Prism[n]arene-alkyl dibromide (n = 5, 6) synergy: Molecular affinity in the solid state

Abstract

Single crystals of prism[5]arene and prism[6]arene were grown from solutions containing either 1,6-dibromohexane or 1,8-dibromooctane. The deeper cavity of the prism[5]arene macrocycle efficiently encapsulated longer alkyl dibromide guests compared to pillar[5]arene, forming 1:1 inclusion complexes stabilized by multiple C-H···π and C-H···O interactions. Both inclusion complexes self-assembled into linear supramolecular polymers within the crystal network, facilitated by guest halogen interactions (C-H···Br and Br···Br interactions). Prism[6]arene co-crystals grown from 1,6-dibromohexane and 1,6-dibromooctane formed a unique 1:1 inclusion complex, where the guest adopted an orthogonal orientation within the host cavity. The resulting supramolecular assemblies were fully characterized using single-crystal X-ray diffraction and Hirshfeld surface analysis.