Thorium trifluorideThorium trifluoride is a binary inorganic compound of thorium metal and fluorine with the chemical formula.SynthesisThorium trifluoride is not formed in a reaction of thorium metal with thorium tetrafluoride: Molecules of ThF3 have been prepared by reacting atomic thorium with fluorine gas, and condensation onto a solid inert gas matrix. A solid phase is not known.