Bis(chlorodimethylsilyl)methane is a bifunctional organosilicon compound registered under CAS 5357-38-0. Chemists also call it chloro-[(chloro-dimethylsilyl)methyl]-dimethylsilane, a name that describes its full structure rather than its shorthand form. The compound belongs to the chlorosilane family, and more specifically to the carbosilane group, since a carbon atom bridges its two silicon centers instead of an oxygen atom.
This molecule shows up in labs and production lines that build organosilicon materials, silicone polymers, and specialty coupling agents. Below is a plain look at what it is, how it behaves, and where it fits into real synthesis work.
What Bis(chlorodimethylsilyl)methane Actually Is
The molecule has two silicon atoms connected by a single methylene (CH2) bridge, each silicon carrying two methyl groups and one chlorine atom. This layout gives it the molecular formula C5H14Cl2Si2, with a molecular weight near 201.2 g/mol.
Because both silicon atoms carry a reactive chlorine substituent, the compound acts as a bifunctional building block. One chlorine can react while the other stays intact, or both can react in sequence during a multi-step synthesis. This dual reactivity separates it from simple monofunctional chlorosilanes and puts it closer to disilylmethane compounds used as coupling agents.
Molecular Structure and Naming
The systematic name, chloro-[(chloro-dimethylsilyl)methyl]-dimethylsilane, spells out the connectivity atom by atom: a dimethylsilyl group with one chlorine, linked through a methylene carbon to a second dimethylsilyl group carrying its own chlorine. In practice, suppliers and researchers shorten this to bis(chlorodimethylsilyl)methane, and this shorter form is what shows up most often in catalogs, safety data sheets, and literature searches.
The Si-CH2-Si backbone is the defining feature of the carbosilane monomer class. Unlike siloxanes, where silicon atoms link through oxygen, carbosilanes keep a carbon in the middle of the chain. This carbon bridge changes how the molecule reacts and how stable it stays under heat and moisture, which matters for anyone selecting a building block for a polymer backbone.
Physical and Chemical Properties
Bis(chlorodimethylsilyl)methane is typically supplied as a clear to pale liquid at room temperature, consistent with other low-molecular-weight chlorosilanes. Properties commonly requested by buyers, such as boiling point, refractive index, and density of CAS 5357-38-0, vary slightly by batch and purity grade, so it is worth requesting the current certificate of analysis from the supplier rather than relying on generic figures found online.
What stays consistent across batches is the chemical behavior tied to the Si-Cl bonds. These bonds hydrolyze readily on contact with moisture, releasing hydrogen chloride and forming Si-OH groups that can then condense further. This means the compound needs dry handling conditions and sealed storage, a point covered further down.
Synthesis Routes for CAS 5357-38-0
Production of this compound generally follows established chlorosilane chemistry. One common approach uses Grignard coupling, where a methylene-linked precursor reacts with a methylmagnesium halide to build the disilylmethane skeleton, followed by chlorination to install the two Si-Cl groups. Direct chlorination of the corresponding disilylmethane hydride is another route used in industrial settings, offering better control over the degree of substitution.
Both paths require anhydrous conditions and controlled temperatures, since the same Si-Cl reactivity that makes the product useful downstream also makes premature side reactions a risk during synthesis. Manufacturers with tight control over chlorination steps tend to produce material with more consistent purity, which matters for buyers working on sensitive polymer or coupling applications.
Reactivity of the Si-Cl Bonds
The two chlorine atoms are the working parts of this molecule. Each one is a leaving group that can be swapped out for alkoxy groups, hydroxyl groups, or other nucleophiles, depending on the reagent used. This is what makes bifunctional chlorosilane intermediates like this one valuable for carbosilane polymer synthesis: each end of the molecule can attach to a different growing chain, or the same chain can loop back and cross-link.
Steric bulk from the four methyl groups slows the hydrolysis rate compared to less hindered chlorosilanes, giving chemists a workable window to carry out selective reactions before both chlorines react at once. This balance between reactivity and control is part of why the compound is chosen over less hindered alternatives for stepwise synthesis work.
Applications in Organosilicon Chemistry
The main use of bis(chlorodimethylsilyl)methane is as a reactive disilylmethane building block for functional silicon materials. It serves as an organosilicon synthesis intermediate in several settings:
As a precursor for polycarbosilanes and silicone polymers, where the Si-CH2-Si unit becomes part of the repeating backbone, contributing to the hydrolytic and thermal stability of carbosilane linkages compared to standard siloxane chains.
As a crosslinking agent for functional organosilicon materials, where its two reactive chlorine sites let it bridge separate polymer chains and build denser, more heat-resistant networks. This bridging behavior is explored in more depth in our article on bis(methyldimethoxysilyl)methane in crosslinking technology, which covers a related methoxy-functional analog used for similar network-building work.
As an organodichlorosilane bridging monomer for polymer crosslinking in specialty coatings and sealants, where the carbon bridge improves flexibility over purely siloxane-based systems.
For chemists comparing chlorine-substitution levels on similar carbosilane backbones, our page on bis(trichlorosilyl)methane carbosilane intermediate lays out how a fully trichlorinated version of this same methylene-bridged skeleton behaves differently in terms of reactivity and network density. Readers researching the broader synthesis landscape can also see how this fits among reactive chlorosilane intermediates in organosilicon materials synthesis, which surveys several chlorosilane building blocks side by side.
Storage and Handling
Because the Si-Cl bonds hydrolyze on contact with atmospheric moisture, this compound should be kept in tightly sealed containers under inert gas where possible. Exposure to humid air releases hydrogen chloride gas, which is corrosive and irritating, so handling should happen in a fume hood with appropriate gloves and eye protection.
Cool, dry storage away from bases, alcohols, and amines extends shelf life and keeps the material at full reactive strength for downstream synthesis. Buyers ordering in bulk should confirm packaging under nitrogen or argon with their supplier before shipment.
Sourcing CAS 5357-38-0
Buyers searching for a reliable 5357-38-0 supplier or 5357-38-0 manufacturer typically look for consistent purity, moisture-controlled packaging, and available technical documentation covering the synthesis route used. Dakenchem supplies this cas 5357-38-0 supplier grade material with batch-specific specifications available on request, suited for research quantities as well as larger production orders.
Frequently Asked Questions
1. What is bis(chlorodimethylsilyl)methane used for?
It is mainly used as a bifunctional intermediate in organosilicon synthesis, serving as a building block for polycarbosilanes, crosslinking agents, and other silicone-based materials that need a carbon-bridged silicon backbone.
2. Is CAS 5357-38-0 the same as chloro-[(chloro-dimethylsilyl)methyl]-dimethylsilane?
Chloro-[(chloro-dimethylsilyl)methyl]-dimethylsilane is the full systematic name for the same molecule commonly called bis(chlorodimethylsilyl)methane, both registered under CAS 5357-38-0.
3. Why does this compound react with moisture?
The two Si-Cl bonds hydrolyze when they contact water vapor, releasing hydrogen chloride and forming silanol groups. This is standard behavior for chlorosilanes and is why dry, sealed storage matters.
4. How does this compound differ from bis(trichlorosilyl)methane?
Bis(chlorodimethylsilyl)methane carries two chlorines total, one per silicon, with the rest of the silicon valence filled by methyl groups. Bis(trichlorosilyl)methane carries three chlorines per silicon, giving it higher reactivity and a different crosslink density when used in polymer synthesis.
5. Can this compound be used to build crosslinked silicone networks?
Its two reactive chlorine sites let it link separate polymer chains together, making it useful as a crosslinking agent for functional organosilicon materials, particularly where a carbon-bridged backbone improves flexibility over standard siloxane networks.
