‘Honeycomb’ nanotube assembly based on thiacalix[4]arene derivatives by weak interactions

Abstract

The crystal structures of di-O-propoxy-mono-formyl-thiacalix[4]arene·chloroform (7·CHCl₃), di-O-propoxy-di-formyl-thiacalix[4]arene (8), di-O-propoxy-tri-formyl-thiacalix[4]arene (9), di-O-benzyol-di-formyl-thiacalix[4]arene·water (10·H₂O), mono-O-propoxy-tri-formyl-thiacalix[4]arene (11), and di-O-propoxy-di-cyano-thiacalix[4]arene·chloroform (12·CHCl₃) in the same crystallisation medium have been investigated. These crystals form similar ‘honeycomb’ nanotube architectures and display different assemblies in the solid state. 7·CHCl₃, 8, 9 and 11 assemble to ‘classical’ head-to-head dimers via interdigitation of aromatic rings with π⋯π stacking interactions, while 12·CHCl₃ forms a novel head-to-head dimer motif and its infinite network structures are stabilised by Cl⋯Cl, Cl⋯π and CN⋯Cl interactions. Although 10·H₂O does not form a head-to-head dimer, it has taken on a new cubic close packing (ccp) arrangement, forming a water channel nanotube. X-ray single-crystal diffraction studies reveal that the weak interactions, including C–H⋯O, halogen⋯halogen, C–H⋯π, lone pair (lp)⋯π and π⋯π interactions contribute to the supramolecular assembly.