p-Dimethylaminobenzalrhodanine sample and bottle
| IUPAC name
| Other names
|Molar mass||264.361 g/mol|
|Density||2.009 g/cm3 (23 °C)|
|Melting point||271–272 °C (520–522 °F; 544–545 K) (decomposes)|
|Solubility|| Very soluble in ethyl acetate, formic acid, HCl 37%, methyl acetate, pyridine|
Moderately soluble in acetone, acetonitrile
Very slightly soluble in benzene, butanol, chloroform, diethyl ether, ethanol, isopropanol, methanol, toluene, xylene
Insoluble in ammonia 25%, formaldehyde 37%, hexane
|Solubility in 1,4-Dioxane||0.1 g/100 ml (80 °C)|
|Vapor pressure||~0 mmHg|
|Safety data sheet||Sigma-Aldrich|
|Lethal dose or concentration (LD, LC):|
LD50 (Median dose)
|150 mg/kg (mouse, intraperitoneal)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
p-Dimethylaminobenzalrhodanine or 5-(4-Dimethylaminobenzylidene)rhodanine is an organic compound with the formula C12H12N2OS2, used as a silver-specific dye in chemistry.
5-(4-Dimethylaminobenzylidene)rhodanine is a dye used to detect metal ions.
p-Dimethylaminobenzalrhodanine is a fluffy reddish solid, practically insoluble in water, but very soluble in 85% formic acid, HCl 37%, pyridine, good solubility in esters like ethyl and methyl acetate, slightly soluble in primary and secondary low-chain alcohols, acetic acid and insoluble in 25% aq. ammonia, formaldehyde 37% and hexane. It has a bulk density of 0.225 g/cm3.
Can be purchased online and from chemical suppliers.
Best to buy it rather than make it yourself.
- Colorimetric indicator for copper, gold, mercury, platinum, palladium and silver ions
- Indicator used in the titration of cyanide solutions
Little is known about this compound's toxicity. It doesn't appear to cause irritation, but will stain.
5-(4-Dimethylaminobenzylidene)rhodanine should be kept in closed plastic or glass bottles.
Should be destroyed with an oxidizing solution, like chromic acid, Fenton's reagent, piranha solution, then neutralize the acidic solution and then poured down the drain or taken to a waste disposal center.
- Casas, Jose S.; Macias, Alejandro; Playa, Nuria; Sanchez, Agustin; Sordo, Jose; Varela, Jose M.; Polyhedron; vol. 11; (1992); p. 2231 - 2236
- Veisi, Hojat; Naeimi, Alireza; Maleki, Behrooz; Ashrafi, Samaneh Sedigh; Sedrpoushan, Alireza; Organic Preparations and Procedures International; vol. 47; nb. 4; (2015); p. 1 - 7