Ammonium pentasulfide

Ammonium pentasulfide is a chemical compound with the chemical formula (NH₄)₂S₅.^[1]

Ammonium pentasulfide

Names
IUPAC name Diammonium pentasulfane-1,5-diide
Other names Diammonium pentasulfide
Identifiers
CAS Number	12135-77-2
3D model (JSmol)	Interactive image
ChemSpider	95740767
EC Number	235-223-4
PubChem CID	133108861
CompTox Dashboard (EPA)	DTXCID201333664
InChI InChI=1S/2H3N.H2S5/c;;1-3-5-4-2/h2*1H3;1-2H Key: PRPVKBZLCJDRNZ-UHFFFAOYSA-N
SMILES [NH4+].[NH4+].[S-]SSS[S-]
Properties
Chemical formula	H8N2S5
Molar mass	196.38 g·mol−1
Appearance	Yellow powder
Density	1.6 g/cm3
Solubility in water	decomposes in water
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Synthesis

Passing hydrogen sulfide through a suspension of powdered sulfur in a concentrated ammonia solution:^[2][3]

2NH₃ + H₂S + 4S → (NH₄)₂S₅

Physical properties

Ammonium sulfide forms yellow crystals, decomposing in water, of monoclinic system, space group P2₁/c, cell parameters a = 0.5427 nm, b = 1.6226 nm, c = 0.9430 nm, β = 105.31°, Z = 4.^[4]

The compound can be stored under the mother liquor without air access. When dry, it decomposes quickly in the air. the compound emits sulfur intensively in water and melts in a sealed ampoule at 95 °C to form a red liquid.

Chemical properties

The compound decomposes when stored in air or slightly heated:^[5]

(NH₄)₂S₅ → 2NH₃ + H₂S + 4S