1,2-Dimethylcyclopentane (2452-99-5) Physical and Chemical Properties
1,2-Dimethylcyclopentane
Saturated cycloalkane with moderate volatility, used as a non‑polar solvent and analytical reference in industrial R&D, formulation and QC.
| CAS Number | 2452-99-5 |
| Family | Aliphatic hydrocarbons — cycloalkane |
| Typical Form | Colorless liquid |
| Common Grades | EP |
1,2-Dimethylcyclopentane is a saturated cycloalkane (cyclopentane core) bearing two methyl substituents at adjacent carbon positions. Its molecular formula is \(\ce{C7H14}\) and the compound exists as stereoisomeric 1,2-disubstituted cyclopentanes (cis/trans configurations and enantiomeric pairs where stereocenters are defined or undefined). The molecule is fully saturated, lacks heteroatoms, and therefore has negligible polarity, no hydrogen-bond donors or acceptors, and a calculated topological polar surface area of 0.
Electronic and physicochemical features follow expectations for a small aliphatic hydrocarbon: low dielectric interaction with polar solvents, moderate lipophilicity (XLogP 3.2), and limited specific chemical functionality beyond C–H bonds. It is chemically robust toward nucleophilic or acid–base transformations but is susceptible to radical-mediated reactions (for example, photochemical or thermal autoxidation and halogenation) and to catalytic hydrogenolysis under forcing conditions. Typical industrial relevance stems from its classification as an aliphatic solvent and its role as a minor component or surrogate in fuel and petrochemical streams; its volatility and nonpolarity make it relevant to solvent selection, chromatographic standards, and hydrocarbon processing.
Common commercial grades reported for this substance include: EP.
Physical Properties
Density and Phase
No experimentally established value for this property is available in the current data context. As a saturated C7 cycloalkane it is expected to be a nonpolar, volatile liquid under typical ambient conditions, with physical behavior consistent with low-viscosity aliphatic hydrocarbons.
Melting Point
No experimentally established value for this property is available in the current data context.
Boiling Point
No experimentally established value for this property is available in the current data context.
Vapor Pressure
Experimental vapor pressure is reported as 47.2 \(\mathrm{mmHg}\). (Temperature associated with this measurement is not specified in the present data context.)
Viscosity
No experimentally established value for this property is available in the current data context.
Chemical Properties
Flammability and Combustion
1,2-Dimethylcyclopentane is a flammable aliphatic hydrocarbon. It is classified as a highly flammable liquid and vapor (H225). Combustion of the hydrocarbon yields carbon dioxide and water under complete combustion conditions; incomplete combustion produces carbon monoxide and other partial oxidation products. The material presents an aspiration hazard if swallowed and can produce narcotic effects (drowsiness, dizziness) upon acute inhalation exposure. It is also associated with skin and eye irritation potential and may cause respiratory tract irritation on sufficient exposure.
Standard precautions for flammable hydrocarbon liquids apply: control of ignition sources, grounding/bonding during transfers to prevent static discharge, and use of explosion-proof electrical equipment in handling areas.
Reactivity and Typical Transformations
Chemically this compound is relatively unreactive toward polar reagents and acid–base chemistry due to the absence of polar functional groups. Typical transformations and reaction classes include: - Free-radical halogenation at tertiary and secondary C–H positions under photochemical or thermal initiation. - Autoxidation by atmospheric oxygen producing hydroperoxides and subsequent degradation products under radical chain conditions. - Catalytic dehydrogenation or hydrogenolysis under severe conditions using metal catalysts. - Combustion and catalytic oxidation to lower oxygenates and CO/CO2. - Cracking and other thermal transformations in high-temperature petrochemical processes.
Reactivity toward strong oxidizers should be avoided due to vigorous reaction potential. Typical laboratory-level reactivity is limited; nevertheless, handling should account for radical-initiated degradation and flammability.
Identifiers and Synonyms
Registry Numbers and Codes
- CAS Registry Number: 2452-99-5
- European Community (EC) numbers: 249-193-5; 219-520-6
- ChEBI: CHEBI:187606
- DSSTox Substance ID: DTXSID80873330
- Lipid Maps ID: LMFA11000663
- Metabolomics Workbench ID: 5358
- Nikkaji Number: J23.248C
Molecular and computed descriptors:
- Molecular formula: \(\ce{C7H14}\)
- Molecular weight: 98.19 \(\mathrm{g}\,\mathrm{mol}^{-1}\)
- Exact mass / Monoisotopic mass: 98.109550447
- XLogP3: 3.2
- Topological polar surface area (TPSA): 0
- Hydrogen bond donor count: 0; hydrogen bond acceptor count: 0
- Rotatable bond count: 0
Structural identifiers (provided as codes):
- SMILES: CC1CCCC1C
- InChI: InChI=1S/C7H14/c1-6-4-3-5-7(6)2/h6-7H,3-5H2,1-2H3
- InChIKey: RIRARCHMRDHZAR-UHFFFAOYSA-N
Additional analytical identifiers:
- GC-MS library top m/z peak: 56 (with additional prominent ions at 55 and 70)
- Kovats retention indices (standard non-polar): 686, 689, 682, 677
- Kovats retention index (semi-standard non-polar): 685, 687.8, 682
- Kovats retention index (standard polar): 726
Synonyms and Structural Names
- 1,2-Dimethylcyclopentane
- Cyclopentane, 1,2-dimethyl-
- Cyclopentane, dimethyl-
- 1,2-dimethyl-cyclopentane
- CIS-1,2-DIMETHYL-CYCLOPENTANE (as a stereochemical variant)
- Additional deposit-supplied identifiers and database cross-references appear under various vendor and registry codes.
Industrial and Commercial Applications
Use as Solvent or Fuel Component
The compound is classed among saturated aliphatics and is therefore relevant as a nonpolar solvent for hydrophobic substrates and as a hydrocarbon component in fuel or petrochemical streams. Its volatility and hydrophobic character make it suitable as a laboratory solvent for nonpolar extractions or as a reference component in chromatographic method development for volatile hydrocarbon analysis.
Representative Use Scenarios
Representative scenarios include use as:
- A nonpolar solvent for oil- and fat-soluble substances in analytical or small-scale laboratory contexts.
- A reference standard or column-check compound for gas chromatography and mass spectrometry workflows (GC-MS spectral libraries list characteristic fragments).
- A minor component in hydrocarbon blends, fuels, or petrochemical process streams where C7 cycloalkanes are encountered.
No concise application summary is available in the current data context; in practice this substance is selected based on its general properties described above.
Safety and Handling Overview
Flammability Hazards
The substance is classified as a flammable liquid and vapor (H225). Flash point and autoignition temperature values are not provided in the current data context. Vapors can form explosive mixtures with air; adequate ventilation and avoidance of ignition sources are required. The material poses an aspiration hazard if ingested and may cause central nervous system depression with sufficient inhalation exposure (narcotic effects). It can cause skin and eye irritation and may cause respiratory irritation.
For storage, handling and emergency measures consult a product-specific Safety Data Sheet (SDS) and comply with applicable local regulations and workplace safety practices.
Storage and Handling Considerations
General handling and storage guidance appropriate for low-molecular-weight aliphatic hydrocarbons:
- Store in a cool, well-ventilated area away from heat, sparks, and open flames.
- Keep containers tightly closed and grounded/bonded during transfer to minimize static discharge.
- Segregate from strong oxidizers and incompatible materials.
- Use explosion-proof electrical equipment in storage and handling zones.
- Provide local exhaust or general dilution ventilation to limit inhalation exposure.
- Employ appropriate personal protective equipment (PPE): chemical-resistant gloves, eye protection, and protective clothing; respiratory protection when ventilation is inadequate.
- Prevent environmental release; contain spills and use inert absorbents for recovery.
For detailed hazard, transport and regulatory information, users should refer to the product-specific Safety Data Sheet (SDS) and local legislation.
