1,11-Dibromoundecane
[CAS# 16696-65-4]

Identification

• Classification: Organic raw materials >> Hydrocarbon compounds and their derivatives >> Hydrocarbon halide
• Name: 1,11-Dibromoundecane
• Molecular Formula: C₁₁H₂₂Br₂
• Molecular Weight: 314.10
• CAS Registry Number: 16696-65-4
• EC Number: 240-745-0
• SMILES: C(CCCCCBr)CCCCCBr

Properties

• Density: 1.3±0.1 g/cm³ Calc.^*, 1.335 g/mL (Expl.)
• Melting point: -10.6 ºC (Expl.)
• Boiling point: 327.2 ºC 760 mmHg (Calc.)^*, 350 - 352.6 ºC (Expl.)
• Flash point: 167.1±18.2 ºC (Calc.)^*, 113 ºC (Expl.)
• Index of refraction: 1.491 (Calc.)^*, 1.491 (Expl.)

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

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H302-H315-H319-H335
• Precautionary Statements: P261-P305+P351+P338

Discovory and Applicatios

1,11-Dibromoundecane is an organic compound consisting of an eleven-carbon straight alkyl chain with bromine atoms attached at both terminal carbons. Its molecular formula is C₁₁H₂₀Br₂, and it belongs to the class of α,ω-dihaloalkanes, specifically a dibromoalkane. The presence of bromine atoms at both ends of the molecule imparts high reactivity, making it a versatile intermediate in organic synthesis and materials chemistry.

The synthesis of 1,11-dibromoundecane typically involves the halogenation of 1,11-undecanediol or the dibromination of terminal alkenes with eleven carbon atoms. One common method is the conversion of 1,11-undecanediol to the corresponding dibromide using reagents such as phosphorus tribromide (PBr₃) or hydrobromic acid under controlled conditions to selectively replace the hydroxyl groups with bromine atoms. Alternatively, dibromination of terminal alkenes via addition of bromine across the double bond followed by chain extension can yield the target compound.

1,11-Dibromoundecane’s bifunctional nature, with two electrophilic bromine termini, makes it highly useful as a difunctional alkylating agent. It undergoes nucleophilic substitution reactions readily, allowing the introduction of diverse functional groups such as amines, thiols, azides, or cyanides. These transformations enable its application in the synthesis of bifunctional molecules, macrocycles, and polymers.

A notable application of 1,11-dibromoundecane is in the synthesis of macrocyclic compounds via intramolecular cyclization. Under basic or nucleophilic conditions, the molecule can form eleven-membered rings by displacement of one bromine with a nucleophile present in the molecule or an external nucleophile. These macrocycles are studied for their potential as host molecules in supramolecular chemistry and as building blocks in pharmaceutical and material sciences.

In polymer chemistry, 1,11-dibromoundecane serves as a cross-linker or chain extender. Its two reactive bromine atoms facilitate polycondensation reactions with nucleophilic monomers such as diamines or dithiols to form polyamides, polythioethers, or other types of functional polymers. The eleven-carbon spacer contributes flexibility and hydrophobicity to the polymer backbone, affecting mechanical and thermal properties.

In materials science, the compound is also used for surface functionalization. Its bifunctionality enables covalent attachment to surfaces or nanoparticles through nucleophilic substitution, creating modified surfaces with controlled spacing and hydrophobic character. This functionality is valuable in coatings, adhesives, and nanotechnology.

Physically, 1,11-dibromoundecane is typically a colorless to pale yellow liquid or low-melting solid. It has low water solubility but is soluble in common organic solvents such as ethers, alcohols, and chlorinated hydrocarbons. Its molecular weight and polarizability, increased by the presence of bromine atoms, lead to higher boiling point and density relative to non-halogenated alkanes of similar chain length.

The compound requires careful handling due to its potential as an alkylating agent and possible irritant properties. It is sensitive to heat and light, which can promote elimination or decomposition reactions, necessitating storage under inert atmosphere and protected from moisture.

While 1,11-dibromoundecane itself is not used as a pharmaceutical agent, its derivatives synthesized through nucleophilic substitution are investigated in medicinal chemistry and bioconjugation for linker design and molecular scaffolding.

Overall, 1,11-dibromoundecane is a well-established versatile synthetic intermediate. Its dual bromine functionality and flexible alkyl chain facilitate a wide range of chemical transformations, making it valuable in organic synthesis, polymer science, and materials engineering.

References

2007. Solid-State NMR Studies on the Guest Ordering and Dynamics in α,ω-Dibromoalkane/Urea Inclusion Compounds. Applied Magnetic Resonance, 32(3).
DOI: 10.1007/s00723-007-0030-3

2007. Pragmatic Studies on Protein-Resistant Self-Assembled Monolayers. Monatshefte für Chemie - Chemical Monthly, 138(4).
DOI: 10.1007/s00706-007-0584-7

1989. Liquid crystalline polyethers based on conformational isomerism. Polymer Bulletin, 22(5-6).
DOI: 10.1007/bf00718924