Ammonium hydrosulfide

Ammonium hydrosulfide is the chemical compound with the formula [NH₄]SH.

Ammonium hydrosulfide

Names
IUPAC name ammonium hydrosulfide
Other names ammonium bisulfide ammonium hydrogen sulfide
Identifiers
CAS Number	12124-99-1 Y
3D model (JSmol)	Interactive image
ChemSpider	23805 Y
ECHA InfoCard	100.031.974
EC Number	235-184-3
PubChem CID	25515
RTECS number	BS4900000
UNII	A824D6LXMB
UN number	2683
CompTox Dashboard (EPA)	DTXSID20894064
InChI InChI=1S/H3N.H2S/h1H3;1H2 Y Key: HIVLDXAAFGCOFU-UHFFFAOYSA-N Y InChI=1/H3N.H2S/h1H3;1H2 Key: HIVLDXAAFGCOFU-UHFFFAOYAU
SMILES [SH-].[NH4+]
Properties
Chemical formula	[NH4]SH
Molar mass	51.111 g/mol
Appearance	Yellow-orange fuming liquid (in solution). White rhombic crystals (anhydrous).[1]
Density	1.17 g/cm3[1][2]
Boiling point	56.6 °C (133.9 °F; 329.8 K)
Solubility in water	Miscible
Solubility	soluble in alcohol, liquid ammonia, liquid hydrogen sulfide; insoluble in benzene, hexane and ether
Refractive index (nD)	1.74
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Toxic
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H314, H400.
Precautionary statements	P260, P264, P273, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P391, P405, P501
NFPA 704 (fire diamond)	3 3
Lethal dose or concentration (LD, LC):
LD50 (median dose)	168 mg/kg (rat, oral)[3]
Related compounds
Other anions	Ammonia solution
Other cations	Sodium hydrosulfide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Composition

It is the salt derived from the ammonium cation and the hydrosulfide anion. The salt exists as colourless, water-soluble, micaceous crystals. On Earth the compound is encountered mainly as a solution, not as the solid, but [NH₄]SH ice is believed to be a substantial component of the cloud decks of the gas-giant planets Jupiter and Saturn, with sulfur produced by its photolysis responsible for the color of some of those planets' clouds. It can be generated by mixing hydrogen sulfide and ammonia.

Preparation

Solutions of ammonium hydrosulfide can be prepared by passing hydrogen sulfide gas through concentrated ammonia solution.^[4] According to a detailed 1895 report, hydrogen sulfide reacts with concentrated aqueous ammonia solution at room temperature to give [NH₄]₂S·2[NH₄]SH. When this species is cooled to 0 °C and treated with additional hydrogen sulfide, one obtains [NH₄]₂S·12[NH₄]SH.^[5] An ice-cold solution of this substance kept at 0 °C and having hydrogen sulfide continually passed through it gives the hydrosulfide.

The common "stink bomb" consists of an aqueous solution of ammonium sulfide. The mixture easily converts to ammonia and hydrogen sulfide gases. This conversion illustrates the ease of the following equilibrium:

[NH₄]SH ⇌ NH₃ + H₂S

Ammonia and hydrogen sulfide each have a powerful and unpleasant smell.

Solid ammonium hydrosulfide can be produced by reacting an equimolar mixture of ammonia and hydrogen sulfide under -18 °C:^[6]

NH₃ + H₂S → NH₄SH

"Ammonium sulfide"

A bottle of ammonium sulfide solution

Aqueous solutions of ammonium sulfide (CAS registry number 12135-76-1 ), also known as diammonium sulfide are commercially available, although the composition of these solutions is uncertain as they could consist of a mixture of ammonia and [NH₄]SH. Ammonium sulfide solutions are used occasionally in photographic developing, to apply patina to bronze, and in textile manufacturing. It can be used as a selective reducing agent (cf. 2,4-dinitrochlorobenzene); where there are two nitro groups, only one of them is selectively reduced.

The 1990–91 CRC Handbook of Chemistry and Physics gives information for anhydrous ammonium monosulfide ([NH₄]₂S) and ammonium pentasulfide ([NH₄]₂S₅) as separate from anhydrous ammonium hydrosulfide ([NH₄]SH), describing the former two both as yellow crystalline substances that are soluble in cold water and alcohol, and which both decompose in hot water or at high temperature in general (115 °C for the pentasulfide), but the latter as a white crystalline solid (which also decomposes in hot water).^[1] Thus, it seems that solid ammonium sulfide can be distinct from solid ammonium hydrosulfide, even if this is not true in aqueous solution.

References

1. Lide, David R., ed. (1990). "Physical Constants of Inorganic Compounds". CRC Handbook of Chemistry and Physics (71st ed.). CRC Press, inc. p. 4-45.
2. Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
3. Record of ammonium hydrosulfide in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on October 22, 2010.
4. Goodman, J. T.; Rauchfuss, T. B. (2002). "Useful Reagents and Ligands". Inorganic Syntheses. Inorganic Syntheses. Vol. 33. pp. 107–110. doi:10.1002/0471224502.ch2. ISBN 978-0-471-20825-9.
5. W. P. Bloxam (1895). "The Sulphides and Polysulphides of Ammonium". J. Chem. Soc., Trans. 67: 283. doi:10.1039/CT8956700277.
6. C. D. West (1934). "The Crystal Structures of Some Alkali Hydrosulfides and Monosulfides". Zeitschrift für Kristallographie - Crystalline Materials. 88 (1–6): 97–115. doi:10.1524/zkri.1934.88.1.97. S2CID 100849097.