Supramolecular coexistence of Co(II) and Ag(I) complexes based on polyoxotungstate and imidazoles: synthesis, crystal structure, and spectroscopic study

2014-04-30T11:35:55Z (GMT) by Wei Wang Yunfeng Qiu Lin Xu
<div><p>In this work, [Ag(imi)<sub>2</sub>]<sub>5</sub>[PW<sub>11</sub>O<sub>39</sub>Co(imi)]·2.5H<sub>2</sub>O (<b>1</b>, imi = imidazole) based on both polyoxometalate and imidazole has been synthesized by using the hydrothermal method. Its structure and spectroscopic properties were determined by single-crystal X-ray diffraction, elemental analysis, IR spectrum, diffuse reflectance UV–Vis spectrum, and thermogravimetric analysis. Single-crystal X-ray diffraction analysis indicates that <b>1</b> is a 3-D supramolecular interpenetrating structure, constructed from [Co(imi)]<sup>2+</sup> monosubstituted Keggin-type heteropolytungstate and {[Ag(imi)<sub>2</sub>]<sup>+</sup>}<sub>5</sub> complexes. Imidazole ligands play dual roles in <b>1</b>, both coordination linker and supermolecule linker. The luminescence spectrum of <b>1</b> displays a strong emission peak at 469 nm excited at 208 nm. Coexistence of Co(II) and Ag(I) complexes with 3-D supramolecular architecture may find application in photoluminescent materials and catalysis.</p></div>