Lanthanide complexes of the monovacant Dawson polyoxotungstate [alpha(2)-As2W17O61](10-) with 1D chain: Synthesis, structures, and photoluminescence properties

Six new lanthanide complexes, (H3O)[Ln(3)(H2O)(17)(x(2)-As2W17O61)] center dot nH(2)O ((1) Ln = Ce-III and n approximate to 13; (2) Ln = Pr-III and n approximate to 9; (3) Ln = Nd-III and n approximate to 14; (4) Ln = Sm-III and n approximate to 8; (5) Ln = Eu-III and n approximate to 4; (6) Ln = Gd-III and n approximate to 7). have been isolated by conventional solution method and Characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction. All the complexes are isomorphic and crystallize in the triclinic space group P-1. These complexes are 1D chain-like structures constructed by lanthanide cations and monovacant Dawson-type [x(2)-As2W17O61](10-) polyoxoanions. The striking feature of the structures is that there are three kinds of coordination environments for lanthanide cations, which are responsible for the formation of polymeric structures. Photoluminescence measurements reveal that 4 and 5 exhibit orange and red fluorescent emission at room temperature, respectively. (C) 2008 Elsevier Inc. All rights reserved.