3-Mercaptohexanol (CAS 51755-83-0) — Sweet Top to heart Note Fragrance Ingredient
3-Mercaptohexanol
CAS 51755-83-0
What Is 3-Mercaptohexanol?
3-Mercaptohexanol is a synthetic fragrance ingredient primarily encountered in fine fragrances and some tropical fruit-flavored products. It contributes to the juicy, tropical character of many modern perfumes. This molecule matters because it’s one of the key materials that creates the authentic smell of passionfruit and guava, adding a mouthwatering quality to fragrances that makes them smell deliciously fruity.
Safety Profile
USE WITH AWARENESSWhat Does 3-Mercaptohexanol Smell Like?
3-Mercaptohexanol bursts with an intensely tropical, juicy character reminiscent of ripe passionfruit with hints of guava and grapefruit. The initial impression is bright and slightly sulfury, evolving into a luscious, sweet-fruity heart that lasts remarkably well for a sulfur compound. The dry-down reveals a softer, more diffuse tropical nuance that blends beautifully with citrus and floral materials. At higher concentrations, it can develop a slightly catty aspect, but when used judiciously, it creates an irresistible tropical fruit illusion.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used to create the mouthwatering tropical fruit accord that makes Eros instantly recognizable, blending with mint and citrus for a youthful, energetic opening.
Contributes to the photorealistic coconut and lime cocktail effect, enhancing the tropical vacation fantasy with its juicy passionfruit character.
2D Molecular Structure
SMILES: CCCC(S)CCO
Chemistry, Properties & Perfumer Guide
The Chemistry
3-Mercaptohexanol is a sulfur-containing aliphatic alcohol with the molecular formula C6H14OS. As a thiol, it belongs to the same chemical family as mercaptans, known for their powerful odors. It’s synthesized through various routes including the addition of hydrogen sulfide to hexenol or via Grignard reactions. The molecule exists as enantiomers, with the (R)-form being more potent and fruity-smelling than the (S)-form. Its sulfur group makes it highly reactive, requiring careful handling and stabilization in formulations.
Physical & Chemical Properties
| Boiling Point | ~198 °C (estimated) |
|---|---|
| Density | ~0.95 g/cm³ (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.1-0.5% | Up to 1% | Powerful tropical effect |
| Functional Fragrance | 0.01-0.1% | Up to 0.2% | Shampoos, shower gels |
Classic Accords
Tip: Use in trace amounts with citrus top notes to create photorealistic tropical fruit effects.
Alternatives & Comparisons
More stable ester version with similar tropical character but less sulfury edge, preferred in some applications.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No specific restrictions under current IFRA standards (as of Amendment 49).
GHS Classification
RIFM Assessment
RIFM has evaluated this material and established safe use levels in fragrance applications.
Sustainability
As a synthetic material, 3-Mercaptohexanol doesn’t require agricultural land but does depend on petrochemical feedstocks. Its production requires careful waste management due to sulfur content. Being highly potent, it’s used in small quantities, reducing overall environmental impact compared to less powerful materials.
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References
- Brenna et al. (2002). Synthesis and characterization of tropical fruit thiols. Flavour and Fragrance Journal. DOI:10.1002/ffj.1098
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID70866216
Physical Properties
| Molecular Weight | 134.24 g/mol🔬 EPA CompTox |
| Density | 0.993 g/cm^3📊 OPERA |
| Boiling Point | 198 °C🔬 EPA CTX |
| Melting Point | -23.043 °C📊 OPERA |
| Flash Point | 71.337 °C📊 OPERA |
| Refractive Index | 1.474 Dimensionless📊 OPERA |
| Molar Volume | 139.507 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 1.767 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 1.767 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 1.766 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.97 Log10 unitless📊 OPERA |
| Water Solubility | 0.046 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.129 mmHg📊 OPERA |
| Viscosity | 3.608 cP📊 OPERA |
| Surface Tension | 32.196 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 20.23 Ų💻 Computed |
| H-Bond Donors | 2 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 4 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 39.236 cm^3/mol📊 OPERA |
| Polarizability | 15.554 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.
