Bis(triphenylphosphine)platinum chloride is a metal phosphine complex with the formula PtCl<sub>2</sub>[P(C<sub>6</sub>H<sub>5</sub>)<sub>3</sub>]<sub>2</sub>. 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 about the central platinum atom. The cis isomer is used primarily as a reagent for the synthesis of other platinum compounds.
The cis isomer is the prepared by heating solutions of platinum(II) chlorides with triphenylphosphine. For example, starting from potassium tetrachloroplatinate:
The trans isomer is the prepared by treating potassium trichloro(ethylene)platinate(II) (Zeise's salt) with triphenylphosphine:
With heating or in the presence of excess PPh<sub>3</sub>, the trans isomer converts to the cis complex. The latter complex is the thermodynamic product due to triphenylphosphine being a strong trans effect ligand.
In cis-bis(triphenylphosphine)platinum chloride, the average Pt-P has a bond distance of 2.261 ÃÂ and the average Pt-Cl has a bond distance of 2.346 ÃÂ . In trans-bis(triphenylphosphine)platinum chloride, the Pt-P distance is 2.316ÃÂ ÃÂ and the Pt-Cl distance is 2.300ÃÂ ÃÂ .
The complex also undergoes photoisomerization.