The host compound 3,3′-bis­(9-hydroxy-9-fluorenyl)-2–2′-binaphthyl, H1, has been employed to separate the six isomers of lutidine. Competition experiments showed that the preference for enclathration is in the sequence 3,4-LUT > 2,6-LUT > 2,3-LUT > 2,5-LUT > 2,4-LUT ≈ 3,5-LUT. The structures yielded results that agree with the 1H NMR analyses and with the thermal analysis. The effects of mixed hosts and vapor-phase competitions were briefly explored with two extra hosts, namely, 2,2′-bis­(1-hydroxy-4,5-dihydro-2:3,6:7-dibenzocycloheptadien-1-yl)­biphenyl (H2) or 3,3′-bis­(di-p-tolylhydroxymethyl)-1,1′-binaphthyl (H3).

Cholic acid (CA) and deoxycholic acid (DCA) have been employed to separate the three isomers of trimethoxybenzene (TMB). The selectivity preference is CA: TMB135 > TMB123 ≈ TMB124, while it is reversed for DCA: TMB123 > TMB124 > TMB135. Some of the crystal structures with CA as host suffered from partial disorder, while the DCA structures were grown from pairs of equimolar guest mixtures, and all contained both guests in different proportions. Packing analysis revealed the importance of layering of the hydrophilic and lipophilic regions of the structures with the TMB guests accommodated in the lipophilic layers.

Deoxycholic acid (DCA) includes all the isomers of methylcyclohexanones (MCH). Competition experiments showed that the preference is 2MCH > 3MCH > 4MCH confirmed by crystal structure analysis, NMR, and thermal analysis. DCA resolves 2MCH, enclathrating the S-conformer, whereas 3MCH remains unresolved. However, in competition experiments of rac-2MCH/rac-3MCH, both guests are resolved yielding S-conformers, suggesting that 2MCH has a templating effect on the final structures. The activation energies of desolvation of the clathrates with 2MCH and 3MCH are similar (∼74 kJ/ mol) but significantly lower for 4MCH (∼48 kJ/mol).

Mefenamic acid (MA) formed solvates with 2-picoline (2PIC), 3-picoline (3PIC), 4-picoline (4PIC) and 3-chloropyridine (3CLPYR). The solvates crystallized in the space group P\bar 1 with the carboxylic acid of MA hydrogen-bonded to the nitrogen of the substituted pyridine. Tolfenamic acid (TFA) formed solvates with 2PIC and 3PIC, the crystal structures successfully solved in the space groups P2/n and Pbca, respectively. The fenamate conformation varied depending on the acid and the included solvent. Similarities were observed in the structures involving MA. The two solvate structures of TFA had different packing arrangements. Grinding and slurry experiments were also successful for the preparation of all of the compounds except MA·2PIC. Recrystallization, grinding and slurry investigations of MA and 2PIC yielded a polymorph; the structure was successfully solved in P2/n. Additionally, the thermal stability of the solvates was determined. Desolvation experiments were also performed and the resultant powders were analysed using powder X-ray diffraction.

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