Chemistry flash – nerol and geraniol

Nerol and geraniol are two chemicals with the formulae of C10H18O and molecular weight of 154,25 grams. They both are classified as monoterpenes, at the same time being alcohols thanks to presence of hydroxyl group -OH at the end of the carbon chain. To be even more precise – nerol and geraniol are almost the same substance. Chemist would say that they’re isomeric forms for each other. To make it more clear for those who don’t have much in common with chemistry I can say that geraniol and nerol are like brothers -they may look similar but they’re not 100% the same.

Nerol is a cis-isomer, which means that CH2OH group and the bigger part of the chain are on the same side of double C=C bond. Geraniol is a trans-isomer so CH2OH group and bigger part of the chain are on the opposite sides of C=C bond. This slight difference changes their smell.

Nerol is the aromachemical that was identified for the first time in neroli essential oil, hence its name. In normal conditions it’s a colourless liquid which makes it easy to use for perfumery purposes. Despite the fact it was found in neroli essential oil nerol doesn’t have the characteristic neroli smell. Instead its scent reminds of fresh sweet roses. Sometimes it can be used as a food flavour. Neroli oil containing nerol is a gentle chemical, it’s not toxic, doesn’t cause irritation or skin-sensitizing.

Around 12% of contemporary perfume creations use neroli oil as one of the main ingredients. Rumour has it that neroli oil is one of the ingredients of Coca-Cola (its recipe is top secret). Nerol and neroli oil have aromatherapeutic properties, they soothe nerves, take away tension and anxiety.

Geraniol occurs in small amounts in geranium, lemon and many other essential oils. It was probably found in geranium for the first time as its name might suggest. Its smell is similar to the smell of roses. It’s often used to imitate taste of many fruits – it’s commonly used in flavouring. Geraniol is a good natural mosquito repellent which at the same time attracts bees. Some amounts of geraniol are being added to cigarettes to improve their flavor. This compound is said to have antioxidating abilities and anti-cancerogenic influence on living organisms.

Geraniol is a weak allergene but it’s often used in high concentrations. Around 9,5% of people can get an allergic reactions from using cosmetics with this substance. Moreover it’s really hard to avoid it since it can be found in all kinds of cosmetic products, even those for children, natural or organic.

Perfume featuring either nerol and geraniol can be (couldn’t find a proof):

  • Annick Goutal Neroli
  • Le Labo Fleur d’Oranger 27, Neroli 36
  • Serge Lutens Fleur de Citronnier
  • ChloΓ© Eau de Fleurs Neroli
  • Prada Infusion de Fleurs d’Oranger
  • Miller Harris Geranium Bourbon
  • Jo Malone Iris & Lady Moore
  • Atelier Cologne Sous le toit de Paris
  • YSL Rive Gauche
  • Parfumerie Generale Corps et Ames
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40 thoughts on “Chemistry flash – nerol and geraniol

  1. Dearest Lucas
    Thank you as ever for continuing our education.
    You’ve resolved a couple of points here for The Dandy… first why certain aromachemicals bear the names of plants they don;t smell like and second whether some of the most familiar perfumes are used in food.
    I am now a wiser gentleman on account of you learning.
    Have a fantastically fragrant Friday!
    Yours ever
    The Perfumed Dandy

    • lucasai says:

      You’re welcome. Knowing more is always better.
      There are many aromachemicals that have names based on the source they were found for the 1st time, even though they don’t smell exactly similar to that material.
      Have a good Friday as well.

  2. Jordan River says:

    Wiser too, thank you Łucas.

  3. brie says:

    this was fantastic! Now I know why I like Coca Cola :D!!! Interesting to see Rive Gauche on the list….one of my all time favorites (the original pre re-formulation).

    and I happen to love the smell of neroli essential oil….perfect for late spring/early summer.

    • lucasai says:

      Thank you. πŸ™‚ You think this is the reason? Haha πŸ™‚
      As mentioned, please don’t treat those perfume as really containing nerol or geraniol, these are just my assumptions. For previous post I had a source of confirmation, this time I didn’ have it.

  4. poodle says:

    I really like the chemistry posts. Always interesting.
    I think my niece is going to Warsaw next month for work. Do you know of any good perfume shops there that I could persuade her to go to for me?

  5. Lilybelle says:

    It’s so interesting that nerol doesn’t smell like neroli, but rather roses. And also that geramiol smells like roses, rather than geranium or whatever other plant they get it from. I suppose it makes the case for natural essential oils for aromatherapy purposes. My organic hydrosol rosewater smells a bit vegetal and somewhat briny, not at all like the fresh rose of nerol or geraniol. That’s how I know it’s the real thing, I suppose. I enjoyed your post on lavender oil extraction, too. You make it interesting for non-science majors like me. Thank you, Lucas!

  6. shellyw says:

    Thanks again for the explanation.

  7. Dionne says:

    Lucas, it takes a specific kind of talent to be able to translate science for the layman, and you’ve got it. Describing isomers as brothers is just brilliant, and I plan on stealing it from you when my kids need help with their homework. (Also, although Rose Anonyme didn’t work on me, I passed on my sample a couple of days ago to a friend looking for a rose scent, and she smell fantastic in it. I suspect she’ll buy a bottle within the week.)

    • lucasai says:

      I try to use a simple language so that everyone can understand the general idea what’s the chemistry about πŸ™‚ That’s a good idea, you’ve got my permission to use it πŸ™‚
      Sorry Rose Anonyme didn’t work for you, glad a friend likes it.

  8. Kafkaesque says:

    Really interesting, as always, Lucas. πŸ™‚ As for perfumes featuring one or both of the notes, I know for a fact that Chanel’s 1932 has Geraniol in it. When I got it, Chanel hadn’t even released the notes, so I had to do a blind review relying on the ingredients listed in a photo of the perfume’s box. I remember specifically that Geraniol was listed because I had to research some of the chemical-sounding names to see what they entailed for my review. I recall being extremely surprised to read that Geraniol wasn’t a geranium oil, but something that smelled as you describe/explain here. Nice job with the explanations, by the way, and thank you for always taking the fear or dread out of chemistry. πŸ™‚

  9. Undina says:

    Lucas, it was an ideal post for the series: just enough information but in very plain language and with interesting trivia-like bits to keep it entertaining. Bravo! πŸ™‚

  10. hajusuuri says:

    Lucas, dear, what an interesting post! With geraniol being a mild allergen and almost 10% of the people being sensitive to it, I wonder why it keeps getting used in high concentrations, besides, perhaps, that it is very inexpensive to make?

    • lucasai says:

      Thank you Hajusuuri! I guess it’s reasonably cheap chemical and brands just have to use “something” to scent their products. But there are probably more reasons why brands use so much of it.

  11. TF says:

    What a coincidence! I just turned in a report for my advanced organic class on terpenes and mine was geraniol.

  12. I love these posts! Thanks for the continuing education Lucas!

  13. Natalie says:

    I always love the chemistry posts, and this one was especially interesting, because I have noticed geraniol in the ingredient list in at least one of my skin care products, and wondered about it. Thanks for the info!

  14. fqjcior says:

    Interesting! BTW: as far as I know there is a lot of lime essentail oil in Coca Cola. I haven’t heard about neroli being used in there.

  15. […] Despite the fact it was found in neroli essential oil nerol doesn’t have the characteristic neroli smell. Instead its scent reminds of fresh sweet roses. (Chemist In The Bottle) […]

  16. Ellen says:

    My question…which is what led me here in a search, is, does geranium or (rose geranium) have the same qualities as geraniol in repelling fleas and ticks? Thank you for your time.

  17. […] Despite the fact it was found in neroli essential oil nerol doesn’t have the characteristic neroli smell. Instead its scent reminds of fresh sweet roses. (Chemist In The Bottle) […]

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