Synthesis, characterization and applications of layered double hydroxides containing organic guests

The use of layered inorganic solids as host materials for the creation of inorganic–organic host-guest supramolecular structures is of increasing interest. In this review we outline the preparation, characterization and uses of layered double hydroxides (LDHs) containing organic guests. LDHs consist of stacks of positively charged mixed metal hydroxide layers that require the presence of interlayer anions to maintain overall charge neutrality. A range of organic guests may be incorporated, including aliphatic and aromatic carboxylates, sulfonates and phosphonates as well as porphyrin and phthalocyanine derivatives. Potential applications of organo-LDHs in the areas of catalysis, sorption, photochemistry and electrochemistry are outlined. Overall, it is demonstrated that with LDHs it is possible to create, in a systematic manner, novel inorganic–organic supramolecular structures.