3,3-Dimethylpentane is one of the

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element (chemistry), element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the exi ...

s of

heptane Heptane or ''n''-heptane is the straight-chain alkane with the chemical formula H3C(CH2)5CH3 or C7H16. When used as a test fuel component in anti-knock test engines, a 100% heptane fuel is the zero point of the octane rating scale (the 100 poi ...

. 3,3-Dimethylpentane has a boiling point of 86.0 °C and melting point of −134.9 °C. Its density is 0.6934. The refractive index is 1.39092 at 20 °C.

Preparation

A method to produce 3,3-dimethylpentane is to react ''tert''-amyl chloride (CH₃CH₂(CH₃)C₂Cl) with

propionaldehyde Propionaldehyde or propanal is the organic compound with the formula CH3CH2CHO. It is the 3-carbon aldehyde. It is a colourless, flammable liquid with a pungent and fruity odour. It is produced on a large scale industrially. Production Propiona ...

producing 3,3-dimethylpentan-2-ol. This is then dehydrated to produce 3,3-dimethylpent-2-ene, which when hydrogenated produces some 3,3-dimethylpentane, but also 2,3-dimethylpentane.

Properties

In 1929

Graham Edgar Graham or Graeme may refer to: People * Graham (given name), an English-language given name * Graham (surname), an English-language surname * Graeme (surname), an English-language surname * Graham (musician) (born 1979), Burmese singer * Clan ...

and

George Calingaert George may refer to: Names * George (given name) * George (surname) People * George (singer), American-Canadian singer George Nozuka, known by the mononym George * George Papagheorghe, also known as Jorge / GEØRGE * George, stage name of Gior ...

made 3,3-dimethylpentane and measured its physical characteristics for the first time. The measurements were at 20 °C, not the standard conditions used in later times. For 3,3-dimethylpentane they measured a density of 0.6934 at 20 °C with a rate of change Δd/ΔT of 0.000848. The

dielectric constant The relative permittivity (in older texts, dielectric constant) is the permittivity of a material expressed as a ratio with the electric permittivity of a vacuum. A dielectric is an insulating material, and the dielectric constant of an insul ...

is 1.940. The refractive index at 20° is 1.39114. The adiabatic compressibility is 0.00011455 and isothermal compressibility is 0.00014513 atmospheres. The velocity of sound is 1.1295 km/s.

Coefficient of thermal expansion Thermal expansion is the tendency of matter to increase in length, area, or volume, changing its size and density, in response to an increase in temperature (usually excluding phase transitions). Substances usually contract with decreasing temp ...

is 0.002467/°.

Surface tension Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension (physics), tension is what allows objects with a higher density than water such as razor blades and insects (e.g. Ge ...

is 19.63 dynes/cm.

Viscosity Viscosity is a measure of a fluid's rate-dependent drag (physics), resistance to a change in shape or to movement of its neighboring portions relative to one another. For liquids, it corresponds to the informal concept of ''thickness''; for e ...

is 0.00454. The

heat of combustion The heating value (or energy value or calorific value) of a substance, usually a fuel or food (see food energy), is the amount of heat released during the combustion of a specified amount of it. The ''calorific value'' is the total energy relea ...

is 11470 cal/g which is very similar to other heptanes.

References

Alkanes {{Hydrocarbon-stub