bipyramid (e) octahedron and (Q seesaw. 

The V(IIIj containing complexes V(R2magnetic moments of these air-sensitive compounds are characteristic of two unpaired electrons as is expected for a configuration, the coordination geometry is assumed to be a distorted octahedron (Dj). 

Fig. 3. Projection of the upper and the lower triangle of a geometry between an octahedron and a trigonal prism. Definition of the twist angle y>.

The bond angles at the bridging X atoms in the common octahedron vertices are fixed by geometry (angles M-X-M, M in the octahedron centers) ... 

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