Bisulfide

Not to be confused with disulfide.

The bisulfide ion, also called hydrogensulfide or hydrosulfide, is the anion with the formula [HS]− (also commonly written [SH]− by analogy to [OH]−). This species is the conjugate base of hydrogen sulfide and in its turn also dissociates in sulfide:

H2S → HS− + H+
HS− →  S2− + H+

In aqueous solutions, at pH lower than 7, hydrogen sulfide (H2S) is the dominant species but at pH higher than 7, bisulfide (HS−) dominates. Sulfide (S2−) is an extremely basic group and only dominates in strongly alkaline conditions at elevated pH.

A variety of salts are known, including sodium hydrosulfide and potassium hydrosulfide. Ammonium hydrosulfide, a component of "stink bombs" has not been isolated as a pure solid. Some compounds described as salts of the sulfide dianion contain primarily hydrosulfide. For example, the hydrated form of sodium sulfide, nominally with the formula Na2S · 9 H2O, is better described as NaSH · NaOH · 8 H2O.

Aqueous bisulfide absorbs light at around 230 nm in the UV/VIS spectrum.[1] Research groups have used field spectrometers to measure the absorption due to bisulfide (and hence its concentration) continuously in the ocean[2][3] and in sewage.[4] Bisulfide is sometimes confused with the disulfide dianion, S22−, or −S–S−.

Coordination chemistry

SH− is a soft anionic ligand that forms complexes with most metal ions. Examples include [Au(SH)2]− and (C5H5)2Ti(SH)2, derived from gold(I) chloride and titanocene dichloride, respectively.[5]

See also

References

  1. ^ Goldhaber, M.B.; Kaplan, I.R. (1975), "Apparent dissociation constants of hydrogen sulfide in chloride solutions", Marine Chemistry 3 (1): 83–104, doi:10.1016/0304-4203(75)90016-X 
  2. ^ Johnson, K.S.; Coletti, L.S. (2001), "In situ ultraviolet spectrophotometery for high resolution and long-term monitoring of nitrate, bromide and bisulfide in the ocean.", Deep Sea Research 1 (49): 1291–1305 
  3. ^ Guenther, E.A.; Johnson, K.S.; Coale, K.H. (2001), "Direct ultraviolet spectrophotometric determination of total sulfide and iodide in natural waters", Analytical Chemistry 73 (14): 3481–3487, doi:10.1021/ac0013812, PMID 11476251 
  4. ^ Sutherland-Stacey, L.; Corrie, S.; Neethling, A.; Johnson, I.; Gutierrez, O.; Dexter, R.; Yuan, Z.; Keller, J. et al. (2007), "Continuous measurement of dissolved sulfide in sewer systems", Water Science and Technology 
  5. ^ Peruzzini, M.; de los Rios, I. and Romerosa, A. (2001), "Coordination Chemistry of transition metals with hydrogen chalcogenide and hydrogen chalcogenido ligands", Progress in Inorganic Chemistry, Progress in Inorganic Chemistry 49: 169–543, doi:10.1002/9780470166512.ch3, ISBN 9780470166512.