1,3,5-Undecatriene (CAS 16356-11-9) — Green Top Note Fragrance Ingredient

ByThe Good Scents
Green · Woody

1,3,5-Undecatriene

CAS 16356-11-9

Origin
synthetic
Note
Top
IFRA
Use with awareness
Data as of: Apr 2026

What Is 1,3,5-Undecatriene?

1,3,5-Undecatriene is a synthetic fragrance ingredient primarily used in perfumery to create fresh, green, and slightly woody scent profiles. It’s found in some modern floral and citrus fragrances. This molecule contributes a crisp, natural character that perfumers use to enhance the realism of green notes in compositions.

Safety Profile

USE WITH AWARENESS
Generally safeUse with awarenessProfessional use
✓ Approved for fragrance use
⚠ Limited safety data available
CAS
16356-11-9
Formula
Mixture
MW
Variable
Odor Family
Green · Woody
Layer 1 · Enthusiast

What Does 1,3,5-Undecatriene Smell Like?

1,3,5-Undecatriene delivers a sharp, green burst reminiscent of freshly crushed leaves with a subtle metallic edge. The initial impression is intensely verdant, like snapping a celery stalk, evolving into a cleaner, more refined greenness. As it dries down, it reveals a whisper of woody undertones, creating a bridge between top and heart notes. The overall effect is crisp and energizing, with excellent diffusion that makes it useful for creating naturalistic green accords.

Scent Profile
Layer 2

2D Molecular Structure

1,3,5-Undecatriene

SMILES: CCCCCC=CC=CC=C

Chemistry, Properties & Perfumer Guide

The Chemistry

1,3,5-Undecatriene is a linear hydrocarbon with three conjugated double bonds, belonging to the polyene class. This structure makes it highly reactive and volatile. Synthesized through controlled oligomerization of smaller hydrocarbon units, its conjugated system contributes to its distinctive green odor character. The specific geometric isomerism (E/Z configurations) significantly impacts its olfactory properties.

Physical & Chemical Properties

Perfumer Guide

Note Position
Top
Volatility
Very high (5-30 min)
Blending
Good
ApplicationTypical %RangeNotes
Fine Fragrance0.1-0.5%Up to 1%Green note enhancer
Functional Fragrance0.01-0.1%Up to 0.3%Freshness booster

Classic Accords

Tip: Use in trace amounts to avoid overwhelming compositions with its intense green character.

Alternatives & Comparisons

1
Hexenyl Acetate CAS 3681-71-8

For a softer green effect with fruity undertones

2
Stemone CAS 67634-15-5

When more floral-green character is desired

Layer 3

Safety, Regulatory & Sustainability

⚠ Regulatory Disclaimer

General reference only. Consult current IFRA Standards Library before formulating.

IFRA Status

No current IFRA restrictions

RIFM Assessment

Limited safety assessment available; considered safe at current usage levels.

Sustainability

As a synthetic material, 1,3,5-Undecatriene has minimal environmental impact in production compared to natural alternatives. Its efficient synthesis from petrochemical feedstocks makes it a sustainable choice for green notes, reducing land use requirements versus plant-derived materials.

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References

    Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.

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    Ingredient Data Sheet

    CAS 16356-11-9

    Physical Properties

    Molecular Weight150.26 g/mol🔬 PubChem
    LogP (Octanol-Water)4.8🔬 PubChem
    Boiling Point183.9 °C🔬 EPA CompTox
    Vapor Pressure0.8957 mmHg @ 25°C📊 OPERA
    Flash Point60.5 °C🔬 EPA CompTox
    Involatility Index0.0788💻 Calculated
    log Kp (skin permeability)-0.209💻 Calculated
    SMILESCCCCCC=CC=CC=C🔬 PubChem

    Volatility & Performance

    Fragrance NoteTop💻 Calculated
    Volatility ClassSlow💻 Calculated
    Persistence Score0.5 / 5💻 Calculated

    Odor & Flavor

    Functional Groupsalkene💻 RDKit
    “The title triolefin was synthesized a few years ago after an intensified research aimed at the odorous components in Galbanum. Of the non-terpene components, the title material proved to be one of the more interesting and apparently important to the odor picture of Galbanum. The natural material had a tem-”📖 Arctander
    1,3,5-Undecatriene has a green, melon, pineapple and fruity odor.📖 Fenaroli
    Data Sources & Attribution
    Physical data: PubChem (NIH/NLM), U.S. EPA CompTox Dashboard, EPA OPERA models, RDKit. Odor & flavor: Arctander (Perfume & Flavor Chemicals), Fenaroli's Handbook of Flavor Ingredients, Leffingwell. Thresholds: van Gemert (Compilations of Odour Threshold Values). Regulatory: IFRA Standards 51st, FEMA GRAS. Trade names: Surburg (Common Fragrance & Flavor Materials). All data compiled and cross-referenced for perfumertools.com.

    Physicochemical Properties

    DTXSID: DTXSID9047546

    Physical Properties

    Molecular Weight 150.265 g/mol🔬 EPA CompTox
    Density 0.792 g/cm^3🔬 EPA CTX
    Boiling Point 183.897 °C📊 OPERA
    Melting Point -51.36 °C📊 OPERA
    Flash Point 60.481 °C📊 OPERA

    Partition & Solubility

    LogP (Octanol-Water) 3.865 dimensionless💻 Computed
    Water Solubility 0 mol/L📊 OPERA

    Transport Properties

    Vapor Pressure 0.896 mmHg📊 OPERA
    Viscosity 0.608 cP📊 OPERA
    Surface Tension 21.465 dyn/cm📊 OPERA
    Thermal Conductivity 135.103 mW/(m*K)📊 OPERA

    Molecular Descriptors

    Topological Polar Surface Area 0 Ų💻 Computed
    H-Bond Donors 0 count💻 Computed
    H-Bond Acceptors 0 count💻 Computed
    Rotatable Bonds 6 count💻 Computed
    Aromatic Rings 0 count💻 Computed
    Molar Refractivity 52.62 cm^3/mol💻 Computed

    Data Sources:

    🔬 EPA Experimental data from U.S. EPA CompTox Chemicals Dashboard & CTX APIs. 📊 OPERA Predicted using EPA's OPERA QSAR models. 💻 Computed Calculated from SMILES using RDKit.

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