(-)-beta-Citronellol
[CAS 7540-51-4]

Identification

• Classification: Biochemical >> Plant extracts
• Name: (-)-beta-Citronellol
• Synonyms: (-)-3,7-Dimethyloct-6-en-1-ol
• Molecular Formula: C₁₀H₂₀O
• Molecular Weight: 156.26
• CAS Registry Number: 7540-51-4
• EC Number: 231-415-7
• SMILES: C[C@@H](CCC=C(C)C)CCO

Properties

• Density: 0.8±0.1 g/cm³ Calc.^*, 0.856 g/mL (Expl.)
• Boiling point: 224.5 °C 760 mmHg (Calc.)^*, 221 - 224 °C (Expl.)
• Flash point: 98.3 °C (Calc.)^*, 99 °C (Expl.)
• Index of refraction: 1.451 (Calc.)^*, 1.456 (Expl.)

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H317-H319
• Safety Statements: P261-P264-P264+P265-P272-P280-P302+P352-P305+P351+P338-P321-P332+P317-P333+P317-P337+P317-P362+P364-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Skin sensitization	Skin Sens.	1	H317
Eye irritation	Eye Irrit.	2	H319
Skin sensitization	Skin Sens.	1B	H317
Specific target organ toxicity - single exposure	STOT SE	3	H335
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411

chemBlink Chemical Story

(-)-beta-Citronellol matters because (S)-(-)-citronellol demonstrates that fragrance is three-dimensional chemistry because chiral odorant receptors can distinguish molecular shape. This connection between molecular structure and observable behavior is more informative than a simple list of uses. CAS 7540-51-4 identifies the substance in this chemBlink record, while its practical significance comes from the way its functional groups, composition, or material structure control reactivity and physical properties.

The broader lesson is that chemical identity alone does not determine performance. Conditions such as pH, temperature, formulation, concentration, molecular distribution, or biological environment can decide whether the same underlying chemistry is useful, inactive, or hazardous. For chemists, (-)-beta-Citronellol is therefore a useful case study in connecting molecular-scale behavior with a real laboratory, industrial, biological, or materials-science outcome.

References: PubChem: (S)-beta-Citronellol, CAS 7540-51-4; Sell, The Chemistry of Fragrances

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