Coordination polymers of 1,2,5,8‐tetrahydroxyanthraquinone

From analytical studies, infrared and reflectance spectra, magnetic and thermogravimetric measurements of Cu(II), Ni(II), Co(II), Mn(II), Fe(II), and UO2(VI) complexes of 1,2,5,8‐tetrahydroxyanthraquinone, it was concluded that the complexes are polymeric coordination complexes with octahedral geometry. These were synthesized by refluxing an equimolar mixture of the ligand and hydrated metal acetates in N,N‐dimethylformamide at 140°C. Elemental analyses indicated a ligand: metal ratio of 1 : 1 and the association of water molecules with the central metal. The decreasing order of thermal stability of the complexes is: Mn(360°C)>Fe(340°C) ≈︁ Co(340°C)>Ni(320°C)>Cu(300°C).