1,7-Heptanediol
[CAS# 629-30-1]

Identification

• Classification: Chemical reagent >> Organic reagent >> Fatty alcohol
• Name: 1,7-Heptanediol
• Synonyms: heptane-1,7-diol
• Molecular Formula: C₇H₁₆O₂
• Molecular Weight: 132.20
• CAS Registry Number: 629-30-1
• EC Number: 211-085-0
• SMILES: C(CCCO)CCCO

Properties

• Density: 0.9±0.1 g/cm³ Calc.^*, 0.951 g/mL (Expl.)
• Melting point: 17 - 19 °C (Expl.)
• Boiling point: 262.0 °C 760 mmHg (Calc.)^*, 259 °C (Expl.)
• Flash point: 120.9±13.0 °C (Calc.)^*, 113 °C (Expl.)
• Index of refraction: 1.452 (Calc.)^*, 1.455 (Expl.)

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

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H319
• Safety Statements: P264+P265-P280-P305+P351+P338-P337+P317

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2A	H319

Discovery and Applications

1,7-Heptanediol is an aliphatic diol consisting of a seven-carbon linear hydrocarbon chain with hydroxyl groups attached at both terminal carbons. Its molecular formula is C₇H₁₆O₂. As an α,ω-diol, it contains two primary alcohol functional groups separated by a flexible alkyl chain, making it a valuable intermediate in polymer chemistry and specialty chemical synthesis.

The synthesis of 1,7-heptanediol can be accomplished through catalytic hydrogenation of heptanedioic acid (pimelic acid) or its derivatives such as esters or acid chlorides. Catalysts like Raney nickel or copper chromite are employed under elevated temperatures and pressures to reduce the carboxyl groups to primary alcohols. Alternative synthetic routes involve multi-step sequences starting from shorter-chain compounds with subsequent carbon chain extension.

1,7-Heptanediol’s bifunctional alcohol groups enable its use as a monomer or intermediate in the preparation of polyesters, polyurethanes, and other polymers. The seven-carbon alkyl chain imparts flexibility, moderate hydrophobicity, and thermal stability to polymer chains. Polymers derived from 1,7-heptanediol exhibit balanced mechanical strength and elasticity, useful in coatings, adhesives, fibers, and biodegradable plastics.

Besides polymer production, 1,7-heptanediol is utilized in the manufacture of surfactants, plasticizers, and lubricant additives. Chemical modifications such as esterification or etherification generate amphiphilic molecules applicable in detergents, emulsifiers, and personal care products. The balance between hydrophilic hydroxyl groups and hydrophobic alkyl chain facilitates interactions with both polar and nonpolar phases.

Physically, 1,7-heptanediol is typically a colorless to pale yellow liquid or solid depending on purity and temperature. It exhibits limited solubility in water but dissolves well in organic solvents including alcohols, ethers, and hydrocarbons. The compound is chemically stable under normal storage conditions but can be reactive toward strong oxidizing agents or hydrolysis under acidic or basic environments.

Toxicological data indicate low acute toxicity and good biodegradability, supporting its use in environmentally friendly chemical processes. It can be produced from renewable resources, aligning with sustainable chemistry practices.

In summary, 1,7-heptanediol is a bifunctional diol with hydroxyl groups at each end of a seven-carbon chain. Its chemical properties and structural features make it an important intermediate for polymer synthesis and specialty chemical applications.

References

2017. Synthesis of cyclic ethers from diols in the presence of copper catalysts. Russian Journal of Organic Chemistry, 53(12).
DOI: 10.1134/s1070428017120090

2013. Sorption behavior of polymeric gels based on alkoxysilane and aliphatic diol. Journal of Polymer Research, 20(11).
DOI: 10.1007/s10965-013-0305-3

2009. New synthesis of nematocidal natural products dithiocynates thiocyanatin A and 1,8,16-trihydroxyhexadecane. Natural Product Research, 23(10).
DOI: 10.1080/14786410802587073