Modern industrial chemistry and materials science rely heavily on organosilicon compounds. These adaptable molecules have a wide range of uses. Diisopropyldimethoxysilane (CAS 18230-61-0) is one compound that is especially significant. As a structural control agent and electron donor in particular chemical reactions, this functional silane is necessary. Its special qualities make it valuable to chemists and engineers, particularly in the production of polymers. Its industrial importance is demonstrated by its application as an internal electron donor for polymerization, particularly in propylene polymerization catalysts. Professionals involved in polymer synthesis and catalysis must comprehend this organosilicon compound.
Diisopropyldimethoxysilane’s molecular formula and structure (CAS 18230-61-0)
The molecular structure of a compound determines its reactivity and chemical behavior. The molecular formula for diisopropyldimethoxysilane is C8H20O2Si. Eight carbon atoms, twenty hydrogen atoms, two oxygen atoms, and one central silicon atom make up each molecule.
A central silicon atom is joined to two methoxy groups (-OCH3) and two isopropyl groups (-CH(CH3)2) in the structure. Significant steric hindrance is provided around the silicon atom by this particular configuration. This bulkiness is an important feature. It has a direct impact on the molecule’s interactions with other substances, especially when a catalytic environment is present. Its efficacy as a structural control agent is thus primarily due to this steric bulk.
COSi(OC)C(C)C is the compound’s Simplified Molecular-Input Line-Entry System (SMILES) code. The molecular structure is represented simply and textually by this notation. It demonstrates the atoms’ interconnectedness quite clearly. While the two methoxy groups offer reactive sites for hydrolysis, the two isopropyl groups encircle the silicon in a crowded environment. It is a specialized tool for chemists because of its steric bulk and reactivity. It serves as a hydroxyl protecting reagent in organic chemistry and is a useful precursor in functional silane synthesis, for example.
Diisopropyldimethoxysilane’s Chemical and Physical Characteristics
The physical and chemical characteristics of a substance are fundamental to its practical application, determining its suitability for various industrial processes and dictating the necessary handling and storage protocols. For researchers, chemists, and process engineers, a comprehensive understanding of these traits is not merely academic; it is a critical prerequisite for safe, efficient, and successful implementation. In the case of Diisopropyldimethoxysilane (CAS 18230-61-0), its unique combination of properties makes it an ideal, highly specialized tool for specific functions, particularly in the realm of polymer science. Each property, from its molecular weight to its reactivity, plays a distinct role in its performance and safety profile.
The main physical and chemical characteristics of this organosilicon compound are listed in the table below.
| Property | Value | Significance in Application |
| Molecular Weight | 176.33 g/mol | Necessary for stoichiometric calculations in synthesis and catalyst formulation. |
| Appearance | Colorless transparent liquid | Ensures no color is imparted to end products like polymers or resins. |
| Purity (by GC) | ≥ 99.0% | High purity is critical for consistent performance, especially in sensitive catalytic systems. |
| Density | 0.865 g/cm³ at 25 °C | Important for accurate dosing and handling in industrial-scale processes. |
| Boiling Point | 152-154 °C | Indicates its volatility; useful for purification via distillation and for process temperature control. |
| Refractive Index | 1.408 at 20 °C | A key quality control parameter used to verify purity and consistency between batches. |
| Flash Point | 33 °C (91.4 °F) | Classifies the material as flammable. Dictates strict safety protocols for handling and storage. |
| Hydrolytic Sensitivity | Reacts with water | The methoxy groups are prone to hydrolysis. This reaction is important for its job as a crosslinking agent, but it needs to be stored in dry circumstances. |
The suitability of this organosilicon compound hinges on a delicate balance of these attributes. Its colorless liquid form plays an essential role in applications that require the final product, such as a high-clarity polymer, to remain free from discoloration. The boiling point indicates its volatility, a crucial parameter for managing process temperatures and preventing unwanted evaporation. Perhaps most critically, the compound’s flammability, shown by its low flash point, and its hydrolytic sensitivity define the operational boundaries for its use. The flash point demands strict adherence to safety measures to mitigate fire hazards. Simultaneously, its tendency to react with water—a reaction harnessed for its function as a crosslinking agent—requires storage under dry, inert conditions to prevent premature degradation. This dual nature of its reactivity highlights why a deep-seated knowledge of its chemical behavior is indispensable.
Diisopropyldimethoxysilane’s Industrial Uses
Diisopropyldimethoxysilane’s main and most important use is in polymer chemistry. In Ziegler-Natta catalysts used for propylene polymerization, it acts as a very efficient external electron donor. It performs the function of a stereoregulator, sometimes referred to as a structural control agent. Its job is to regulate the resulting polypropylene chain’s stereochemistry.
The addition of this silane enhances the stereospecificity of the propylene polymerization catalyst during the process. The non-stereospecific active sites on the catalyst surface are specifically poisoned by the large isopropyl groups on the silicon atom. The stereospecific sites can operate more efficiently as a result of this action. Consequently, polypropylene with extremely high isotacticity is produced by the polymerization process. A polymer with high isotacticity, therefore, exhibits better mechanical qualities such as stiffness and tensile strength, along with greater crystallinity and a higher melting point. For the production of high-performance grades of polypropylene, this silane coupling agent is therefore necessary.
This compound has applications outside of catalysis. Functional silane synthesis can begin with it as a precursor. For specific uses, chemists can alter it to produce more intricate organosilicon compounds. In some formulations, it can also act as a crosslinking agent. The methoxy groups hydrolyze to produce reactive silanol groups. A crosslinked network can be formed by these condensing into stable siloxane bonds (-Si-O-Si-). Because of this characteristic, it may be used as a silicone rubber additive to increase the elastomers‘ resilience and thermal stability. Additionally, it can be used as a hydroxyl protecting reagent during intricate organic synthesis in lab settings.
Guidelines for Diisopropyldimethoxysilane Safety and Handling
It is imperative to follow the correct safety protocols when handling diisopropyldimethoxysilane (CAS 18230-61-0). This substance can irritate the skin upon contact and falls under the category of flammable liquids. Before handling the substance, therefore, review its Material Safety Data Sheet (MSDS) carefully.
Employees are required to always wear the proper personal protective equipment (PPE). This includes a face shield or safety goggles to shield the eyes from splashes. To avoid skin contact, gloves that are resistant to chemicals, like those composed of nitrile or neoprene, are necessary. To prevent vapor inhalation. The work area must have easy access to a safety shower and emergency eyewash station.
Another important component of safety is storage. The substance is sensitive to moisture and flammable. Therefore, keep it away from direct sunlight, heat sources, sparks, and open flames. Additionally, to prevent hydrolysis from atmospheric moisture, ensure the containers remain tightly sealed and store them under an inert atmosphere, such as nitrogen. Keep the chemical away from bases, acids, and oxidizing agents. Consequently, following these recommendations reduces risks and ensures the chemical remains stable and effective for its intended use. Use non-flammable absorbent materials to clean up spills and dispose of waste in accordance with local laws.
Commonly Asked Questions (FAQs)
Diisopropyldimethoxysilane has what molecular structure?
C8H20O2Si is the molecular formula.
What is Diisopropyldimethoxysilane’s molecular weight?
About 176.33 g/mol is the molecular weight.
Diisopropyldimethoxysilane has what main uses?
Its primary function in Ziegler-Natta catalysts for propylene polymerization is as an external electron donor and stereoregulator.
Diisopropyldimethoxysilane has what SMILES code?
COSi(OC)C(C)C is the SMILES code.
When handling diisopropyldimethoxysilane, what safety measures should be taken?
In accordance with all MSDS instructions, you must handle it in a well-ventilated area, wear the appropriate PPE, and store it away from moisture and sources of ignition.
