Crystal structure and supra-molecular features of a host-guest inclusion complex based on A1/A2-hetero-difunctionalized pillar[5]arene

Abstract

A host-guest supra-molecular inclusion complex was obtained from the co-crystallization of A1/A2-bromo-but-oxy-hy-droxy difunctionalized pillar[5]arene (PilButBrOH) with adipo-nitrile (ADN), C₄₇H_53.18Br_0.82O₁₀·C₆H₈N₂. The adipo-nitrile guest is stabilized within the electron-rich cavity of the pillar[5]arene host via multiple C-H⋯O and C-H⋯π inter-actions. Both functional groups on the macrocyclic rim are engaged in supra-molecular inter-actions with an adjacent inclusion complex via hydrogen-bonding (O-H⋯N or C-H⋯Br) inter-actions, resulting in the formation of a supra-molecular dimer in the crystal structure.

Keywords: crystal structure; hetero difunctionalized pillar[5]arene; inclusion complex; supra­molecular dimer.

Figure 1

Crystal structure (displacement ellipsoid representation; 30% probability) of PilButBrOH·ADN. Only the major components of the disordered moieties are shown. Hydrogen atoms except the OH hydrogen are omitted for clarity.

Figure 2

Inter­molecular inter­actions between the pillar[5]arene host and adipo­nitrile guest. π1–π4 are the centroids of the C1–C6, C8–C13, C15–C20 and C22–C27 phenyl rings, respectively.

Figure 3

Pillar[5]arene–pillar[5]arene supra­molecular systems resulting from the hy­droxy as well as bromo­but­oxy-mediated dimeric inter­actions in PilButBrOH·ADN; Symmetry codes: (i) 1 − x, 1 − y, 2 − z; (ii) 1 − x, −y, 2 − z.

Figure 4

Inter­molecular inter­actions experienced by a given pillar[5]arene mol­ecule involving its neighbouring counterparts; Symmetry code: (i) 1 − x, 1 − y, 2 − z; (ii) 1 − x, −y, 2 − z; (iii)  − x, − + y,  − z; (iv)  − x,  + y,  − z.

Figure 5

Hirshfeld surfaces (mapped with d_norm) of PilButBrOH·ADN. The adjacent pillar[5]arene counterparts are also shown to illustrate the O—H⋯N, C—H⋯N and C—H⋯Br inter­actions.