Selective Ion-Exchange Intercalation of Isomeric Dicarboxylate Anions into the Layered Double Hydroxide [LiAl₂(OH)₆]Cl·H₂O

Abstract

The dicarboxylate anions 1,4-benzenedicarboxylate and fumarate can be selectively intercalated into the layered double hydroxide [LiAl 2 (OH) 6 ]Cl‚H 2 O from equimolar molar mixtures of the 1,2-, 1,3-, and 1,4-benzenedicarboxylate and fumarate and maleate isomers, respectively. Time-resolved in situ energy-dispersive X-ray diffraction studies have shown that these are the thermodynamic products following the conversion of an initial phase in which all the anions are simultaneously intercalated.

Selective Sorption of Organic Molecules by the Flexible Porous Hybrid Metal−Organic Framework MIL-53(Fe) Controlled by Various Host−Guest Interactions

“…Similar separation behavior has been reported for layered double hydroxides in the presence of a solution of carboxylate anions: when exposed to a mixture of two anions the initial rapid uptake of both takes place before the sole product containing one anion is formed with expulsion of the other. 43,44 Studies of the separation of both the gas phase and the liquid phase separation of xylene (and other aromatic) isomers by materials with the MIL-53 structure have recently been reported by other groups. For example, Alaerts et al showed that MIL-53(Al) would preferentially bind ortho-isomers of xylene, ethyltoluene, and so forth in liquid phase separations, and rationalized the selectivity as arising from strong interactions between methyl groups of the sorbates and carboxylate moieties in the pore corners.…”

The selective intercalation of organic carboxylates and sulfonates into hydroxy double salts

“…18 LiAl 2 -Cl has also been found to preferentially intercalate 1,4-BDC over 1,2-BDC with > 95% selectivity. 17 The same preferential intercalation of 1,4-BDC occurs for the [Ca 2 Al(OH) 6 ]NO 3 $2H 2 O LDH, 19 and other LDH systems such as [MAl 4 (OH) 12 ](NO 3 ) 2 $yH 2 O (M ¼ Zn, Cu, Ni, or Co). 20 Analogous trends are observed for nitrophenols (4-nitrophenol is intercalated in preference to the 2-and 3-nitrophenol isomers).…”

“…A range of isomer mixtures have been explored by a number of scientists. For instance, fumarate is found to be intercalated preferentially over maleate into the LDH [LiAl 2 (OH) 6 ]Cl$H 2 O (LiAl 2 -Cl), 17 and also into [Mg 2 Al(OH) 6 ] Cl$1.5H 2 O. 18 LiAl 2 -Cl has also been found to preferentially intercalate 1,4-BDC over 1,2-BDC with > 95% selectivity.…”

Quantitative Analyses of Shape-Selective Intercalation of Isomeric Mixtures of Muconates into [LiAl2(OH)6]Cl·yH2O Layered Double Hydroxide

“…Therefore, it is important to examine how the guest anions such as muconates intercalate into the interlayer of LDH accompanying the structural modification of inorganic host lattice and how it is possible to selectively separate one isomer from the various isomeric mixtures. Recently, O'Hare et al reported on the selective intercalation into the interlayer of [LiAl 2 (OH) 6 ]Cl · H 2 O and Ca 2 Al(OH) 6 · NO 3 · 2H 2 O LDHs for the ion-exchange reaction with equimolar isomeric mixtures of dicarboxylates by kinetics studies using the time-resolved in situ energy dispersive X-ray powder diffraction method (41)(42)(43)(44)(45). They suggested that the selective ion-exchange reactions involved the initial kinetic insertion of all the isomers followed by a collapse to the thermodynamically most stable intercalate phase as a result of expelling the disfavored anions.…”