Chemical Properties
Colorless liquid
Uses
Tris(trimethylsilyl) phosphite (TMSPi) is a film-forming additive for high voltage cathode material in lithium-ion batteries. Tris (trimethylsilyl) phosphate is cleaved by alkali-metal fluorides, nitrates, and acetates at give the trimethylsilyl esters of the corresponding acids.
Definition
ChEBI: Tris(trimethylsilyl) phosphate is an organosilicon compound that is phosphoric acid in which the three hydroxy groups are substituted by (trimethylsilyl)oxy groups. It is a phosphoric acid derivative and an organosilicon compound.
Preparation
Tris(trimethylsilyl)phosphine is prepared by treating trimethylsilyl chloride, white phosphorus, and sodium-potassium alloy:
1/4 P4 + 3 Me3SiCl + 3 K → P(SiMe3)3 + 3 KCl
General Description
Tris(trimethylsilyl) phosphate has been investigated as a novel film-forming additive for LiNi0.5Co0.2Mn0.3O2 cycling at high cut-off potential in LiPF6-based electrolyte. Tris(trimethylsilyl) phosphate [Tris(trimethylsilyl) ester of phosphoric acid] undergoes dealkylsilylation reaction with alumazene to yield heteroadamantane molecule.
Reactivity Profile
Tris(trimethylsilyl)phosphine and its more reactive derivative lithium bis-(trimethylsilyl)phosphide·2tetrahydrofuran are very useful reagents for the preparation of compounds with a single or a multiple element phosphorus bond. They react readily with various element halides, with carboxylic acid chlorides, and with carboxylic esters, as well as with other organic electrophiles via a substitution of lithium and/or a cleavage of the weak polar Si-P bonds.
Flammability and Explosibility
Notclassified
Synthesis
General procedure for the synthesis of tris(trimethylsilyl)phosphorus from trimethylchlorosilane: In a 1000 ml three-necked flask equipped with a thermometer and a reflux condenser, 352 g (3.24 mol) of trimethylchlorosilane and 115 g (1 mol) of ammonium dihydrogen phosphate were added. The reaction mixture was heated to 78 °C under stirring conditions and maintained for 3 hours. After completion of the reaction, the reaction mixture was filtered and the resulting filtrate was the crude product of tris(trimethylsilyl) phosphate. Subsequently, the crude product was subjected to vacuum distillation and the fraction at 125-128 °C/30 mmHg was collected to obtain 282 g of tris(trimethylsilyl) phosphate in 89.6% yield. Throughout the reaction, an exhaust gas absorption unit needs to be connected to the outlet of the reflux condenser to absorb the hydrogen chloride gas generated in the reaction with water.
References
[1] Inorganic Chemistry, 2018, vol. 57, # 15, p. 9348 - 9353
[2] Patent: CN105949233, 2016, A. Location in patent: Paragraph 0018; 0019; 0021; 0023; 0025; 0027; 0029
[3] Zhurnal Obshchei Khimii, 1957, vol. 27, p. 1476,1479, 1480; engl.Ausg.S. 1550, 1553
[4] Journal of Organometallic Chemistry, 2014, vol. 749, p. 197 - 203
[5] Inorganic Chemistry, 2017, vol. 56, # 17, p. 10699 - 10705
