Preparation and Characterization of New Lanthanide materials: Layered Double Hydroxide Intercalated by Luminescent Polyoxometalate Anions with Dawson-like [Eu(a1-P2W17O61]7- and Keggin-like[Eu2(PW11O39)2]8-
C.Zhang, R. C. Howell, Q-H Luo, K. B. Scotland, M. Peralta and L. C. Francesconi
Ph.D candidate, US
Keywords: Layered double hydroxide, lanthanide, polyoxometalate anions, luminescence, micropores.
Dawson-like [Eu(a1-P2W17O61]7- and Keggin-like [Eu2(PW11O39)2]8- were first isolated and x-ray crystallized in our group. In relation to previous work, we are interested in synthesizing new lanthanide materials by incorporating the title polyoxometalates (POMs) anions into layered double hydroxides (LDHs). The pillaring of Mg3Al LDH by the title POM anions were accomplished by ion exchange reaction of the LDH-hydroxide and –adipate precursors with the POM anions at ambient, 50°C or refluxing temperatures. A study was performed on each of the LDH precursors to determine any problematic steps in the overall synthesis. The structural, thermal, textural and luminescence properties of the POM-incorporated compounds were elucidated based on PXRD, TGA, FTIR, TEM, N2 adsorption/desorption studies and Raman, Fluorescence, UV-Vis and solid state NMR spectroscopies. Solid state NMR is a powerful technique to locate the environment of P in the title materials. N2 adsorption/desorption studies for the LDH intercalates showed that access to the gallery micropores could be achieved upon POM intercalation. The Raman and Fluorescence studies showed that the title LDH materials are potential useful as luminescence sensors.
NSTI Nanotech 2003 Conference Technical Program Abstract