4-(Trimethoxysilyl)butyronitrile
[CAS# 55453-24-2]

Identification

• Classification: Organic raw materials >> Organosilicon compound
• Name: 4-(Trimethoxysilyl)butyronitrile
• Synonyms: All Photos(1)
• Molecular Formula: C₇H₁₅NO₃Si
• Molecular Weight: 189.28
• CAS Registry Number: 55453-24-2
• EC Number: 259-646-9
• SMILES: CO[Si](CCCC#N)(OC)OC

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Hazard Statements: H315-H318-H335
• Precautionary Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P354+P338-P317-P319-P321-P332+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Serious eye damage	Eye Dam.	1	H318
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	4	H332
Aspiration hazard	Asp. Tox.	1	H304
Eye irritation	Eye Irrit.	2	H319

• Transport Information: UN 1993

Discovory and Applicatios

4-(Trimethoxysilyl)butyronitrile is an organosilane compound commonly used as a surface modifier and coupling agent in materials science, especially in the preparation of functionalized silica surfaces and hybrid organic-inorganic materials. The molecule consists of a trimethoxysilyl group attached to a four-carbon aliphatic chain that terminates in a nitrile (–C≡N) group. This structural combination allows the compound to anchor onto inorganic surfaces via the alkoxysilane moiety while presenting a reactive nitrile group for further chemical transformations or interactions.

The development and application of 4-(trimethoxysilyl)butyronitrile are rooted in the broader field of silane coupling agents, which began to gain industrial significance in the mid-20th century. Organosilanes with trialkoxy groups were extensively studied and commercialized for their ability to form strong covalent bonds with hydroxyl-rich surfaces, such as those of glass, metal oxides, and silica. The trimethoxysilyl group in this compound hydrolyzes readily in the presence of water to form silanols, which then condense with surface hydroxyl groups to produce stable siloxane linkages. This process results in durable grafting of the organic chain onto the surface.

The nitrile functionality of 4-(trimethoxysilyl)butyronitrile provides an additional site for post-synthetic modification. This group can be reduced to primary amines, hydrolyzed to carboxylic acids, or subjected to condensation reactions, offering diverse pathways for functionalization of the modified surface. Such versatility makes the compound particularly attractive in the design of advanced materials and in analytical and preparative chemistry.

One of the most common applications of 4-(trimethoxysilyl)butyronitrile is in the synthesis of functionalized silica for chromatography and solid-phase extraction (SPE). By reacting this compound with silica gel or other metal oxide substrates, scientists can produce materials with pendant nitrile groups. These materials can interact with polar compounds or metal ions, enhancing selectivity in separation processes. After grafting, the surface can be further derivatized to tailor the stationary phase properties for specific applications in gas chromatography (GC) or liquid chromatography (LC).

The compound is also employed in the preparation of hybrid sol-gel materials. In these processes, it acts as a co-precursor with tetraalkoxysilanes such as tetraethoxysilane (TEOS) during sol-gel polymerization. The incorporation of 4-(trimethoxysilyl)butyronitrile into the silica network introduces organic functionality into the otherwise inorganic matrix. These hybrid materials are used in coatings, membranes, sensors, and as supports for catalysts.

In polymer composites, 4-(trimethoxysilyl)butyronitrile serves as a coupling agent to improve adhesion between inorganic fillers (like silica or glass fibers) and organic polymers. The silane end of the molecule binds to the filler surface, while the organic nitrile tail can interact with or be covalently linked to the polymer matrix. This interfacial adhesion enhances the mechanical properties and durability of the composite material.

Another area of use is in the creation of self-assembled monolayers (SAMs) on silicon-based surfaces. By applying 4-(trimethoxysilyl)butyronitrile to clean silica or silicon wafers, researchers can generate thin, uniform monolayers that present nitrile groups at the surface. These surfaces are employed in analytical chemistry, biosensor fabrication, and microelectronic device preparation, particularly where further functionalization of the nitrile is required.

The hydrolysis and condensation behavior of the compound must be carefully controlled during use, as uncontrolled polymerization can result in gelation or non-uniform coatings. It is typically handled in dry conditions or in the presence of controlled amounts of water and acid/base catalysts to initiate silane condensation at a desired rate.

As with other alkoxysilanes, 4-(trimethoxysilyl)butyronitrile must be stored in airtight containers to prevent premature hydrolysis and should be handled with appropriate precautions, including the use of gloves and eye protection. The compound has moderate volatility and can cause irritation upon inhalation or skin contact.

Overall, 4-(trimethoxysilyl)butyronitrile is a valuable reagent in surface chemistry and materials science. Its ability to simultaneously anchor to inorganic substrates and present a modifiable nitrile group enables its use in diverse applications ranging from chromatography and catalysis to advanced composite materials and surface engineering.

References

1997 Fuel-Cell Type Ceramic-Carbon Oxygen Sensors. Journal of Sol-Gel Science and Technology, 8(1-3).
DOI: 10.1007/bf02436987

2017 Synthesis of piperazine functionalized magnetic sporopollenin: a new organic-inorganic hybrid material for the removal of lead(II) and arsenic(III) from aqueous solution. Environmental Science and Pollution Research, 24(26).
DOI: 10.1007/s11356-017-9820-9

2022 Cerium oxide�doped PEDOT nanocomposite for label-free electrochemical immunosensing of anti-p53 autoantibodies. Microchimica Acta, 189(6).
DOI: 10.1007/s00604-022-05322-5