New Hydrogen Peroxide Adducts of Alkali Metal Tetracyanoplatinates A2[Pt(CN)4] ·H2O2 (A = K, Rb, Cs)

Abstract

The title compounds have been synthesized by adding hydrogen peroxide to an aqueous solution of A2[Pt(CN)4] (A = K, Rb, Cs). They grow as yellow needles after concentrating and cooling to 4 °C. The structures were elucidated from single crystal analysis. The isostructural compounds crystallize monoclinically, in space group C2/c with Z = 4. K2Pt(CN)4 ·H2O2: a = 13.3751(7), b = 11.2713(6), c = 6.5461(3) Å, β = 105.432(1)◦, V = 951.3(3) Å3. Rb2Pt(CN)4 ·H2O2: a = 13.6103(2), b = 11.6759(1), c = 6.5683(7) Å, β = 106.588(2)0, V = 1000.3(2) Å3. Cs2 Pt(CN)4 ·H2O2: a = 13.9569(2), b = 12.2023(2), c = 6.5857(9) Å, β = 107.590(3)0, V = 1069.1(2) Å3. As a remarkable feature, the hydrogen bonds O-H···N vary significantly with the cation size: in the Cs compound the O-H bonds are weakest, and the N· · ·H interactions are strongest. All three compounds were characterized by differential thermal analysis, thermogravimetry and infrared spectroscopy.