(3-Bromophenyl)triphenylsilane: Properties, Synthesis & Applications

(3-Bromophenyl)triphenylsilane is a bifunctional organosilicon compound bearing both an aryl bromide handle and a triphenylsilyl group, making it a versatile building block for transition-metal-catalyzed cross-coupling reactions, materials science, and the synthesis of complex silicon-containing architectures.

CAS Number

18776-12-0

Molecular Formula

C₂₄H₁₉BrSi

Molecular Weight

427.40 g/mol

Functional Groups

Aryl bromide, triphenylsilyl

Physical State

Solid at room temperature

Key Application

Cross-coupling reactions and organosilicon material synthesis

SKU

B152792

Chemical Identity and Physical Properties

(3-Bromophenyl)triphenylsilane (CAS 18776-12-0) has the molecular formula C₂₄H₁₉BrSi and a molecular weight of approximately 427.40 g/mol. The compound consists of a central silicon atom bonded to three phenyl rings and a meta-bromophenyl substituent, giving it a highly arylated, sterically encumbered structure. At room temperature the compound exists as a crystalline solid. The silicon–carbon bond lengths are consistent with those of other tetraarylsilanes, and the meta-bromo substituent provides a reactive handle without introducing the steric strain associated with ortho substitution. The compound is expected to be stable under dry, ambient storage conditions and should be handled away from strong bases and moisture, which can promote Si–C bond hydrolysis under forcing conditions.

Synthesis and Preparation Routes

(3-Bromophenyl)triphenylsilane is typically prepared by the reaction of a suitable (3-bromophenyl) organometallic species—such as (3-bromophenyl)magnesium bromide or (3-bromophenyl)lithium—with triphenylchlorosilane (Ph₃SiCl). The Grignard route is the most widely used: 1,3-dibromobenzene undergoes selective monolithiation or mono-Grignard formation at one bromide, and the resulting nucleophile attacks the electrophilic silicon center of triphenylchlorosilane, displacing chloride and forming the Si–C bond. Careful control of stoichiometry and reaction temperature is essential to minimize formation of bis- or tris-(3-bromophenyl)silane byproducts. An alternative approach uses palladium-catalyzed silylation of 1,3-dibromobenzene with triphenylsilane under appropriate conditions, though selectivity for mono-functionalization requires optimization. After workup, the crude product is purified by recrystallization or column chromatography.

Research Applications and Reactivity

The bifunctional nature of (3-Bromophenyl)triphenylsilane makes it particularly valuable in several research domains:

• Cross-Coupling Chemistry: The aryl bromide moiety is an excellent electrophilic partner in palladium-catalyzed reactions such as Suzuki–Miyaura, Negishi, Kumada, and Buchwald–Hartwig couplings. Researchers use this compound to introduce the bulky triphenylsilyl-phenyl fragment into complex target molecules via standard coupling protocols.
• Directed Metalation: The triphenylsilyl group acts as a directed metalation group (DMG) under certain conditions, and the aryl bromide enables orthogonal functionalization through oxidative addition to low-valent transition metals.
• Organic Electronic Materials: Triarylsilane-containing conjugated systems are of significant interest in organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs), and photovoltaic devices, where bulky silyl groups improve solubility, film morphology, and excited-state dynamics.
• Polymer Science: The compound can serve as a monomer or chain-end-capping reagent for silicon-containing conjugated polymers.

Its meta substitution pattern minimizes steric conflict during coupling while preserving electronic communication across the extended aryl system.

Handling, Storage, and Safety Considerations

Although (3-Bromophenyl)triphenylsilane is generally considered to be of moderate hazard relative to many reactive organosilicon reagents, standard laboratory precautions apply. The compound should be stored in a tightly sealed container under dry, inert-atmosphere conditions to prevent moisture-induced degradation, ideally at room temperature or under refrigeration as specified on the product datasheet. Personal protective equipment (PPE) including laboratory coat, chemical-resistant gloves, and eye protection should be worn when handling the compound. The aryl bromide functional group is relatively stable under ambient conditions but may generate hydrogen bromide under strongly acidic or hydrolytic conditions. Users should consult the current Safety Data Sheet (SDS) provided by Aladdin Scientific (SKU B152792) for precise hazard classifications, GHS pictograms, first-aid measures, and disposal guidance. Waste containing this compound should be disposed of in accordance with local regulations for halogenated organic waste.

Purity, Specifications, and Quality Assurance

Aladdin Scientific supplies (3-Bromophenyl)triphenylsilane (SKU B152792) with analytical quality control data to support reliable research outcomes. Key characterization methods for this compound typically include:

• ¹H and ¹³C NMR Spectroscopy: Confirms the connectivity of the meta-bromophenyl and three phenyl groups around silicon and verifies the absence of byproducts such as diphenyl or tetraphenylsilane derivatives.
• GC or HPLC Purity Analysis: Provides quantitative purity assessment to ensure the compound meets the specification stated on the Certificate of Analysis (CoA).
• Elemental Analysis or High-Resolution Mass Spectrometry (HRMS): Confirms the molecular formula C₂₄H₁₉BrSi.

Researchers requiring the highest purity should request the current CoA for the specific lot in use. Lot-specific data are available upon request from Aladdin Scientific. Any discrepancies between received material and the CoA should be reported to the Aladdin Scientific technical service team promptly.

Frequently asked questions

What distinguishes (3-Bromophenyl)triphenylsilane from tetraphenylsilane or other bromophenylsilanes?

(3-Bromophenyl)triphenylsilane uniquely combines the inertness and bulk of the triphenylsilyl group with a reactive aryl bromide at the meta position, providing a single chemically addressable handle for further functionalization. Tetraphenylsilane lacks any reactive halide, while ortho- or para-isomers differ in steric and electronic profiles that affect coupling kinetics and regioselectivity.

Can (3-Bromophenyl)triphenylsilane be used directly in Suzuki–Miyaura coupling reactions?

Yes. The aryl bromide group in (3-Bromophenyl)triphenylsilane participates readily as the electrophilic coupling partner in Suzuki–Miyaura reactions with aryl- or heteroarylboronic acids under standard palladium catalysis conditions (e.g., Pd(PPh₃)₄ or Pd(dppf)Cl₂, base, aqueous-organic solvent). The triphenylsilyl group remains intact under typical Suzuki conditions because Si–C bonds in tetraarylsilanes are not cleaved under mild basic aqueous conditions used in this reaction.

What are the recommended storage conditions for (3-Bromophenyl)triphenylsilane (SKU B152792)?

The compound should be stored in a tightly sealed container, protected from moisture and light, under dry conditions. Please refer to the current product datasheet and SDS provided by Aladdin Scientific for the specific storage temperature, as recommendations may vary by lot. Inert-atmosphere storage (nitrogen or argon) is advisable for long-term preservation.

How can I verify the purity of the received (3-Bromophenyl)triphenylsilane?

Request the Certificate of Analysis (CoA) for the specific lot from Aladdin Scientific (SKU B152792). The CoA typically reports purity by GC or HPLC, along with NMR confirmation data. Independent verification in-house can be performed using ¹H NMR, GC-MS, or HPLC against a known reference standard.

Is (3-Bromophenyl)triphenylsilane suitable for use as a building block in OLED material synthesis?

Yes. Triphenylsilyl-substituted arenes are well-established structural motifs in organic electronic materials, particularly OLEDs, where they improve thermal stability, increase the triplet energy, and reduce intermolecular aggregation. The aryl bromide in (3-Bromophenyl)triphenylsilane allows incorporation into extended conjugated frameworks via palladium-catalyzed coupling.

References

1. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press: Oxford, 2012. (General organosilicon chemistry reference)
2. Hartwig, J. F. Organotransition Metal Chemistry: From Bonding to Catalysis; University Science Books: Sausalito, CA, 2010. (Cross-coupling mechanisms)
3. Miyaura, N.; Suzuki, A. Palladium-Catalyzed Cross-Coupling Reactions of Organoboron Compounds. Chem. Rev. 1995, 95, 2457–2483. doi:10.1021/cr00039a007
4. Aladdin Scientific Product Datasheet and Safety Data Sheet for (3-Bromophenyl)triphenylsilane, SKU B152792. (Internal document; consult current version at aladdin-e.com)

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