Hexaborane(10)

Hexaborane, also called hexaborane(10) to distinguish it from hexaborane(12) (B₆H₁₂), is a boron hydride cluster with the formula B₆H₁₀. It is a colorless liquid that is unstable in air.^[1]

Hexaborane(10)

Identifiers
CAS Number	23777-80-2
3D model (JSmol)	Interactive image
InChI InChI=1S/B6H10/c7-1-2-3(1)4(1,7)6(3,9-4)5(2,3,8-2)10-6/h1-6H Key: RNDYOGWDQULVQP-UHFFFAOYSA-N
SMILES [BH]1234[BH]5([H]6)[BH]61([H]7)[BH]72([H]8)[BH]83([H]9)[BH]945
Properties
Chemical formula	B6H10
Molar mass	74.94 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Structure

NMR interpretation of hexaborane(10), showing its structure

Hexaborane(10) is classified as a nido-cluster.^[2]: 152 The boron atoms define a pentagonal pyramid, with four bridging hydrogen atoms and six terminal ones. The point group of the molecule is C_s.^[3]

Preparation and reactions

A laboratory route begins with bromination of pentaborane(11) followed by deprotonation of the bromide to give [BrB₅H₇]⁻. This anionic cluster is reduced with diborane to give the neutral product:^[1]

K[BrB₅H₇] + 1/2 B₂H₆ → KBr + B₆H₁₀

It can also be generated by pyrolysis of pentaborane(11).

B₆H₁₀ can be deprotonated to give [B₆H₉]⁻ or protonated to give [B₆H₁₁]⁺.^[1] It can act as a Lewis base towards reactive borane radicals, forming various conjuncto-clusters.^[2]: 162