1,1,3,3-Tetramethyldisiloxane
[CAS# 3277-26-7]

Identification

• Classification: Chemical reagent >> Organic reagent >> Siloxane
• Name: 1,1,3,3-Tetramethyldisiloxane
• Molecular Formula: C₄H₁₄OSi₂
• Molecular Weight: 134.32
• CAS Registry Number: 3277-26-7
• EC Number: 221-906-4
• SMILES: C[Si](C)O[Si](C)C

Properties

• Density: 0.759 g/mL (4 ºC) (Expl.)
• Melting point: -78 ºC (Expl.)
• Refractive index: 1.37 (Expl.)
• Boiling Point: 70.8±9.0 ºC (760 mmHg), Calc.^*, 71 ºC (Expl.)
• Flash Point: -3.4±18.7 ºC, Calc.^*, -20 ºC (Expl.)
• Water solubility: DECOMPOSES

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

Safety Data

• Hazard Symbols: GHS02;GHS07 Danger
• Hazard Statements: H225-H315-H319-H335
• Precautionary Statements: P210-P233-P240-P241-P242-P243-P261-P264-P264+P265-P271-P280-P302+P352-P303+P361+P353-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P370+P378-P403+P233-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	2	H225
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319

• Transport Information: UN 1993

Discovory and Applicatios

1,1,3,3-Tetramethyldisiloxane, a silicon-based compound, is widely recognized for its unique properties in hydrosilylation and its application in synthetic chemistry. Discovered as part of ongoing research into siloxane compounds, it belongs to a group of organosilicon compounds known for their thermal stability, low surface tension, and hydrophobic properties. Structurally, this compound consists of a siloxane backbone flanked by two methyl groups on each silicon atom, providing steric stability and resistance to various chemical reactions.

One of the most significant applications of 1,1,3,3-tetramethyldisiloxane is in hydrosilylation, a key process for introducing silicon-hydrogen bonds into organic molecules. The compound’s ability to donate these bonds allows it to act as a selective reducing agent in organic synthesis. For instance, it facilitates the reduction of carbonyl and alkene groups in the presence of suitable catalysts, creating silicon-organic frameworks used in the production of pharmaceuticals, specialty chemicals, and silicone polymers. The stability of 1,1,3,3-tetramethyldisiloxane in these reactions is enhanced by its unique siloxane structure, which prevents unwanted side reactions and ensures higher yields of the desired product.

Additionally, 1,1,3,3-tetramethyldisiloxane is valuable in the field of polymer chemistry, where it serves as a cross-linking agent to modify the properties of silicones. This application is critical in the creation of silicone elastomers and resins, which benefit from improved flexibility, durability, and resistance to environmental degradation. Its use in the formulation of high-performance materials, including coatings, adhesives, and sealants, underscores the compound’s versatility and stability, which are essential for industrial applications where long-term exposure to heat, chemicals, and mechanical stress is common.

The compound’s role extends into cosmetics and personal care products, where it serves as an emollient and conditioning agent. Its low surface tension enables it to spread easily on the skin, creating a smooth, soft finish that is non-greasy and resistant to moisture. This characteristic makes it suitable for use in skin creams, hair products, and antiperspirants, providing a protective barrier that locks in moisture without blocking pores.