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 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 ...

about the central platinum atom. The cis isomer is used primarily as a reagent for the synthesis of other platinum compounds.

Preparation

The cis isomer is the prepared by heating solutions of platinum(II) chlorides with

triphenylphosphine Triphenylphosphine (IUPAC name: triphenylphosphane) is a common organophosphorus compound with the formula P(C6H5)3 and often abbreviated to P Ph3 or Ph3P. It is widely used in the synthesis of organic and organometallic compounds. PPh3 exists ...

. For example, starting from

potassium tetrachloroplatinate Potassium tetrachloroplatinate(II) is the chemical compound with the formula K2PtCl4. This reddish orange salt is an important reagent for the preparation of other coordination complexes of platinum. It consists of potassium cations and the squar ...

: :K₂PtCl₄ + 2 PPh₃ → ''cis''-Pt(PPh₃)₂Cl₂ + 2 KCl The trans isomer is the prepared by treating potassium trichloro(ethylene)platinate(II) (

Zeise's salt Zeise's salt, potassium trichloro(ethylene)platinate(II), is the chemical compound with the formula K platinum">PtCl3(C2H4).html" ;"title="platinum.html" ;"title="/nowiki>PtCl3(C2H4)">platinum.html"_;"title="/nowiki>platinum">PtCl3(C2H4)�H2O.__Th ...

) with

: :KPt(C₂H₄)Cl₃ + 2 PPh₃ → ''trans''-Pt(PPh₃)₂Cl₂ + KCl + C₂H₄ With heating or in the presence of excess PPh₃, the trans isomer converts to the cis complex. The latter complex is the thermodynamic product due to triphenylphosphine being a strong

trans effect In inorganic chemistry, the trans effect is the increased lability of ligands that are trans to certain other ligands, which can thus be regarded as trans-directing ligands. It is attributed to electronic effects and it is most notable in square pla ...

ligand. In ''cis''-bis(triphenylphosphine)platinum chloride, the average Pt-P has a bond distance of 2.261 Å and the average Pt-Cl has a bond distance of 2.346 Å. In ''trans''-bis(triphenylphosphine)platinum chloride, the Pt-P distance is 2.316 Å and the Pt-Cl distance is 2.300 Å. The complex also undergoes

photoisomerization In chemistry, photoisomerization is a form of isomerization induced by photoexcitation. Both reversible and irreversible photoisomerizations are known for photoswitchable compounds. The term "photoisomerization" usually, however, refers to a re ...

References

{{Platinum compounds Platinum(II) compounds Homogeneous catalysis Triphenylphosphine complexes Chloro complexes B

Preparation

See also

References