Platinum(IV) chloride is the chemical compound with the empirical formula PtCl4. This brown solid features platinum in the 4+ oxidation state. Typical of Pt(IV), the metal centers adopt the octahedral geometry. This geometry is achieved by forming a polymer wherein half of the chloride ligands bridge between the platinum atoms. Because of its polymeric structure, PtCl4 dissolves only upon breaking the chloride bridges. Thus, addition of HCl give H2PtCl6. Lewis base adducts of Pt(IV) of the type cis-PtCl4L2 are known but most are prepared by oxidation of the Pt(II) derivatives.
PtCl4 is mainly encountered in the handling of chloroplatinic acid, a soluble form of platinum obtained upon dissolution of Pt metal in aqua regia. Heating H2PtCl6 gives PtCl4 which then loses chlorine to give PtCl2.
The heavier halides, PtBr4 and PtI4, are also known.