Synthesis and Crystal Structures of the Bis(oxalato)metallates trans-K3[RhCl2(C2O4)2] · 4 H2O and cis-K3[IrCl2(C2O4)2] · H2O

Abstract

By treatment of RhCl3 or IrCl3 with K2C2O4 the bis(oxalato)metallates trans-K3[RhCl2(C2O4)2] and cis-K3[IrCl2(C2O4)2] are formed. From the aqueous solutions single crystals were grown by slow diffusion of ethanol and X-ray structure determinations of trans-K3[RhCl2(C2O4)2] · 4 H2O (monoclinic, space group I2/m, a = 6.218(1), b = 11.837(2), c - 10.357(2) Å, β = 95.55(3)°, Z = 2) and cis-K3[IrCl2(C2O4)2] · H2O (monoclinic, space group /2/a, a = 14.060(3), b = 7.586(2), c = 23.488(5) Å, β = 90.44(3)°, Z = 8) have been performed. The oxalato and chloro ligands of the complex anions are connected via hydrogen bonds and electrostatic interactions to water molecules and potassium ions. The potassium ions are eightfold and in one case ninefold coordinated.