Supramolecular architecture of metal-lustrous inclusion crystals based on aromatic CH-π interaction:: versatile inclusion of 1-(p-ethoxphenyl)-2-(2-thienl)-5-[5-(tricyanoethenyl)-2-thienyl]pyrrole host with various electron-rich aromatic guest molecules

1-(p-Ethoxyphenyl)-2-(2-thienyl)-5-[5-(tricyanoethenyl)-2-thienyl] pyrrole, a novel pi-conjugated organic compound, shows particularly stronger affinities to various electron-rich aromatic guest molecules to form 2:1 inclusion complexes with gold- or bronze-like metallic luster. All of the complexes crystallize with the same so-called herringbone packing motif in which the pi-system of the guest is sandwiched diagonally between the host molecules around it. The unique aromatic CH-pi interactions between the host and the guest molecules essentially ascribe to the architecture of these complexes. The sidewise intermolecular pi-pi contacts ((CNC)-C-...=C) between the host molecules deeply affect the crystal appearance. (C) 2002 Published by Elsevier Science Ltd.