3,3-Dimethylpentane

3,3-Dimethylpentane is one of the isomers of heptane. 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.^[1]

3,3-Dimethylpentane

Skeletal structure of 3,3-dimethylpentane
Ball-and-Stick model of 3,3-dimethylpentane
Names
Preferred IUPAC name 3,3-Dimethylpentane
Identifiers
CAS Number	562-49-2 Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL3188231
ChemSpider	10755
ECHA InfoCard	100.008.392
EC Number	209-230-8
PubChem CID	11229
UNII	R1RH0VBD2L
CompTox Dashboard (EPA)	DTXSID0049319
InChI InChI=1S/C7H16/c1-5-7(3,4)6-2/h5-6H2,1-4H3 Key: AEXMKKGTQYQZCS-UHFFFAOYSA-N
SMILES CCC(C)(C)CC
Properties
Chemical formula	C7H16
Molar mass	100.205 g·mol−1
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H225, H304, H315, H336, H410
Precautionary statements	P210, P233, P240, P241, P242, P243, P261, P264, P271, P273, P280, P301+P310, P302+P352, P303+P361+P353, P304+P340, P312, P321, P331, P332+P313, P362, P370+P378, P391, P403+P233, P403+P235, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Preparation

A method to produce 3,3-dimethylpentane is to react tert-amyl chloride (CH₃CH₂(CH₃)C₂Cl) with propionaldehyde 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.^[2]

Properties

In 1929 Graham Edgar and George Calingaert 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.^[3]

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 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 is 0.002467/°. Surface tension is 19.63 dynes/cm. Viscosity is 0.00454. The heat of combustion is 11470 cal/g which is very similar to other heptanes.^[3]