Diphenyldimethoxysilane
[CAS# 6843-66-9]

Identification

• Classification: Chemical reagent >> Organic reagent >> Silane
• Name: Diphenyldimethoxysilane
• Molecular Formula: C₁₄H₁₆O₂Si
• Molecular Weight: 244.36
• CAS Registry Number: 6843-66-9
• EC Number: 229-929-1
• SMILES: CO[Si](C1=CC=CC=C1)(C2=CC=CC=C2)OC

Properties

• Density: 1.1±0.1 g/cm³, Calc.^*, 1.079 g/mL (Expl.)
• Index of Refraction: 1.543, Calc.^*, 1.545 (Expl.)
• Boiling Point: 286.6±13.0 °C (760 mmHg), Calc.^*, 161 °C (15 mmHg) (Expl.)
• Flash Point: 159.1±7.4 °C, Calc.^*, 121 °C (Expl.)

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

Safety Data

• Hazard Symbols: GHS07;GHS09 Warning
• Risk Statements: H315-H411
• Safety Statements: P264-P273-P280-P302+P352-P321-P332+P317-P362+P364-P391-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Eye irritation	Eye Irrit.	2	H319
Reproductive toxicity	Repr.	1B	H360
Specific target organ toxicity - repeated exposure	STOT RE	1	H372
Flammable liquids	Flam. Liq.	2	H225
Specific target organ toxicity - single exposure	STOT SE	1	H370
Acute toxicity	Acute Tox.	4	H302

Discovery and Applications

Diphenyldimethoxysilane is an organosilicon compound widely used in materials science, organic synthesis, and the production of high-performance coatings. Structurally, it consists of two phenyl groups and two methoxy groups attached to a silicon atom. This combination allows it to act as a useful intermediate for creating silicon-based materials with tailored properties. The versatility of this compound arises from the reactivity of the methoxy groups and the hydrophobic nature of the phenyl groups.

The compound was first identified in the context of organosilicon chemistry research in the early to mid-20th century when chemists were exploring silicon-based alternatives to carbon-based molecules. The pioneering work of researchers like Rochow and Müller laid the foundation for understanding the synthesis and applications of such silanes. Diphenyldimethoxysilane quickly garnered attention for its potential use in creating functional siloxane polymers and coatings due to its bifunctional nature.

The synthesis of diphenyldimethoxysilane typically involves the reaction of dichlorodiphenylsilane with methanol. This process proceeds through the replacement of chlorine atoms with methoxy groups, facilitated by the formation of hydrogen chloride as a byproduct. The reaction is typically carried out under controlled conditions to ensure a high yield of the desired product. This method remains one of the most efficient and widely adopted routes for producing diphenyldimethoxysilane.

Diphenyldimethoxysilane is primarily used as a precursor in the synthesis of silicone resins and functionalized siloxanes. These materials exhibit excellent thermal stability, hydrophobicity, and chemical resistance, making them suitable for applications in coatings, adhesives, and sealants. It also plays a role in surface modification processes, where it imparts water-repellent properties to materials. Additionally, diphenyldimethoxysilane is used in the production of hybrid organic-inorganic materials, which combine the advantages of both organic polymers and inorganic silicates.

In the field of electronics, this compound is used to create protective coatings for semiconductors and other components requiring stability under harsh conditions. Its application extends to the development of optical materials, where it helps enhance the durability and performance of lenses and other devices. Continued research focuses on optimizing the properties of materials derived from diphenyldimethoxysilane for use in emerging technologies, including nanocomposites and advanced functional coatings.

References

2019. 1,3-Dimethoxy-1,3-dimethyl-1,3-diphenyl- and 1,3-dimethoxy-1,3-tetraphenyldisiloxanes: synthesis and structure. Russian Chemical Bulletin, 68(8).
DOI: 10.1007/s11172-019-2596-y

2018. Applications of melting gels. Journal of Sol-Gel Science and Technology, 86(1).
DOI: 10.1007/s10971-018-4599-9

2019. Polypropylene synthesis in liquid monomer with titanium-magnesium catalyst: effect of different alkoxysilanes as external donors. Journal of Polymer Research, 26(6).
DOI: 10.1007/s10965-019-1794-5