Perfluoro-C2-18-Alkylethyl Iodides: Properties & Applications

Perfluoro-C2-18-alkylethyl iodides is a family of fluorinated telomer iodide compounds bearing perfluoroalkyl chains of varying length (C2–C18) that serve as versatile reactive intermediates in the synthesis of fluorosurfactants, polymer additives, and surface-active materials.

Chemical Class

Perfluoroalkylethyl iodides (fluorotelomer iodides)

Chain Length Range

C2 to C18 perfluoroalkyl backbone

Key Functional Group

Terminal C–I bond enabling radical and ionic chemistry

Primary Use

Synthetic intermediate for fluorosurfactants, coatings, and polymer additives

Typical Physical State

Colorless to pale yellow liquids or low-melting solids depending on chain length

SKU

P1530043

Chemical Identity and Structure

Perfluoro-C2-18-alkylethyl iodides, also referred to as fluorotelomer iodides, are compounds with the general structure F(CF₂CF₂)_nCH₂CH₂I, where n ranges from 1 to 9, giving perfluoroalkyl chain lengths from C2 to C18. The fully fluorinated carbon chain confers exceptional chemical and thermal stability, extremely low surface energy, and high hydrophobicity and oleophobicity. The terminal iodo group provides a reactive handle for further functionalization via radical addition, nucleophilic substitution, and elimination reactions.

The carbon–iodine bond in these telomers is significantly weaker than a typical C–F bond, making it the preferred site for chemical transformation while leaving the perfluoroalkyl backbone intact. This selectivity is central to their utility as building blocks in fluorochemical synthesis.

Synthesis and Telomerization Chemistry

These compounds are classically prepared by free-radical telomerization of tetrafluoroethylene (TFE) using iodoperfluoroalkanes or alkyl iodides as chain-transfer agents (telogens). The reaction proceeds under thermal or photochemical initiation, and the chain length distribution—and therefore the C2–C18 mixture composition—is controlled by the ratio of TFE to telogen and reaction conditions. Commercial grades are typically supplied as mixtures enriched in specific even-numbered chain lengths, reflecting the two-carbon repeat unit added per TFE insertion.

The ethylene spacer (–CH₂CH₂–) between the perfluoroalkyl chain and the iodine atom is a defining structural feature that distinguishes these telomer iodides from directly perfluorinated alkyl iodides; this spacer improves processing characteristics and provides a hydrocarbon bridge that facilitates subsequent chemical reactions.

Research and Industrial Applications

Perfluoro-C2-18-alkylethyl iodides serve as key intermediates in a broad range of applications:

• Fluorosurfactant synthesis: Conversion to acrylates, methacrylates, sulfonates, or phosphates yields surface-active agents used in coatings, firefighting foams, and emulsion polymerization.
• Polymer additives: Incorporation into polymer backbones imparts low-friction, anti-fouling, and oil/water repellent properties to textiles, films, and molded parts.
• Surface modification: Used to prepare self-assembled monolayers (SAMs) and covalently grafted fluorinated surfaces for study in wettability, tribology, and biomedical device research.
• Radical chemistry probes: The labile C–I bond is exploited in atom-transfer radical addition (ATRA) and related processes to introduce perfluoroalkyl groups onto olefins and other substrates under mild conditions.
• Fluorinated pharmaceutical and agrochemical intermediates: Longer-chain variants provide hydrophobic fluorinated modules for medicinal chemistry exploration.

Handling, Safety, and Storage

As with all perfluoroalkyl-containing compounds, researchers should consult the Safety Data Sheet (SDS) prior to use. General precautions include:

• Storage: Store in a cool, dry, well-ventilated area away from light and moisture. Tightly sealed containers prevent absorption of atmospheric moisture and photochemical degradation of the C–I bond.
• Personal protective equipment: Use chemical-resistant gloves, safety goggles, and work in a fume hood to avoid inhalation of vapor or aerosols.
• Environmental considerations: Perfluoroalkyl substances (PFAS) are subject to increasing regulatory scrutiny due to environmental persistence. Dispose of waste in accordance with local regulations for halogenated organic compounds.
• Reactivity: The C–I bond can be activated by light or heat; avoid prolonged UV exposure or heating above recommended temperatures without appropriate controls.

Users are encouraged to review current PFAS regulations in their jurisdiction before large-scale use or disposal.

Ordering Information and Specifications

Aladdin Scientific supplies Perfluoro-C2-18-alkylethyl iodides under SKU P1530043. For detailed purity specifications, available pack sizes, certificate of analysis (CoA), and current pricing, please refer to the product page or contact our technical sales team. Custom quantities and purity grades may be available upon request.

For research requiring defined chain-length fractions rather than the broad C2–C18 mixture, please inquire about specific telomer cuts or related single-chain-length perfluoroalkylethyl iodide products in our catalog.

Frequently asked questions

What is the difference between perfluoro-C2-18-alkylethyl iodides and perfluoroalkyl iodides?

Perfluoro-C2-18-alkylethyl iodides contain a two-carbon hydrocarbon spacer (–CH2CH2–) between the perfluoroalkyl chain and the iodine atom, whereas simple perfluoroalkyl iodides have the iodine directly bonded to the fluorocarbon chain. This ethylene bridge improves handling characteristics and broadens the range of accessible downstream chemistry.

Why are these compounds supplied as a C2–C18 mixture rather than a single chain length?

The telomerization process inherently produces a distribution of chain lengths because each TFE insertion step can either continue or terminate. Commercial mixtures are the natural output of this process and are suitable for many applications. When a specific chain length is needed, purified single-cut fractions can often be requested separately.

Are perfluoro-C2-18-alkylethyl iodides subject to PFAS regulations?

Perfluoroalkyl-containing substances broadly fall under the PFAS classification in many regulatory frameworks, and their use, handling, and disposal may be subject to regional restrictions. Researchers should consult up-to-date local and international regulations (e.g., EU REACH, US EPA PFAS rules) before procurement and use.

How should perfluoro-C2-18-alkylethyl iodides be stored to maintain stability?

Store tightly sealed in a cool, dark, and dry location. The C–I bond is susceptible to homolytic cleavage upon UV irradiation or prolonged heating, so protection from light and excessive heat is essential. Under recommended storage conditions, the compounds are expected to be stable for extended periods.

References

1. Hiyama, T. Organofluorine Compounds: Chemistry and Applications. Springer, 2000.
2. Kirsch, P. Modern Fluoroorganic Chemistry: Synthesis, Reactivity, Applications. Wiley-VCH, 2004.
3. Aladdin Scientific Product Page: Perfluoro-C2-18-alkylethyl iodides, SKU P1530043.

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.