Mercury(II) sulfate, commonly called mercuric sulfate, is the chemical compoundHgSO4. It is an odorless salt that forms white granules or crystalline powder. In water, it separates into an insoluble basic sulfate with a yellow color and sulfuric acid.[3]
Structure
Portion of structure of HgSO4 illustrating the distorted tetrahedral geometry at Hg (dark blue spheres).
The anhydrous compound features Hg2+ in a highly distorted tetrahedral HgO4 environment. Two Hg-O distances are 2.22 Ã… and the others are 2.28 and 2.42 Ã….[5] In the monohydrate, Hg2+ adopts a linear coordination geometry with Hg-O (sulfate) and Hg-O (water) bond lengths of 2.179 and 2.228 Ã…, respectively. Four weaker bonds are also observed with Hg---O distances >2.5 Ã….[6]
History
In 1932, the Japanese chemical company Chisso Corporation began using mercury sulfate as the catalyst for the production of acetaldehyde from acetylene and water. Though it was unknown at the time, methylmercury is formed as side product of this reaction. Exposure and consumption of the mercury waste products, including methylmercury, that were dumped into Minamata Bay by Chisso are believed to be the cause of Minamata disease in Minamata, Japan.[7]
Production
Mercury sulfate can be produced
by treating mercury with hot concentrated sulfuric acid:[8]
Hg + 2 H2SO4 → HgSO4 + SO2 + 2 H2O
Alternatively yellow mercuric oxide reacts also with concentrated sulfuric acid.[9]
Conversion of 2,5-dimethylhexyne-2,5-diol to 2,2,5,5-tetramethylte-trahydrofuran-3-one
Mercury sulfate, as well as other mercury(II) compounds, are commonly used as catalysts in oxymercuration-demercuration, a type of electrophilic addition reaction that results in hydration of an unsaturated compound. The hydration of an alkene gives an alcohol. The regioselectivity is that predicted by Markovnikov's rule. For an alkyne, the result is an enol, which tautomerizes to give the carbonyl.[11] At one time, this chemistry was employed commercially for the preparation of acetaldehyde from acetylene:[12]
C2H2 + H2O → CH3CHO
A related and specialized example is the conversion of 2,5-dimethylhexyne-2,5-diol to 2,2,5,5-tetramethyltetrahydrofuran using aqueous mercury sulfate without the addition of acid.[13]
Health issues
Inhalation of HgSO4 can result in acute poisoning: causing tightness in the chest, difficulties breathing, coughing and pain. Exposure of HgSO4 to the eyes can cause ulceration of conjunctiva and cornea. If mercury sulfate is exposed to the skin it may cause sensitization dermatitis. Lastly, ingestion of mercury sulfate will cause necrosis, pain, vomiting, and severe purging. Ingestion can result in death within a few hours due to peripheral vascular collapse.[1]
It was used in the late 19th century to induce vomiting for medical reasons.[14]
^Aurivillius, Karin; Stålhandske, Claes (1980). "A Reinvestigation of the Crystal Structures of HgSO4 and CdSO4". Zeitschrift für Kristallographie - Crystalline Materials. 153 (1–2): 121–129. Bibcode:1980ZK....153..121A. doi:10.1524/zkri.1980.0011.
^Stålhandske, C. (1980). "An X-ray and Neutron Diffraction Study of Mercury(II) Sulphate Monohydrate". Acta Crystallographica Section B: Structural Crystallography and Crystal Chemistry. 36: 23–26. doi:10.1107/s0567740880002361.
^Simon, Matthias; Jönk, Peter; Wühl-Couturier, Gabriele; Halbach, Stefan (2006). "Mercury, Mercury Alloys, and Mercury Compounds". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a16_269.pub2. ISBN3527306730.
^Robey, R. F.; Robertson, N. C. (May 1947). "Test for tert-Butyl and Isopropyl Alcohols with Deniges Reagent". Analytical Chemistry. 19 (5): 310–311. doi:10.1021/ac60005a007.
^Wasacz, J. P.; Badding, V. G. (1982). "A hydration of an alkyne illustrating steam and vacuum distillation". Journal of Chemical Education. 59 (8): 694. Bibcode:1982JChEd..59..694W. doi:10.1021/ed059p694.
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