Appearance white solid | ||
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Bis(triphenylphosphine)platinum chloride is a metal phosphine complex with the formula PtCl2[P(C6H5)3]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 about the central platinum atom. The cis isomer is used primarily as a reagent for the synthesis of other platinum molecules.
Preparation
The cis isomer is the prepared by heating solutions of platinum(II) chlorides with triphenylphosphine. For example, starting from potassium tetrachloroplatinate:
K2PtCl4 + 2 PPh3 → cis-Pt(PPh3)2Cl2 + 2 KClThe trans isomer is the prepared by treating potassium trichloro(ethylene)platinate(II) (Zeise's salt) with triphenylphosphine:
KPt(C2H4)Cl3 + 2 PPh3 → trans-Pt(PPh3)2Cl2 + KCl + C2H4Heat or excess phosphine ligand causes the trans isomer to isomerize to the white 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 Å and the average Pt-Cl has a bond distance of 2.346 Å.