1,3,5-Undecatriene (CAS 16356-11-9) — Green Top Note Fragrance Ingredient
1,3,5-Undecatriene
CAS 16356-11-9
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 AWARENESSWhat 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.
2D Molecular Structure
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
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.1-0.5% | Up to 1% | Green note enhancer |
| Functional Fragrance | 0.01-0.1% | Up to 0.3% | Freshness booster |
Classic Accords
Tip: Use in trace amounts to avoid overwhelming compositions with its intense green character.
Alternatives & Comparisons
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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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 |
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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