Title: Dithizone
CAS Registry Number: 60-10-6
CAS Name: Phenyldiazenecarbothioic acid 2-phenylhydrazide
Synonyms: (phenylazo)thioformic acid 2-phenylhydrazide; diphenylthiocarbazone
Molecular Formula: C13H12N4S
Molecular Weight: 256.33
Percent Composition: C 60.91%, H 4.72%, N 21.86%, S 12.51%
Line Formula: C6H5N=NCSNHNHC6H5
Literature References: Prepn: E. Fischer, E. Besthorn,
Ann. 212, 316 (1882). Use as an analytical reagent: A. Stock, E. Pohland,
Angew. Chem. 39, 791 (1926); H. Fischer,
ibid. 46, 442 (1933);
50, 919 (1937);
Organic Reagents for Metals (Hopkins & Williams, 1934). Crystal structure: M. Laing,
J. Chem. Soc. Perkin Trans. 2 1977, 1248. Conformation in soln: A. T. Hutton, H. M. Irving,
Chem. Commun. 1981, 735. Monograph:
Analytical Sciences Monograph No. 5 entitled "Dithizone", H. M. Irving, Ed. (Chemical Society, London, 1977) 112 pp.
Review: idem, Crit. Rev. Anal. Chem. 8, 321-405 (1980).
Properties: Bluish-black cryst powder, mp 168° (dec). Insol in water. Sparingly sol in alc, freely in carbon tetrachloride, chloroform. Solns are not stable, but may be preserved by a layer of aq SO2.
Melting point: mp 168° (dec)
CAUTION: Has caused glycosuria and ocular injury in exptl animals.
Use: Sensitive reagent for several heavy metals, Co, Cu, Pb, and Hg; esp for the estimation of minute amounts of Pb.
