2-Bromophenanthrene: Properties, Handling & Lab Use Guide

2-Bromophenanthrene is a brominated polycyclic aromatic hydrocarbon (PAH) serving as a versatile aryl bromide building block in transition-metal-catalyzed cross-coupling reactions and advanced organic synthesis.

CAS Number

573-56-8

Molecular Formula

C₁₄H₉Br

Molecular Weight

257.13 g/mol

Appearance

White to off-white crystalline solid

Recommended Storage

Room temperature, sealed, away from light and moisture

Primary Application

Cross-coupling reactions (Suzuki, Kumada, Negishi), PAH synthesis

Chemical Identity and Physical Properties

2-Bromophenanthrene (CAS 573-56-8) is a monobromo-substituted derivative of phenanthrene, a tricyclic aromatic hydrocarbon. Its molecular formula is C₁₄H₉Br, giving a molecular weight of approximately 257.13 g/mol. The compound typically appears as a white to off-white crystalline solid at ambient conditions.

The bromine substituent is located at the 2-position of the phenanthrene ring system, placing it on the outer ring adjacent to the 1-position. This regiochemistry is significant because it influences the electronic density around the C–Br bond and, consequently, the reactivity of the compound in metal-catalyzed coupling reactions. The C–Br bond in aryl bromides generally exhibits sufficient reactivity for oxidative addition into palladium(0) and nickel(0) catalyst centers, making 2-bromophenanthrene a useful electrophilic coupling partner.

Key physical parameters (literature estimates for aryl bromide PAHs of this class; verify against Certificate of Analysis):

• Melting point: reported in the range of 60–68 °C (flag for confirmation)
• Boiling point: estimated above 350 °C at atmospheric pressure (flag for confirmation)
• Solubility: soluble in common organic solvents (dichloromethane, THF, toluene, DMF); poorly soluble in water
• LogP: high (lipophilic character typical of brominated PAHs)

Synthetic Applications and Research Uses

2-Bromophenanthrene is principally employed as an aryl halide building block in transition-metal-catalyzed cross-coupling chemistry. Its well-defined regiochemistry at the 2-position allows chemists to install diverse functional groups selectively on the phenanthrene scaffold.

Key synthetic applications include:

• Suzuki–Miyaura coupling: Reaction with arylboronic acids in the presence of a palladium catalyst (e.g., Pd(PPh₃)₄ or Pd(dppf)Cl₂) and a base yields 2-arylphenanthrene derivatives useful in OLED materials research and supramolecular chemistry.
• Kumada coupling: Reaction with Grignard reagents under nickel or palladium catalysis provides access to 2-alkyl- or 2-aryl-phenanthrenes.
• Negishi coupling: Use of organozinc reagents enables further functionalization with high functional-group tolerance.
• Buchwald–Hartwig amination: Introduction of amine groups at the 2-position, relevant for the synthesis of nitrogen-containing PAH derivatives used in organic electronics.
• Lithiation/metal-halogen exchange: The C–Br bond can be used as a handle for directed ortho-metalation or halogen–metal exchange to generate 2-phenanthryllithium or related organometallic nucleophiles.

In materials science, phenanthrene-based compounds produced via coupling of 2-bromophenanthrene are investigated as components of organic semiconductors, fluorescent probes, and liquid-crystal materials. In medicinal chemistry, functionalized phenanthrenes derived from this building block may serve as scaffolds for bioactive compound libraries.

Safe Handling, Storage, and Waste Disposal

As a brominated polycyclic aromatic hydrocarbon, 2-bromophenanthrene should be handled with appropriate precautions in a properly ventilated laboratory environment.

Personal Protective Equipment (PPE):

• Wear nitrile or neoprene gloves to prevent skin contact.
• Use safety glasses or chemical splash goggles.
• A laboratory coat is required; consider a dust mask or half-face respirator when handling powder to avoid inhalation of fine particles.

Storage Guidelines:

• Store in a tightly sealed container at room temperature (15–25 °C), away from direct light, heat sources, and moisture.
• Keep away from strong oxidizers.
• Verify long-term stability and any specific storage temperature requirements on the product Certificate of Analysis (CoA) supplied by Aladdin Scientific.

Waste Disposal:

• Do not dispose of brominated aromatic compounds via drain or general waste streams.
• Collect in appropriate halogenated waste containers and dispose of in accordance with local, regional, and national environmental regulations.
• Consult your institution's Environmental Health and Safety (EHS) office for guidance.

Note: Always consult the current Safety Data Sheet (SDS) for this product before use. Hazard classifications should be confirmed against the most up-to-date SDS provided by Aladdin Scientific.

Quality, Purity, and Specification Guidance

For reproducible results in synthetic chemistry and materials research, reagent purity is a critical parameter when working with 2-bromophenanthrene.

Typical purity grades available: Research-grade 2-bromophenanthrene is commonly offered at ≥97% or ≥98% purity (GC). Researchers requiring higher purity for sensitive applications (e.g., OLED device fabrication) should request sublimed or HPLC-purified material and verify the specification with Aladdin Scientific before ordering.

Analytical characterization methods:

• GC or GC-MS: Used to determine chemical purity and confirm molecular identity (M⁺ = 256/258, isotope pattern characteristic of monobromide).
• ¹H NMR and ¹³C NMR: Confirm regiochemistry; the aromatic proton pattern should be consistent with 2-substitution on the phenanthrene ring.
• Melting point determination: A sharp, reproducible melting point is indicative of high purity.
• HPLC: Useful for quantifying trace impurities, including positional isomers (e.g., 3-bromophenanthrene, 9-bromophenanthrene).

Isomeric impurities: Researchers should be aware that commercial syntheses of 2-bromophenanthrene may co-produce positional isomers. Confirm isomeric purity with the supplier's CoA or conduct independent HPLC analysis if high regiochemical fidelity is required for the target application.

Contact Aladdin Scientific technical support for custom purity specifications, bulk quantities, or tailored analytical documentation.

Frequently asked questions

What is 2-Bromophenanthrene primarily used for in research?

2-Bromophenanthrene is primarily used as an aryl halide building block in transition-metal-catalyzed cross-coupling reactions such as Suzuki–Miyaura, Kumada, and Negishi couplings, enabling the synthesis of functionalized phenanthrene derivatives for organic electronics, materials science, and medicinal chemistry applications.

How should 2-Bromophenanthrene be stored to maintain stability?

Store 2-Bromophenanthrene in a tightly sealed container at room temperature (15–25 °C), protected from light, heat, and moisture. Keep it away from strong oxidizing agents. Always confirm specific storage requirements on the product Certificate of Analysis provided by Aladdin Scientific.

Are there positional isomers to be aware of when purchasing 2-Bromophenanthrene?

Yes. Commercial synthesis of 2-bromophenanthrene can co-produce positional isomers such as 3-bromophenanthrene and 9-bromophenanthrene. Researchers requiring high regiochemical purity should request the supplier's Certificate of Analysis and, if necessary, verify isomeric purity by independent HPLC analysis before use in sensitive applications.

What solvents are suitable for dissolving 2-Bromophenanthrene?

2-Bromophenanthrene is soluble in common organic solvents including dichloromethane, tetrahydrofuran (THF), toluene, and DMF. It is poorly soluble in water due to its highly lipophilic polycyclic aromatic structure. Solvent selection should be guided by the specific reaction or analytical method being used.

What purity grade of 2-Bromophenanthrene should I order for OLED research?

For OLED device fabrication and other performance-critical materials applications, we recommend requesting sublimed-grade or HPLC-purified 2-bromophenanthrene with purity ≥98% (or higher if available). Contact Aladdin Scientific technical support to discuss custom purity specifications and appropriate analytical documentation for your application.

References

1. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press: Oxford, 2012. (General reference for cross-coupling chemistry and aryl halide reactivity.)
2. Miyaura, N.; Suzuki, A. Palladium-Catalyzed Cross-Coupling Reactions of Organoboron Compounds. Chem. Rev. 1995, 95, 2457–2483. doi:10.1021/cr00039a007
3. Harvey, R. G. Polycyclic Aromatic Hydrocarbons; Wiley-VCH: New York, 1997. (Reference for PAH chemistry and bromination regiochemistry.)

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