Ceramics-Silikáty 48, (4) 155 - 158 (2004) |
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Zn-Al LAYERED DOUBLE HYDROXIDE PILLARED BY DIFFERENT DICARBOXYLATE ANIONS |
Gago Sandra, Pillinger Martyn, Santos Teresa M.,
Gonçalves Isabel S. |
Department of Chemistry, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
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Keywords: Layered double hydroxides, Layered compounds, Carboxylate anions, Host-guest systems |
Zn-Al layered double hydroxides (LDHs) intercalated by terephthalate (TPH) and biphenyl-4,4'-dicarboxylate (BPH) anions
have been synthesized by direct co-precipitation from aqueous solution. The Zn/Al ratio in the final materials was 1.8. The
products were characterized by powder X-ray diffraction, thermogravimetric analysis, FTIR and FT Raman spectroscopy, and
MAS NMR spectroscopy. The basal spacing for the TPH-LDH intercalate was 14.62 Ă, indicating that the guest anions stack
to form a monolayer with the aromatic rings perpendicular to the host layers. For the LDH intercalate containing BPH
anions, a basal spacing of at least 19.2 Ă would be expected if the anions adopted an arrangement similar to that for the TPH
anions. The observed spacing was 18.24 Ă, suggesting that the anions are tilted slightly with respect to the host layers. |
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