Boron interatomic distance

Fig. 31. Boron-boron interatomic distances in boranes with skeletons based on an octahedron closo-BgHg ", nido-BsHg, and arachno- iRio.

Strong boron-transition metal interaction interatomic distances are shorter by 5-10%, as compared to the sum of the metal radii. 

The C—C and C—B interatomic distances in carboranes can also be related to the coordination numbers of the skeletal atoms. Two factors tend to make these distances shorter than the B —B distances in comparable boranes the preference of the carbon atoms for sites of low coordination number and the greater electronegativity of carbon than boron, which increases the electron density in the region of the carbon atoms and so strengthens the bonds that they form. Table IX lists some C—C distances for closo- and wido-carboranes 13, 20, 21, 26, 98,121,168) and metal-acetylene 50, 58,112) complexes, relating them... 

We performed structural optimization using ideal B6, B12-co, and B12-ico clusters (shown in Figure 8.1) with a 64-silicon-atom supercell. Table 8.1 shows the interatomic distances of these clusters and nearest-neighbor distances between boron and silicon atoms. The B6 cluster kept its octahedral symmetry during optimization, and the structure of the B12-co cluster was not altered appreciably its symmetry was lowered from Oh to Ta following that of the bulk. In contrast, the B12-ico cluster underwent distortion and its symmetry was reduced drastically from Ih to C3. 

One of the lasting practical results of treating metals in this model has been the tabulation of atomic radii and interatomic distances in metals [39-42]. Another interesting application of the unsynchronized-resonating-covalent-bond-theory of metal is its use in the elucidation of the to the structure and properties of elemental boron and the boranes [43]. 

Boron phosphide (BP), a very hard refractory semiconductor, has a zinc blende structure as most III-V (13-15) semiconductors, such as GaAs and InP. It has a bandgap of 2eV and a slightly larger interatomic distance than SiC or AIN. 

Fig. 14.8 Boron-boron, boron-oxygen and oxygen-oxygen partial raditd distribution functions obtained at 300 K for the boroxol-poor (BP, f = 22%) and boroxol-tich (BR, / = 75%) models. Interatomic distances more pronounced in the BR model are highlighted...

Table 4.9 Tourmaline interatomic distances the data are from a sample of dravite which is a sodium- magnesium variety. The 9- 6- and 4-coordinated groups are shown as polyhedra with the boron shown as individual atoms. In this view, the six tetrahedra are shown with their bases toward the viewer.

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