iso-Methyl-beta-ionone (CAS 79-89-0) — Floral Heart to base Note Fragrance Ingredient
iso-Methyl-beta-ionone
CAS 79-89-0
What Is iso-Methyl-beta-ionone?
Iso-Methyl-beta-ionone is a synthetic fragrance molecule that creates warm, powdery violet and woody notes. You’ll find it in perfumes, soaps, and luxury skincare products. This ingredient matters because it adds a sophisticated, velvety floral character that’s more stable than natural violet extracts. It helps create the ‘expensive perfume’ effect in many modern fragrances.
Safety Profile
USE WITH AWARENESSWhat Does iso-Methyl-beta-ionone Smell Like?
Iso-Methyl-beta-ionone unfolds like crushed violet petals dusted with powdered sugar, revealing a soft woody-iris heart. The initial burst has a fruity-floral lift reminiscent of raspberries dipped in violet honey. As it dries down, it develops a suede-like texture with whispers of orris root and cedar. Unlike sharper ionones, this isomer has a rounded, almost gourmand quality that lingers close to the skin like expensive face powder.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
2D Molecular Structure
SMILES: CC(=O)C(C)=CC1=C(C)CCCC1(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
Iso-Methyl-beta-ionone belongs to the ionone family, cyclic terpenoids structurally related to beta-ionone. The methyl group at position 3 creates a more stable molecule than alpha or beta ionones. Industrially produced via acid-catalyzed cyclization of pseudoionone, with the iso-methyl variant selectively isolated through fractional distillation. The chiral center at C3 means different enantiomers may exhibit slightly different olfactory profiles, though most commercial material is racemic.
Physical & Chemical Properties
| Boiling Point | 266 °C (estimated) |
|---|---|
| Density | 0.932 g/cm³ (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-3% | Up to 5% | Powdery floral modifier |
| Soap | 0.5-1% | Up to 2% | Adds luxury feel |
Classic Accords
Tip: Use with ionones and damascones to create complex violet-rose effects without becoming cloying.
Alternatives & Comparisons
More expensive but provides a sharper, greener iris character preferred in niche perfumery.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No restrictions under IFRA 49th Amendment. Maximum recommended 5% in leave-on products.
EU Allergen Declaration
Not listed in EU allergen regulation (EC) No 1223/2009 Annex III.
RIFM Assessment
RIFM evaluation confirms safe use at current industry levels.
Sustainability
Synthetic production avoids overharvesting of natural violet sources. The manufacturing process has relatively low environmental impact compared to some floral absolutes. No animal derivatives used.
Explore iso-Methyl-beta-ionone
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References
- Bauer et al. (2001). Modern Fragrance Chemistry. Wiley-VCH.
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID0052544
Physical Properties
| Molecular Weight | 206.329 g/mol🔬 EPA CompTox |
| Density | 0.935 g/cm^3🔬 EPA CTX |
| Boiling Point | 280.318 °C📊 OPERA |
| Melting Point | 42.546 °C📊 OPERA |
| Flash Point | 116.833 °C📊 OPERA |
| Refractive Index | 1.514 Dimensionless📊 OPERA |
| Molar Volume | 219.959 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.149 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 4.149 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.149 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 7.18 Log10 unitless📊 OPERA |
| Water Solubility | 0.001 mol/L📊 OPERA |
| Henry's Law Constant | 0.001 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.022 mmHg📊 OPERA |
| Surface Tension | 32.702 dyn/cm📊 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 | 2 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 66.179 cm^3/mol📊 OPERA |
| Polarizability | 26.236 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.
