Formation and optical properties of metal/10-hydroxybenzo[h]quinolone complexes in the interlayer spaces of magadiite by solid–solid reactions

Abstract

Intercalation and in situ formation of three fluorescent complexes, Al(III)-, Cr(III)- and Cu(II)-10-hydroxybenzo[h]quinolone (M-HBQ, M = Al, Cr and Cu), in the interlayer spaces of magadiite (mag) were studied by solid–solid reactions between metal ions exchanged mags (M-mag, M = Al, Cr and Cu) and HBQ. Results show that the basal spacings of the intercalated composites increase after the intercalation of HBQ into M-mags. The amount of HBQ in the intercalated compounds is different due to the amount of metal ions and the diversification of coordination ability of metal ions, and the order of the coordination ability of these three metal ions is Cu2+ > Cr3+ > Al3+. The amount of the metal cations in the interlayer of mag is enough for the in situ complex formation of M-HBQ complexes. The slight shift of the absorption and luminescence bands of the complexes suggests the different microstructures, including molecular packing of the complexes in the interlayer spaces of mags, resulting that the host–guest interactions are formed. These findings show that the intercalation and in situ formation of M-HBQ complexes (M = Al, Cr and Cu) in the interlayer space of mag are successfully achieved in the current work.

Progress in Development of Magadiite to Produce Multifunctional Lamellar Materials

“…Several properties of magadiite were described, such as its crystallinity, purity, porosity, presence of acid sites with moderate force, hydrophobicity (in addition to applications such as ion exchanger, adsorbent, and absorbent), and, most importantly, high degree of expansiveness between the lamellae. All of these aspects are directly related to different synthesis procedures. ,,,− ,,,,− In general, two main methods are commonly described for the preparation of magadiite: (i) direct synthesis or bottom-up strategy, which consists of a mixture of reagents under specific reaction conditions to obtain solid magadiite in a single step and (ii) postsynthesis or top-down strategy, where the preformed magadiite is added to a solution containing the precursor or the active phase. In addition, in both methods, different wet or dry reaction pathways can be followed, in particular intercalation reactions, , pillarization, , delamination, , silylation, , dry impregnation, encapsulation, , seed-induced crystallization, , hydrothermal methods, , and recrystallization. , Depending on the approach applied, different active sites can be formed (e.g., open or closed, hydrated or dehydrated, framework species or extra-framework oxides), which can give rise to magadiite samples with distinct properties and with important morphological and structural differences.…”