What does bisulphide mean?
A bisulphide is a chemical compound in which two atoms of sulfur are combined with another element or group — the word being the British spelling of the American "bisulfide". It appears most often in technical and historical chemistry writing, where familiar examples include sodium bisulphide and carbon bisulphide (better known today as carbon disulphide, CS2, once widely used as a solvent and insecticide). Like many older chemical terms, "bisulphide" has partly given way to more precise systematic nomenclature, so it now reads as somewhat dated, though it remains perfectly correct in British scientific contexts. Its spelling preserves the traditional British rendering of "sulphur" with a "ph", contrasting with the internationally standardised American form "sulfur". Understanding the term is chiefly useful when reading older textbooks, industrial reports, or British chemical literature from the nineteenth and twentieth centuries.
nounA chemical compound containing two atoms of sulfur combined with another element or group; the British spelling of "bisulfide".
- A compound in which an element or radical is combined with two sulfur atoms, written with the British spelling (the American spelling being bisulfide).
- More loosely in older usage, any salt or compound of the type M(HS)₂ formed from a metal and hydrogen sulphide.
"Carbon bisulphide was once widely used as an industrial solvent and insecticide."
"The chemist prepared a solution of sodium bisulphide for the reduction experiment."
"Nineteenth-century textile mills relied on carbon bisulphide to dissolve rubber and other resins."
The plural is regular and is used when referring to multiple compounds of this class.
"Several metal bisulphides were analysed in the study."
"Bisulphide" is simply the British way of writing "bisulfide" — same chemistry, different spelling, thanks to a long-standing transatlantic divide over whether sulfur should carry an "f" or a "ph".
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bisulphide
The word combines "bi-", from Latin meaning "two", with "sulphide", derived from "sulphur" (Latin sulfur/sulphur) plus the chemical suffix "-ide". The "ph" spelling follows traditional British orthography, which long preserved the "ph" in sulfur-derived terms even after international bodies adopted the American spelling "sulfur" in the twentieth century. As a result, "bisulphide" and its cognates "sulphide", "sulphate", and "sulphite" survive chiefly in British usage alongside their American counterparts "bisulfide", "sulfide", "sulfate", and "sulfite".
Related word forms
How bisulphide is actually used
The spelling "bisulphide" reflects traditional British practice, which retains "ph" in words derived from Latin/Greek "sulphur"; American usage standardised on "sulfur" and hence "bisulfide". The word belongs chiefly to technical and historical chemistry texts rather than everyday English, and modern IUPAC naming tends to prefer more precise systematic names over "bisulphide" generally.
Easily confused with bisulphide
In a bisulphide, two sulfur atoms are separately bound to one atom of another element (as in NaSH's formal description), whereas in a disulphide such as carbon disulphide (CS2) a single central atom bonds to two sulfur atoms — the terms are often used interchangeably in older chemical literature.
A sulphide contains only one sulfur atom per formula unit, while a bisulphide contains two.