Neopentane

Neopentane, also called dimethylpropane or 2,2-dimethylpropane, is a double-branched-chain alkane with five carbon atoms. Neopentane is an extremely flammable gas at room temperature and pressure which can condense into a highly volatile liquid on a cold day, in an ice bath, or when compressed to a higher pressure.

Nomenclature
IUPAC nomenclature retains the trivial name neopentane. Dimethylpropane is the systematic name. The respective substituent numbers (the 2,2-) are unnecessary because there can be no isomers of this molecule with dimethylpropane as part of their names.

A neopentyl substituent or a neopentyl compound has the structure Me3C-CH2- for instance neopentyl alcohol.

Isomers
Neopentane is one of three structural isomers with the molecular formula C5H12, the others being pentane and isopentane.

Proton NMR spectrum
Neopentane has Td symmetry. As a result, all protons are chemically equivalent leading to a single chemical shift at &delta; 0.902 in carbon tetrachloride. This is similar to the silane analog, tetramethylsilane which has a single chemical shift, defined as &delta; 0 by convention.

Related
Chirally deuterated neopentane ([2H1,2H2,2H3]-neopentane) is an interesting molecule. The neopentane is rendered chiral by the isotopic substitution of hydrogen. Its chirality arises solely by the mass distribution of its nuclei, while its electron distribution is completely achiral.