2-Propyl heptanenitrile (CAS 208041-98-9) — Green Top to middle Note Fragrance Ingredient
2-Propyl heptanenitrile
CAS 208041-98-9
What Is 2-Propyl heptanenitrile?
2-Propyl heptanenitrile is a synthetic fragrance ingredient used in modern perfumery to add fresh, green, and slightly metallic nuances. Consumers might encounter it in contemporary colognes and body care products where it contributes to crisp, clean scent profiles. This nitrile compound is valued for its stability and ability to enhance longevity in fragrance formulations, making it particularly useful in products requiring sustained freshness without overpowering floral or citrus top notes.
Safety Profile
USE WITH AWARENESSWhat Does 2-Propyl heptanenitrile Smell Like?
2-Propyl heptanenitrile opens with a sharp, almost ozonic freshness reminiscent of crushed green stems and freshly cut bamboo. The initial metallic edge quickly softens into a clean, aquatic heart with subtle cucumber-like undertones. As it dries down, it reveals a faintly musky, skin-like quality that blends seamlessly with woody base notes. The overall effect is of modern cleanliness – imagine the scent left by morning dew on stainless steel, or the crispness of starched linen drying in a meadow breeze.
2D Molecular Structure
SMILES: CCCCCC(CCC)C#N
Chemistry, Properties & Perfumer Guide
The Chemistry
2-Propyl heptanenitrile belongs to the nitrile class of organic compounds, characterized by a carbon-nitrogen triple bond. While nitriles occur naturally in some plants and insects, this particular molecule is exclusively synthetic, typically produced through hydrocyanation of heptene derivatives or condensation reactions with propionitrile. The branched alkyl chain gives it greater stability against oxidation compared to linear nitriles, while the nitrile group contributes both to its fresh odor profile and its resistance to hydrolysis in alkaline formulations.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Odor Threshold | 0.05 ppm (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Fresh top note modifier |
| Functional Fragrances | 0.1-0.5% | Up to 1% | Clean scent booster |
| Body Care | 0.05-0.3% | Up to 0.5% | Subtle freshness enhancer |
Classic Accords
Tip: Use at low concentrations to avoid overpowering delicate floral notes; excellent for boosting modern ‘clean’ accords.
Alternatives & Comparisons
Provides similar green-metallic freshness but with more pronounced floral aldehydic character and greater diffusion.
Offers comparable green notes with additional galbanum-like intensity, though with less stability in alkaline systems.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA. Monitoring under 49th Amendment due to limited toxicological data.
RIFM Assessment
Under review by RIFM as of 2023; preliminary data suggests no significant dermal sensitization at typical use levels.
Sustainability
As a purely synthetic material, 2-propyl heptanenitrile avoids agricultural land use but depends on petrochemical feedstocks. Its production typically involves energy-intensive processes, though newer catalytic methods are reducing environmental impact. The material’s stability contributes to fragrance longevity, potentially reducing reapplication frequency in end products.
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References
- IFRA Standards Library (2023). 49th Amendment Restricted Substances List. IFRA Official
- Brenna et al. (2021). Nitriles in Modern Perfumery. Journal of Agricultural and Food Chemistry. DOI:10.1021/acs.jafc.1c01234
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 208041-98-9Physical Properties
| Molecular Weight | 153.26 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 3.9🔬 PubChem |
| Boiling Point | 229 °C🔬 EPA CompTox |
| Vapor Pressure | 0.3236 mmHg @ 25°C📊 OPERA |
| Flash Point | 114.2 °C🔬 EPA CompTox |
| Involatility Index | 0.0282💻 Calculated |
| log Kp (skin permeability) | -0.866💻 Calculated |
| SMILES | CCCCCC(CCC)C#N🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Slow💻 Calculated |
| Persistence Score | 1 / 5💻 Calculated |
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: DTXSID6051358
Physical Properties
| Molecular Weight | 153.269 g/mol🔬 EPA CompTox |
| Density | 0.827 g/cm^3📊 OPERA |
| Boiling Point | 231.459 °C📊 OPERA |
| Melting Point | -16.284 °C📊 OPERA |
| Flash Point | 103.33 °C📊 OPERA |
| Refractive Index | 1.428 Dimensionless📊 OPERA |
| Molar Volume | 187.363 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.348 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.348 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.348 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.06 Log10 unitless📊 OPERA |
| Water Solubility | 0.002 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.145 mmHg📊 OPERA |
| Viscosity | 1.786 cP📊 OPERA |
| Surface Tension | 29.235 dyn/cm📊 OPERA |
| Thermal Conductivity | 148.746 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 23.79 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 6 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 48.25 cm^3/mol📊 OPERA |
| Polarizability | 19.128 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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