Extended Data Fig. 8: Comparison of hydrogen-bond patterns between ZnGGH-6⋅(F) and ZnGGH-7⋅(FA).
From: Chemical control of structure and guest uptake by a conformationally mobile porous material
The furfural (F) and furfuryl alcohol (FA) guests produce two distinct structures, ZnGGH-6⋅(F) and ZnGGH-7⋅(FA) respectively. Although these structures feature peptide conformations that place them in the ‘straight linker’ cluster (Fig. 4a), they present different hydrogen-bond patterns, placing them in distinct subgroups in Fig. 4b. ZnGGH-6⋅(F) exhibits the same three intraframework hydrogen bonds as ZnGGH-5⋅(H2O-DMF), and the carbonyl group of furfural forms a hydrogen bond with the terminal NH2. By contrast, in ZnGGH-7⋅(FA), the hydroxyl of furfuryl alcohol is hydrogen-bonded to the glycine–glycine amide group and to the terminal NH2, while the flexible Gly–Gly chain of the linker has been rotated towards the guest to form these interactions, thereby disrupting two of the three intraframework hydrogen bonds observed in ZnGGH-6⋅(F): one between the Gly–Gly amide groups (green circle) and one between the terminal NH2 and the Gly–His amide group (purple circle). The only intraframework hydrogen bond that is present in ZnGGH-7⋅(FA) is between the histidine carboxylate and the Gly–His amide (black circle).
