Synthesis and characterization of host-guest materials obtained by inserting coumarin into hydrotalcite layers for LED applications

The possible interactions between luminescent moieties with hydrotalcite (HTLC) host have been investigated. We present the work done in synthesizing luminescent materials containing coumarin-3-carboxylic acid (3CCA).Ahydrothermal synthesis is carried out to intercalate the 3CCA into the HTLC with empirical formula: [M(II) _0.65M(III) _0.35 (OH) ₂](X) _0.35 · nH ₂0], where MII=(Zn ²⁺), MIII=Al ³⁺, X=3CCA ^- or NO ^-3 . The ZnAl HTLC materials with [M(II)/M(III)≈2.0] thus synthesized were characterized by XRPD/FTIR/ICP-MS/TGA/SEM techniques and solid-state luminescent measurements. The thermal stability and the luminescent properties of obtained hybrid materials are promising because of the observed photoluminescence in the visible region and their hightemperature resistance indicated by the in situ XRPD measurements and TGA/DTG analysis.