THIONALIDE Property

Melting point:

111-112°

Density 

1.1799 (rough estimate)

refractive index 

1.6000 (estimate)

solubility 

Sparingly soluble in water, readily soluble in organic solvents. The solubility in water is considerably increased by addition of relatively small amounts of ethanol or acetic acid.

form 

White or pale yellow needles.

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H315Causes skin irritation

H318Causes serious eye damage

H335May cause respiratory irritation

H411Toxic to aquatic life with long lasting effects

Precautionary statements

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P310Immediately call a POISON CENTER or doctor/physician.

P321Specific treatment (see … on this label).

P332+P313IF SKIN irritation occurs: Get medical advice/attention.

P362Take off contaminated clothing and wash before reuse.

THIONALIDE Chemical Properties,Usage,Production

Uses

Thionalide reacts with a variety of metal ions to give chelate complexes which are sparingly soluble in water. The difference in stability of complexes formed by the reagent with various metal ions in some cases assures a certain analytical selectivity.
1. Copper(II), silver(I), mercury(II), bismuth(III), arsenic(III), tin(IV), gold(I), platinum(IV) and palladium(II) give precipitates with the reagent in acidic media (mineral acids).
2. The copper(II), mercury(II), cadmium(II), thallium(I) and gold(I) complexes precipitate from alkaline solutions containing tartrate.
3. Thallium(I), antimony(III) and bismuth(III) complexes are precipitated by the reagent from solutions containing cyanide and tartrate.
4. The thallium(I) complex also precipitates from alkaline (sodium hydroxide) solution containing cyanide and tartrate.
The above classification shows that the reaction can be made specific for thallium by appropriate choice of the pH of the solution and application of suitable masking agents. Similarly, the selectivity of the precipitation reaction can be increased for other ions too, by application of other masking agents. For instance, tin(IV) can be masked selectively in the presence of arsenic(III) and antimony(III) with phosphoric acid, while these latter two ions can be precipitated with thionalide.
The analytical application of thionalide is stimulated by the fact that its metal complexes are of stoichiometric composition, and can be dried at 105-110°C and weighed directly.
The reagent may also be utilized in volumetric analytical procedures. The thionalide content, which is equivalent to the metal to be determined, can be titrated directly iodometrically, according to the equation: 2C10H7-NH-CO-CH2-SH+I2=C10H7-NH-CO-CH2-S-S-CH2-CO-NH-C10H7+2HI.

Uses

As a reagent for copper, mercury, silver, thallium, and bismuth.