Hydrotalcite-quinolinate composites as catalysts in a coupling reaction

Samples of layered double hydroxides were prepared by a sol–gel procedure. Quinolinate Al(C₉H₆NO)₃ units were added during the synthesis, leading to composite quinolinate hydrotalcite-like compounds. The amount of quinolinate was varied, showing that the number of organic building blocks determines the physicochemical properties of materials, which differ significantly from those commonly reported for hydrotalcites without any quinolinate. The order of layers, specific surface area and coordination of aluminium were the parameters most significantly influenced by the presence of the quinolinate as a part of the brucite-like layers. The composite quinolinate-hydrotalcite materials were tested to catalyse the Kabachnik–Fields reaction.

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Graphical abstract Adding of quinolinate Al(C₉H₆NO)₃ to hydrotalcite-like compounds creates disorder in the stack of brucite-like layers, leading to a significant modification of structural, textural and catalytic properties. The presence of quinolinate inhibits the enchainment of octahedral blocks in hydrotalcite but develop specific surface areas as high as 600 m²g^?1.