Platinum tetrafluoride is the inorganic compound with the chemical formula PtF
4. In the solid state, the compound features platinum(IV) in octahedral coordination geometry.[2]
The compound was first reported by Henri Moissan by the fluorination of platinum metal in the presence of hydrogen fluoride.[3] A modern synthesis involves thermal decomposition of platinum hexafluoride.[4]
Platinum tetrafluoride vapour at 298.15 K consists of individual molecules. The enthalpy of sublimation is 210 kJmol−1.[5] Original analysis of powdered PtF4 suggested a tetrahedral molecular geometry, but later analysis by several methods identified it as octahedral, with four of the six fluorines on each platinum bridging to adjacent platinum centres.[6]
A solution of platinum tetrafluoride in water is coloured reddish brown, but it rapidly decomposes, releasing heat and forming an orange coloured platinum dioxide hydrate precipitate and fluoroplatinic acid.[7]When heated to a red hot temperature, platinum tetrafluoride decomposes to platinum metal and fluorine gas. When heated in contact with glass, silicon tetrafluoride gas is produced along with the metal.[7]
Platinum tetrafluoride can form adducts with selenium tetrafluoride and bromine trifluoride.[7] Volatile crystalline adducts are also formed in combination with BF3, PF3, BCl3, and PCl3.[7]
The fluoroplatinates are salts containing the PtF62− ion. Fluoroplatinic acid H2PtF6 forms yellow crystals that absorb water from the air. Ammonium, sodium, magnesium, calcium, strontium, and rare earth including lanthanum fluoropalatinate salts are soluble in water.[7] Potassium, rubidium, caesium, and barium salts are insoluble in water.[7]