Dimethyl-2

Updated: 2026-07-21

Overview

2,2-Dimethylpropane is a branched-chain alkane with a unique tetrahedral molecular structure where four methyl groups are bonded to a central carbon atom. This configuration gives it exceptional chemical stability compared to linear pentanes. First synthesized in 1891 by Wilhelm Ramsay, it's now industrially produced through catalytic isomerization of straight-chain hydrocarbons. As the simplest alkane with a quaternary carbon, neopentane serves as a reference compound in organic chemistry studies. Its commercial production reached approximately 20,000 metric tons globally in 2022, primarily from petrochemical refiners in Asia and North America.

Physical and Chemical Properties

With a boiling point of just 9.5°C, neopentane exists as a gas at room temperature but can be liquefied under moderate pressure (approximately 2 bar at 20°C). Its density of 0.591 g/cm³ makes it one of the lightest liquid hydrocarbons. The symmetrical structure results in no dipole moment, explaining its insolubility in polar solvents like water. The compound exhibits remarkable thermal stability, decomposing only above 450°C. Its octane rating of 85.5 makes it valuable for fuel blending, though volatility limits practical use. The heat of combustion is 3,510 kJ/mol, comparable to other pentane isomers but with cleaner combustion characteristics.

Main Applications

Approximately 65% of neopentane production is used as a blowing agent for expanded polystyrene (EPS) foam, where its low boiling point creates uniform cell structures. In chromatography, ultra-pure grades (99.99%) serve as calibration standards due to predictable retention times. The petrochemical industry utilizes it as a process solvent in alkylation units. Emerging applications include use in low-temperature refrigeration blends (-50°C to -10°C range) and as a precursor for specialty chemicals like neopentyl glycol. Military applications exploit its rapid vaporization for aerosol propulsion systems.

Safety and Storage

Classified as an extremely flammable gas (H220), neopentane requires storage in ASME-certified pressure vessels with pressure relief devices. Facilities must implement Class I, Division 1 electrical systems and maintain oxygen detectors near storage areas, as it can displace breathable air. Transport follows UN 2044 regulations with mandatory 2-inch pressure relief valves on containers. Leak detection should use infrared sensors rather than catalytic types, as the molecule's stability can poison conventional detectors. Personal protective equipment must include chemically resistant gloves and face shields during handling.

B2B Procurement Guide

Industrial buyers should specify purity requirements (technical grade 95% vs. chromatographic grade 99.9%), as impurities like isopentane affect performance in critical applications. Cylinder sizes range from 1L lecture bottles to 180L ton containers, with bulk ISO tank shipments available for quantities exceeding 5 metric tons. Leading manufacturers include ExxonMobil Chemical, INEOS, and Maruzen Petrochemical. Recent supply chain disruptions have caused price volatility, with contract pricing typically 15-20% below spot market rates. Quality certifications to request include ASTM D2163 for purity analysis and ISO 9001 for production standards.