What does borane mean?
Borane is the name given to any binary compound of boron and hydrogen, though it most specifically denotes the simplest member of this family, BH₃. That molecule is so chemically restless that it cannot exist on its own: it immediately combines with another BH₃ unit to form diborane (B₂H₆), an electron-deficient gas with unusual bridging bonds, or binds to donor molecules such as ethers to form stable complexes. The boranes are a landmark subject in chemistry because their bonding defied classical valence theory and helped inspire new models of chemical structure. In practical terms, borane reagents are workhorses of the synthetic laboratory, valued for reducing functional groups and for the hydroboration reaction, which earned H.C. Brown a Nobel Prize. The word derives ultimately from "boron" plus "-ane," by analogy with other element–hydrogen compounds like methane. Outside scientific writing, borane is rarely encountered, but within chemistry it is precise, well-established vocabulary.
nounA binary compound of boron and hydrogen, especially the simple molecule BH₃, which exists only transiently and is typically encountered as its dimer diborane (B₂H₆) or in complexes with Lewis bases.
- Any binary compound of boron and hydrogen, particularly the neutral hydrides of boron such as BH₃ and B₂H₆
- More narrowly, the monomer BH₃ (borane proper), a reactive electron-deficient species usually encountered bound to Lewis bases or as the dimer diborane
"The chemist reduced the ketone using a borane reagent under mild conditions."
"Diborane, the dimer of borane, was first systematically studied by the German chemist Alfred Stock in the early twentieth century."
"In organic synthesis, borane complexes are prized for selectively reducing carboxylic acids in the presence of esters."
The plural refers collectively to members of the family of boron–hydrogen compounds rather than to multiple copies of a single substance.
"The higher boranes, such as pentaborane and decaborane, display remarkably varied structures."
The simplest borane, BH₃, is so unstable it can't be bottled — it instantly pairs up with itself to form diborane, a gas that famously bursts into flame on contact with air.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of borane
The word "borane" is formed from "boron," the name of the element itself, combined with "-ane," the suffix conventionally attached to binary hydrides (as in methane, ammonia's analogues, and phosphine). Boron's own name traces back through "borax," borrowed into European languages via medieval Latin from Arabic būrāq, ultimately of Persian origin. Systematic study of the boron hydrides began in earnest in the early twentieth century through the pioneering vacuum-line experiments of Alfred Stock, whose work gave the family its modern nomenclature.
Related word forms
How borane is actually used
"Borane" is a technical term used almost exclusively in chemistry — inorganic chemistry for the hydrides themselves, and organic chemistry for reagents like borane–THF complex used in hydroboration–oxidation. It carries no everyday or informal usage. In speech, chemists often simply say "BH three" when referring to borane in context.
Easily confused with borane
Boron is the chemical element itself, while borane is specifically a compound of that element combined with hydrogen.
Borax is a common sodium borate mineral used as a cleaning agent, not a hydrogen compound of boron.