Hydrate, K2 FHF

See basic chemical equations given in Section 32-A.l and substitute K for Cs, KF for CsCl, and H202 for Cl2. 

Initially, 1.55 g (3.59 mmole) of K2[Pt(CN)4] -3H207 is dissolved in 6 mL of water followed by 1.5 lg (26.0mmole) of anhydrous KF and then 3 mL concentrated HF(aq), all in a 50-mL polyethylene beaker. Three drops (40 drops/mL) (0.7mmole) 30% H202 are then added. The solution is swirled and allowed to evaporate at room temperature until the beaker is filled with crystals, being cautious not to allow drying to occur. The crystals are collected in a 

As in the chemical method, 1.55 g (3.59 mmole) K2[Pt(CN)4]-3H20 is dissolved in 6 mL water. KF (anhydrous) (1.51 g, 26.0mmole)is added and the KF dissolves leaving a fine, white suspension. Finally, 3 mL concentrated HF(aq) (24 M) is added to acidify the solution and promote solution of the white suspension. The clear solution is then transferred to the electrolytic cell, which consists of a 50-mL polyethylene beaker with two small opposing holes drilled 6 mm from the bottom. Two platinum electrodes 25 mm in length are held in place using epoxy cement and with the electrode tips separated by 2 mm. 

After 2 hours of electrolysis10 at 1.5 V, the product, having filled the bottom of the beaker, is filtered in a plastic funnel. The crystals are then washed with two 6-mL portions of cold water and allowed to air dry. The yield of 1.4-1.5 g (3.2-3.4mmole) represents 88-94% based on original K2[Pt(CN)4] 3H20. Using X-ray diffraction powder patterns, it is established that the products of both syntheses given above are identical.8 The platinum oxidation state of 2.29(1) is established by iodine-thiosulfate titrations.8 

The compound K2[Pt(CN)4](FHF)0.3 3H2O forms tetragonal crystals which have a reddish-bronze metallic luster. The full X-ray diffraction crystal structure analysis has been reported.14 The powder pattern indicates that K2[Pt(CN)4](FHF)0.3 3H2O is isostructural with K2[Pt(CN)4]Cl0.3 3H20, which also has a platinum oxidation state of +2.30. The first 10 reflections of the powder pattern correspond to the following d-spacings (A)8 9.671 (vs), 8.770 (M), 8.104 (M), 6.884 (s), 4.878 (s), 4.651 (w), 4.362 (vs), 4.264 (vs), 4.076 (vw), and 3.944 (vw). 

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