Antimony (III) Ethoxide

Antimony (III) Ethoxide, or antimony triethoxide, is a clear pale yellow liquid at room temperature.  It is moisture-sensitive and combustible.  It is used in atomic layer deposition, is an effective catalyst, and has been recently demonstrated to be an efficient flame retardant additive for lithium-ion batteries.

As with many alkoxides, Antimony (III) Ethoxide is suitable for atomic-layer deposition for preparing thin films.  For example, when researchers from the University of Dresden combined Antimony Triethoxide with Tris(trimethylsilyl)antimony as a precursor, they were able to prepare high-purity Antimony thin films with higher electrical conductivity than previously reported Antimony thin films prepared by atomic layer deposition.

Antimony (III) Ethoxide has also been used as a catalyst.  It was recently used by researchers from Purdue University in the synthesis of siderophore for use with an antibiotic against Bacillus bacteria.  The Antimony Ethoxide was able to facilitate the conversion of an ester-amide exchange with a 75% yield.

Recently, Antimony (III) Ethoxide was found to be an effective flame-retardant synergist.  Researchers from Anhui University of Technology in Maanshan, China, are working on finding innovative ways of addressing the flammability of the organic electrolytes in Lithium-ion batteries.  They incorporated Antimony Ethoxide into the battery electrolyte with the fluorinated flame retardant fluoroethylene carbonate. The researchers found that upon thermal decomposition, the Antimony Ethoxide decomposed into Antimony Oxide (Sb₂O₃).  This catalyzed the defluorination of fluoroethylene carbonate, suppressing combustion and flame propagation.  As an added benefit, the Antimony Ethoxide improved the cycling stability of the Lithium-ion cells.

1. He, S., Bahrami, A., Zhang, X., Julin, J., Laitinen, M., & Nielsch, K. (2023). Low-temperature ALD of highly conductive antimony films through the reaction of silylamide with alkoxide and alkylamide precursors. Materials Today Chemistry, 32, 101650. https://doi.org/10.1016/J.MTCHEM.2023.101650
2. Pandey, R. K., Jarvis, G. G., & Low, P. S. (2012). Efficient synthesis of the siderophore petrobactin via antimony triethoxide mediated coupling. Tetrahedron Letters, 53(13), 1627–1629. https://doi.org/10.1016/J.TETLET.2012.01.074
3. Li, L., Ren, K., Yu, Q., Wu, S., Xu, Z., Li, H.-W., Jiang, Z., & Li, Y. (2025). Antimony Ethoxide as a Flame-Retardant Synergist for Enhancing the Safety of Lithium-Ion Batteries. ACS Energy Letters, 4353–4360. https://doi.org/10.1021/ACSENERGYLETT.5C01847