Trimethylsilyl acetate

Trimethylsilyl acetate
Names
IUPAC name
Trimethylsilyl acetate[1]
Other names
  • Acetic acid trimethylsilyl ester[1]
  • Acetoxytrimethylsilane
  • TMSOAc
Identifiers
3D model (JSmol)
EC Number
  • 220-404-2
UNII
  • InChI=1S/C5H12O2Si/c1-5(6)7-8(2,3)4/h1-4H3
    Key: QHUNJMXHQHHWQP-UHFFFAOYSA-N
  • CC(=O)O[Si](C)(C)C
Properties
CH3COOSi(CH3)3
Molar mass 132.234 g·mol−1
Appearance Colorless liquid[2][3][4]
Odor Mild, sweet[3]
Density 0.882 g/cm3, relative vapor density 4.57 (air = 1)[2][4]
Melting point −32 °C (−26 °F; 241 K)[2]
Boiling point 107.5 °C (225.5 °F; 380.6 K)[2]
Soluble[5], reacts[4][5]
Solubility Soluble in diethyl ether and ethanol
Vapor pressure 47 hPa at 30 °C[2]
1.388[4]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Highly flammable[2]
GHS labelling:
Danger
H225, H315, H319
P210, P233, P240, P241, P242, P243, P264, P280, P303+P361+P353, P370+P378, P403+P235, P501
Flash point 19 °C (66 °F; 292 K)[5]
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Trimethylsilyl acetate, also known as TMSOAc, is an organosilicon compound with the chemical formula CH3COOSi(CH3)3. It is a colorless liquid. It is the silyl ester analog of tert-butyl acetate, having a trimethylsilyl group −Si(CH3)3 in place of the tert-butyl group −C(CH3)3.

Synthesis

Trimethylsilyl acetate can be prepared by the reaction of trimethylsilyl chloride with sodium acetate in hexanes or diethyl ether in the presence of a phase-transfer catalyst to speed up the reaction.[6]

(CH3)3SiCl + CH3COONa+ → CH3COOSi(CH3)3 + NaCl

Applications and reactions

A trimethylsilyl acetate and methane mixture can be used to produce a-C:H:SiOx coatings using plasma-enhanced chemical vapor deposition (PECVD), which have a hardness of up to 11 GPa.[7]

Other coatings can be produced with a trimethylsilyl acetate and oxygen mixture, again using PECVD.[8]

Trimethylsilyl acetate can also be used for acetylation of alcohols.[9]

References

  1. ^ a b "Silanol, 1,1,1-trimethyl-, 1-acetate". pubchem.ncbi.nlm.nih.gov.
  2. ^ a b c d e f https://www.sigmaaldrich.com/GB/en/sds/aldrich/284459
  3. ^ a b "CAS 2754-27-0: Trimethylsilyl acetate | CymitQuimica". cymitquimica.com.
  4. ^ a b c d "Trimethylsilyl acetate | 2754-27-0". ChemicalBook.
  5. ^ a b c https://assets.thermofisher.com/DirectWebViewer/private/document.aspx?prd=ALFAAB22037~~PDF~~MTR~~CGV4~~EN~~2025-09-06%2005:01:56~~Trimethylsilyl%20acetate~~#:~:text=Physical%20and%20Chemical%20Hazards,known%20or%20suspected%20endocrine%20disruptors.
  6. ^ https://patents.google.com/patent/CN103755734A/en
  7. ^ Kelarová, Štĕpánka; Václavik, Richard; Přibyl, Roman; Stupavská, Monika; Buršíková, Vilma (2024). "Development of a-C:H coatings doped with trimethylsilyl acetate prepared using plasma enhanced chemical vapor deposition". Diamond and Related Materials. 147 111233. Elsevier BV. doi:10.1016/j.diamond.2024.111233. ISSN 0925-9635.
  8. ^ Kelarová, Štěpánka; Homola, Vojtěch; Stupavká, Monika; Čermák, Martin; Vohánka, Jiří; Přibyl, Roman; Zábranský, Lukáš; Buršíková, Vilma (2020). "Deposition of organosilicon coatings from trimethylsilyl acetate and oxygen gases in capacitively coupled RF glow discharge". Progress in Organic Coatings. 149 105927. Elsevier BV. doi:10.1016/j.porgcoat.2020.105927. ISSN 0300-9440.
  9. ^ Pantawane, Amit Ravindra; Thul, Mayur; Lin, Yi-Jyun; Lin, Michelle; Lin, Wesley; Julakanti, Satyanarayana Reddy; Wu, Hsin-Ru; Luo, Shun-Yuan (2021-07-07). "Mild and Efficient Tunable Brønsted Acidic Ionic Liquid Catalyzed O-Acetylation and O-Trimethylsilylation with Trimethylsilyl Acetate (TMSOAc) and Hexamethyldisilazane (HMDS)". Catalysts. 11 (7). MDPI AG: 825. doi:10.3390/catal11070825. ISSN 2073-4344.