Selectivity considerations of host compound trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid when presented with pyridine and picoline mixtures: charge-assisted versus classical hydrogen bonding

Abstract

trans-9,10-Dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid (H1) was assessed for its host behaviour in pyridine (PYR) and 2-, 3- and 4-methylpyridine (2MP, 3MP and 4MP). Each of these guest compounds was enclathrated, and host:guest...

Complementary host behaviour of three anthracenyl-derived roof-shaped compounds in mixed pyridines

“…13,14 The roof-shaped compounds derived from anthracene and fumaric acid were designed by Edwin Weber in 1996 and were shown to be highly effective host compounds for the complexation of a large variety of guest species. 15 In subsequent investigations in our own laboratories, these types of host compounds were demonstrated to possess enhanced selectivities in aromatic positional isomeric mixtures such as the xylenes (and ethylbenzene), [16][17][18] dichlorobenzenes, 19 the MePys (and Py), 20 methylanisoles (and anisole), 21,22 and bromoanisoles (and anisole). 23 In many of these recrystallization experiments that employed guest mixtures, host selectivity coefficients (K) were significant (greater than 10), alluding to the feasibility of separating such mixtures on a practical platform, as reported by Nassimbeni and co-workers.…”

trans-9,10-Dihydro-9,10-ethanoanthracene-11,12-dicarboxylic Acid: Remarkable Host Selectivities in the Presence of Mixtures of Anisole and Bromoanisole Isomers

“…trans-9,10-Dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid (DED, Scheme 1) is a roof-shaped host compound that was first reported by Weber et al in 1996, together with the crystal structures of its complexes with ethanol, nitromethane, and benzene. 25 This compound has also been reported to possess enhanced selectivities when recrystallized from various mixtures including ethylbenzene and the xylenes, 26 dichlorobenzenes, 22 and methylpyridines, 27 selecting preferentially for p-xylene, p-dichlorobenzene, and o-or m-methylpyridine (experimental conditions-dependent), respectively. Since DED displayed such selectivity in mixtures, we embarked upon an investigation of its separation or purification potential for the bromoanisole isomers (together with unsubstituted anisole) through recrystallization experiments of DED from various mixtures of these potential guest solvents.…”

Host Compound DED: Guest Accommodation Type, Noncovalent Host···Guest Interactions, Crystal Densities, and Thermal Stabilities Ensure High Host Selectivities for 4-Methylanisole in Anisole and Methylanisole Mixtures

“…In the present work, trans-9,10-dihydro-9,10ethanoanthracene-11,12-dicarboxylic acid (DED), dimethyl trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylate (H1), and trans-α,α,α′,α′-tetraphenyl-9,10-dihydro-9,10-ethanoanthracene-11,12-dimethanol (H2) (Scheme 1), host compounds based on the roof-shaped skeleton synthesized via a Diels−Alder reaction on anthracene, as reported by Weber et al, 22 were investigated for their selectivity behavior in these mixed anisoles in a search for the optimal host compound for such separations. Recently, a derivative of H2, trans-α,α,α′,α′-tetrakis(4-chlorophenyl)-9,10-dihydro-9,10ethanoanthracene-11,12-dimethanol (H3, Scheme 1), was reported to possess enhanced selectivities for ANI and 3-MA depending on which guest compounds were present in the mixture: 23 equimolar binary guest solutions produced complexes with between 90.7 and 95.3% of either of these two guest compounds; furthermore, ternary solutions ANI/2-MA/ 4-MA and 2-MA/3-MA/4-MA furnished mixed complexes, but the selectivity toward ANI and 3-MA remained significant (82.6 and 89.5%, respectively). These encouraging observations stimulated a closer scrutiny of the behaviors of related molecules DED, H1, and H2 in analogous experimental conditions.…”

“…These encouraging observations stimulated a closer scrutiny of the behaviors of related molecules DED , H1 , and H2 in analogous experimental conditions. While the selectivity of various roof-shaped host compounds has been explored in mixed picolines, dichlorobenzenes (DCBs), and ethylbenzene/xylenes with remarkable selectivity data being obtained in these instances, the host behavior of DED , H1 , and H2 has not been assessed when presented with anisole mixtures. As such, here, successfully formed complexes were analyzed by both single-crystal X-ray diffraction (SCXRD) and thermal analyses to understand any selectivity displayed by these host compounds, to observe noncovalent interactions responsible for guest retention and also to investigate the relative thermal stabilities of the so-formed complexes.…”

“…These experiments have demonstrated that DED would be a highly effective host candidate to facilitate the separation 4-MA from such equimolar mixtures. Furthermore, since the preference of DED is for 4-MA and that of H3 is for ANI or 3-MA,23 these two guests serve a…”