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Acenaphthene is a fused-ring polycyclic aromatic hydrocarbon occurring naturally in coal tar and produced commercially as an aromatic chemical intermediate.
Acenaphthene consists of a naphthalene-derived aromatic system bridged by a saturated two-carbon unit, giving a characteristic tricyclic structure that distinguishes it from the closely related unsaturated compound acenaphthylene.
Acenaphthene is primarily valued as a starting material for dyes, pigments, plastics, resins, naphthalic derivatives, and other specialty organic intermediates.
CHEMICAL IDENTITY AND COMMON NAMES
Acenaphthene is systematically identified as 1,2-dihydroacenaphthylene.
The structure contains twelve carbon atoms arranged in a fused aromatic and five-membered ring framework.
Acenaphthene should be distinguished from acenaphthylene, which contains two fewer hydrogen atoms and an additional carbon-carbon double bond in the five-membered ring.
This structural difference changes the molecular formula, physical properties, reactivity, and CAS identity of the two substances.
Synonyms and Common Names: Acenaphthene, 1,2-Dihydroacenaphthylene, 1,2-Dihydro-acenaphthylene, Acenaphthylene, 1,2-dihydro-, 1,8-Ethylenenaphthalene, peri-Ethylenenaphthalene, Peri-ethylenenaphthalene, Naphthyleneethylene, Ethylenenaphthalene, 1,8-Dihydroacenaphthalene, Acenaphtene
TECHNICAL IDENTIFICATION
CAS Number: 83-32-9
EC / EINECS Number: 201-469-6
Molecular Formula: C12H10
Molar Mass: 154.21 g/mol
IUPAC Name: 1,2-Dihydroacenaphthylene
Chemical Class: Polycyclic aromatic hydrocarbon
UN Number: 3077
PHYSICAL AND CHEMICAL PROPERTIES
Appearance: White to beige crystalline solid
Physical State: Solid
Molecular Formula: C12H10
Molar Mass: 154.21 g/mol
Melting Point: Approximately 93–95 °C
Boiling Point: Approximately 279 °C
Density: Approximately 1.2 g/cm³
Water Solubility: Approximately 0.004 g/L at 25 °C
Vapour Pressure: Approximately 0.3 Pa at 25 °C
Relative Vapour Density: Approximately 5.3, air = 1
Flash Point: Approximately 135 °C, open cup
Autoignition Temperature: Above 450 °C
Log Pow: Approximately 3.9–4.5
Volatility: Low at ambient temperature
Solubility Characteristics: Very slightly soluble in water and soluble to varying degrees in organic solvents
Combustibility: Combustible solid
Dust Behaviour: Finely dispersed particles can form explosive mixtures with air
Chemical Stability: Stable under appropriate normal storage conditions
Incompatibility: Strong oxidizing agents
The high melting point and low vapour pressure of Acenaphthene make it a low-volatility crystalline material under normal ambient conditions.
Its low water solubility and comparatively high octanol-water partition coefficient reflect the hydrophobic nature expected from its fused hydrocarbon structure.
Acenaphthene dissolves much more readily in suitable organic media than in water.
This behaviour is important in chemical synthesis, purification, crystallization, formulation, and analytical sample preparation.
The saturated carbon bridge differentiates Acenaphthene chemically from acenaphthylene.
Oxidation at the bridge and adjacent positions provides access to important oxygenated derivatives, including compounds used in naphthalic and specialty aromatic chemistry.
FUNCTIONAL CHARACTERISTICS
Acenaphthene functions mainly as a reactive aromatic building block rather than as a formulation additive with a single universal performance function.
Its industrial value comes from the ability of its fused-ring structure to undergo oxidation, nitration, halogenation, and other substitution reactions.
Oxidation chemistry is particularly important because Acenaphthene can be converted into naphthalene-1,8-dicarboxylic acid derivatives and naphthalic anhydride.
These products provide useful intermediate structures for dyes, pigments, specialty polymers, and functional organic compounds.
The aromatic portion of Acenaphthene also permits electrophilic substitution before further oxidation or conversion.
This route provides access to substituted acenaphthene and naphthalic intermediates in which the location and identity of ring substituents determine downstream colour, reactivity, solubility, and functional performance.
Acenaphthene is therefore most useful when a manufacturing route requires the compact peri-fused carbon skeleton already present in the starting material.
Using this preformed framework can simplify synthesis of more complex naphthalene and naphthalimide-related structures.
PRODUCTION AND COMMERCIAL FORM
Acenaphthene occurs as a constituent of high-temperature coal tar produced during carbonization and coking of coal.
Industrial coal-tar fractionation provides an acenaphthene-rich oil fraction from which Acenaphthene can be separated and purified.
Crystallization is an important separation step because Acenaphthene becomes a crystalline solid while many accompanying coal-tar components remain in the liquid fraction.
Further purification can be applied when higher assay or tighter impurity control is required for chemical synthesis.
Commercial Acenaphthene is generally supplied as crystalline material, powder, flakes, or related solid forms depending on processing and packaging.
Purity, appearance, melting range, moisture, particle characteristics, and aromatic impurity profile are useful purchasing parameters.
Higher-purity Acenaphthene is particularly relevant for controlled synthetic chemistry where impurities may affect oxidation, substitution, reaction yield, colour, or purification.
Technical applications may instead place greater emphasis on reliable assay, handling characteristics, and cost-efficient feedstock performance.
APPLICATIONS AND INDUSTRIES
DYE AND PIGMENT INTERMEDIATES
Acenaphthene is an established intermediate in the manufacture of aromatic compounds used in dye and pigment chemistry.
Its fused carbon framework can be chemically modified to generate substituted naphthalic and related structures with useful chromophoric properties.
Oxidation of Acenaphthene provides access to naphthalic acid and naphthalic anhydride chemistry.
These intermediates can subsequently undergo reactions that introduce amino, imide, halogen, or other functional groups used in colourant synthesis.
Substitution can also be carried out at the Acenaphthene stage before oxidation.
This approach allows manufacturers to control the substitution pattern transferred into the resulting naphthalic derivative.
The colour industry therefore uses Acenaphthene primarily as a feedstock rather than as a finished dye.
Its value lies in providing a structurally defined aromatic intermediate from which more highly functionalized colourants can be constructed.
NAPHTHALIC ANHYDRIDE PRODUCTION
One of the technically important transformations of Acenaphthene is oxidation to naphthalene-1,8-dicarboxylic acid or its corresponding anhydride, commonly known as naphthalic anhydride.
Oxidation converts the saturated two-carbon bridge of Acenaphthene into the peri-dicarboxylic functionality required for this intermediate.
Naphthalic anhydride chemistry is used as a platform for producing naphthalimides and other functional aromatic derivatives.
These structures occur in specialty dyes, pigments, fluorescent compounds, optical materials, polymer-related intermediates, and fine chemicals.
Acenaphthene therefore provides an efficient starting skeleton when the desired downstream product requires two adjacent peri-functional groups on a naphthalene framework.
Purity becomes increasingly important when the oxidation product will undergo additional high-selectivity synthesis.
SPECIALTY ORGANIC SYNTHESIS
Acenaphthene serves as a building block in specialty organic synthesis because its aromatic rings and saturated bridge offer several chemically distinct reaction positions.
Oxidation, nitration, halogenation, and related transformations allow a broad family of substituted derivatives to be prepared.
Nitrated Acenaphthene derivatives can be converted further into amino compounds or oxidized into substituted naphthalic intermediates.
Halogenated derivatives similarly provide starting points for additional substitution, coupling, or oxidation chemistry.
This synthetic flexibility makes Acenaphthene useful in fine-chemical development where a rigid fused aromatic framework is required.
Selection of reaction sequence is particularly important because functionalization before or after oxidation can produce different substitution patterns and product distributions.
PLASTICS AND POLYMER CHEMISTRY
Acenaphthene has established use as a chemical intermediate in the production of materials associated with plastics and resin chemistry.
Its importance in this sector is principally connected with downstream derivatives rather than direct incorporation of unchanged Acenaphthene into most finished polymers.
Oxidized and substituted derivatives can provide rigid aromatic structures for specialty polymer intermediates, resin-related chemistry, and functional additives.
The fused-ring skeleton contributes aromatic character and structural rigidity to appropriately designed downstream molecules.
Polymer-related applications therefore place particular emphasis on chemical purity and control of aromatic impurities.
Impurities capable of altering polymer colour, reaction kinetics, molecular structure, or thermal properties can become important even at comparatively low concentrations.
RESINS AND FUNCTIONAL ORGANIC MATERIALS
Acenaphthene can be used as a precursor in routes leading to specialty resin and functional aromatic compounds.
Chemical modification of the fused-ring framework allows incorporation of reactive groups required for subsequent condensation, polymerization, or crosslinking chemistry.
Naphthalic and naphthalimide derivatives prepared through Acenaphthene chemistry are also important platforms for functional organic materials.
Electronic structure, fluorescence, colour, thermal behaviour, and molecular interactions can be adjusted through substitution of the aromatic system.
These applications generally require more controlled starting-material quality than bulk technical processing.
Assay, colour, trace aromatic impurities, and consistency between batches can influence downstream synthesis and final material performance.
AGROCHEMICAL INTERMEDIATES
Acenaphthene has historically been associated with insecticide and fungicide chemistry and with the manufacture of pesticide-related compounds.
Its principal technical relevance in modern chemical supply is as an aromatic intermediate from which more highly functionalized molecules can be synthesized.
Chemical transformations of the Acenaphthene ring system provide access to substituted structures suitable for further agrochemical research and intermediate manufacture.
The required grade depends on the subsequent synthetic sequence and the impurity sensitivity of the target compound.
ANALYTICAL AND ENVIRONMENTAL APPLICATIONS
Acenaphthene is one of the polycyclic aromatic hydrocarbons commonly included in environmental analytical methods for semivolatile organic compounds.
High-purity material is consequently used in analytical standards, calibration mixtures, reference solutions, and method-development work.
Gas chromatography and gas chromatography-mass spectrometry are commonly used for measurement of Acenaphthene in environmental and industrial samples.
Its defined retention behaviour and characteristic mass spectrum support identification and quantification in complex PAH mixtures.
Environmental analysis may examine Acenaphthene in water, soil, sediment, industrial effluent, combustion-derived material, coal-tar products, and contaminated sites.
Analytical-grade applications require accurately characterized purity and traceable concentration when the material is supplied as a reference preparation.
COAL-TAR AND COKE-OVEN PROCESSING
Acenaphthene is associated naturally with coal-tar streams generated during high-temperature coal processing.
Fractionation and crystallization of these streams allow recovery of Acenaphthene as a commercially useful aromatic feedstock.
Control of neighbouring coal-tar components is important during purification.
Naphthalene, acenaphthylene, fluorene, phenanthrene, and other aromatic compounds may be relevant components of feed streams or impurity profiles depending on the separation process.
Efficient crystallization depends on composition, temperature profile, cooling rate, and subsequent solid-liquid separation.
Further purification can be used when downstream synthesis requires tighter compositional control.
GRADE SELECTION AND PRODUCT SUITABILITY
Assay is one of the principal quality parameters for Acenaphthene intended for chemical synthesis.
Higher assay provides more predictable reaction stoichiometry and reduces the amount of unrelated aromatic material entering the downstream process.
Melting range is useful both as an identity parameter and as a practical purity indicator.
A narrow melting interval close to the characteristic melting temperature supports consistent crystalline quality.
Appearance can provide additional information concerning general product condition.
High-purity material is normally white to pale or beige crystalline material, while stronger colour can be relevant when the product is intended for colour-sensitive downstream chemistry.
Organic impurity profile is particularly significant for Acenaphthene recovered from coal-tar-derived feedstocks.
Acenaphthylene, naphthalene, fluorene, phenanthrene, and other neighbouring aromatic compounds may require control according to the intended reaction.
Particle size and physical form affect pouring, conveying, dissolution, melting, charging, and dust formation.
A finer powder can increase dissolution rate and surface area but also increases the need for effective dust control.
Moisture is generally less chemically critical than aromatic impurity composition for this hydrophobic hydrocarbon, but controlled moisture remains useful for weighing consistency, packaging stability, and moisture-sensitive downstream processes.
Analytical and reference-material grades require a substantially different quality profile from bulk chemical-intermediate grades.
These applications emphasize high chemical purity, analytical characterization, traceability, and accurate concentration where the material is supplied in solution.
FORMULATION AND PROCESS CONSIDERATIONS
The very low water solubility of Acenaphthene makes aqueous dissolution impractical for most processing applications.
Organic solvent systems, melting, or heterogeneous reaction conditions are more appropriate when the compound must be incorporated into a chemical process.
Solvent selection should consider Acenaphthene solubility, reaction chemistry, operating temperature, product isolation, solvent recovery, and downstream purification.
Aromatic and other compatible organic solvents can provide substantially greater solubility than water.
Processes conducted close to or above the melting point can handle Acenaphthene as a molten material.
Temperature control should prevent unnecessary overheating while maintaining sufficient fluidity for transfer and mixing.
Powder charging requires control of airborne particulate matter.
Enclosed transfer, local exhaust ventilation, suitable grounding and bonding practices, and prevention of dust accumulation improve industrial handling.
Finely divided Acenaphthene can form combustible dust-air mixtures.
Process equipment used for powder handling should therefore minimize ignition sources and uncontrolled dust dispersion.
Oxidation reactions involving Acenaphthene can be strongly dependent on catalyst, oxidant, solvent, temperature, and mass-transfer conditions.
Reaction systems should provide adequate agitation and heat removal when oxidative conversion is conducted on industrial scale.
Crystallization and filtration are useful downstream operations because of the defined solid-state behaviour and limited water solubility of Acenaphthene.
Cooling profile and solvent composition can affect crystal size, filtration rate, washing efficiency, and final purity.
QUALITY, SPECIFICATIONS AND DOCUMENTATION
Relevant quality parameters for Acenaphthene commonly include assay, appearance, melting range, organic impurity profile, moisture, and physical form.
Particle-size distribution may also be specified where dissolution, dust control, or automated solids handling is important.
Gas chromatographic assay is particularly suitable for evaluating Acenaphthene and related volatile or semivolatile aromatic impurities.
Chromatographic impurity profiling can help distinguish Acenaphthene from acenaphthylene and other coal-tar-derived hydrocarbons.
Melting-point testing provides an additional practical identity and purity check.
Significant broadening or depression of the melting range can indicate the presence of other organic components.
Colour becomes an important specification parameter when Acenaphthene is used in dye, pigment, optical, or polymer intermediates where coloured impurities can carry into subsequent stages.
Consistent appearance can therefore complement quantitative analytical testing.
A Certificate of Analysis provides batch-specific results for the agreed release parameters.
A Technical Data Sheet provides product characteristics and commercial information, while the Safety Data Sheet provides hazard, handling, transport, storage, and emergency-response information.
SAFETY AND REGULATORY CONSIDERATIONS
Acenaphthene is a combustible organic solid.
Open flames, hot surfaces, sparks, and other ignition sources should be controlled during powder handling and processing.
Finely divided Acenaphthene can form explosive dust-air mixtures.
Dust generation and accumulation should therefore be minimized through appropriate equipment design, housekeeping, ventilation, and ignition control.
Acenaphthene is classified as very toxic to aquatic life with long-lasting effects.
Release to drains, surface water, soil, or uncontrolled environmental pathways should be prevented.
Combustion can generate carbon monoxide and other irritating or toxic combustion products.
Firefighting methods suitable for combustible organic solids include water spray, dry extinguishing powder, foam, and carbon dioxide according to the surrounding fire conditions.
Strong oxidizing agents are incompatible with Acenaphthene and should be segregated during storage.
The material should be protected from contamination with reactive substances.
Workplace handling should minimize inhalation of airborne dust and direct contact with eyes and skin.
Local exhaust ventilation, protective gloves, safety goggles, and appropriate protective clothing provide practical exposure control during routine industrial use.
FIRST AID
Inhalation: Move the exposed person to fresh air and keep at rest.
Obtain medical attention if discomfort or respiratory symptoms develop or persist.
Skin Contact: Remove contaminated clothing and wash affected skin thoroughly with water and soap.
Obtain medical attention if persistent irritation develops.
Eye Contact: Rinse immediately with plenty of clean water for several minutes and remove contact lenses when easy to do.
Continue rinsing and obtain medical attention if irritation or discomfort persists.
Ingestion: Rinse the mouth thoroughly.
Obtain medical advice following significant ingestion or development of symptoms.
Note to Physicians: Treatment should be based on the route of exposure and observed clinical condition.
HANDLING AND STORAGE
Handling: Avoid generation and dispersion of Acenaphthene dust.
Keep away from flames, hot surfaces, sparks, and strong oxidizing agents.
Ventilation: Provide effective general ventilation and local exhaust at charging, transfer, grinding, sampling, or other operations capable of producing airborne dust.
Storage: Store Acenaphthene in tightly closed containers in a cool, dry, well-ventilated location.
Protect the material from ignition sources, contamination, excessive heat, and incompatible oxidizing materials.
Incompatibilities: Strong oxidizing agents.
Environmental Protection: Prevent Acenaphthene from entering drains, sewers, soil, and surface water.
PACKAGING AND PROCUREMENT CONSIDERATIONS
Acenaphthene should be supplied in clean, dry, chemically compatible packaging that protects the crystalline material from contamination and product loss.
Packaging selection should also minimize dust release during opening, charging, and transfer.
Industrial buyers should define the required assay according to the downstream use.
Chemical synthesis and colour-sensitive applications can benefit from higher purity and tighter aromatic impurity limits, while other technical processes may prioritize consistent feedstock performance.
Acenaphthylene content can be particularly relevant because the closely related unsaturated compound differs in reactivity and oxidation behaviour.
Other neighbouring aromatic hydrocarbons may also be important depending on the manufacturing origin and downstream chemistry.
Melting range, appearance, moisture, and particle form provide additional purchasing criteria.
Particle size should be considered together with dissolution requirements, solids-handling equipment, dust-management systems, and preferred charging method.
For dye and pigment intermediate manufacture, colour and impurity control can influence subsequent reactions and final product appearance.
For naphthalic anhydride manufacture, assay and oxidation-reactive impurity profile are particularly relevant to conversion, selectivity, and purification.
For analytical applications, accurately characterized high-purity Acenaphthene or prepared reference solutions are appropriate.
These grades are selected for measurement and calibration rather than bulk chemical processing.
Transportation of Acenaphthene is associated with UN 3077, Environmentally hazardous substance, solid, n.o.s., Class 9, Packing Group III.
Packaging and shipping arrangements should therefore correspond to the applicable quantity, mode of transport, and dangerous-goods requirements.
Procurement planning can include required purity, impurity limits, particle form, packaging size, annual consumption, batch requirements, analytical documentation, and intended processing route.
Clear definition of the downstream application allows commercially meaningful specifications to be prioritized.
Ataman Kimya can support Acenaphthene enquiries concerning purity, grade selection, chemical specifications, impurity requirements, documentation, packaging, application requirements, and supply planning.
For product and procurement information, contact Ataman Kimya at +90 216 577 10 10 or [info@atamankimya.com](mailto:info@atamankimya.com).
