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A borane is a compound with the formula BR x H y although examples include multi-boron derivatives. A large family of boron hydride clusters is also known. In addition to some applications in organic chemistry , the boranes have attracted much attention as they exhibit structures and bonding that differs strongly from the patterns seen in ...
Boron hydride clusters are compounds with the formula B x H y or related anions, where x ≥ 3. Many such cluster compounds are known. Common examples are those with 5, 10, and 12 boron atoms. Although they have few practical applications, the borane hydride clusters exhibit structures and bonding that differs strongly from the patterns seen in ...
A large number of anionic boron hydrides are known, e.g. [B 12 H 12] 2−. The formal oxidation number in boranes is positive, and is based on the assumption that hydrogen is counted as −1 as in active metal hydrides. The mean oxidation number for the boron atoms is then simply the ratio of hydrogen to boron in the molecule.
Borane makes a strong adduct with triethylamine; using this adduct requires harsher conditions in hydroboration. This can be advantageous for cases such as hydroborating trienes to avoid polymerization. More sterically hindered tertiary and silyl amines can deliver borane to alkenes at room temperature. Borane(5) is the dihydrogen complex of
The predominant driving force for this face-selective, intramolecular hydride transfer is the simultaneous activation of the borane reagent by coordination to the Lewis basic nitrogen and the enhancement of the Lewis acidity of the endocyclic boron atom for coordination to the ketone. [5]
Structure of a rare monomeric boron hydride, R = i-Pr. [4] The most-studied class of organoboron compounds has the formula BR n H 3−n. These compounds are catalysts, reagents, and synthetic intermediates. The trialkyl and triaryl derivatives feature a trigonal-planar boron center that is typically only weakly Lewis acidic.
In the special case of boron hydride clusters, each boron atom connected to 3 or more vertices has one terminal hydride, while a boron atom connected to two other vertices has two terminal hydrogen atoms. If more hydrogen atoms are present, they are placed in open face positions to even out the coordination number of the vertices.
The great variety of boranes show a huge covalent cluster chemistry, but the heavier group 13 hydrides do not. Despite their formulae, however, they tend to form polymers. Alane(aluminum trihydride) is a strong reducing agent with octahedrally coordinated aluminium atom