Cation Effect on Formation of Preyssler‐type 30‐Tungsto‐5‐phosphate: Enhanced Yield of Na‐encapsulated Derivative and Direct Synthesis of Ca‐ and Bi‐Encapsulated Derivatives
|
| |
Authors: | Akio Hayashi Terufumi Haioka Keita Takahashi Bassem S Bassil Ulrich Kortz Tsuneji Sano Masahiro Sadakane |
| |
Institution: | 1. Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, 1–4‐1, Kagamiyama, Higashi‐Hiroshima, 739–8527, Japan;2. Department of Life Sciences and Chemistry, Jacobs University, P. O. Box 750561, 28725 Bremen, Germany;3. Department of Chemistry, Faculty of Sciences, University of Balamand, P.O. Box 100, Tripoli, Lebanon |
| |
Abstract: | The effect of cations in a reaction mixture for the preparation of the Preyssler‐Jeannin‐Pope type 30‐tungsto‐5‐phosphate P5W30O110Na]14– is investigated. Reaction of phosphate and tungstate with a P/W ratio of ca. 3.9 in an acidic aqueous solution without cations selectively leads to the Dawson‐type 18‐tungsto‐2‐phosphate, P2W18O62]6–. Amongst all the alkali cations, only Na+ allows formation of the Preyssler‐type polyanion P5W30O110Na]14–, with an encapsulated Na+ ion, and the product yield can be improved by increasing Na+ amount. The presence of Li+ ions instead results in the Dawson‐type polyanion P2W18O62]6–, whereas K+, Rb+, and Cs+ selectively result in the Keggin‐type polyanion PW12O40]3–. An improved synthetic procedure for the Na+‐encapsulated Preyssler‐ion leading to a higher isolated yield is presented. Furthermore, addition of Ca2+ and Bi3+ compounds allows formation of the Ca2+‐ and Bi3+‐encapsulated Preyssler‐type polyanions, P5W30O110Ca]13– and P5W30O110Bi]12–, respectively. Furthermore, single‐crystal XRD structure of the Bi3+‐encapsulated Preyssler‐type polyanions, P5W30O110Bi]12–, is presented for the first time. |
| |
Keywords: | Polyoxometalates Tungsten Phosphorous Alkali metals Template synthesis |
|
|