N749 Black Dye

• CAT Number: M440133
• CAS Number: 359415-47-7
• Molecular Formula: C69H117N9O6RuS3
• Molecular Weight: 1365.98
• Purity: 95.0%
• Synonyms: Tris(N,N,N-tributyl-1-butanaminium)[[2,2′′6′,2′′-terpyridine]-4,4′,4′′-tricarboxylato(3-)-N1,N1′,N1′′]tris(thiocyanato-N)hydrogen ruthenate, Ruthenium 620
• Solubility: Ethanol or acetonitrile/tert-butanol (v/v = 1)
• Appearance: Dark green powder
• Storage: Room Temperature (Recommended in a cool and dark place)
• HOMO / LUMO: HOMO = -5.2 eV, LUMO = -3.8 eV

N749 dye, [(C₄H₉)₄N]₃[Ru(Htcterpy)(NCS)₃], also known as black dye, is a ruthenium-based sensitizer engineered for broad spectral sensitization of wide band-gap oxide semiconductors, such as TiO₂, extending absorption beyond 800 nm. Its molecular structure incorporates a ruthenium center coordinated with one tricarboxylated terpyridine ligand and three thiocyanato ligands, enabling strong anchoring to semiconductor surfaces. Although N749 exhibits a lower absorption extinction coefficient compared to other ruthenium dyes, it has achieved certified conversion efficiencies of up to 11.1% when paired with high-haze TiO₂ electrodes. This balance of broad absorption and strong efficiency makes N749 a benchmark sensitizer in DSSCs.