Heteroboranes are classes of

boranes Boranes is the name given to compounds with the formula BxHy and related anions. Many such boranes are known. Most common are those with 1 to 12 boron atoms. Although they have few practical applications, the boranes exhibit structures and bond ...

, at least one

boron Boron is a chemical element with the symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the ''boron group'' it has th ...

atom is replaced by another element. Like many of the related

, these clusters are

polyhedra In geometry, a polyhedron (plural polyhedra or polyhedrons; ) is a three-dimensional shape with flat polygonal faces, straight edges and sharp corners or vertices. A convex polyhedron is the convex hull of finitely many points, not all on t ...

and are similarly classified as ''closo-, nido-, arachno-, hypho-,'' according to the so-called

electron count Electron counting is a formalism used for classifying compounds and for explaining or predicting electronic structure and chemical bond, bonding. Many rules in chemistry rely on electron-counting: *Octet rule is used with Lewis structures for mai ...

. ''Closo-'' represents a complete polyhedron, while ''nido-'', ''arachno-'' and ''hypho-'' stand for polyhedrons that are missing one, two and three vertices. Structurally, various heteroboranes can be derived from the icosahedral (''I''_h) B₁₂H₁₂^2– via formal replacement of its BH fragments with isoelectronic CH⁺, P⁺ or S²⁺ fragments, e.g. ''closo''-1-CB₁₁H₁₂^–, ''closo''-1,2-C₂B₁₀H₁₂, ''closo''-1,2-P₂B₁₀H₁₀ or ''closo''-1-SB₁₁H₁₁.

References

{{reflist Boron compounds Cluster chemistry Boranes

See also

References