Dihydro-.gamma.-ionone (CAS 13720-12-2) — Floral Heart to base Note Fragrance Ingredient
Dihydro-.gamma.-ionone
CAS 13720-12-2
What Is Dihydro-.gamma.-ionone?
Dihydro-γ-ionone is a synthetic fragrance ingredient prized for its soft, woody-orris character. You’ll encounter it in luxury perfumes, especially those with powdery or violet-like accords. This molecule matters because it bridges floral and woody notes, adding sophistication without overpowering. It’s a subtle workhorse behind many ‘your skin but better’ fragrances.
Safety Profile
GENERALLY SAFEWhat Does Dihydro-.gamma.-ionone Smell Like?
Dihydro-γ-ionone unfolds like a silk handkerchief dusted with violet powder—initially a tender floralcy reminiscent of orris root and parma violets, then revealing a suede-like texture with whispers of raspberry jam. As it dries, the sweetness recedes into a polished woody base with the faintest hint of tea leaves. Unlike its more aggressive cousin α-ionone, this molecule lingers as a transparent veil rather than a bold statement, making it ideal for skin-scent effects.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
The powdery elegance of dihydro-γ-ionone amplifies the cosmetic quality of the orris, creating a fragrance that smells like high-end face powder in a carved wooden compact.
Here it softens the violet overdose, adding a plush quality that prevents the floral notes from becoming screechy or candied.
2D Molecular Structure
SMILES: CC(=O)CCC1C(=C)CCCC1(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
Dihydro-γ-ionone belongs to the ionone family of cyclic terpenoids, specifically a hydrogenated derivative of γ-ionone. Unlike α- and β-ionones which have conjugated double bonds, this saturated version offers greater stability and a more subdued olfactory profile. Industrial synthesis typically involves acid-catalyzed cyclization of pseudoionone followed by selective hydrogenation. The lack of chiral centers makes it easier to produce consistently compared to some natural isolates.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | ~250°C (estimated) |
| Density | ~0.93 g/cm³ |
| Refractive Index | ~1.49 |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-5% | Up to 8% | For powdery-violet effects |
| Personal Care | 0.1-1% | Up to 2% | Soap-compatible floral modifier |
Classic Accords
Tip: Use with ionones to create depth without increasing perceived sweetness.
Alternatives & Comparisons
More intense violet character with higher impact but less subtlety. Better for bold floral statements.
Woodier and more tenacious. Prefer for masculine or oriental compositions needing longevity.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No restrictions under current IFRA standards (Amendment 49).
RIFM Assessment
Considered safe for use in fragrance based on RIFM’s 2015 evaluation of structural analogs.
Sustainability
As a purely synthetic material, dihydro-γ-ionone avoids pressure on natural violet resources. Modern manufacturing routes have reduced solvent waste compared to earlier processes. The molecule’s potency means small quantities suffice, lowering overall environmental load versus weaker materials requiring higher doses.
Explore Dihydro-.gamma.-ionone
Browse essential oils and aroma compounds.
Browse on iHerb →Affiliate disclosure: we may earn a small commission at no extra cost to you.
References
- Brenna et al. (2002). Ionones and damascones: Biotechnological production. Flavour and Fragrance Journal. DOI:10.1002/ffj.1096
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID1051694
Physical Properties
| Molecular Weight | 194.318 g/mol🔬 EPA CompTox |
| Density | 0.889 g/cm^3📊 OPERA |
| Boiling Point | 244.015 °C📊 OPERA |
| Melting Point | 18.632 °C📊 OPERA |
| Flash Point | 94.765 °C📊 OPERA |
| Refractive Index | 1.462 Dimensionless📊 OPERA |
| Molar Volume | 217.779 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.067 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 4.067 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.067 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 6.13 Log10 unitless📊 OPERA |
| Water Solubility | 0.001 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.027 mmHg📊 OPERA |
| Viscosity | 3.046 cP📊 OPERA |
| Surface Tension | 30.22 dyn/cm📊 OPERA |
| Thermal Conductivity | 129.175 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 17.07 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 3 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 59.833 cm^3/mol📊 OPERA |
| Polarizability | 23.72 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.
