Fast Sulphon Black

Fast Sulphon Black F

Names
IUPAC name 1-hydroxy-8-(2-hydroxy-1-naphthylazo)-2-(4-sulfo-1-naphthylazo)-naphthalene-3,6-disulfonic acid
Other names Fast Sulphon Black
Identifiers
CAS Number	3682-47-1 Y
3D model (JSmol)	Interactive image
ECHA InfoCard	100.020.879
SMILES c1ccc2c(c1)ccc(c2/N=N/c3cc(cc4c3c(c(c(c4)S(=O)(=O)O)/N=N/c5ccc(c6c5cccc6)S(=O)(=O)O)O)S(=O)(=O)O)O
Properties
Chemical formula	C30H20N4O11S3
Molar mass	708.695
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Fast Sulphon Black F is a complexometric indicator used with EDTA, almost exclusively used in copper complexation determination.

Fast Sulphon Black is purple when complexed with copper, and turns green when titrated against EDTA, as the EDTA displaces it, being the better complexing agent due to the chelate effect.