Deficient, Partially Oxidized Tetracyanoplatinates

The metallic character of the cation-deficient partially oxidized tetracyano-platinate complexes is of considerable interest because of their unusual anisotropic electrical properties. The method used in the preparation of these compounds is a modification of the procedure used by Levy1 and gives a higher yield of pure product than the syntheses previously described in the literature2 5 (only the potassium compound has been reported to date). 

CESIUM TETRACYANOPLATINATE (2 1) MONOHYDRATE AND CESIUM TETRACYANOPLATINATE (1.75 1) DIHYDRATE 

The Ba[Pt(CN)4] 4H20 used as the starting material for this preparation is synthesized and purified as described by Maffly et al.6 The Cs2S04 used should be 99.9% pure to minimize any possible cation contamination, especially by potassium. All other chemicals are reagent grade. Distilled water is used throughout the procedure. 

8Cs2[Pt(CN)4]-H20 + H202 +H2S04 + 6H20 8CSl 7S [Pt(CN)4J-2H20 + 

Cs2S04. The 7.0 g (1.20 X 10 2 mole) of Cs2 [Pt(CN)4]-H20 obtained in reaction 1 is dissolved, with stirring, in 25 mL of hot water. Then 1 M H2S04 is added slowly to acidify the solution (pH = 1) followed by 0.65 mL of 20% H2 027 (4 X 10 3 mole). The heating and stirring are continued for 1 hour. The solution is then covered and allowed to cool, and the product is allowed to crystallize for 24 hours. 

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Partially oxidized tetracyanoplatinates have attracted much attention in recent years because of their highly anisotropic physical properties.1 Although partially oxidized salts of K+, Na+, Rb and Mg+2 have been reported, the analogous bromide-deficient guanidinium salt is the only such compound containing an organic cation.2 A procedure for the preparation of this guanidinium salt has not been previously reported. 

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