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]

Preparation

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]

Properties

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]

Reactions

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]

Related compounds

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]

References

  1. ^ a b c Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, FL: CRC Press. p. 4.81. ISBN 1-4398-5511-0.
  2. ^ a b c Mueller, B. G.; Serafin, M. (1992). "Single-crystal investigations on PtF4 and PtF5". European Journal of Solid State Inorganic Chemistry. 29: 625–633. doi:10.1002/chin.199245006.[full citation needed]
  3. ^ Moissan, H. "Platinum tetrafluoride". Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences. 109: 807–9.
  4. ^ Slivnik, J. E.; Z̆emva, B.; Druz̆ina, B. (1980). "New syntheses of platinum (IV) and platinum (VI) fluorides". Journal of Fluorine Chemistry. 15 (4): 351. doi:10.1016/S0022-1139(00)81471-2.
  5. ^ Bondarenko, A.A; Korobov, M.V; Mitkin, V.N; Sidorov, L.N (March 1988). "Enthalpy of sublimation of platinum tetrafluoride". The Journal of Chemical Thermodynamics. 20 (3): 299–303. doi:10.1016/0021-9614(88)90125-5.
  6. ^ "Solid State Structures of the Binary Fluorides of the Transition Metals". Advances in Inorganic Chemistry and Radiochemistry. Vol. 27. Academic Press. 1983. Section V: Tetrafluorides, pages 97–103. ISBN 9780080578767.
  7. ^ a b c d e f Derek Harry Lohmann (October 1961). The fluorides of platinum and related compounds (Thesis). University of British Columbia.