Shigeki Onuma

Crystal and Molecular Structure of Potassium Acetylacetonate Hemihydrate

The crystal structure of potassium acetylacetonate hemihydrate, KC5H7O2· 1/2H2O, has been determined by X-ray diffraction method. Crystals are triclinic with space group P\barl, a=10.86, b=8.74, c=7.45 A, α=90.5, β=95.8, γ=91.9°, and Z=4. The final R value was 0.109 for 1589 visually estimated reflection data. Each potassium ion is surrounded by seven oxygen atoms, at distances of 2.65 to 3.05 A, six of which belong to four acetylacetone anions and the rest is a water molecule. The bond lengths and angles of the acetylacetone anion are very similar to those of acetylacetone groups in heavy metal chelates, but differ from those of the free molecule of acetylacetone.