Borane BnHnS derivatives

Boron Hydrides, Derivatives and Fuels Boron Hydrides(Boranes). These constitute a group of compds which may be represented by two generic formulas BnHn + 4 and BnHn+ 6... 

We have seen that the general formula of close-shell boranes, i.e. whose polyhedral vertices are all occupied, (called closo ), is BnHn (n = 6- 12). If a fragment is removed from the borane, no electron is removed from the cluster, and thus the cluster remains unchanged, except for one less vertex. The general formula of the boranes whose strnctnre is derived from the closo boranes, but with one less summit, is BnHn ". This family is called nido . For instance, if a BH vertex is removed from the octahedron B6Hi2 , the tetragonal pyramid BsHs" is obtained. 

If a second BH + fragment is removed, a new family called arachno is obtained, and its structure is derived from the preceding one by elimination of two vertices. Its general formula is BnHn. In general, the number n of vertices of a borane of... 

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