Single-Crystal X-ray Diffraction Study of [c2] Daisy Chains and Inclusion Complexes from A1/A2-Functionalized Pillar[5]arenes with Variable Chain Lengths

A1/A2-Asymmetric difunctionalized pillar[5]arenes bearing either n-decyloxy and propargyloxy groups or n-octyloxy and propargyloxy groups are synthesized and investigated for their supramolecular assembly behavior under different crystallization conditions. Distinct crystal systems are obtained depending on the co-crystallization medium. Host–guest inclusion complexes with adiponitrile form when crystallization is carried out from solutions containing adiponitrile, whereas cyclic [ c2 ] daisy chain (“double-threaded dimer”) architectures are produced from mixed chloroform/cyclohexane solutions. The resulting supramolecular assemblies are characterized by single crystal X-ray diffraction and Hirshfeld surface analyses. Variation in alkyl chain length (n-decyloxy versus n-octyloxy) on the pillar[5]arene framework exerts a pronounced effect on the non-covalent interactions and the consequent self-assembly modes within the crystal networks.