1,8-Octanediol
[CAS 629-41-4]

Identification

• Classification: Chemical reagent >> Organic reagent >> Fatty alcohol
• Name: 1,8-Octanediol
• Synonyms: Octane-1,8-diol; Octamethylene glycol
• Molecular Formula: C₈H₁₈O₂
• Molecular Weight: 146.23
• CAS Registry Number: 629-41-4
• EC Number: 211-090-8
• SMILES: C(CCCCO)CCCO

Properties

• Density: 0.9±0.1 g/cm³ Calc.^*
• Melting point: 57 - 61 °C (Expl.)
• Boiling point: 278.8 °C 760 mmHg (Calc.)^*, 322.1 °C (Expl.)
• Flash point: 128.0±13.0 °C (Calc.)^*, 120 °C (Expl.)
• Index of refraction: 1.455 (Calc.)^*

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

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H319
• Safety Statements: P280-P305+P351+P338-P337+P313

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Flammable solids	Flam. Sol.	2	H228

Discovery and Applications

1,8-Octanediol is a linear aliphatic diol consisting of an eight-carbon hydrocarbon chain with hydroxyl groups attached at both terminal carbons. Its molecular formula is C₈H₁₈O₂. As an α,ω-diol, it features two primary alcohol functional groups separated by a flexible alkyl chain, which makes it an important intermediate in polymer chemistry and specialty chemical synthesis.

The synthesis of 1,8-octanediol is commonly achieved through catalytic hydrogenation of octanedioic acid (suberic acid) or its derivatives such as esters or acid chlorides. Catalysts such as Raney nickel or copper chromite are typically used under elevated temperature and pressure to reduce the carboxyl groups to primary alcohols. Alternative synthetic methods include multi-step sequences starting from shorter-chain precursors followed by chain extension.

1,8-Octanediol’s bifunctional alcohol groups make it a valuable monomer or intermediate in the production of polyesters, polyurethanes, and other polymers. The eight-carbon alkyl spacer contributes flexibility, moderate hydrophobicity, and thermal stability to polymer chains. Polymers derived from 1,8-octanediol exhibit balanced mechanical strength and elasticity, useful for applications in coatings, adhesives, fibers, and biodegradable plastics.

Beyond polymer synthesis, 1,8-octanediol is used in manufacturing surfactants, plasticizers, and lubricant additives. Chemical modifications such as esterification or etherification yield amphiphilic molecules used in detergents, emulsifiers, and personal care products. The balance between hydrophilic hydroxyl groups and the hydrophobic alkyl chain enables interactions with both polar and nonpolar phases.

Physically, 1,8-octanediol is typically a colorless to pale yellow liquid or solid depending on purity and temperature. It has limited solubility in water but dissolves well in organic solvents such as alcohols, ethers, and hydrocarbons. The compound is chemically stable under normal conditions but can react with strong oxidizers or undergo hydrolysis in acidic or basic environments.

Toxicological data indicate low acute toxicity and good biodegradability, supporting its use in environmentally friendly chemical manufacturing. It can also be produced from renewable feedstocks, aligning with green chemistry principles.

In summary, 1,8-octanediol is a bifunctional diol featuring hydroxyl groups at both ends of an eight-carbon chain. Its chemical reactivity and structural properties make it a valuable intermediate for polymer production and specialty chemical applications.

References

2024. Bio-upcycling of even and uneven medium-chain-length diols and dicarboxylates to polyhydroxyalkanoates using engineered Pseudomonas putida. Microbial Cell Factories, 23(1).
DOI: 10.1186/s12934-024-02310-7

2023. Accurate Measurements of the Thermal Conductivity of n-Docosane, n-Tetracosane, 1,6-Hexanediol, and 1,8-Octanediol in the Solid and Liquid Phases. International Journal of Thermophysics, 44(7).
DOI: 10.1007/s10765-023-03182-6

2023. Catalytic synthesis of spiromacrocyclic diperoxides based on α,ω-diols. Russian Chemical Bulletin, 72(5).
DOI: 10.1007/s11172-023-3884-0