Cyclobutane
Cyclobutane is a cycloalkane organic compound with the formula (CH2)4, a colorless gas at room temperature. Cyclobutane is usually sold as a liquified gas (a gas that has been pressurized or frozen to be in a state that isn't natural). Variants of cyclobutane are called cyclobutanes. Cyclobutane has no uses in commerce or biology, but compounds containing cyclobutane are important in biology and biotechnology.