An alternating chain of spider-like tris(peptides) stabilized by stacking and by N–H/N and N–H/OaC hydrogen bonding

The X-ray crystal structure of the novel spider-like trispeptide N,N0,N00-tris(2-aminopyridine)benzene-1,3,5-tricarboxamide shows the unexpected formation of a new extended polymeric architecture. The structure is characterized by cooperative hydrogen bonding generating neighbouring pairs by self-assembly, and stacking between rings. Pairs of amide groups related by an inversion centre are connected into dimers via two N–H/Ocarbonyl and two N–H/Npyridyl intermolecular hydrogen bonds. The offset-stacked layers are tightly inter-linked (spacing of 3.477 A ° ) by hydrogen bonding and aromatic p–p stacking interactions. These dimers are further linked into polymeric chains by hydrogen bonding through bridging methanol solvent molecules. The central aromatic rings of molecules in adjacent dimers are once again related by inversion symmetry, with a perpendicular separation of 3.619 A ° . q 2005 Elsevier B.V. All rights reserved.