Isolongifolene (CAS 1135-66-6) — Woody Base Note Fragrance Ingredient

ByThe Good Scents
Woody · Balsamic

Isolongifolene

CAS 1135-66-6

Origin
synthetic
Note
Base
IFRA
Generally safe
Data as of: Apr 2026

What Is Isolongifolene?

Isolongifolene is a synthetic fragrance ingredient used to add woody, ambery depth to perfumes and scented products. It’s commonly found in masculine fragrances, candles, and home fragrances where a rich, long-lasting base is desired. This molecule enhances fragrance longevity and helps blend other ingredients smoothly, making it valuable for creating complex scent profiles.

Safety Profile

GENERALLY SAFE
Generally safeUse with awarenessProfessional use
✓ No known major safety concerns
⚠ Use standard handling precautions
CAS
1135-66-6
Formula
Mixture
MW
Variable
Odor Family
Woody · Balsamic
Layer 1 · Enthusiast

What Does Isolongifolene Smell Like?

Isolongifolene presents a deep, woody character with subtle amber undertones and a touch of earthy complexity. It evolves slowly on the skin, revealing a dry, slightly resinous quality reminiscent of aged cedarwood or the dry-down of fine leather. The scent lacks sharp edges, instead offering a smooth, enveloping warmth that acts as an excellent fixative for brighter top notes.

Scent Profile
Layer 2

2D Molecular Structure

(-)-Isolongifolene

SMILES: CC1(C)[C@H]2CC[C@]3(C2)C1=CCCC3(C)C

Chemistry, Properties & Perfumer Guide

The Chemistry

Isolongifolene is a sesquiterpene hydrocarbon derived through chemical synthesis, typically via cyclization of suitable terpene precursors. Its structure features a complex bridged ring system that contributes to its stability and low volatility. While not found abundantly in nature, it shares structural similarities with natural wood-derived terpenes, allowing it to blend well with essential oils.

Physical & Chemical Properties

Perfumer Guide

Note Position
Base
Volatility
Very low (hours to days)
Blending
Good
ApplicationTypical %RangeNotes
Fine Fragrance1-5%Up to 10%Base note fixative
Home Fragrance3-8%Up to 15%Amber/woody accords

Classic Accords

Tip: Use as a base note blender to add depth and extend fragrance longevity.

Alternatives & Comparisons

1
Ambroxan CAS 6790-58-5

For a cleaner, more diffusive amber effect with similar fixative properties.

Layer 3

Safety, Regulatory & Sustainability

⚠ Regulatory Disclaimer

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

IFRA Status

No IFRA restrictions apply to isolongifolene.

RIFM Assessment

RIFM considers isolongifolene safe for current fragrance use levels.

Sustainability

As a synthetic material, isolongifolene offers consistent quality without natural sourcing pressures. Its production can be optimized for minimal environmental impact through green chemistry principles. Being highly effective at low concentrations reduces the overall material requirement in formulations.

Explore Isolongifolene

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References

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

    Report a data error

    Perfumer’s Notes

    MW: 204.35

    LogP: 5

    Ingredient Data Sheet

    CAS 1135-66-6

    Physical Properties

    Molecular Weight204.35 g/mol🔬 PubChem
    LogP (Octanol-Water)5🔬 PubChem
    Boiling Point258 °C🔬 EPA CompTox
    Vapor Pressure0.002 mmHg @ 25°C📊 OPERA
    Flash Point102.6 °C🔬 EPA CompTox
    Involatility Index0.0002💻 Calculated
    log Kp (skin permeability)-0.397💻 Calculated
    SMILESCC1(CCC=C2C13CCC(C3)C2(C)C)C🔬 PubChem

    Volatility & Performance

    Fragrance NoteBase💻 Calculated
    Volatility ClassVery slow💻 Calculated
    Persistence Score6.4 / 5💻 Calculated

    Odor & Flavor

    Functional Groupsalkene💻 RDKit
    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: DTXSID1044518

    Physical Properties

    Molecular Weight 204.357 g/mol🔬 EPA CompTox
    Density 0.93 g/cm^3📊 OPERA
    Boiling Point 262.783 °C📊 OPERA
    Melting Point 41.033 °C📊 OPERA
    Flash Point 104.738 °C📊 OPERA
    Refractive Index 1.518 Dimensionless📊 OPERA
    Molar Volume 214.724 cm^3/mol📊 OPERA

    Partition & Solubility

    LogP (Octanol-Water) 5.405 Log10 unitless📊 OPERA
    LogD (pH 5.5) 5.405 Log10 unitless📊 OPERA
    LogD (pH 7.4) 5.405 Log10 unitless📊 OPERA
    LogKoa (Octanol-Air) 6.72 Log10 unitless📊 OPERA
    Water Solubility 0 mol/L📊 OPERA
    Henry's Law Constant 0.005 atm-m3/mole📊 OPERA

    Transport Properties

    Vapor Pressure 0.034 mmHg📊 OPERA
    Surface Tension 32.588 dyn/cm📊 OPERA
    Thermal Conductivity 107.039 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 0 count💻 Computed
    Aromatic Rings 0 count💻 Computed
    Molar Refractivity 65.052 cm^3/mol📊 OPERA
    Polarizability 25.789 Å^3📊 OPERA

    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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