Inorganic Chemistry, Vol.45, No.11, 4364-4371, 2006
Intercalation and photophysical properties of the tetra-(8-hydroxyquinolinato) boron complex and 3,3', 4,4'-benzophenone tetracarboxylic anion into Mg-Al layered double hydroxides
The tetra-(8-hydroxyquinolinato) boron complex (Bq) and 3,3',4,4'-benzophenone tetracarboxylic anion ( BPTC) were successfully intercalated into layered double hydroxides with an ion-exchange method. Elemental analyses, powder X-ray diffraction, FTIR spectra, and thermogravimetric analyses indicated that the hydrothermal treatment could efficiently improve the reaction process, the purity and crystallinity of products, and that Bq and BPTC molecules steadily arranged with C2 axis perpendicular to the layer plane, and the J-type aggregate in the host interlayer, respectively. The fluorescence studies showed that, compared with those observed in the dilute solutions of the guests, the spectra of Mg3Al - Bq and Mg3Al - BPTC evolved to the high-energy side and the low-energy side with increasing their loading, respectively, which were attributed to various arrangements of guests and the increased intermolecular interaction. Furthermore, their fluorescence intensity gradually decreased with increasing the intercalated guest content due to the concentration quenching, and Mg3Al - Bq exhibits enhanced solid-state blue luminescence due to a more rigid and constrained environment of the host.