ANTHRAQUINONE

Anthraquinone is the parent aromatic diketone behind a broad family of colorants, pulping catalysts, redox carriers, and specialty organic intermediates.
Its pale-yellow appearance is deceptively modest because the intense reds, blues, greens, and violets associated with anthraquinone chemistry usually emerge only after amino, hydroxy, halogen, sulfonic acid, or other substituents are introduced.
This distinction matters commercially: parent Anthraquinone is a defined chemical intermediate and process additive, not a universal substitute for every anthraquinone derivative.
Its rigid fused-ring structure, paired carbonyl groups, and reversible reduction chemistry explain both its synthetic importance and its direct function in alkaline pulp cooking.

CHEMICAL IDENTITY AND COMMON NAMES

Anthraquinone conventionally denotes the 9,10-isomer in which two opposing carbonyl groups occupy the central ring of the anthracene framework.
The preferred structural name is anthracene-9,10-dione, while 9,10-Anthraquinone remains the most familiar systematic alternative in industry.
The compound is distinct from 1,2-anthraquinone, 1,4-anthraquinone, hydroxyanthraquinones, aminoanthraquinones, and alkylanthraquinones.
That positional and substitution identity should remain explicit in purchase orders, specifications, analytical methods, and regulatory records.

Synonyms and Common Names: Anthraquinone, 9,10-Anthraquinone, anthracene-9,10-dione, 9,10-anthracenedione, anthracenedione, anthracene-9,10-quinone, 9,10-anthracenequinone, 9,10-dioxoanthracene, dioxoanthracene, anthradione, and diphenylene diketone.

TECHNICAL IDENTIFICATION

CAS Number: 84-65-1.
EC Number: 201-549-0.
European Union Index Number: 606-151-00-4.
Molecular Formula: C14H8O2.
Molar Mass: 208.21 g/mol.
InChIKey: RZVHIXYEVGDQDX-UHFFFAOYSA-N.
Chemical Family: Anthracenediones, aromatic quinones, and fused-ring aromatic ketones.
Structural Description: Three linearly fused six-membered rings form a planar conjugated system, with carbonyl groups at positions 9 and 10 on the central ring.

THE TWO CARBONYLS DEFINE THE CHEMISTRY

Anthraquinone behaves differently from anthracene because oxidation of the central ring installs two electron-accepting carbonyl groups without destroying the extended aromatic framework.
The resulting quinone can accept hydrogen and electrons to form anthrahydroquinone or related reduced species, then return to Anthraquinone through oxidation.
This reversible redox pair is the essential mechanism behind its catalytic behavior in alkaline pulping and the wider process chemistry of substituted anthraquinones.
Strong reducing systems produce reduced or leuco forms, while air or another suitable oxidant restores the quinone carbonyls.
The flat conjugated nucleus also provides an excellent chromophore platform, although useful dye shade and fiber affinity normally depend on carefully selected substituents.
Hydroxy and amino groups strengthen electron donation into the quinone system and markedly alter absorption, while sulfonic acid groups add water compatibility and halogen or alkyl groups tune reactivity, solubility, and performance.
The parent compound is resistant to ordinary aqueous hydrolysis and has very low volatility, so industrial behavior is governed more by particle contact, dissolution in the chosen medium, and redox conditions than by evaporation.

PHYSICAL AND CHEMICAL PROPERTIES

Appearance: Anthraquinone is a light-yellow crystalline solid and is commonly handled as a pale-yellow crystalline powder.
Odour: The material is essentially odourless.
Melting Point: Pure Anthraquinone melts at approximately 286 °C.
Boiling Point: The boiling point is approximately 380 °C.
Density: The density is approximately 1.44 g/cm3 at 20 °C.
Water Solubility: Solubility in water is approximately 1.35 mg/L at 25 °C, which makes the compound practically insoluble for most process purposes.
Solvent Behavior: Anthraquinone dissolves in acetone and hot aromatic solvents, remains only slightly soluble in many alcohols and ethers, and dissolves in concentrated sulfuric acid through strong acid interaction.
Partition Behavior: A log Kow of approximately 3.39 reflects preference for organic phases over water.
Volatility: Vapour pressure is negligible at ambient temperature, so workplace exposure arises mainly from airborne powder rather than vapour.
Autoignition Temperature: Autoignition occurs at approximately 650 °C.
pH: A pH value is not applicable to the dry pure solid.
Stability: Anthraquinone is stable under normal dry storage conditions but participates readily in deliberate reduction and oxidation processes.
Combustibility: The solid is combustible, and a sufficiently fine airborne powder can create a combustible dust atmosphere.
Thermal Decomposition: Fire or severe overheating produces carbon oxides and irritating decomposition fumes.

PRODUCTION AND PURIFICATION

The established industrial route begins with refined anthracene and converts it to Anthraquinone by catalytic vapour-phase oxidation with air.
This direct oxidation preserves the fused three-ring carbon skeleton and introduces the two central carbonyl groups in a single process concept.
Control of feed purity, oxidation selectivity, temperature, residence time, and catalyst condition limits unreacted anthracene and secondary oxygenated aromatic compounds.

A second important synthesis builds the carbon framework through Friedel–Crafts acylation of benzene with phthalic anhydride.
The resulting ortho-benzoylbenzoic acid intermediate undergoes ring closure and dehydration to furnish the anthraquinone nucleus.
This route has a different impurity fingerprint, with control focused on residual acidic material, incomplete cyclization products, catalyst-derived residues, and positional by-products.

Crystallization, washing, thermal treatment, and sublimation-based refining are used individually or in combination to establish assay, color, melting behavior, ash, and organic impurity profile.
Production route is therefore more than a manufacturing detail because residual anthracene is especially relevant to anthracene-oxidation material, while acid and catalyst residues receive greater attention in ring-closure material.
A pale and consistent product color usually signals effective removal of strongly colored oxidation by-products, but chromatographic assay remains the decisive measure of chemical purity.

APPLICATIONS AND INDUSTRIES

Anthraquinone dye and pigment intermediates

The largest chemical significance of Anthraquinone lies in its use as the parent intermediate for anthraquinone-based dyes and organic pigments.
Sulfonation, nitration, halogenation, amination, hydroxylation, and related substitution sequences transform the pale parent nucleus into compounds with strong color, targeted solubility, and affinity for specific fibers or coating systems.
The resulting chemistry supports vat, disperse, acid, reactive, mordant, and solvent-colorant families as well as high-performance pigments.
Anthraquinone itself should be described as a colorant building block rather than as the finished dye represented by those derivatives.
For this application, assay, residual anthracene, melting range, color, moisture, ash, metal residues, and the complete organic impurity profile influence reaction selectivity and final shade cleanliness.

Vat-dye chemistry

Anthraquinone derivatives occupy a central place in vat dyes because their quinone groups can be reduced to soluble leuco species and subsequently oxidized back to insoluble colored molecules.
The reduced form penetrates the fiber from an alkaline vat, after which air oxidation regenerates the durable pigment-like form inside and around the fiber structure.
This cycle produces characteristic wash fastness and chemical resistance without requiring the parent Anthraquinone itself to be the finished textile colorant.
Intermediate manufacturers value a narrow impurity profile because small amounts of isomeric or strongly colored by-products can alter hue, brightness, reduction behavior, and reproducibility across dye batches.

Alkaline pulping

Anthraquinone has a direct process role as a redox catalyst in soda and kraft pulping rather than merely serving as a precursor.
Under alkaline cooking conditions, reducing ends in wood carbohydrates convert Anthraquinone into anthrahydroquinone species.
The reduced catalyst promotes cleavage of lignin beta-aryl ether structures and is oxidized back to Anthraquinone, allowing the cycle to repeat at low dosage.
At the same time, oxidation of carbohydrate reducing ends suppresses alkaline peeling reactions and helps preserve usable fiber yield.
The combined effect is faster delignification, improved selectivity between lignin removal and carbohydrate loss, and the possibility of adjusting cooking time, temperature, or effective alkali demand.
Particle size and dispersibility are unusually important here because a water-insoluble powder must make effective contact with hot cooking liquor and wood chips before its redox function can be fully used.
Fine or readily dispersible pulping grades provide more uniform distribution than coarse crystalline material and reduce the risk of local underdosing.
United States food-contact rules list the disodium salt of 1,4-dihydro-9,10-dihydroxyanthracene as a pulping catalyst rather than parent Anthraquinone, so these chemical identities are not interchangeable in regulated procurement.

Hydrogen peroxide derivative manufacture

The well-known anthraquinone auto-oxidation process for hydrogen peroxide usually relies on substituted alkylanthraquinones dissolved in an organic working solution.
Two-alkyl derivatives are selected because their solubility, hydrogenation behavior, phase distribution, and cycling performance are engineered for that process.
Unsubstituted Anthraquinone can serve as a synthetic nucleus or development reference for such derivatives, but it is not a drop-in replacement for 2-ethylanthraquinone or another specified working carrier.
Procurement for this value chain must therefore identify the exact substitution pattern rather than using “anthraquinone” as a family-level shorthand.

Regulated avian-repellent formulations

Anthraquinone has been used directly in seed treatments and surface formulations that discourage feeding by birds through a learned post-ingestive response.
This is a pesticide application governed by active-substance approval, formulation authorization, crop or site restrictions, residue requirements, labeling, and environmental controls.
Anthraquinone is not approved as a pesticide active substance in the European Union, so historical repellent use does not establish present authorization there.
Material intended for an authorized regional use requires an application-specific impurity profile, controlled particle characteristics, formulation compatibility, and complete regulatory documentation.

Specialty organic synthesis

Anthraquinone is a robust starting point for preparing sulfonated, nitrated, halogenated, amino, hydroxy, alkyl, and condensed-ring derivatives.
Its two carbonyl groups support reduction, addition, and derivatization chemistry, while the aromatic rings accept electrophilic substitution under controlled conditions.
These transformations feed fine-chemical, functional-material, colorant, and research-intermediate programs.
The anthraquinone skeleton also appears in numerous natural products and biologically active derivatives, but the parent substance does not inherit the performance, purity requirements, or regulatory status of those substituted molecules.

Analytical and research use

High-purity Anthraquinone is used as a chromatographic reference, identity standard, organic synthesis substrate, and model quinone in redox and electrochemical studies.
Its sharp melting behavior and well-characterized spectra make it useful for method development and compound identification.
Analytical material places greater emphasis on chromatographic purity, traceability, identity spectra, and controlled packaging than a technical intermediate or pulping additive.

PARENT COMPOUND AND DERIVATIVE BOUNDARIES

The word anthraquinone is frequently used both for the single substance CAS 84-65-1 and for an entire chemical family, which creates avoidable sourcing errors.
Hydroxyanthraquinones are not parent Anthraquinone, aminoanthraquinones are not parent Anthraquinone, and alkylanthraquinones used as industrial redox carriers are not parent Anthraquinone.
Anthrahydroquinone is the reduced dihydroxy form, while its salts have their own identities, solubilities, transport behavior, and regulatory positions.
Commercial descriptions should therefore connect the exact CAS number and molecular formula to the intended function before grade, packaging, or quantity is selected.
A request that names only an end-use family such as “peroxide anthraquinone,” “pulping quinone,” or “anthraquinone dye” is chemically incomplete until the required molecule is fixed.

GRADE SELECTION AND PROCUREMENT

Technical intermediate grade is suited to downstream reactions in which high assay, controlled color, and a predictable organic impurity profile are more important than extremely fine particle size.
Pulping grade emphasizes active content, small and consistent particle size, rapid dispersion, low grit, low ash, and reliable delivery into alkaline liquor.
High-purity and analytical grades emphasize chromatographic purity, traceability, identity data, and low levels of closely related aromatic impurities.
An application involving catalytic or electronic behavior also benefits from tight limits on iron, other metals, ionic residue, and moisture.

The purchase specification should identify assay method, minimum assay, appearance, melting range, water or loss on drying, ash or sulfated ash, insoluble matter, residual anthracene, named organic impurities, and particle-size distribution where dispersion matters.
Color measurement is useful for dye-intermediate production because a visually acceptable yellow powder can still contain trace chromophoric impurities that affect a sensitive downstream shade.
Chromatographic area percentage alone does not replace named limits for critical impurities when those compounds have different toxicological or process consequences.
A representative sample and agreed test method help align material approval with the actual reactor, mill, formulation, or analytical workflow.

FORMULATION AND PROCESSING CONSIDERATIONS

Low water solubility is the central formulation constraint for parent Anthraquinone.
Direct addition to an aqueous process requires controlled wetting, sufficient agitation, and particle size suited to the available mixing energy.
Pre-dispersion in a compatible carrier can improve dosing uniformity, while dry addition systems need enclosure to prevent dust escape and segregation.
Heating increases solubility in suitable organic media, but solvent selection must account for recovery, fire protection, worker exposure, and the stability of every downstream component.

In reduction processes, contact between Anthraquinone, reductant, and alkaline medium controls the rate at which the active reduced species forms.
Oxygen entry then determines how quickly the reduced form returns to the quinone state.
In synthetic reactions, the planar aromatic solid can crystallize strongly, so solvent ratio, cooling profile, seeding, and agitation affect filtration rate and final particle form.
Metal contamination and strongly oxidizing or reducing residues should be controlled when the product is intended for a precise redox cycle.

QUALITY CONTROL AND DOCUMENTATION

Identity is established by infrared spectroscopy, chromatographic retention, mass spectrometry, or a combination of orthogonal techniques.
Assay is commonly measured by gas or liquid chromatography, with the method selected to resolve Anthraquinone from anthracene and oxygenated aromatic neighbors.
Melting range provides a rapid purity check because residual feedstock and related aromatic compounds can broaden or depress the transition.
Moisture testing protects weighing accuracy and flow behavior, while ash testing detects nonvolatile inorganic residue from catalysts, filtration aids, or handling equipment.
Particle-size analysis is essential for pulping and dispersion uses but has less significance for material that will be fully dissolved before reaction.

A lot-specific Certificate of Analysis records conformance to the agreed specification.
The Technical Data Sheet describes identity, physical form, application guidance, and storage conditions, while the Safety Data Sheet defines hazards, exposure controls, emergency measures, and disposal requirements.
Change control is particularly valuable when production route, purification sequence, particle milling, or impurity methods affect a qualified downstream process.

SAFETY AND EXPOSURE CONTROL

European Union harmonized classification places Anthraquinone in Carcinogenicity Category 1B with hazard statement H350: May cause cancer.
Industrial handling should therefore use a formal carcinogen-control approach built around substitution review, closed transfer, restricted access, exposure monitoring, hygiene, and documented training.
Anthraquinone can also cause skin sensitization and allergic skin reactions, making repeated unprotected contact unacceptable.
Powder can irritate the eyes and respiratory tract, while its negligible ambient vapour pressure makes dust containment the primary engineering objective.

Local exhaust ventilation should capture dust at charging, sampling, milling, bag emptying, and packaging points.
Closed screw feeding, sealed vacuum transfer, contained sampling, and high-efficiency filtered extraction reduce airborne exposure and product loss.
Operators should use chemical-resistant gloves, protective clothing, safety goggles or a face shield, and suitable respiratory protection whenever engineering controls do not fully contain particulate exposure.
Contaminated work clothing should remain in controlled laundering or disposal systems and should not be taken into clean areas.

The powder is combustible, and fine particles dispersed in air can present a dust-fire or dust-explosion hazard.
Ignition sources should be eliminated, equipment should be bonded and grounded, and dust deposits should not be allowed to accumulate on hot or elevated surfaces.
Water spray, foam, dry chemical, or carbon dioxide can be used for fire control, with fire-fighters protected by self-contained breathing apparatus and full protective equipment.
Strong oxidizing agents and strong reducing agents should be segregated because they can initiate unwanted reaction with the quinone system.

FIRST AID

After inhalation, move the affected person to fresh air, keep the person at rest, and obtain medical attention for cough, breathing difficulty, or significant exposure.
After skin contact, remove contaminated clothing and wash the skin thoroughly with soap and water, with medical evaluation for redness, rash, or sensitization symptoms.
After eye contact, rinse cautiously with clean water for at least 15 minutes, remove contact lenses when easy to do, and obtain medical attention if irritation continues.
After ingestion, rinse the mouth, do not induce vomiting, and seek prompt medical advice.
Following significant exposure or concern related to carcinogenicity, obtain medical advice and provide the product Safety Data Sheet to the treating professional.

STORAGE AND HANDLING

Store Anthraquinone in tightly closed original or chemically compatible containers in a cool, dry, well-ventilated area.
Keep the product away from heat, open flame, sparks, direct moisture, strong oxidizers, strong reductants, foodstuffs, and incompatible process chemicals.
Carcinogen-designated storage should be access-controlled, clearly labeled, and arranged to prevent package damage or accidental cross-contamination.
Use dedicated or thoroughly cleaned transfer equipment to protect both worker safety and the product impurity profile.

Avoid dropping bags, pouring from excessive height, or using compressed air to clean residues because these practices generate airborne dust.
Ground conductive equipment during bulk transfer and use tools and electrical systems appropriate for combustible powder service.
Keep containers closed between operations, and rotate inventory by lot to preserve documentation traceability.

SPILL RESPONSE AND WASTE MANAGEMENT

Isolate the spill area, remove ignition sources, stop dust-generating activity, and prevent unprotected personnel from entering.
Collect the powder with a high-efficiency filtered vacuum or by careful dampened pickup that does not spread contamination.
Do not dry-sweep, use compressed air, or wash the material into drains, soil, or surface water.
Place recovered material and contaminated cleaning media in closed, labeled containers for approved hazardous-chemical waste treatment.

Anthraquinone waste, off-specification product, contaminated packaging, and process residues should be managed through a licensed hazardous-waste route.
Controlled high-temperature incineration with appropriate off-gas treatment is a suitable destruction method for organic residues.
Empty packaging should be treated as contaminated until decontaminated or disposed of under the applicable waste system.

PACKAGING AND SUPPLY

Suitable industrial packaging includes sealed multiwall bags with barrier liners, lined fiber drums, and larger closed-transfer units selected for shipment volume and plant handling method.
The inner contact layer should resist puncture, exclude moisture, contain fine powder, and avoid introducing plastic fragments or other foreign matter.
Pulping operations often benefit from packaging designed for fast contained charging, while analytical and high-purity users require smaller clean packs that minimize repeated opening.
Each package should carry the exact chemical name, CAS number, net weight, batch number, hazard labeling, storage information, and traceability data.

Ataman Kimya supports Anthraquinone sourcing for dye and pigment manufacture, alkaline pulping, derivative synthesis, analytical work, and other qualified industrial applications, with grade selection centered on assay, impurity profile, particle size, documentation, and packaging.
For product availability, technical questions, or commercial inquiries, contact Ataman Kimya at +90 216 577 10 10 or info@atamankimya.com.