2,2-DIMETHYLPROPANE Chemical Properties

Melting point:

-19.8°

Boiling point:

bp 9.5°

Density 

d00 0.613 (liq)

vapor pressure 

1,074.43 at 19.492 °C, 1,267.75 at 24.560 °C (ebulliometry, Osborn and Douslin, 1974)

refractive index 

1.3390

solubility 

Soluble in alcohol and ether (Weast, 1986).

pka

>14 (Schwarzenbach et al., 1993)

Water Solubility 

33.2 mg/kg at 25 °C (shake flask-GC, McAuliffe, 1966)

Henry's Law Constant

3.70(atm?m³/mol) at 25 °C (Mackay and Shiu, 1981)

Exposure limits

ACGIH TLV: TWA 600 ppm (adopted).

Dielectric constant

1.9099999999999999

CAS DataBase Reference

463-82-1(CAS DataBase Reference)

EPA Substance Registry System

2,2-Dimethylpropane (463-82-1)

Safety Information

Hazard Codes 

F+,N

Risk Statements 

12-51/53

Safety Statements 

9-16-33-61

RIDADR 

2044

OEB

A

OEL

TWA: 120.0 ppm; 350.0 mg/m3, STEL: 610.0 ppm; 1800.0 mg/m3

HazardClass 

2.1

HS Code 

2901100000

Hazardous Substances Data

463-82-1(Hazardous Substances Data)

Toxicity

Acute oral LD50 (intraperitoneal) for mice 100 mg/kg (quoted, RTECS, 1985).

2,2-DIMETHYLPROPANE Usage And Synthesis

Chemical Properties

Colorless gas or very volatile liquid.Soluble in alcohol; insoluble in water.

Chemical Properties

Neopentane is an extremely flammable gas and volatile liquid.

Chemical Properties

2,2-Dimethylpropane, C5H12, is a flammable liquid and is physically similar to butane. It is an important component of petroleum fuel mixtures.

Physical properties

Colorless, extremely flammable gas which may have a faint, pleasant odor similar to butane. Usually present as a compressed gas or liquid.

Uses

2,2-Dimethylpropane is manufactured by petroleum refining operations. It is used as a chemical intermediate for agricultural chemicals, and as a component of high-octane motor and aviation fuels.

Uses

Neopentane is a useful hydrocarbon solution to study intermolecular potential functions for liquid hydrocarbons.

Uses

Research, butyl rubber.

Definition

ChEBI: Neopentane is an alkane.

General Description

Boiling point 40°F. May liquefy in cool or cold weather. Less dense than water. Flash point -85°F. Autoignition temperature 842°F. Insoluble in water but soluble in alcohol. Under prolonged exposure to fire or heat, the containers may rupture violently and rocket.

Air & Water Reactions

Highly flammable. Insoluble in water.

Reactivity Profile

2,2-DIMETHYLPROPANE may be incompatible with strong oxidizing agents like nitric acid. Charring may occur followed by ignition of unreacted hydrocarbon and other nearby combustibles. In other settings, mostly unreactive. Not affected by aqueous solutions of acids, alkalis, most oxidizing agents, and most reducing agents. Burns exothermically if heated sufficiently or when ignited in the presence of air, oxygen or strong oxidizing agents to produce carbon dioxide and water.

Hazard

Highly flammable, dangerous fire risk, explosive limits in air 1.4–7.5%

Health Hazard

Vapors may cause dizziness or asphyxiation without warning. Some may be irritating if inhaled at high concentrations. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire may produce irritating and/or toxic gases.

Fire Hazard

EXTREMELY FLAMMABLE. Will be easily ignited by heat, sparks or flames. Will form explosive mixtures with air. Vapors from liquefied gas are initially heavier than air and spread along ground. CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Methane (UN1971) are lighter than air and will rise. Hydrogen and Deuterium fires are difficult to detect since they burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.) Vapors may travel to source of ignition and flash back. Cylinders exposed to fire may vent and release flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket.

Safety Profile

Poison by intraperitoneal route. An inhalation hazard. Both the gas and the liquid are flammable when exposed to heat or flame; can react vigorously with oxidlzing materials. When heated to decomposition it emits acrid smoke and irritating fumes.

Potential Exposure

Neopentane is used as a gasoline blending component; for making butyl rubber. A research chemical. Reacts with strong oxidizers, causing fire and explosion hazard. Attacks some plastics, rubbers, and coatings.

Source

California Phase II reformulated gasoline contained 2,2-dimethylpropane at a concentration of 110 μg/kg (Schauer et al., 2002).

Environmental Fate

Photolytic. A rate constant of 6.50 x 10^-11 cm³/molecule?sec was reported for the reaction of 2,2- dimethylpropane with OH radicals in air at 298 (Greiner, 1970). Rate constants of 9.0 x 10^-13 and 8.49 x 10^-13 cm³/molecule?sec were reported for the reaction of 2,2-dimethylpropane with OH in air (Atkinson et al., 1979; Winer et al., 1979).
Chemical/Physical. Complete combustion in air yields carbon dioxide and water vapor. 2,2- Dimethylpropane will not hydrolyze because it has no hydrolyzable functional group.

Shipping

UN2044 2,2-Dimethylpropane, Hazard Class: 2.1; Labels: 2.1-Flammable gas. Cylinders must be transported in a secure upright position, in a well-ventilated truck. Protect cylinder and labels from physical damage. The owner of the compressed gas cylinder is the only entity allowed by federal law (49CFR) to transport and refill them. It is a violation of transportation regulations to refill compressed gas cylinders without the express written permission of the owner.

Purification Methods

It is freed from isobutene by passage over conc H2SO4 or P2O5, and through silica gel. [Beilstein 1 H 141, 1 I 50, 1 II 104, 1 369, 1 IV 333.] Nerolidol (3,7,11-trimethyl-1,6,10-dodecatrien-3-ol) M 222.4 [cis/trans 7212-44-4] b

Incompatibilities

Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides.

Waste Disposal

Return refillable compressed gas cylinders to supplier. Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed.

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