Three polyoxometalate-based inorganic–organic hybrid compounds, namely nanoclusters [Cu(en)2H2O]3[(α-SiW11O39)Nd(H2O)(η2,μ-1,1)-CH3COO]·3.5H2O (1) and [Cu(en)2H2O]3[(α-SiW11O39)Sm(H2O)(η2,μ-1,1)-CH3COO]·3H2O (2), and 1D H2[Cu(en)2H2O]8[Cu(en)2]3[{(α-SiW11O39)Ce(H2O)(η2,μ-1,1)-CH3COO}4]·22H2O (3) (en = 1,2-ethylenediamine) have been isolated. 1 and 2 are isomorphic and consist of [(α-SiW11O39)Ln(H2O)(η2,μ-1,1)-CH3COO]6– polyanions modified by [Cu(en)2H2O]2+ fragments. In 3, [Cu(en)2H2O]2+ are grafted on [(α-SiW11O39)Ce(H2O)(η2,μ-1,1)-CH3COO]6– polyanions and further connected by [Cu(en)2]2+ groups, representing the first example in polyoxometalate chemistry of a 1D ladder-like polyanion chain consisting of monovacant Keggin-type polyanions, lanthanide complexes and transition metal complexes. In these compounds, copper complexes coordinate to not only terminal O atoms but also bridging O atoms of the polyanions. Magnetic studies of 1 and 3 reveal weak antiferromagnetic interactions exist in them.
Synthesis, structure, semiconductive and photoluminescent properties of [{Eu(NC5H4COOH)3(H2O)2}(1.5ZnCl4)·(2H2O)]n
