A series of new polyoxoanion-based inorganic-organic hybrids: (C6NO2H5)[(H2O)(4)(C6NO2H5)Ln(CrMo6H6O24)]center dot 4H(2)O (Ln = Ce, Pr, La and Nd) with a chiral layer structure

Four new polyoxoanion-based hybrids with a chiral layer structure, (C6NO2H5)[(H2O)(4)(C6NO2H5)Ln(CrMo6H6O24)]center dot 4H(2)O (Ln = Ce, 1; Pr, 2; La, 3 and Nd, 4), have been synthesized and characterized by elemental analysis, IR spectroscopy, TG analysis and single crystal X-ray diffraction. All the compounds are isostructural and crystallize in the monoclinic space group C2/c. Their crystal structures consist of two kinds of chiral layers, one left-handed and the other right-handed, each built up from the same-handed rare earth polyoxometalate helical chains, which leads to mesomeric solid state compounds. To our knowledge, this represents the first example of a 2D chiral layer framework consisting of rare earth polyoxometalate helical chains and organic bridging ligands. The magnetic properties of compounds 1, 2 and 4 have been studied by measuring their magnetic susceptibility over the temperature range of 2-300 K.