Einsteinium trifluoride

Einsteinium fluoride is a binary inorganic chemical compound of einsteinium and fluorine with the chemical formula EsF3.

Synthesis
Einsteinium fluoride can be precipitated from einsteinium(III) chloride solutions upon reaction with fluoride ions. An alternative preparation procedure is to expose einsteinium(III) oxide to chlorine trifluoride (ClF3) or F2 gas at a pressure of 1–2 atmospheres and a temperature between 300 and 400 °C. The EsF3 crystal structure is hexagonal, as in californium(III) fluoride (CfF3) where the Es3+ ions are 8-fold coordinated by fluorine ions in a bicapped trigonal prism arrangement.

Physical properties
The compound forms crystals and is insoluble in water.

Chemical properties
The compound is reduced by metallic lithium:


 * EsF3 + 3Li -> Es + 3 LiF