Pigment Green 7 (49-27-5) Physical and Chemical Properties
Pigment Green 7
High-performance chlorinated copper phthalocyanine pigment supplied as a bright green powder for industrial formulation of coatings, inks and plastics.
| CAS Number | 49-27-5 |
| Family | Phthalocyanine pigments |
| Typical Form | Powder or particulate pigment |
| Common Grades | BP, EP, Technical Grade, USP |
Pigment Green 7 is a chlorinated copper phthalocyanine — a metal-centered, macrocyclic aromatic pigment of the phthalocyanine class. Structurally it comprises a large, planar conjugated tetrapyrrolic macrocycle bearing multiple chlorine substituents and a central copper(II) ion coordinated within the tetradentate N4 cavity. The high degree of conjugation and substitution produces intense green chromaticity and confers electronic delocalization across the macrocycle; the central Cu(II) contributes to the complex's electronic stabilization and characteristic spectral properties.
Electron-withdrawing chlorine atoms substantially reduce the electron density of the macrocycle relative to non-chlorinated phthalocyanines, increasing chemical robustness and lipophilicity while lowering aqueous solubility. The material is formally a neutral coordination complex (overall charge 0) in its isolated solid form, lacks classical proton-donating functional groups (hydrogen-bond donors = 0), and presents multiple Lewis-basic pyrrolic/pyridinic nitrogens that can participate in coordination chemistry or weak protonation under strongly acidic conditions. As a consequence of its large aromatic surface area and extensive chlorination, Pigment Green 7 is highly lipophilic with very low water solubility and a tendency to partition into organic matrices; it is chemically resistant to simple hydrolysis and shows high photochemical and oxidative stability relative to many low‑molecular‑weight dyes.
Industrial relevance stems from its role as a high-performance green pigment: it is widely employed in coatings, inks, plastics, and specialty colorants where lightfastness, chroma, and chemical resistance are required. It is commonly formulated and distributed as powder pigments, concentrates and surface-treated dispersions for use in paints, printing inks, plastics, and certain cosmetic colorant applications. Common commercial grades reported for this substance include: BP, EP, Technical Grade, USP.
Basic Physical Properties
Solubility and Hydration
Experimental solubility for Pigment Green 7 is very low: reported as less than \(1\,\mathrm{mg}\,\mathrm{mL}^{-1}\) at \(70\,^\circ\mathrm{F}\). The compound is described as insoluble in water and is supplied and handled primarily as a dry or solvent-wetted powder or as a dispersion. The combination of a large planar aromatic core and extensive chlorination explains the minimal aqueous solubility and strong affinity for organic media and polymer matrices.
No experimentally established value for hydration (stoichiometric hydrate formation) is available in the current data context.
Thermal Stability and Decomposition
Quantitative melting point or decomposition temperatures are not provided for this substance in the available data. Class-level behavior for phthalocyanine pigments indicates substantial thermal robustness: these materials typically do not melt cleanly but instead decompose at elevated temperatures, and are resistant to moderate thermal stress encountered in pigment processing and polymer compounding. Flash-point data are not available; the material is probably combustible in bulk solid form and should be handled as a combustible powder where ignition sources are present.
Chemical Properties
Complex Formation and Coordination
Pigment Green 7 is the copper(II) complex of a heavily chlorinated phthalocyanine ligand. The copper center is formally in the +2 oxidation state and occupies the square-planar N4 pocket of the macrocycle, producing a stable chelate complex. The macrocycle offers a delocalized π-system that stabilizes the metal center; additional axial coordination is limited under typical conditions but possible with strong Lewis bases or under specialized chemical conditions. The multiple chlorine substituents are strongly electron-withdrawing, reducing electron density on the macrocycle and modifying redox and coordination behavior relative to non‑chlorinated analogues.
Reactivity and Stability
The substance is chemically stable under normal handling and use conditions. It is classified within the phthalocyanine dye family, which are generally resistant to hydrolysis and oxidative degradation; photostability and lightfastness are characteristic strengths. The material is reported to be insoluble in water and to behave as a weak base in aqueous media due to lone pairs on ring nitrogen atoms; however, it lacks ionizable protons and is effectively non-ionized under neutral pH. Reactive functional group classes noted in association with the compound include amines, phosphines, pyridines, and aryl halides, indicating potential interaction pathways (e.g., coordination or substitution reactions) under strongly reactive conditions. Under aggressive chemical attack (strong oxidizers, extreme reductive conditions, or high-temperature pyrolysis) decomposition products may form; specific decomposition pathways and products are not provided here.
Molecular Parameters
Molecular Weight and Composition
- Molecular formula: C32HCl15CuN8
- Molecular weight: \(1092.7\,\mathrm{g}\,\mathrm{mol}^{-1}\)
- Exact mass: \(1090.485954\,\mathrm{Da}\)
- Monoisotopic mass: \(1084.494805\,\mathrm{Da}\)
- Heavy atom count: 56
- Topological polar surface area (TPSA): \(79.3\,\text{Å}^2\)
- Formal charge: 0
- Molecular complexity (computed): 1440
The composition reflects a large, chlorine-rich macrocycle with a single copper atom centrally coordinated. The combination of high molecular weight, planar aromatic surface and heavy halogenation is consistent with low solubility and strong adsorption into hydrophobic matrices.
LogP and Ionization State
No experimentally determined octanol–water partition coefficient (logP) value is available in the current data context. At the class level, heavily chlorinated phthalocyanines are strongly lipophilic and are expected to exhibit high partitioning into organic phases and polymers with minimal partitioning into aqueous solution.
The isolated solid exists as a neutral coordination complex containing Cu(II) in the macrocyclic cavity; it contains no classical Brønsted acidic protons and displays only weak basic behavior in aqueous solution due to ring nitrogens. Ionization (protonation) is not a significant feature in typical use conditions.
Identifiers and Synonyms
Registry Numbers and Codes
- CAS (primary listed): 49-27-5
- InChIKey: GUYIZQZWDFCUTA-UHFFFAOYSA-N
- SMILES: C1=C2C(=C(C(=C1Cl)Cl)Cl)C3=NC4=NC(=NC5=NC(=NC6=C7C(=C([N-]6)N=C2[N-]3)C(=C(C(=C7Cl)Cl)Cl)Cl)C8=C5C(=C(C(=C8Cl)Cl)Cl)Cl)C9=C4C(=C(C(=C9Cl)Cl)Cl)Cl.[Cu+2]
- European Community (EC) numbers reported: 215-524-7; 250-523-5; 670-228-9
- UNII: BPO9294G4W
- RXCUI: 1918055
(These identifiers appear among the deposited substance descriptors and registry listings for this material.)
Synonyms and Structural Names
Common and depositor-supplied synonyms include: - phthalocyanine green - PHTHALOCYANINE GREEN - Copper Phthalocyanine Green - C.I. Pigment Green 7 - C.I. 74260 - CI 74260 - Copper, (pentadecachlorophthalocyaninato(2-))- - Numerous commercial/trade names and legacy synonyms (examples): Heliogen Green G, Monastral Green G, Phthalocyanine Green LX, Brilliant Green Phthalocyanine, Fastogen Green B, Irgalite Green GLN, SolFast Green, and many pigment-grade trade designations.
(Supplied nomenclature in registries includes systematic IUPAC-like names for the chlorinated phthalocyaninato copper complex as well as many commercial product names and pigment codes.)
Industrial and Commercial Applications
Use as Salt Form or Excipient
Pigment Green 7 is produced and supplied primarily as a pigment-grade solid (powder) or as formulated dispersions and concentrates for incorporation into coatings, inks, plastics and other matrix materials. It is not used as a pharmaceutical active ingredient; its role in formulations is as a colorant/pigment rather than as an excipient with functional pharmacotechnical activity. Typical commercial forms include dry powders, surface-treated pigment dispersions, and masterbatches for polymer compounding.
Representative Use Cases
Documented applications and representative uses include: - Pigment for paints, printing inks and lacquers. - Colorant in plastics, linoleum, rubber and polymer products. - Coloring of paper surfacing, wallpapers, book cloth and leather goods. - Artists' materials and colored pencils/chalks. - Cosmetic colorant applications including hair-dyeing formulations (subject to regulatory restrictions and formulation-specific assessments). - Listed as a color additive for certain device uses; some specific uses (e.g., contact lenses) are restricted under regulatory specifications.
Manufacturing methods reported include chlorination of copper phthalocyanine with elemental chlorine in various media (eutectic salt melts, molten phthalic anhydride, or sulfuryl chloride processing) or heating copper phthalocyanine in sulfur dichloride under pressure to introduce chlorine substituents. Production is concentrated on pigment-grade material meeting relevant pigment specifications.
Safety and Handling Overview
Toxicological Considerations
Available hazard characterizations indicate that Pigment Green 7 is not classified as a hazardous substance by many reporting entities and does not meet GHS hazard criteria in the majority of submissions; the aggregated reporting indicates "Not Classified" for most hazard endpoints. Acute irritation potential is low in standard animal assays: it is generally reported as not irritating to skin or eyes, although some sources indicate it may cause mild eye irritation. Systemic acute toxicity data are limited in the current context; specific toxicological studies (including longer-term or carcinogenicity assessments) may exist but are not summarized numerically here.
Because the compound is a respirable powder in many handling situations, inhalation of dust should be minimized. Normal industrial hygiene measures are advised: avoid dust generation, provide adequate ventilation, and use appropriate respiratory protection when handling the neat powder or during processes that aerosolize the pigment.
First-aid measures summarized for pigment exposure indicate standard responses: flushing of eyes and skin with water following contact, removal from exposure and fresh air for inhalation incidents, and seeking medical advice for ingestion or persistent symptoms. For detailed toxicological profiles consult product-specific safety documentation and authoritative toxicology data.
Storage and Handling Guidelines
- Storage: store in a cool, dry place away from strong oxidizers; some product handling guidance recommends refrigeration for long-term storage of test materials, but commercial pigment stocks are typically stored under dry, ambient conditions with moisture control and in sealed containers to prevent contamination.
- Handling: minimize dust formation; employ local exhaust ventilation and dust collection. For weighing and transfer of neat powder, use respiratory protection (e.g., half-face respirator with organic vapor/acid gas cartridge and particulate filter where recommended), chemical-resistant gloves and protective clothing.
- Spill response: small spills may be controlled by dampening with dilute acetic acid and collecting the dampened material into suitable containers for disposal; contaminated surfaces should be washed with dilute acetic acid followed by detergent solution as a precautionary decontamination measure.
- Firefighting: specific flash-point data are not available; fires can generally be controlled with dry chemical, carbon dioxide or Halon-type extinguishers. Avoid generating airborne dust in the presence of ignition sources.
- Regulatory and product-specific guidance: for detailed hazard, transport and regulatory information, users should refer to the product-specific Safety Data Sheet (SDS) and applicable local legislation.
For procurement, quality control and formulation purposes, select the appropriate commercial grade (BP, EP, Technical Grade, USP) and verify certificate of analysis parameters (particle size distribution, tinting strength, bulk density and any surface treatments) with the supplier prior to use.
