Pigment Yellow 180

• CAS: 77804-81-0
• Catalog Number: ACM77804810
• Category: Main Products
• Molecular Weight: 732.70
• Molecular Formula: C₃₆H₃₂N₁₀O₈
• Synonyms: fast yellow hg;C.I. 21290;2,2'-[ethylenebis(oxyphenyl-2,1-eneazo)]bis[n-(2,3-dihydro-2-oxo-1h-benzimidazol-5-yl)-3-oxo-butanamide;PIGMENT YELLOW 180;2,2'-[ethylenebis(oxyphenyl-2,1-eneazo)]bis[N-(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)-3-oxobutyramide;BE
• IUPAC Name: 2-[[2-[2-[2-[[1,3-dioxo-1-[(2-oxo-1,3-dihydrobenzimidazol-5-yl)amino]butan-2-yl]diazenyl]phenoxy]ethoxy]phenyl]diazenyl]-3-oxo-N-(2-oxo-1,3-dihydrobenzimidazol-5-yl)butanamide
• SMILES: CC(=O)C(C(=O)NC1=CC2=C(C=C1)NC(=O)N2)N=NC3=CC=CC=C3OCCOC4=CC=CC=C4N=NC(C(=O)C)C(=O)NC5=CC6=C(C=C5)NC(=O)N6
• InChI Key: PUNNQKXGKNOLTB-UHFFFAOYSA-N
• Boiling Point: 825.2ºC at 760 mmHg
• Flash Point: 452.9ºC
• Density: 1.52
• Appearance: Yellow powder
• EC Number: 278-770-4
• Exact Mass: 732.24000

Case Study

Pigment Yellow 180 as a Solvent-Responsive Pigment: Color Tuning via Dissolution-Reprecipitation

Ye, Kairu, et al. Processes 11.10 (2023): 2951.

Pigment Yellow 180 (PY180), a bisazo pigment, exhibits solvent-dependent pigmentation behavior. The choice of solvent during post-processing systematically shifts the final color from reddish-yellow to greenish-yellow, driven by changes in crystallinity and particle size without altering chemical or crystal structure.
Experimental Protocol: PY180 was pigmented in ten different solvents. Samples were characterized by FTIR, XRD, TEM, and colorimetric analysis (CIE L*a*b*). Hansen solubility parameters (HSPs) and molecular polarity index (MPI) were used to correlate solvent properties with color variation.
Performance Evaluation: All solvents enhanced brightness and shifted hue toward green. XRD confirmed increased crystallinity and crystal size as the main cause. Solvents with low HSP difference (Δδ) relative to PY180 induced greater color changes. Among solvents with similar solubility, those with higher MPI (stronger polarity) produced larger color differences, attributed to dipole-dipole interactions promoting dissolution-reprecipitation. The pigmentation process is surface-energy-driven; lower surface energy leads to slower recrystallization and slower color change.