What Is Dimethylcyclohexane?
Dimethylcyclohexane is a generic name for a compound consisting of cyclohexane (an alicyclic organic compound) with two methyl groups attached.
There are several types depending on the location of the methyl groups. There are four structural isomers: 1,1-Dimethylcyclohexane, 1,2-Dimethylcyclohexane, 1,3-Dimethylcyclohexane, and 1,4-Dimethylcyclohexane.
The two methyl groups facing the same direction with respect to the dimethylcyclohexane ring are called the cis isomer, and those facing the opposite direction are called the trans isomer. The one in which the two methyl groups face the same direction with respect to the cyclohexane ring is called cis, and the one in which they face the opposite direction is called trans.
The molecular formula for each is C8H16, and the molecular weight is 112.216. This substance is flammable.
Uses of Dimethylcyclohexane
Dimethylcyclohexane is mainly used as an intermediate in organic synthesis. As a nonpolar cycloalkane, it can also be used as a nonpolar solvent, but in practice it has few uses as a nonpolar solvent because other chemicals are in general use. It is mainly used as a special building block.
1,1-dimethylcyclohexane is used as an additive to facilitate natural gas hydration operations at moderate pressures, and 1,3-dimethylcyclohexane has been used to study iridium-catalyzed ring opening reactions.
The dimethylcyclohexane group of compounds has a long history of use in the study of stable conformations of cyclohexanes, as the methyl group is a model substituent for steric hindrance.
Characteristics of Dimethylcyclohexane
1. 1,1-Dimethylcyclohexane
1,1-dimethylcyclohexane has a boiling point of 118-120°C and is a colorless liquid at room temperature. Its density is 0.777 g/cm3 and its CAS registration number is 590-66-9.
2. 1,2-Dimethylcyclohexane
1,2-dimethylcyclohexane has two stereoisomers, cis/trans in principle, but the cis form is most commonly sold. This is believed to be due to the synthetic route and stability of the compound.
The CAS number for cis-1,2-dimethylcyclohexane is 2207-01-4. It has a boiling point of 129-130°C and is a pale yellow liquid at room temperature. Its density is 0.796 g/cm3.
The CAS number for trans-1,2-dimethylcyclohexane is 2207-01-4. It has a boiling point of 124°C and is a colorless liquid at room temperature. Its density is 0.78 g/cm3.
3. 1,3-Dimethylcyclohexane
1,3-dimethylcyclohexane is available in three forms: cis, trans, and mixtures of cis and trans.
At room temperature, all are nearly colorless liquids with boiling points of 120°C (cis) and 124°C (trans) and specific gravities of 0.77 (cis) and 0.78 (trans).
4. 1,4-Dimethylcyclohexane
1,4-Dimethylcyclohexane is available in three forms: cis, trans, and mixtures of cis and trans.
At room temperature, all are nearly colorless liquids with boiling points of 125°C (cis) and 119°C (trans) and specific gravities of 0.78 (cis) and 0.76 (trans).
Types of Dimethylcyclohexane
Dimethylcyclohexane is sold primarily as a reagent product for research and development. As mentioned above, several isomers exist, but the commercialized products are as follows:
- 1,1-Dimethylcyclohexane
- cis-1,2-Dimethylcyclohexane
- cis-1,3-Dimethylcyclohexane
- trans-1,3-Dimethylcyclohexane
- cis-1,4-Dimethylcyclohexane
- trans-1,4-Dimethylcyclohexane
- 1,3-Dimethylcyclohexane (mixture of cis and trans)
- 1,4-Dimethylcyclohexane (mixture of cis and trans)
All are treated as reagent products that can be stored at room temperature. They are available in 1g, 5g, 10g, 25g, 50g, 25mL, and 500mL capacities, and are sold in small capacities that are easy to handle in the laboratory.