Ammonium hexabromomercurate(II)

Ammonium hexabromomercurate(II)

Names
Other names Ammonium hexabromomercurate
Identifiers
Properties
Chemical formula	Br6H16HgN4
Molar mass	752.172 g·mol−1
Appearance	crystals
Density	3.2 g/cm3 [1]
Solubility in water	soluble
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Ammonium hexabromomercurate(II) is a chemical compound with the chemical formula (NH₄)₄[HgBr₆].

Synthesis

Heating of a mixture of mercury(II) bromide and ammonium bromide:

HgBr₂ + 4NH₄Br → (NH₄)₄[HgBr₆]

Physical properties

The compound forms black crystals of tetragonal system, space group P4/mnc, cell parameters: a = 0.925560 nm, c = 0.88657 nm, Z = 2. ^{[2] [3]}

At a temperature of 200 K, the compound enters a phase of the monoclinic system, space group P2₁/n. At 250 K, it forms crystals of the orthorhombic system, space group Pnnm. ^[4]

References

1. "mp-604295". Materials Project . Retrieved 22 February 2025.
2. Donnay, Joseph Désiré Hubert (1973). Crystal Data: Inorganic compounds. National Bureau of Standards. p. T-70. Retrieved 22 February 2025.
3. Nockemann, Peter; Pantenburg, Ingo; Meyer, Gerd (2006). "The Ammonium Bromomercurates(II) (NH4)Hg5Br11 and (NH4)4HgBr6". Zeitschrift für anorganische und allgemeine Chemie . 632 (12–13): 1975–1978. doi:10.1002/zaac.200600132. ISSN   1521-3749 . Retrieved 22 February 2025.
4. Loukil, M.; Kabadou, A.; Svoboda, I.; Ben Salah, A.; Fuess, H. (1 February 2008). "Structural Analysis of the Phase Transitions of (NH4)4HgBr6". Journal of Chemical Crystallography . 38 (2): 85–91. doi:10.1007/s10870-007-9266-x. ISSN   1572-8854 . Retrieved 22 February 2025.