Thioacetamide
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| Names | |
|---|---|
| IUPAC name
Thioacetamide
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| Other names
acetothioamide, ethanethioamide, TAA, thioacetimidic acid, TA
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| Identifiers | |
3D model (JSmol)
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| ECHA InfoCard | 100.000.493 |
| RTECS number |
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CompTox Dashboard (EPA)
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| Properties | |
| C2H5NS | |
| Molar mass | 75.13 g/mol |
| Appearance | colourless crystals, slight mercaptan odor |
| Density | 1.269 g/cm³ |
| Melting point | 115 °C |
| Boiling point | decomp. |
| good, with hydrolysis | |
| Structure | |
| monoclinic | |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
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stench |
| Flash point | ?°C |
| Related compounds | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Thioacetamide is an organosulfur compound with the formula C2H5NS. This white crystalline solid is soluble in water and serves as a source of hydrogen sulfide in the synthesis of organic and inorganic compounds. It is a prototypical thioamide.
Coordination chemistry
Thioacetamide was widely used in classical qualitative inorganic analysis as an in situ source for sulfide ions. Thus, treatment of aqueous solutions of many metal cations to a solution of thioacetamide affords the corresponding metal sulfide:
- M2+ + CH3C(S)NH2 + H2O → MS + CH3C(O)NH2 + 2 H+ (M = Ni, Pb, Cd, Hg)
Related precipitations occur for sources of soft trivalent cations (As3+, Sb3+, Bi3+) and monovalent cations (Ag+, Cu+).
Preparation
Thioacetamide is prepared by treating acetamide with phosphorus pentasulfide as shown in the following idealized reaction:[1]
- CH3C(O)NH2 + 1/4 P4S10 → CH3C(S)NH2 + 1/4 P4S6O4
Structure
The C2NH2S portion of the molecule is planar; the C-S and C-N distances are 1.713 and 1.324 Å, both indicating multiple bonding.[2]
Safety
Thioacetamide is carcinogen class 2B.
References
- ^ George Schwarz (1955). "2,4-Dimethylthiazole". Organic Syntheses; Collected Volumes, vol. 3, p. 332.
- ^ Mary R. Truter "An accurate determination of the crystal structure of thioacetamide" Journal of the Chemical Society, 1960, pp. 997-1007. DOI: 10.1039/JR9600000997
- ""Thioacetamide (Sulfo amine)"". Chemical Land 21. Retrieved February 14.
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