An extensive and systematic study of the intercalation of a number of commercially important anions into a range of layered double hydroxides (LDHs) has been undertaken. A pseudo-combinatorial approach was employed to determine rapidly the ideal reaction conditions for the intercalation of each guest. Over 50 LDH nanohybrids are reported, the vast majority of them having never previously been synthesized. Guest anions include key drugs, important agrochemicals, vitamins, fragrances, a dye, and a color fixant. The immense potential of LDH systems as reservoirs and to remove agrochemical pollutants from effluvium flows was demonstrated. The release of the guest anions was studied in representative conditions. Some of the thiosulfate intercalates show temperature programmable release characteristics which have not be observed previously.

The intercalation chemistry of a recently synthesized family of layered double hydroxides, [MAl 4 (OH) 12 ](NO 3 ) 2 ?yH 2 O (M = Zn, Cu, Ni, Co), has been explored. A range of dicarboxylates, mono-and disulfonates have been intercalated successfully, and the resulting materials fully characterised. The interlayer spacing of the dicarboxylates is found not to vary linearly with the length of the carboxylate chain, but instead the acid species are arranged so that the ends of the dicarboxylate chains point directly at the localized metal atoms in the layers. In situ diffraction experiments have been performed to investigate the kinetics and mechanisms of the intercalation processes. The dicarboxylates are found to intercalate very quickly, with the reactions being complete within a few minutes at room temperature. In contrast, the sulfonates intercalate more slowly, and quantitative kinetic parameters may be measured for these reactions. All the reactions were found to be direct one-step transformations. The sulfonate intercalation processes are proposed to be nucleation controlled in the vast majority of cases for the M = Zn, Cu and Co materials, with the rate limiting step being the expansion of the interlayer space to accommodate the relatively large organic guest anions. In contrast, the reactions of the M = Ni LDH are found to be purely diffusion controlled: as soon as the guest reaches the host particles, it intercalates.

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