Potassium tetrachloroplatinate(II) is the

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

K₂PtCl₄. This reddish orange

salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quant ...

is an important

reagent In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a ...

for the preparation of other

coordination complexes A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many ...

platinum Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver". Pla ...

. It consists of

potassium Potassium is the chemical element with the symbol K (from Neo-Latin '' kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmos ...

cation An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...

s and the

square planar The square planar molecular geometry in chemistry describes the stereochemistry (spatial arrangement of atoms) that is adopted by certain chemical compounds. As the name suggests, molecules of this geometry have their atoms positioned at the corne ...

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...

PtCl₄²⁻. Related salts are also known including Na₂PtCl₄, which is brown-colored and soluble in alcohols, and

quaternary ammonium salts In chemistry, quaternary ammonium cations, also known as quats, are positively charged polyatomic ions of the structure , R being an alkyl group or an aryl group. Unlike the ammonium ion () and the primary, secondary, or tertiary ammonium cations ...

, which are soluble in a broader range of organic solvents.

Preparation

Potassium tetrachloroplatinate is prepared by reduction of the corresponding hexachloroplatinate salt with

sulfur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic a ...

. K₂PtCl₄ is one of the salts that is most easily obtained from platinum ores. The complex is appreciably soluble only in water. Treatment with alcohols, especially in the presence of base, causes reduction to platinum metal. Organic tetrachloroplatinate salts, such as /nowiki>PPN/nowiki>₂PtCl₄ are soluble in chlorocarbons.

Reactions

The chloride ligands on tCl₄sup>2− are displaced by many other

ligand In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's elect ...

s. Upon reaction with triphenylphosphine, tCl₄sup>2− converts to ''cis''-

bis(triphenylphosphine)platinum chloride Bis(triphenylphosphine)platinum chloride is a metal phosphine complex with the formula PtCl2 (C6H5)3sub>2. Cis- and trans isomers are known. The cis isomer is a white crystalline powder, while the trans isomer is yellow. Both isomers are square p ...

: :PtCl₄²⁻ + 2 PPh₃ → ''cis''-PtCl₂(PPh₃)₂ + 2 Cl⁻ The anti-cancer drug

Cisplatin Cisplatin is a chemotherapy medication used to treat a number of cancers. These include testicular cancer, ovarian cancer, cervical cancer, breast cancer, bladder cancer, head and neck cancer, esophageal cancer, lung cancer, mesothelioma, ...

can similarly be prepared: :PtCl₄²⁻ + 2 NH₃ → ''cis''-PtCl₂(NH₃)₂ + 2 Cl⁻ Enedithiolates displace all four chloride ligands to give bis(

dithiolene Dithiolene metal complexes are complexes containing 1,2-dithiolene ligands. 1,2-Dithiolene ligands, a particular case of 1,2-dichalcogenolene species, are unsaturated bidentate ligand wherein the two donor atoms are sulfur. 1,2-Dithiolene metal ...

) complexes. Reduction gives colloidal platinum of potential interest for catalysis. Historically, an important reaction involves ammonia and tCl₄sup>2−. This reaction affords a deep green precipitate with

empirical formula In chemistry, the empirical formula of a chemical compound is the simplest whole number ratio of atoms present in a compound. A simple example of this concept is that the empirical formula of sulfur monoxide, or SO, would simply be SO, as is the ...

PtCl₂(NH₃)₂. This material, known as Magnus' green salt, is a semiconducting

coordination polymer A coordination polymer is an inorganic or organometallic polymer structure containing metal cation centers linked by ligands. More formally a coordination polymer is a coordination compound with repeating coordination entities extending in 1, 2 ...

consisting of chains of alternating tCl₄sup>2− and t(NH₃)₄sup>2+ centres.

References

{{Chlorine compounds Platinum(II) compounds Chloro complexes Metal halides Potassium compounds