4,7-METHANO-1H-INDENE, 3a,4,7,7a-TETRAHYDRO-

4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is a bicyclic hydrocarbon more commonly known as dicyclopentadiene (DCPD), the Diels-Alder dimer of cyclopentadiene.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is a major petrochemical building block used in the production of unsaturated polyester resins, specialty polymers, and synthetic rubber intermediates.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- also serves as a masked source of monomeric cyclopentadiene, releasing it on heating for use in Diels-Alder synthesis, resin manufacturing, and fine-chemical production.

CAS Number: 77-73-6
EC Number: 201-052-9
Molecular Formula: C10H12
Molecular Weight: 132.20 g/mol

Synonyms: Dicyclopentadiene, DCPD, Cyclopentadiene Dimer, 1,3-Cyclopentadiene Dimer, Bicyclopentadiene, Biscyclopentadiene, Tricyclo[5.2.1.0(2,6)]deca-3,8-diene, Tricyclodecadiene, 3a,4,7,7a-Tetrahydro-4,7-methano-1H-indene, 3a,4,7,7a-Tetrahydro-4,7-methanoindene, 4,7-Methanoindene, 3a,4,7,7a-Tetrahydro-, Ultrene, Ultrene 99, Ultrene DCPD, Prometa XP 100, DCPD 103, NSC 7352, UN 2048, UNII-88Z4HUV8LI, RTECS PC1050000

APPLICATIONS

4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used as the primary raw material for unsaturated polyester resins employed in fiberglass-reinforced plastics, boat hulls, and construction panels.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in gel-coat formulations to improve chemical resistance, hardness, and weatherability of finished composite surfaces.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in the production of hydrocarbon and petroleum resins applied in adhesives, inks, and coatings.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in specialty resin blends requiring high heat resistance and dimensional stability.

4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used as the monomer for ring-opening metathesis polymerization (ROMP), producing high-impact polydicyclopentadiene (pDCPD) engineering plastics.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in reaction-injection-molded (RIM) components for heavy-truck body panels, agricultural equipment housings, and wind-turbine nacelle covers.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in the manufacture of large, tough, corrosion-resistant molded parts where traditional sheet-molded composites are impractical.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in low-pressure molding processes valued for producing large parts with minimal tooling investment.

4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used as a precursor to ethylidene norbornene (ENB), the diene component used in EPDM synthetic rubber production.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in the broader elastomer industry to manufacture specialty rubber grades for automotive weatherstripping, seals, and hoses.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used as a feedstock in the production of norbornene derivatives for specialty polymer and coatings applications.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in cross-linking and vulcanization chemistry research involving strained bicyclic diene structures.

4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used as a coproduct recovered from the steam cracking of naphtha and gas oils during ethylene production.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used as a starting material for the synthesis of adamantane through acid-catalyzed rearrangement in the presence of aluminum chloride.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in the production of specialty cage-hydrocarbon compounds valued in lubricant and pharmaceutical research.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used as a chemical intermediate in the synthesis of a wide range of downstream fine chemicals.

4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used, following hydrogenation to its saturated derivative, as a precursor in the production of high-energy-density jet fuels for specialized aerospace applications.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in energetic-materials and propellant research as a hydrocarbon feedstock valued for its high volumetric energy density.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in fuel-chemistry research investigating strained bicyclic hydrocarbons as combustion enhancers.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used only within properly licensed and regulated industrial and research facilities given its flammability and reactivity.

4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used, upon thermal cracking to regenerate monomeric cyclopentadiene, as a diene component in Diels-Alder synthesis of insecticidal and agrochemical intermediates historically produced via this route.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in the synthesis of fragrance and flavor intermediates that rely on cyclopentadiene-based Diels-Alder chemistry.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in academic and industrial organic chemistry to demonstrate reversible dimerization and retro-Diels-Alder cracking behavior.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in heterocyclic and cage-compound research as a versatile diene source for constructing complex ring systems.

4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used as an indirect food-contact additive in select adhesive and coating formulations, subject to applicable regulatory limits.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in ink formulations requiring fast-curing, resin-forming hydrocarbon components.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used in paint and coating resin systems valued for gloss, hardness, and drying-time characteristics.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is used according to the purity grade and stabilizer content appropriate to the intended resin, elastomer, fuel, or synthesis application.

DESCRIPTION

4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is typically a colorless crystalline solid or, depending on temperature and formulation, a colorless to pale liquid with a camphor-like odor.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- consists of two fused bicyclic ring systems formed by the Diels-Alder self-dimerization of cyclopentadiene, containing one double bond in the norbornene ring and one in the cyclopentene ring.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is produced as a coproduct of naphtha and gas-oil steam cracking during ethylene manufacture, where cyclopentadiene formed in the process spontaneously dimerizes on cooling.

4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is practically insoluble in water but is very soluble in diethyl ether and ethanol, and soluble in acetone, dichloromethane, ethyl acetate, n-hexane, and toluene.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- undergoes reversible retro-Diels-Alder cracking on heating, regenerating reactive monomeric cyclopentadiene that is consumed in downstream synthesis before it can redimerize.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is chemically reactive due to its two strained, unsaturated ring double bonds, which readily participate in further Diels-Alder, metathesis, and addition reactions.

4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is a highly flammable liquid or low-melting solid with a low flash point, requiring careful control of ignition sources during handling and storage.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is stable at room temperature under normal storage conditions but may form explosive peroxides if stored in prolonged contact with air, particularly in the absence of stabilizers.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is typically supplied with an added stabilizer, such as BHT, to inhibit premature polymerization and peroxide formation during storage and transport.

4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is harmful by inhalation and if swallowed, and is irritating to the eyes, respiratory system, and skin upon direct contact.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- has a reported oral LD50 in rats of approximately 353 mg/kg, indicating moderate acute oral toxicity, and a much higher dermal LD50 in rabbits of approximately 4,940 mg/kg.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is classified under the NFPA 704 rating system with a health hazard of 1, a flammability hazard of 3, and a reactivity hazard of 1, reflecting its significant fire risk relative to its acute toxicity and reactivity profile.

4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- serves as a versatile platform chemical bridging the petrochemical, polymer, elastomer, and fine-chemical industries through its dual roles as a stable dimer and a masked diene source.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- is supplied in various purity grades, from technical resin-grade material to high-purity grades used in synthesis and analytical applications.
4,7-Methano-1H-Indene, 3a,4,7,7a-Tetrahydro- must be handled according to current flammable-liquid and reactive-chemical regulations given its low flash point and peroxide-forming tendency.

PROPERTIES

Chemical Formula: C10H12
Molecular Weight: 132.20 g/mol
Common Name: Dicyclopentadiene (DCPD)
CAS Number: 77-73-6
EC Number: 201-052-9
UN Number: 2048
Appearance: Colorless crystalline solid or colorless to pale liquid
Odor: Camphor-like
Melting Point: Approximately 32–33°C
Boiling Point: Approximately 170°C (decomposes)
Flash Point: Approximately 32–33°C
Autoignition Temperature: Approximately 503°C
Density: Approximately 0.98–0.99 g/cm³
Solubility in Water: Approximately 0.02%
Solubility: Very soluble in diethyl ether and ethanol; soluble in acetone, dichloromethane, ethyl acetate, n-hexane, and toluene
Explosive Limits (LEL–UEL): Approximately 0.8%–6.3% (v/v)
Acute Oral Toxicity: LD50 (rat) approximately 353 mg/kg
Acute Dermal Toxicity: LD50 (rabbit) approximately 4,940 mg/kg
NFPA 704 Rating: Health 1, Flammability 3, Reactivity 1
Stability: Stable at room temperature when stabilized; may form explosive peroxides on prolonged air exposure without stabilizer
Storage Temperature: Approximately 2–30°C, in a cool, ventilated area
Shelf Life: Grade, stabilizer content, and packaging dependent; typically 12–24 months

FIRST AID

Inhalation
Remove to fresh air immediately.
Seek medical attention if coughing, respiratory irritation, or breathing difficulty persists.
Keep the affected person at rest in a position comfortable for breathing.

Skin Contact
Remove contaminated clothing and wash the affected area immediately with plenty of soap and water.
Seek medical advice if irritation, redness, or a burning sensation develops.

Eye Contact
Rinse immediately and continuously with plenty of water for at least 15 minutes, including under the eyelids.
Remove contact lenses if present and easy to do so, then continue rinsing.
Seek immediate medical attention if irritation persists.

Ingestion
Do not induce vomiting due to the risk of aspiration.
Rinse mouth with water and seek immediate medical attention.
Never give anything by mouth to an unconscious person.

Note to Physicians
Treat symptomatically and provide supportive care, with attention to respiratory and gastrointestinal effects.
Monitor for aspiration pneumonitis if ingestion or vomiting has occurred.
There is no specific antidote; management is supportive.

HANDLING AND STORAGE

Handling
Handle only in well-ventilated areas or under fume-hood extraction to minimize vapor exposure.
Keep away from all ignition sources, open flames, sparks, and hot surfaces, given the substance's low flash point.
Wash hands and exposed skin thoroughly after handling and before eating, drinking, or smoking.

Engineering Controls
Use grounded and bonded equipment during transfer operations to prevent the buildup of static electricity.
Provide explosion-proof electrical equipment and local exhaust ventilation in areas of frequent handling.

Personal Protection
Wear chemical-resistant gloves, safety goggles, and flame-resistant protective clothing when handling unstabilized or bulk material.
Use a face shield where splashing is possible, particularly during transfer or reaction charging.

Storage
Store in a cool, dry, well-ventilated area, sealed and away from heat, sparks, open flames, and direct sunlight.
Keep containers tightly closed and check periodically for adequate stabilizer content, as depletion can lead to peroxide formation or uncontrolled exothermic polymerization.
Store away from strong oxidizers, acids, and polymerization initiators.

Material Compatibility
Avoid contact with strong oxidizing agents and radical initiators, which can trigger hazardous exothermic polymerization.
Use containers and equipment constructed of materials demonstrated to be compatible with reactive diene compounds.

Spill and Leak Procedures
Eliminate all ignition sources in the area and ventilate thoroughly before beginning cleanup.
Absorb spilled material with inert, non-combustible absorbent material and place in a suitable closed container for disposal.
Prevent the material from entering drains, soil, groundwater, and surface water.

Decontamination
Ventilate the affected area thoroughly before permitting re-entry.
Dispose of contaminated absorbents, clothing, and cleaning materials as flammable/hazardous waste in accordance with applicable regulations.

Handling Precautions
Handle as a flammable and peroxide-forming material, minimizing storage duration and monitoring stabilizer levels regularly.
Maintain fire-suppression equipment and an emergency eyewash/shower station near the work area.
Follow the current safety data sheet, flammable-liquid storage regulations, and all applicable transport and hazardous-materials requirements.