2,2,4,4,6,6-Hexamethylcyclotrisilazane

2,2,4,4,6,6-Hexamethylcyclotrisilazane was first synthesized in 1948 by Brewer and Haber via the reaction of dimethyldichlorosilane Si(CH3)2Cl2 with liquid ammonia NH3, followed by extraction and precipitation with benzene.

2,2,4,4,6,6-Hexamethylcyclotrisilazane is a colorless liquid that is soluble in water. It has an odor similar to ether and a boiling point of about 100 degrees Celsius. The chemical formula for this compound is CH3(CH2)6SiCl6. 2,2,4,4,6,6-Hexamethylcyclotrisilazane has been used as a solvent for producing polymers and as a reagent for organic synthesis. It may also be used as a precursor to silicon dioxide nanoparticles used in producing semiconductors and solar cells. 2,2,4,4,6,6-Hexamethylcyclotrisilazane reacts with hydrochloric acid to produce hydrogen chloride gas and zirconium oxide. It also reacts with sodium citrate in the presence of fatty acids to form an ester product called methyl eth.

clear colorless liquid

2,2,4,4,6,6-Hexamethylcyclotrisilazane has been extensively studied as a precursor for silicon nitride and silicon carbonitride deposition and can also be used as an additive in photoresists. As one of the common silazanes, it is also a good monomer for synthesizing polymers. It readily undergoes ring-opening and copolymerizes with various monomers in the presence of hydroxyl groups, and has wide applications in the synthetic rubber and engineering plastics industries.

Moderately toxic by ingestion.

Flammable

Purify it by fractional distillation at atmospheric pressure until the temperature reaches 200o. It is moisture sensitive. The residue in the flask is mostly octamethylcyclotetrasilazane. [Brewer & Haber J Am Chem Soc 70 3888 1948, Beilstein 4 III 1887.]

The ITSL for hexamethylcyclotrisilazane is 0.1 μg/m3 based on an annual averaging time.