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In common with other Hg(I) (mercurous) compounds which contain linear X-Hg-Hg-X units, Hg 2 I 2 contains linear IHg 2 I units with an Hg-Hg bond length of 272 pm (Hg-Hg in the metal is 300 pm) and an Hg-I bond length of 268 pm. [2] The overall coordination of each Hg atom is octahedral as it has in addition to the two nearest neighbours there are four other I atoms at 351 pm. [2] The compound ...
Mercury(II) iodide is a chemical compound with the molecular formula Hg I 2. It is typically produced synthetically but can also be found in nature as the extremely rare mineral coccinite . Unlike the related mercury(II) chloride it is hardly soluble in water (<100 ppm).
Sequence of 123-iodide human scintiscans after an intravenous injection, (from left) after 30 minutes, 20 hours, and 48 hours. A high and rapid concentration of radio-iodide is evident in extrathyroidal organs like cerebrospinal fluid (left), gastric and oral mucosa, salivary glands, arterial walls, ovary and thymus.
For example, in the molecules represented by CH 3 X, where X is a halide, the carbon-X bonds have strengths, or bond dissociation energies, of 115, 83.7, 72.1, and 57.6 kcal/mol for X = fluoride, chloride, bromide, and iodide, respectively. [2] Of the halides, iodide usually is the best leaving group.
Hypervalent iodine oxyanions are known for oxidation states +1, +3, +5, and +7; organic analogues of these moieties are known for each oxidation state except +7. In terms of chemical behavior, λ 3 ‑ and λ 5 ‑iodanes are generally oxidizing and/or electrophilic species. They have been widely applied towards those ends in organic synthesis. [1]
The low solubility of silver iodide and lead iodide reflects the covalent character of these metal iodides. A test for the presence of iodide ions is the formation of yellow precipitates of these compounds upon treatment of a solution of silver nitrate or lead(II) nitrate. [2] Aqueous solutions of iodide salts dissolve iodine better than pure ...
The name calomel is thought to come from the Greek καλός "beautiful", and μέλας "black"; or καλός and μέλι "honey" from its sweet taste. [4] The "black" name (somewhat surprising for a white compound) is probably due to its characteristic disproportionation reaction with ammonia, which gives a spectacular black coloration due to the finely dispersed metallic mercury formed.
An experiment for the preparation of mercuric oxide was first described by 11th century Arab-Spanish alchemist, Maslama al-Majriti, in Rutbat al-hakim. [6] It was historically called red precipitate (as opposed to white precepitate being the mercuric amidochloride).