Fast Sulphon Black F

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

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 Na salt: Interactive image
ChemSpider	21542668
ECHA InfoCard	100.020.879
EC Number	222-966-4
PubChem CID	407699 Na salt: 2733870
InChI InChI=1S/C30H20N4O11S3/c35-24-11-9-16-5-1-2-6-19(16)28(24)33-32-23-15-18(46(37,38)39)13-17-14-26(48(43,44)45)29(30(36)27(17)23)34-31-22-10-12-25(47(40,41)42)21-8-4-3-7-20(21)22/h1-15,35-36H,(H,37,38,39)(H,40,41,42)(H,43,44,45) Key: WQWKYALNLSYERE-UHFFFAOYSA-N
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 Na salt: C1=CC=C2C(=C1)C=CC(=C2N=NC3=C4C(=CC(=C3)S(=O)(=O)[O-])C=C(C(=C4O)N=NC5=CC=C(C6=CC=CC=C65)S(=O)(=O)[O-])S(=O)(=O)[O-])O.[Na+].[Na+].[Na+]
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 verify (what is YN ?) Infobox references

Application

Fast Sulphon Black is purple when complexed with copper, and turns green when titrated against EDTA,^[1] as the EDTA displaces it, being the better complexing agent due to the chelate effect.