Controlled photocycloaddition of unsaturated carboxylates intercalated in hydrotalcite clay interlayers

The effect of UV radiation on cinnamate/layered double hydroxide (LDH) composites

“…Additionally, Takagi et al reported that the photodimerization of CA occurred on the surface of hydrotalcite in the suspension. 20) They also reported that the majority of the dimerization state was a syn-Head-to-Head (syn-HH) type (parallel type). Compared with these reports, the same photodimerization of cinnamate occurred in the cinnamate/LDH composite prepared by reconstruction using SC solutions.…”

“…19) Same phenomenon was observed in the suspension of hydrotalcite clay with cinnamic acid. 20), 21) Recently, cinnamic acid was intercalated into ZnAl LDH by coprecipitation and the obtained cinnamic acid/LDH showed UV absorption ability. 22) However, there is no report on the change of interlayer cinnamic acid after UV irradiation.…”

Facile synthesis of Zn-Al layered double hydroxide from aqueous suspension of zinc oxide and aluminum hydroxide

“…8)- 10) In addition to the studies on the mechanism of the LDH formation and their structures, the introduction of guest species into the interlayer space of LDHs has been reported for such applications as catalysts, 11)-16) controlled photochemical reactions, 17), 18) electrodes, 19)-21) bioactive nanocomposites, 22)-26) and polymer additives, 27)-29) and so on. The wide range of application of LDHs and their intercalates motivates researchers to develop a simple, economically viable synthetic method.…”

Preparation and Structural Characterization of Alkaline Earth−Iron(III) Layered Double Hydroxides and their Acrylate-Intercalated Derivatives

“…It was found that photodimerization tended to give overwhelmingly the β-dimer over the α-dimer [112,113]. The selective formation of the β-dimer (head-to-head dimer) may be explained by the importance of intermolecular distances of two double bonds of adjacent carboxylates [113], which was ~5.2 Å and ~7 Å for the parallel and antiparallel arrangements, respectively (form the gallery height data a monolayer of the cinnamate anions was deduced). These distances are approximate and average ones.…”

“…It was observed that the relative amounts of isomerization and dimerization depended on the stoichiometry of the parent layered double hydroxide, i.e., on the density of charges, which is related to the relative quantity of the trivalent ion, the aluminum ion that is [114]. It was found that photodimerization tended to give overwhelmingly the β-dimer over the α-dimer [112,113]. The selective formation of the β-dimer (head-to-head dimer) may be explained by the importance of intermolecular distances of two double bonds of adjacent carboxylates [113], which was ~5.2 Å and ~7 Å for the parallel and antiparallel arrangements, respectively (form the gallery height data a monolayer of the cinnamate anions was deduced).…”