Unusual potassium-oxalate coordination in the two-dimensional trimetallic [CoCl(NH3)_5][KCr(C2O4)_3]·0.5H2O complex

摘要

Anewheterometalliccompound,[CoCl(NH3)_5][KCr(C2O4)_3]·0.5H2O(1),hasbeensynthesizedandcharacterizedbyelementalanalysis,IR and electronic spectra, thermal analysis, variable temperature magnetic susceptibility measurements, and single crystal X-ray diffraction. Compound 1 consists of two-dimensional [{KCr(C2O4)_3}_n]~(2n-) layers, [CoCl(NH3)_5]~(2+) ions and water molecules. Within the 2-D layer, three different types of oxalate coordination modes are present. Each K cation is coordinated by eight oxygen atoms from oxalate groups and also weakly interacts with the ninth oxygen atom. The extensive network of hydrogen bond is formed between the [KCr(C2O4)_3]~(2–) layer and the [CoCl(NH3)_5]~(2+) ions. These interactions involve all hydrogen atoms of ammonia ligands and water molecule.