Potassium diplatinum(II) tetrakispyrophosphite (abbreviated as t₂(pop)₄sup>4−) is the inorganic compound with the formula K₄ t₂(HO₂POPO₂H)₄ It is a water-soluble yellow salt. The compound has a long-lived, strongly luminescent excited state, with an emission maximum at ∼510 nm and a lifetime near 10 μs.

Synthesis and reactions

The complex is prepared by heating a mixture of

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 ...

and

phosphorous acid Phosphorous acid (or phosphonic acid (singular)) is the compound described by the formula H3PO3. This acid is diprotic (readily ionizes two protons), not triprotic as might be suggested by this formula. Phosphorous acid is an intermediate in th ...

: :2K₂PtCl₄ + 8H₃PO₃ → K₄ t₂(HO₂POPO₂H)₄ + 8HCl + 4H₂O Several

quat salt 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 catio ...

derivatives are known. The anion reacts with

boron trifluoride Boron trifluoride is the inorganic compound with the formula BF3. This pungent, colourless, and toxic gas forms white fumes in moist air. It is a useful Lewis acid and a versatile building block for other boron compounds. Structure and bondin ...

to give the BF₂-capped complex t₂(P₂PO₅)₄(BF₂)₈sup>4-. The compound reacts with halogens to give Pt(III) dimers: :K₄ t₂(HO₂POPO₂H)₄ + Cl₂ → K₄[Pt₂(HO₂POPO₂H)₄Cl₂ With substoichiometric halogen, linear chain compounds result.

Structure

The pair of square-planar platinum(II) centers are bridged by four pyrophosphito (HO(O)POP(O)OH^2-) ligands. The ligands interact via hydrogen bonds between the POH and P=O group. The Pt---Pt separation is 293 pm for the dihydrate. In the Pt(III) dichloride, the Pt-Pt distance is 270 pm, indicating Pt-Pt bonding.

References

{{Chlorine compounds Platinum(II) compounds Potassium compounds