What Is 1,2,4-Triethylbenzene?

1,2,4-Triethylbenzene (CAS 877-44-1, molecular formula C₁₂H₁₈, MW 162.27 g/mol) is an alkylated aromatic hydrocarbon in which three ethyl substituents occupy the 1-, 2-, and 4-positions of the benzene ring. This unsymmetrical substitution pattern distinguishes it from the symmetric 1,3,5-isomer and gives the compound a unique combination of steric and electronic properties.

At room temperature it is a colorless to pale yellow liquid with a characteristic aromatic odor. It is miscible with common organic solvents such as ethanol, diethyl ether, and hydrocarbons, but is essentially insoluble in water, consistent with its non-polar character.

Aladdin Scientific offers 1,2,4-triethylbenzene under SKU T304818, providing researchers with a reliably sourced material for synthetic, analytical, and physical chemistry applications.

Physicochemical Properties and Structural Characteristics

The compound's three ethyl groups substantially increase the lipophilicity and boiling point relative to benzene itself. The literature boiling point is approximately 218 °C at atmospheric pressure, and the density is close to 0.87 g/mL, though researchers should consult the certificate of analysis (CoA) supplied with each lot for batch-specific data.

The 1,2,4-substitution pattern creates a molecule with no plane of symmetry through the substituent positions, resulting in a relatively simple but informative ¹H NMR spectrum: three distinct aromatic proton signals and two sets of ethyl CH₂/CH₃ resonances that can serve as useful fingerprints for purity assessment.

Its flash point is reported in the range of approximately 80–90 °C, classifying it as a combustible liquid rather than a flammable liquid under most regulatory frameworks, though local regulations should always be consulted. The compound is stable under normal laboratory conditions and is not known to polymerize spontaneously.

Common Laboratory Applications

Reference standard and analytical calibration: The well-defined isomeric composition of 1,2,4-triethylbenzene makes it a useful internal or external reference standard in gas chromatography (GC) and mass spectrometry (MS) studies of alkylbenzene mixtures, including environmental monitoring of petroleum-derived contaminants.

Synthetic intermediate: As a symmetry-breaking trialkylbenzene, it serves as a starting material or substrate in electrophilic aromatic substitution reactions where regioselectivity studies are of interest. The three distinct ring positions (C-3, C-5, C-6 relative to substituents) allow investigation of directing effects.

Physical chemistry and thermodynamic studies: High-boiling, thermally stable aromatic liquids such as 1,2,4-triethylbenzene are employed as heat-transfer media, reference liquids in viscometry, and model compounds in studies of molecular dynamics or solvation phenomena.

Material science research: Trialkylbenzenes have been explored as components in liquid-crystal host systems and as solvents or diluents in specialty coating formulations, although specific product suitability should be verified for each application.

Safe Handling, Storage, and Disposal

Personal protective equipment: Handle 1,2,4-triethylbenzene in a well-ventilated fume hood. Wear chemical-resistant gloves (nitrile recommended), safety goggles, and a lab coat. Avoid prolonged inhalation of vapors.

Storage: Store in a tightly sealed container away from heat, ignition sources, and incompatible oxidizing agents. Ambient or slightly cool (15–25 °C), dry storage is generally appropriate. Keep away from open flames given its combustible nature.

Regulatory and safety documentation: Always consult the Safety Data Sheet (SDS) provided by Aladdin Scientific before use. The SDS contains GHS hazard classifications, first-aid measures, spill response procedures, and transport information specific to this product.

Disposal: Dispose of as halogen-free organic solvent waste in accordance with institutional and local environmental regulations. Do not pour down the drain.

Ordering and Quality Information

1,2,4-Triethylbenzene is available from Aladdin Scientific under SKU T304818. Each lot is accompanied by a certificate of analysis (CoA) documenting purity, physical constants, and lot-specific test data. Researchers requiring special purity grades or larger quantities are encouraged to contact Aladdin's technical sales team for custom sourcing options.

For procurement teams, Aladdin Scientific supports institutional purchase orders, online ordering, and multiple payment methods. Refer to the Aladdin website or contact customer service for current pricing, available pack sizes, and lead times.