KEU(CH3COO)3, THE 1ST TERNARY EUROPIUM(II) ACETATE

The reaction of EuCl2 with a melt of dry potassium acetate yields pale greenish-yellow single crystals (300-degrees-C, sealed glass ampoule, EuCl2 and K(CH3COO) in a molar ratio of 1:3). The crystal structure determination (orthorhombic, P2(1)2(1)2(1) (no. 19), Z = 8, a = 1 166.3 (1) pm, b = 1 288.4(2) pm, c = 1 493.9(2) pm, R = 0.043, R(w) = 0.032) revealed the composition KEu(CH3COO)3. The structure consists of one-dimensional chains built up by bridging acetate groups in the [100] and [001] directions in which potassium and europium alternate as central atoms. Eu2+ is surrounded by nine and eight and K+ by seven and six oxygen atoms, respectively. These chains are linked in the [010] direction so that a three-dimensional network is formed. The high coordination numbers of the acetate oxygen atoms of up to four are remarkable. Therefore, the acetate groups have highly bridging functions in addition to their chelating coordination of the cations.