What is the Difference Between Geraniol and Nerol?

Geraniol and nerol are two chemicals with the formula C10H18O and a molecular weight of 154.25. They are both classified as monoterpenes and alcohols due to the presence of a hydroxyl group (-OH) at the end of the carbon chain. The primary difference between geraniol and nerol is their geometric isomerism:

• Geraniol: This is a trans-isomer, meaning that the CH2OH group and the larger part of the chain are on opposite sides of the double C=C bond. Geraniol is the primary component of rose oil and palmarosa oil and typically occurs as a colorless or yellow-colored liquid.
• Nerol: This is a cis-isomer, meaning that the CH2OH group and the larger part of the chain are on the same side of the double C=C bond. Nerol was first identified in neroli essential oil, hence its name, and is a colorless liquid that is used in perfumery. Like geraniol, nerol has a sweet rose odor, but it is considered to be fresher.

The slight difference in their molecular arrangement results in different odors for each compound. Geraniol is considered more potent than nerol, with an odor threshold of 14 ng/L compared to nerol's odor threshold of 60 ng/L. Despite their differences, both geraniol and nerol share some similarities, such as being isomers of each other and having similar citrus-like, floral odors.

Comparative Table: Geraniol vs Nerol

Geraniol and nerol are both monoterpenoid alcoholic compounds with the chemical formula C10H18O and a molecular weight of 154.25. They are isomeric forms of each other, with geraniol being the cis isomer and nerol being the trans isomer. Here is a table comparing the differences and similarities between geraniol and nerol:

Despite their differences, geraniol and nerol share some similarities, such as their monoterpenoid structure and the presence of a hydroxyl group -OH at the end of the carbon chain.