Tris[3-hydroxy-2(1H)-pyridinonato] complexes of Al3+, Cr3+, and Fe3+ - Crystal and molecular structures of 3-hydroxy-2(1H)-pyridinone and tris[3-hydroxy-2(1H)-pyridinonato]chromium(III)

Tris[3-hydroxy-2(1 H)-pyridinonato] complexes of complexes of Al3+, Cr3+ an d Fe3+ are obtained by reactions of 3-hydroxy-2(1 H)pyridinone with the hyd rates of AlCl3, CrCl3 or Fe(NO3) in aqueous alkaline solutions as polycryst alline precipitates. The compounds are isotypic. X-ray structure determinat ions were performed on single crystals of the uncoordinated 3-hydroxy-2(1 H )-pyridinone (1) (orthorhombic, space group P2(1)2(1)2(1), a = 405.4(1), b = 683.0(1), c = 1770.3(3) pm, Z = 4) and of the chromium compound 3 (rhombo hedral with hexagonal setting, space group R (3) over bar c, a = 978.1(1), c = 2954.0(1) pm, Z = 6).