Thioacetamide

Structural formula
General
Surname	Thioacetamide
other names	TAA; Thioacetic acid amide;
Molecular formula	C 2 H 5 NS
Brief description	colorless, crystalline solid with a smell of rotten eggs
External identifiers / databases
EC number	200-541-4
ECHA InfoCard	100,000,493
PubChem	2723949
ChemSpider	2006 126
Wikidata	Q416253
properties
Molar mass	75.13 g mol −1
Physical state	firmly
density	1.37 g cm −3
Melting point	113-114 ° C
solubility	easily in water (163 g l −1 )
safety instructions
H and P phrases	H: 350-302-315-319-412
	P: 201-273-308 + 313-305 + 351 + 338-302 + 352
Toxicological data	301 mg kg −1 ( LD 50 , rat , oral )
Thermodynamic properties
ΔH f 0	−71.7 kJ / mol
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Thioacetamide is the amide of thioacetic acid . It has the molecular formula C ₂ H ₅ NS and is structurally closely related to acetamide .

use

When heated in aqueous solution, it breaks down into hydrogen sulfide and ammonium acetate . That is why it is used in the classic cation separation process and in gravimetric copper determination for the in-situ generation of hydrogen sulfide.

Formation of hydrogen sulfide from thioacetamide in aqueous solution

Advantages over the direct use of hydrogen sulfide gas are the very convenient metering and application, the favorable course of the homogeneous precipitation and above all the fact that no toxic H ₂ S gas has to be stored and used.

Thioacetamide on a watch glass dish

Thioacetamide is toxic and carcinogenic in itself , but easy to handle because it is a solid. In the laboratory it is usually the better alternative, in technology the much cheaper hydrogen sulfide gas is still used.

TAA also plays a role as a profibrogenic substance for research into fibrosis of organs, especially liver fibrosis and cirrhosis . Here it is used to induce liver damage in animal models.

Individual evidence

↑ ^a ^b ^c ^d ^e Entry on thioacetamide in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
↑ ^a ^b Data sheet thioacetamide (PDF) from Merck , accessed on January 18, 2011.
↑ Entry on thioacetamides in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-22.
↑ Pauline Heizer: Deoxyribose nuclei acid (DNA) content and size of rat liver nuclei during thioacetamide intoxication and recovery. In: Chromosoma 7: 281-327, 1955.

[GESTIS-1] Entry on thioacetamide in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .

[merck-2] Data sheet thioacetamide (PDF) from Merck , accessed on January 18, 2011.

[CLP_100.000.493-3] Entry on thioacetamides in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[CRC90_5_22-4] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-22.

[5] Pauline Heizer: Deoxyribose nuclei acid (DNA) content and size of rat liver nuclei during thioacetamide intoxication and recovery. In: Chromosoma 7: 281-327, 1955.