4-Bromotetraphenylsilane: Properties, Handling & Lab Guidelines

4-Bromotetraphenylsilane is a brominated tetraarylsilane building block widely employed in organometallic synthesis, cross-coupling reactions, and the construction of advanced functional materials.

CAS / SKU

18737-40-1 / B152791

Molecular Formula

C₂₄H₁₉BrSi

Molecular Weight

427.39 g/mol

Appearance

White to off-white crystalline solid

Key Functional Groups

Aryl bromide; tetracoordinate silicon centre

Primary Applications

Cross-coupling substrates, functional material precursors, ligand synthesis

Chemical Identity and Physical Properties

4-Bromotetraphenylsilane (SKU B152791, CAS 18737-40-1) is a member of the tetraarylsilane family in which one para-hydrogen of a phenyl ring is replaced by a bromine atom. Its molecular formula is C₂₄H₁₉BrSi with a molecular weight of approximately 427.39 g/mol. The compound presents as a white to off-white crystalline solid at ambient conditions.

The silicon centre adopts a tetrahedral geometry with four phenyl substituents, rendering the molecule highly symmetric apart from the single bromo substituent. This structural feature imparts a relatively high melting point typical of tetraarylsilanes, good thermal stability, and low volatility, making it convenient to weigh and handle on the bench. The compound is sparingly soluble in polar protic solvents but dissolves readily in common organic solvents such as dichloromethane, tetrahydrofuran, toluene, and chloroform.

Synthetic Applications and Reactivity

The aryl bromide functionality in 4-Bromotetraphenylsilane serves as a versatile handle for a broad range of synthetic transformations. It is particularly valued as a substrate in transition-metal-catalysed cross-coupling reactions, including Suzuki–Miyaura, Kumada, Negishi, and Buchwald–Hartwig couplings, enabling the introduction of diverse aryl, heteroaryl, vinyl, or amino groups at the para-position of the pendant phenyl ring.

In materials science, 4-Bromotetraphenylsilane is used as a precursor for the synthesis of star-shaped or dendritic architectures, where the tetrahedral silicon core provides a three-dimensional scaffold. Derivatives prepared from this building block find application in organic light-emitting diodes (OLEDs), host materials for phosphorescent emitters, and porous organic frameworks. The silicon centre also imparts electronic insulation between peripheral groups, which is exploited in the design of non-conjugated functional molecules.

Additionally, lithiation protocols — achieved by halogen–metal exchange using n-butyllithium — allow conversion of the aryl bromide to the corresponding aryllithium species, which can be quenched with a wide variety of electrophiles to install functional groups such as boronic esters, aldehydes, or stannanes.

Safe Handling, Storage, and Waste Disposal

Personal Protective Equipment: When handling 4-Bromotetraphenylsilane, wear appropriate laboratory personal protective equipment including chemical-resistant gloves (nitrile recommended), a laboratory coat, and safety glasses or goggles. Conduct all weighing and dissolution operations in a well-ventilated fume hood to minimise inhalation of dust or aerosols.

Storage: Store the compound in a tightly sealed container in a cool, dry location away from strong oxidising agents, moisture, and direct light. A storage temperature of 2–8 °C or room temperature under inert atmosphere is generally suitable for maintaining long-term stability; consult the Certificate of Analysis for lot-specific recommendations. Keep the container tightly closed when not in use to prevent moisture uptake.

Spill Management: In the event of a spill, avoid generating dust. Carefully sweep or vacuum solid material and transfer it to a labelled waste container. Clean the affected area with an appropriate solvent and dispose of all waste in accordance with local and institutional regulations for halogenated organic waste.

First Aid: In case of skin or eye contact, flush immediately with copious amounts of water for at least 15 minutes and seek medical attention if irritation persists. If ingested or inhaled, remove the individual from exposure and seek prompt medical advice. Always consult the Safety Data Sheet (SDS) before use.

Quality, Purity, and Procurement Guidance

Aladdin Scientific supplies 4-Bromotetraphenylsilane (SKU B152791) with purity specifications confirmed by standard analytical techniques such as high-performance liquid chromatography (HPLC) or gas chromatography (GC). Each lot is accompanied by a Certificate of Analysis (CoA) detailing purity, appearance, and other key quality attributes. Researchers should verify the CoA before use, particularly for sensitive applications in catalysis or materials fabrication where trace impurities may affect outcome.

For cross-coupling and lithiation reactions, high purity (≥98%) is recommended to minimise competing side reactions arising from halide impurities or protodebrominated by-products. In cases where ultra-high purity is required, recrystallisation from an appropriate solvent system (e.g., ethanol or acetone/hexane) can be employed to upgrade purity prior to use.

Procurement enquiries, bulk pricing, and custom quantities can be directed to the Aladdin Scientific sales team. Volume discounts may be available; contact customer support for current promotions and lead times.

Frequently Asked Questions at a Glance

This section consolidates the most common technical and logistical queries received from researchers ordering or using 4-Bromotetraphenylsilane. Detailed answers are provided in the FAQ section below. For additional support, Aladdin Scientific's technical team is available via the website contact form or telephone.

Frequently asked questions

What solvents are recommended for dissolving 4-Bromotetraphenylsilane?

4-Bromotetraphenylsilane dissolves readily in common aprotic organic solvents such as dichloromethane, tetrahydrofuran, toluene, and chloroform. It has limited solubility in polar protic solvents like water, methanol, and ethanol. For reactions requiring a coordinating solvent, THF is generally the preferred choice.

How should 4-Bromotetraphenylsilane be stored to maintain stability?

The compound should be stored in a tightly sealed container under cool, dry conditions, away from moisture, strong oxidants, and direct light. Storage at 2–8 °C under an inert atmosphere (nitrogen or argon) is recommended for long-term preservation. Always consult the lot-specific Certificate of Analysis for any additional storage requirements.

Can 4-Bromotetraphenylsilane be used directly in Suzuki–Miyaura cross-coupling reactions?

Yes, the aryl bromide moiety in 4-Bromotetraphenylsilane is well-suited for Suzuki–Miyaura coupling with aryl- or heteroarylboronic acids in the presence of a suitable palladium catalyst and base. Standard palladium catalysts such as Pd(PPh₃)₄ or Pd(dppf)Cl₂ are typically employed. Reaction conditions should be optimised with respect to solvent, base, catalyst loading, and temperature for each specific coupling partner.

Is 4-Bromotetraphenylsilane air-sensitive or moisture-sensitive?

4-Bromotetraphenylsilane is not acutely air-sensitive, but prolonged exposure to atmospheric moisture may lead to gradual degradation. It is best handled and stored under dry conditions, ideally under an inert atmosphere for long-term storage. Brief bench-top exposure during weighing is generally acceptable for a solid of this type.

What is the typical purity of B152791 supplied by Aladdin Scientific?

Aladdin Scientific supplies 4-Bromotetraphenylsilane (B152791) with purity confirmed by analytical methods such as HPLC or GC. The exact purity specification is stated on the Certificate of Analysis accompanying each lot. Researchers are encouraged to download the CoA from the product page or contact customer support for lot-specific data.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley-Interscience: New York, 1992. (General reference for aryl halide reactivity and cross-coupling.)
2. Miyaura, N.; Suzuki, A. Palladium-Catalyzed Cross-Coupling Reactions of Organoboron Compounds. Chem. Rev. 1995, 95, 2457–2483. doi:10.1021/cr00039a007
3. Aladdin Scientific Certificate of Analysis, 4-Bromotetraphenylsilane, SKU B152791. (Lot-specific purity and quality data; available on request or product page.)

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