1-Bromohexane
[CAS# 111-25-1]

Identification

• Classification: Organic raw materials >> Hydrocarbon compounds and their derivatives >> Hydrocarbon halide
• Name: 1-Bromohexane
• Synonyms: n-Hexyl bromide
• Molecular Formula: C₆H₁₃Br
• Molecular Weight: 165.07
• CAS Registry Number: 111-25-1
• EC Number: 203-850-2
• SMILES: CCCCCCBr

Properties

• Density: 1.2±0.1 g/cm³ Calc.^*, 1.176 g/mL (Expl.)
• Melting point: -85 ºC (Expl.)
• Boiling point: 154.9±3.0 ºC 760 mmHg (Calc.)^*, 154 - 158 ºC (Expl.)
• Flash point: 57.2 ºC (Calc.)^*, 57 ºC (Expl.)
• Index of refraction: 1.447 (Calc.)^*, 1.448 (Expl.)

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

Safety Data

• Hazard Symbols: GHS02;GHS07;GHS09 WarningGHS02
• Hazard Statements: H226-H315-H319-H335-H411
• Precautionary Statements: P210-P233-P240-P241-P242-P243-P261-P264-P264+P265-P271-P273-P280-P302+P352-P303+P361+P353-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P370+P378-P391-P403+P233-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	3	H226
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Eye irritation	Eye Irrit.	2	H319
Eye irritation	Eye Irrit.	2A	H319

• Transport Information: UN 1993

Discovory and Applicatios

1-Bromohexane is a straight-chain organobromine compound with the molecular formula C₆H₁₃Br. It is a colorless to pale yellow liquid at room temperature, possessing the characteristic odor associated with alkyl bromides. The compound belongs to the family of primary bromoalkanes, with the bromine atom located at the terminal carbon of a six-carbon chain. Its preparation and study date back to the early developments in halogenated hydrocarbon chemistry in the nineteenth century, when systematic halogenation reactions and substitution processes were being explored to understand the reactivity of organic molecules. The introduction of alkyl bromides such as 1-bromohexane provided researchers with versatile reagents for substitution and elimination reactions, which were central to the growth of organic synthesis.

The compound is typically synthesized by the reaction of 1-hexanol with hydrobromic acid or with reagents that generate bromide ions in situ, such as phosphorus tribromide or thionyl bromide in the presence of hydrogen bromide. These transformations, well documented in classical organic chemistry, established reliable methods for preparing primary alkyl bromides and demonstrated the predictable reactivity of alcohols when converted to halides. 1-Bromohexane was one of the many homologous compounds studied to examine how chain length and substitution pattern influenced physical properties and reactivity.

One of the most important aspects of 1-bromohexane is its role as an alkylating agent. In substitution reactions, the bromine atom serves as a good leaving group, enabling the introduction of a six-carbon linear chain into a wide variety of nucleophiles. This property has made 1-bromohexane valuable for the synthesis of amines, ethers, thiols, and other functional derivatives. The ability to selectively append a hexyl group to diverse substrates gave the compound an enduring place in the toolkit of organic chemists.

Beyond laboratory-scale transformations, 1-bromohexane has practical applications in industrial and materials chemistry. It serves as an intermediate in the synthesis of surfactants, plasticizers, and lubricants. The hexyl group introduced by this compound imparts hydrophobicity and influences the physical properties of the resulting materials. In particular, alkyl-substituted amines and quaternary ammonium salts derived from 1-bromohexane have found utility as surfactants and phase transfer catalysts, broadening its scope of application in chemical manufacturing.

In the field of research, 1-bromohexane has been used to investigate the mechanisms of nucleophilic substitution and elimination reactions. Studies of its kinetics and product distributions in various solvent systems have contributed to a deeper understanding of how reaction conditions affect competing pathways. Its structure as a primary bromide allows comparisons with secondary and tertiary analogs, making it a useful model compound for establishing principles in physical organic chemistry.

From a physical standpoint, 1-bromohexane is moderately dense, immiscible with water, and soluble in common organic solvents such as ethanol, ether, and benzene. Its boiling point is higher than that of non-halogenated hexane due to the polarizability of the bromine atom, a trend consistent across the series of alkyl bromides. These properties have been studied in the context of solvent design and partitioning behavior, where halogenated hydrocarbons display distinctive interactions compared to hydrocarbons of similar chain length.

Safety considerations have accompanied the use of 1-bromohexane since its identification. Like other alkyl bromides, it is harmful if inhaled, ingested, or absorbed through the skin. Exposure can irritate the eyes, respiratory system, and skin, and prolonged contact may have toxic effects on the liver and nervous system. Industrial and laboratory protocols emphasize proper ventilation, personal protective equipment, and safe handling to mitigate these risks. Its environmental persistence as a halogenated hydrocarbon has also prompted careful waste management practices.

The discovery and utilization of 1-bromohexane illustrate the importance of simple halogenated hydrocarbons in advancing both theoretical and applied chemistry. As a reagent, it has facilitated the construction of countless molecular structures, and as a subject of study, it has helped clarify fundamental aspects of reactivity and structure–property relationships. Today, 1-bromohexane continues to function as a useful intermediate in synthetic and industrial chemistry, bridging the gap between laboratory-scale transformations and practical applications in materials, surfactants, and fine chemicals.

References

2023. Ionic Liquid Applications. Journal of Solid State Electrochemistry, 27(9).
DOI: 10.1007/s10008-023-05763-9

2024. Surfactant Properties. Studies in Systems, Decision and Control, 519.
DOI: 10.1007/978-3-031-81564-5_39

2024. CO2 Solubility. Korean Journal of Chemical Engineering, 41(5).
DOI: 10.1007/s11814-024-00127-z