Synthesis and Crystal Structure of a New Double Complex Salt K[Co(NH3)6][Cr2(C3H2O4)4(OH)2]·5.33H2O

Crystals of a new double complex salt K[Co(NH3)6][Cr2(C3H2O4)4(OH)2]Cl·5.33H2O (1) are prepared for first time by the isothermal evaporation of an aqueous solution containing hexammine cobalt(III) chloride, chromium(III) nitrate, and potassium malonate. The new compound crystallizes in the monoclinic crystal system, C2/c space group, a = 13.6657(3) Å, b = 15.2499(3) Å, c = 15.8264(7) Å, β = 114.285(3)°, V = 3006.37(2) Å3. The crystal structure of the new compound contains a relatively rare [Cr2(C2H3O4)4](OH)2]4– dinuclear anion.