Molecule structure of Direct Black GB NB (CAS NO.116897-98-4):

IUPAC Name: (6Z)-4-Amino-3-[4-[[4-[(2Z)-2-(4-amino-6-oxocyclohexa-2,4-dien-1-ylidene)hydrazinyl]benzoyl]amino]phenyl]diazenyl-5-oxo-6-(phenylhydrazinylidene)naphthalene-2,7-disulfonic acid 
Molecular Weight: 781.77378 g/mol
Molecular Formula: C₃₅H₂₇N₉O₉S₂
Density: 1.641 g/cm³
Index of Refraction: 1.768
Molar Refractivity: 197.538 cm³
Molar Volume: 476.485 cm³
Polarizability: 78.31×10^-24 cm³
Surface Tension: 78.926 dyne/cm 
XLogP3-AA: 3.5
H-Bond Donor: 7
H-Bond Acceptor: 17
Rotatable Bond Count: 10
Tautomer Count: 1000
Exact Mass: 781.137315
MonoIsotopic Mass: 781.137315
Topological Polar Surface Area: 298
Heavy Atom Count: 55
Complexity: 1900 
Canonical SMILES: C1=CC=C(C=C1)NN=C2C(=CC3=CC(=C(C(=C3C2=O)N)N=NC4=CC=C(C=C4)NC(=O)C5=CC=C(C=C5)NN=C6C=CC(=CC6=O)N)S(=O)(=O)O)S(=O)(=O)O
Isomeric SMILES: C1=CC=C(C=C1)N/N=C/2\C(=CC3=CC(=C(C(=C3C2=O)N)N=NC4=CC=C(C=C4)NC(=O)C5=
CC=C(C=C5)N/N=C\6/C=CC(=CC6=O)N)S(=O)(=O)O)S(=O)(=O)O
InChIKey of Direct Black GB NB (CAS NO.116897-98-4): DQNHQRWKYWKOHV-VCJGDSFLSA-N

Mutation data reported. When heated to decomposition it emits toxic vapors of NO_x and SO_x.

 Direct Black GB NB (CAS NO.116897-98-4) is also named as 2,7-Naphthalenedisulfonic acid, 4-amino-3-((4-((4-((4-amino-2-hydroxyphenyl)azo)benzoyl)amino)phenyl)azo)-5-hydroxy-6-(phenylazo)- .