Methylcyclohexane
IUPAC name	methylcyclohexane
Other names	Hexahydrotoluene Cyclohexylmethane Toluene hexahydride
Identifiers
CAS number	108-87-2 Y
PubChem	7962
SMILES	CC1CCCCC1
Properties
Molecular formula	C7H14
Molar mass	98.1861
Appearance	colorless liquid
Density	.77 g/ml
Melting point	-126.3 °C (146.7 K)
Boiling point	101 °C (374 K)
Solubility in water	insoluble in water
Hazards
Main hazards	severe fire hazard
Flash point	-3 °C (270 K)
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Methylcyclohexane is a colourless liquid with a faint benzene-like odour. Its molecular formula is C₇H₁₄. Methylcyclohexane is used in organic synthesis and as a solvent for cellulose ethers. It is a component of jet fuel. Is also a component of correction fluids.

[edit] Structure

Monosubstituted methylcyclohexane has one methyl branch on one carbon of the cyclohexane ring. Like all substituted cyclohexanes, it can ring-flip rapidly between two chair conformations. However,a monosubstituted Methylcyclohexane exists exclusively in the equatorial position rather than axial. When the methyl group occupies the axial position, there is steric crowding by the axial hydrogens on the same side of the ring (known as the 1,3-diaxial interactions). Each methyl and hydrogen strain is approximately 1.82 kcal/mol and there are two of them on monosubstiuted. However, the equatorial conformation experiences no such interaction so it is more stable.

[edit] Disubstituted cyclohexanes

Cyclohexanes could also have more than one methyl branch. Disubstituted cyclohexane, or also known as dimethylcyclohexane has two methyl branches. Unlike the monosubstituted cyclohexane, there are several possible structures. The methyl groups could be on the same carbon, separate carbons and it doesn't necessarily have to be on the same face. The 1,3-diaxial strain interactions still apply to the disubstituted. If the methyl groups are on different faces and both in axial positions, there are diaxial interactions with the axial hydrogen groups on both faces. If they are on the same face, both methyl groups interact with the one hydrogen that is in axial position and there is also a methyl-methyl interaction with a steric energy of approximately 3.65 kcal/mol. If the methyl groups are on adjacent carbons of the cyclohexane, with one of them axial and the other equatorial, there would be a gauche interaction which adds to the the total strain energy the molecule has. For the dimethylcyclohexane which has two methyl groups on one carbon (1,1-dimethylcyclohexane), one methyl group is axial and the other equatorial. It would have the same total strain energy as the monosubstituted cyclohexane with axial methyl.